Attracting Animals to Detection Devices - Gwern.net266 NONINVASIVE SURVEY METHODS FOR CARNIVORES...

For wildlife research purposes, an attractant is anysubstance, material, device, or technique used to at-tract a target species. Attractants are used with mostof the survey methods described in this book, ex-cluding natural sign surveys (chapter 3), some trackstations (chapter 4), remote cameras on trails (chap-ter 5), hair collection from natural rub objects oralong travel routes (chapter 6), and scat detectiondogs (chapter 7). Indeed, the selection of an attrac-tant is often an integral part of the survey-planningprocess. This chapter describes the various sub-stances and methods used to draw North Americancarnivores to noninvasive sampling devices—fromhistorical, scientific, and traditional perspectives.Further, it provides practical recommendations onhow to acquire, apply, and store baits, lures, andother attractants and describes scientific efforts totest their efficacy.

Although the terms bait and lure are often usedinterchangeably, each has a unique meaning in thecontext of surveying wildlife:

• Bait is a food item or other substance that at-tracts an animal by appealing to its sense oftaste and smell. Baits are typically intended tobe consumed by the target species, although

nonreward baits (discussed later in the chap-ter) may preclude consumption.

• Lures include scent lures, visual lures, andsound lures. A scent lure is any substance thatdraws animals closer via their sense of smell.Visual lures engage an animal’s sense of sight,while sound lures elicit a curiosity approach bysimulating noises made by prey species or con-specifics.

• Natural attractants are objects in the existingenvironment (e.g., trees, snags, or latrine sites)that are regularly used by target animals as partof their behavioral repertoire.

Background

Over thousands of years, humans developed varioustrapping methods to capture animals for food andhides, and to protect themselves and their propertyfrom predators. Through trial and error, trap effec-tiveness was increased by the refinement of methodsto entice animals into traps. Many historical furtrappers had their own “secret formula” for attract-ing target species, and were reluctant to share thelists of ingredients with others because of competi-tion and the potential loss of income (Geary 1984).

Chapter 10

Attracting Animals to Detection DevicesFredrick V. Schlexer

As a result, multiple baits and scent lures were devel-oped for each furbearing species.

This traditional knowledge base—accumulatedfrom the combined experience of indigenous peo-ples, hunters, trappers, and naturalists—has beenincorporated into modern efforts to attract animalsfor wildlife research. Unfortunately, most attractantshave not been scientifically tested and are used onthe basis of tradition rather than proven effective-ness. Numerous researchers have endeavored toevaluate and standardize traditional attractants (e.g.,Graves and Boddicker 1987; McDaniel et al. 2000;Stanley and Royle 2005), but the predominant re-liance on unverified methods to draw animals tosurvey devices underscores the need for additionaland rigorous scientific testing (see Evaluating the Ef-fectiveness of Baits and Lures later in this chapter).

The use of attractants in carnivore surveys has along history (e.g., Cook 1949; Wood 1959). Early at-tempts to evaluate attractants were directed at thedevelopment of a reliable method to estimate coyote(Canis latrans) abundance using scented track sta-tions (see chapter 4). Natural scent lures were testedwith captive animals (Roughton 1979) and in thefield (Linhart and Knowlton 1975; Linhart et al.1977; Roughton and Bowden 1979), and efforts weresoon expanded to include synthetic scents (Tur -kowski et al. 1979; Martin and Fagre 1988). A syn-thetic fatty acid scent (FAS) was ultimately selectedas a standard lure for coyotes by the US Fish andWildlife Service (Roughton 1982), and a standard-ized delivery method was developed in the form ofan inexpensive plaster disk saturated with this scent(Roughton and Sweeny 1982). FAS continues to beused today, primarily for canid and felid scent sta-tion surveys (e.g., Harris and Knowlton 2001; Zoel-lick et al. 2004). More often, however, researchersemploy commercially available scent lures (e.g.,Caven’s Gusto, Carman’s MegaMusk) for noninva-sive carnivore surveys (Romain-Bondi et al. 2004;Zielinski et al. 2005; Gompper et al. 2006; also seeappendix 10.1). Although many such lures are cre-ated based on traditional recipes—and at least someyield positive results—most have not been rigor-

264 NONINVASIVE SURVEY METHODS FOR CARNIVORES

ously tested (see Evaluating the Effectiveness of Baitsand Lures).

Valuable information about attractants can befound in unpublished reports produced by fish andwildlife agencies at the national, provincial, state,and local levels. Private wildlife groups (e.g., WorldWildlife Fund, Wildlife Conservation Society) arealso rich sources of relevant research. Many of theseunpublished reports can be accessed via the internet(e.g., Henschel and Ray 2003; Uresk et al. 2003;Kendall et al. 2004). Traditional attractants are fur-ther discussed in furbearer trapping “how-to” books(e.g., Carman 1975; Wyshinski 2001) and popularoutdoor magazines (e.g., Fish and Fur, Field andStream, Outdoor Life). Last, trapping supply distrib-utors usually include information on attractantsboth in print catalogs and on their websites (see ap-pendix 10.2).

Description of Attractants

This section describes various types of attractantsthat can be used individually or in combinations. Alist of recommended attractants for each target spe-cies or group is presented in table 10.1.

Baits

Baits are typically composed of food, and fall intoseveral general categories, including both natural di-etary items and less customary consumables. Freshor decomposed meat, poultry, and fish are oftenused as bait, as are canned fish and canned or driedpet foods. Live animals are also occasionally de-ployed as bait or lures (e.g., Zezulak and Schwab1979; Caso 1994; Dillon 2005); researchers wishingto use live animals should follow Institutional Ani-mal Care and Use Committee guidelines (ACUC1998; IACUC 2006). Some carnivores respond tononmeat baits such as fruits or vegetables, fruit jams,seeds and nuts, baked goods, and cheese (table 10.1;appendices 10.1, 10.3). It is also possible to combineseveral types of bait at a single detection device to

Attracting Animals to Detection Devices 265

Table 10.1. Recommended attractants for carnivore surveys, in order of preference, listed by target species or group

Species or group Baits Scent lures Visual lures Sound lures

Canids (except foxes) Raw chicken (pieces or whole) FASa VRb

Meat or whole carcassesc Canid glands or urineFish (whole or canned) Catnipd oil

Raw woolCommercial lurese, f, g, h

Foxes Raw chicken (pieces or whole) FASa

(except arctic fox) Fish (whole or canned) Fox glands or urineDog or cat food (dry or canned) Catnipd oilMeat or whole carcassesc Commercial lurese, f, g, h, i

Nuts, raisins, other fruits

Tropical felidsj Live animalsk Felid glands or urine Flashers VRb

Fish (whole or canned) Commercial luresf, g, l, m

Raw chicken (pieces or whole) FASa

Catnipd (oil, dried, or fresh)

Temperate felidsn Meat or whole carcassesc Catnipd (oil, dried, or fresh) Flashers VRb

Fish (whole or canned) Commercial luresf, g, l, m

Raw chicken (pieces or whole) Beaver castoreumFASa

Felid glands or urine

Mephitids Raw chicken (pieces or whole) Commercial skunk-scented lureo

Fish (whole or canned) FASa

Rabbit or beaver meat Fish oilChicken eggs

MustelidsWolverine Meat or whole carcassesc Commercial skunk-scented lureo Flashers

Fish (whole or canned) Fish oilRaw chicken (pieces or whole) Beaver castoreumRotten meat

North American river otter Fresh, whole fish

American marten, Raw chicken (pieces or whole) Commercial skunk-scented lureo Flashersfisher, weasels Fish (whole or canned) Fish oil(Mustela spp.) Rabbit or beaver meat

American mink Fresh, whole fish Mink glands and urineFresh meatp (rabbit, beaver, muskrat, birds) Fish oil

American badger Raw chicken (pieces or whole) Commercial skunk-scented lureo

Fresh meat (rabbit, beaver, muskrat, birds)

ProcyonidsRingtail Raw chicken (pieces or whole) Commercial skunk-scented lureo

Dog or cat food (dry or canned) Ringtail glands or urineFish (whole or canned) FASa

Rabbit or beaver meat Fish oilFruit jam

White-nosed coati Dog or cat food (dry or canned) FASa

Fish (whole or canned) Fish oilLive animalsk Commercial lureg

Marshmallows

increase the probability of detecting a given speciesor to attract multiple species (see Target Species).Proprietary commercial baits are available, but theirsuperiority to commonly available meat or fish baitshas not been demonstrated.

The attraction capabilities of meat or fish bait decline over time due to decomposition. At highconcentrations, the wide variety of amines and sul-fur compounds characteristic of microbial activityserves as a cue to the target animal, allowing it toidentify a piece of meat as rotten and inedible

(Janzen 1977). At lower concentrations, however,these same compounds signal the presence of ediblebait (Stager 1964). Thus, the products of decay areboth attractive and repulsive, depending on theirconcentration. The optimal condition of bait (afunction of detectability and desirability) is reachedwhen the carcass is odorous enough to be detected ata distance, but not so rotten as to discourage investi-gation. Because carnivores possess a more sensitiveolfactory system than do humans, and are thus ableto detect odors at lower concentrations (Hepper and


Table 10.1. (Continued)

Species or group Baits Scent lures Visual lures Sound lures

Raccoon Raw chicken (pieces or whole) Commercial skunk-scented lureo

Fish (whole or canned) Fish oilDog or cat food (dry or canned) FASa

Rabbit or beaver meatFruit jam

Ursids Raw chicken (pieces or whole) Commercial skunk-scented lureo

Fish (whole or canned) Liquid fish fertilizerMeat or whole carcassesc Fish oilFish food pellets Anise oil or vanilla extractMolasses, maple syrup, or honey (diluted

with water)Livestock bloodFruit jamFruits and vegetables (apples, corn)Stale pastries (e.g., bagels, donuts, cookies)Rotten meat

Note: Attractants were selected based on a synthesis of those used in the surveys included in appendix 10.1, and on the author’s experience andprofessional opinion. Actual attractant(s) chosen should depend on survey goals, season, and availability.aSynthetic fatty-acid tablets.bVocalization recording.cE.g., wild ungulate, domestic livestock, beaver.dNepeta cataria.eE.g., any commercial liquid fox lure, liquid coyote lure, or fox gland lure, such as Caven’s Fox #1, Caven’s Fox #2, Caven’s Canine Force.fE.g., Marak’s Bobcat Lure, Marak’s Coyote Lure, Marak’s Gray Fox Lure, Marak’s Raccoon Lure.gE.g., Carman’s Canine Call, Pro’s Choice, Bobcat Gland Lure, Trophy Deer Lure, and Mega Musk.hE.g., Carman’s Canine Call.iE.g., Trailing Scent.jLeopardus spp., Puma yagouaroundi, Panthera onca.kE.g., chickens or chicks, rabbits, quail, pigeons.lE.g., Hawbaker’s Wildcat #2.mE.g., Weaver’s Cat Call.nLynx spp., Puma concolor.oE.g., Caven’s Gusto.pDo not use rotted fish or meat.

Wells 2005), it is impossible for researchers to accu-rately assess where a given bait falls along the attrac-tion-repulsion scale for a given target species.

Bait deployed such that it can be consumed by thetarget species is considered a reward bait. This typeof bait presentation can limit sampling to the firstanimal that reaches the site—a potentially desirableoutcome in some instances (e.g., if genetic methodscan only utilize samples collected from one individ-ual at a time; see chapter 6)—but may contribute torepeated sampling of the same individual if the baitis regularly replaced and the animal becomes habitu-ated to obtaining food (Brongo et al. 2005). Inacces-sible or nonreward baits alleviate this problem andwill continue to draw additional individuals to thesite until the bait becomes unattractive. Nonrewardbaits also serve well as scent lures.

Carnivores usually respond best to baits compris-ing potential prey species (Schemnitz 1996; Cypherand Spencer 1998; Kamler et al. 2002). Ethical con-siderations and animal care and use protocols pro-hibit the harvest of prey animals for baiting pur-poses (Powell and Proulx 2003), but effectivesubstitutes (e.g., commercially available meat andfish) are widely available (appendix 10.1).

Scent Lures

Scent lures (also known as long-distance lures or calllures) exploit an animal’s hunger or curiosity or con-vey social or territorial signals. Scent lures are avail-able in a variety of forms (e.g., solid, viscous, liquid,granulated, or powdered), and can be animal-based,vegetable/fruit-based, inorganic, or synthetic. Formany carnivore species, attraction to a survey loca-tion may be maximized by using scent lures in com-bination with bait (Kucera et al. 1995a; Zielinski1995). Further, some baits, such as rotten meat orfish, can effectively serve as scent lures because theyrelease volatile compounds (Bullard 1982).

Scent lures sometimes contain plants or plant ex-tracts, such as catnip (Nepeta cataria), for example(McDaniel et al. 2000; Weaver et al. 2005). Fresh or

dried catnip attracts a variety of carnivores (appen-dices 10.1, 10.3) but is primarily used for felids(Tucker and Tucker 1988). Other ingredients used intraditional scent lure manufacture include fixatives(i.e., stabilizing agents), essential oils, and seafoodessences (appendix 10.3).

Commercial scent lures are proprietary mixturesof animal blood, organs, urine, glands or other items(some trappers even add small amounts of cheapperfume to their mixtures [Schemnitz 1996]), oftenfermented for weeks or months. Lures may includescents from prey or nonprey species, such as Ameri-can beaver (Castor canadensis) castoreum and musk -rat (Ondatra zibethicus) scent glands. Every trapperor animal damage control agent has a favorite lure,and these lures work with varying degrees of success(Baker and Dwyer 1987; Graves and Boddicker 1987;Dobbins 2004). Although many lure manufacturersadvertise “proven results” or that their lures havebeen “trapline tested,” details of such tests are usuallyunavailable. Several commercial lures have been sci-entifically evaluated (e.g., Martin and Fagre 1988;Stapper et al. 1992), and a few brands have consis-tently been used in carnivore surveys (appendix10.1).

Species-specific scent lures that stimulate socialor territorial responses usually include urine, musk,and/or macerated scent glands from the target spe-cies (Wyshinski 2001; Dobbins 2004). These luresare often called matrix lures by trappers (Hanson1989). Although many proprietary lure mixtures arederived from such substances, the basic ingredientscan also be acquired from trapping supply distribu-tors or from zoos and game ranches.

Most scent lures are combined with a base ma-terial or an extending medium that assists in distrib-uting the scent and acts as an antifreeze, diluent,evaporative retardant, additional attractant, or pre-servative (table 10.2). Examples include lanolin,which allows a concentrated lure to be easily spreadover multiple sites, and molasses, which supple-ments the attractant qualities of the lure. Blood luresrequire the use of an anticoagulant (e.g., sodium cit-


rate) to be effective. Due to their physical character(e.g., liquid, powder), most scent lures must be de-ployed using absorbent materials or containers(table 10.2; see Deployment of Attractants).

Visual Lures

Commercial trappers and wildlife researchers fre-quently use visual lures (collectively known as flash-ers or flags; Young 1958; Geary 1984; Baker andDwyer 1987), sometimes in concert with scent luresor baits. Flashers typically consist of a lightweightobject—for example, a piece of aluminum foil or apie pan (figure 10.1A), a whole dried bird wing or alarge feather (figure 10.1B), a patch of fur, a piece oflight-colored cloth, or an old cassette tape or com-pact disk (figure 10.1C)—suspended above the de-tection device with string or fishing line, and insome cases a swivel (figure 10.1D). In a slight varia-tion, an opaque piece of cloth or burlap hung acrossthe front of track plate stations has been shown toattract mustelids and raccoons (Procyon lotor; Louk-mas et al. 2003). Flashers are generally designed toflutter or move in a breeze, and are effective at at-tracting the attention of numerous carnivore species(Zielinski 1995). Visual lures are most commonlyused with felids (Mowat et al. 1999, Weaver et al.2005), which are more responsive to visual stimulithan to scents (Kitchener 1991). In areas wheredense vegetation limits visibility, scent lures can help

draw target animals close enough to notice theflasher (Kucera et al. 1995a). It is not known whetherany carnivores are repelled by flashers.

Sound Lures

Imitating the vocalizations of conspecifics or distresscalls of prey animals will often attract predators(Wise et al. 1999; Shivik 2006). This attractionmethod employs mechanical or electronic sounds toengage the target species and stimulate explorationor a territorial approach. While such predator callsare often used by hunters, their application in carni-vore surveys is limited because all age and sex classesare not necessarily attracted equally (Windberg andKnowlton 1990). Sound lures have been identified asa potentially effective technique for surveying felidsin tropical habitats (Kitchener 1991).

Natural Attractants

Some objects in the landscape (e.g., trees, posts) nat-urally attract certain carnivore species. Brown bears(Ursus arctos) and American black bears (Ursusamericanus), for example, are especially likely to rubon trees or other objects as they travel through anarea (Kendall et al. 2004; chapter 6), leaving behindhair samples that can be easily collected and used tomeet various survey objectives (Kendall et al. 1992;Kendall and Waits 2003). If natural attractants can


Table 10.2. Common scent lure bases and their uses

Base Use

Glycerine Antifreeze, evaporative retardant, preservativeHoney Antifreeze, attractant, diluent, evaporative retardantLanolin (anhydrous) Antifreeze, evaporative retardantMolasses Antifreeze, attractant, diluent, evaporative retardantPropylene glycola Antifreeze, preservativeSodium benzoate Preservative, antifungalSodium citrateb Anticoagulant for bloodTallow fat Antifreeze, attractant, evaporative retardantVegetable oil or shortening Antifreeze, evaporative retardantZinc valerate Preservative

aSimilar to glycerine but not as viscous.bUse a solution of 1:7 sodium citrate to water in a 1:9 ratio of anti-coagulant to blood.


Figure 10.1. Examples of visual attractants (also known as flashers). (A) Researcher R. Long hangs an aluminum pie pan bentinto an S shape to promote spinning. The pan is suspended from a branch with baling wire, a swivel, and monofilament fishingline (photo by P. MacKay). (B) Bird feathers suspended from a branch with monofilament fishing line (photo by F. Schlexer).(C) Compact disk suspended from a branch with the same setup as in figure 10.1A (photo by P. MacKay). (D) Close-up of theswivel used in figure 10.1A and 10.1C (after Weaver et al. 2005; photo by P. MacKay).

AB

C D

be identified for a given target species, these objectscan be integrated into carnivore survey methods(e.g., barbed wire-wrapped trees for sampling bears;see chapter 6).

Practical Considerations

The success of a given survey depends on the selec-tion of an effective and appropriate attractant for thetarget species, the detection method, and the surveyarea. For example, the ease with which survey sta-tions can be accessed by researchers should be care-fully evaluated when selecting an attractant. Stationslocated in remote areas far from roads restrict theuse of large, heavy baits such as ungulate carcasses,which are often employed for remote camera sur-veys. Track stations and hair collection devices typi-cally use smaller amounts of bait, providing moreleeway for site placement. The replenishment ofbaits and lures is also constrained by difficult site ac-cess. Snowmobiles, all-terrain vehicles, pack ani-mals, or helicopters should be considered where ap-propriate, although these methods of transport canadd considerably to the cost of a project. A num-ber of additional practical considerations for inte-grating attractants into a survey protocol are dis-cussed here.

Target Species

Knowledge of the natural history, ecology, and be-havior of the target species is essential when select-ing attractants for a survey. For example, does thespecies prefer fresh or rotted bait, and in the form ofsmall pieces or whole carcasses? Is it attracted toscent lures, or are flashers a better choice? Is the spe-cies less active in winter? What age and sex classeswill likely be drawn to the attractant? A solid under-standing of these and other species-related questionsshould help researchers design effective surveys.

Surveys focusing on multiple species may experi-ence greater success if several attractants are used

and might also benefit from a combination of baitsand lures. Researchers should keep in mind that thesuite of detectable species may change over time asbait decomposes. Care should be taken to select tar-get species–specific attractants to prevent nontargetspecies from being drawn to (and potentially com-promising) the detection device. Further, it is impor-tant to avoid scenarios in which an attractant for onetarget species repels another (Doty 1986). For exam-ple, scent from fisher (Martes pennanti) glandsplaced at a device may deter American martens(Martes americana), which are preyed upon by fish-ers (Raine 1983). Other such examples of interspe-cific predation among carnivores are described byPalomares and Caro (1999).

For some target species, particularly those withlarge home ranges, detectability (see chapter 2) canbe improved by prebaiting. Prebaiting involves plac-ing consumable bait in the prospective survey area afew days to several months before the survey begins.This allows individual animals to discover and be-come habituated to the presence of bait. Prebaiting isa common practice for furbearer trapping (Bakerand Dwyer 1987) and is effective for noninvasivesurveys when time, site access, and personnel avail-ability permit (Mace et al. 1994; Way et al. 2002;Shivik et al. 2005).

Deployment of Attractants

Once attractants have been selected, the next step isto determine the presentation method. Reward baitstations are easier to set up than nonreward bait sta-tions (which require additional wire and other ma-terials to isolate the bait), but reward baits must bereplenished frequently and should be used withscent lures in case the bait is consumed early in thesampling occasion (see Survey Design Issues).

Detection methods involving attractants have spe-cific requirements for positioning bait or scent lures.The position and amount of attractant will vary bymethod and target species, but it is always critical toconfigure the survey station such that animals must


contact or otherwise trigger the detection device toinvestigate the attractant. Placing bait above a barbedwire-wrapped post or tree bole, for example, enticesthe target animal to climb across the wire—thus de-positing hair (see chapter 6; figure 6.6). Chapters 4, 5,and 6 discuss method-specific considerations for lo-cating attractants at detection stations.

When deploying baits and scent lures, care mustbe taken to avoid transferring odors to detection devices, which could potentially be disturbed or de-stroyed by curious or hungry animals. This is espe-cially true for costly remote cameras, camera sen-sors, and sensor wires that are easily contaminated ifthe same person handles both the attractants and thedevice (chapter 5). To avoid loss of data and damageto equipment, two-person crews should be usedduring setups involving attractants, with one personinstalling the detection device and the other han-dling the bait and/or scent lure. Bears are particu-larly notorious for destroying cameras and track sta-tions when this protocol is not followed (seechapters 4 and 5).

Baits

Bait placement can be as simple as laying a piece ofchicken on a track plate (see figure 6.8A). Such a re-ward presentation allows the animal to remove thebait, which must then be regularly replenished untilthe survey is terminated. In contrast, the presenta-tion of nonreward bait must preclude animals fromstealing the bait. One common technique entailspuncturing a can of fish several times and nailing itto a tree above the detection device (figure 10.2A);fish odor can escape, but the can itself cannot be re-moved for consumption. Frozen meat baits can benailed directly to a tree (figure 10.2B) or wrappedagainst the trunk with wire (figure 10.2C; but seeWildlife Heath and Safety).

Another deployment strategy, especially suit-able for larger pieces of bait, is to hang the bait— unprotected or inside a breathable, cloth bag thatlimits insect damage—from an overhanging branchabove the detection device. If hanging branches are

unavailable, a catenary system can be constructedusing steel cable (figure 10.3), but be aware that baitspresented in this way may become accessible to ani-mals after a snowfall. Care should be taken to pre-vent bait removal by nontarget animals. For exam-ple, whenever possible, place large baits under adense forest canopy or cover them to minimize visitsby avian scavengers (Bortolotti 1984; Baker andDwyer 1987; Aubry et al. 1997).

Scent Lures

Scent lures can be used in their original formulationor mixed with a viscous substance (see table 10.2) todilute and extend the service life of concentratedlures and allow them to be spread easily on vegeta-tion (figure 10.4A). Various materials and containerscan also be used to facilitate the dispersal of luresover time (see box 10.1). Naturally occurring appli-cators or vehicles for dispersal, such as sticks orbranches, may be found at the survey site—thus re-ducing material costs and the amount of suppliesthat must be carried into the field.

Liquid or powdered lures are often poured intocontainers, which are then perforated and sus-pended above the detection device. Some containers(e.g., film canisters, cans, bottles) can be acquired atno cost from photo labs or recycling centers. Con-tainers can also be filled with absorbent material,such as wool or cotton, to limit evaporation (figure10.4B). Prepared containers can be sealed for trans-port and then opened or perforated in the field. Ad-ditional cotton balls, pipe cleaners, or rags saturatedwith lure can be hung directly from vegetation usinglightweight string or fishing line (figure 10.4C). Pel-leted lures (e.g., fish meal) are best dispersed inbreathable or mesh bags (figure 10.3), and can bemixed with liquid lures (e.g., molasses). Lures spreadon vegetation should be applied at sufficient heightsto prevent inadvertent contact with field personnel,and lures dispersed in containers should be placedout of reach of animals.

The effective distance of a scent lure changes with variables that can be difficult to control (e.g.,


temperature, precipitation, humidity, wind speedand direction, topography, and vegetation). Suchconfounding factors can affect visitation rates inde-pendent of target species density (Rice et al. 2001)but can often be managed by lure placement. Gener-ally, scent lures should be positioned to allow formaximum diffusion of the scent plume while stillbeing close enough to the survey station to lure ani-mals to the detection device (Carman 1975). Scentlures can be applied to tree branches or to stakes toelevate odor. Topography also affects local air flow,and can be exploited to maximize scent dispersal

(see chapter 7 for a brief introduction to the move-ment of scent across the landscape).

The amount of scent lure required dependslargely on lure viscosity and weather conditions. Asthe volatile molecules produced by lures form amore concentrated and localized odor signal incool, dry, and calm air than in warm, moist and tur-bulent air (Vickers 2000), additional lure should beused when the former conditions prevail. Smallamounts (approximately 5 cc) of liquid lure can be splashed or smeared directly onto trees and vegetation near the detection device, but it is not


Figure 10.2. Various types of nonreward bait presentations that prevent target species from immediately removing the bait. (A)Punctured can of cat food nailed to a tree above the detection device. Canned fish may also be used (photo by F. Schlexer). (B)American marten seizing frozen, raw chicken drumsticks nailed to a tree above the detection device (photo by USDA ForestService). (C) Whole, frozen raw chicken carcass nailed to a tree above the detection device and further secured to the tree trunkwith multiple wraps of baling wire (photo by F. Schlexer).

A

B C


Figure 10.3. Nonreward bait presentation. A breathable mesh bag contains bait or scent lure and is suspended above the detec-tion device—out of reach of the target species and potential scavengers. Illustration by S. Harrison.

Box 10.1

Materials commonly used to disperse scent lures

Containers

cloth bagscotton stockingsempty paint cansfilm canistersmicrocentrifuge tubesnylon stockings or panty hoseplaster disks (also available pre-scented with lure)plastic bottlesplastic vials or capsulespoultry egg shells

Absorbent materials

corn cobscotton balls

cotton lamp wickscotton or felt clothgauze padsnatural sheeps’ wool padspaper towelspipe cleanerstampons

Other materials

naturally available stickscotton-tipped swabsfence poststongue depressorstree or shrub brancheswooden or bamboo stakes


Figure 10.4. Methods of dispersing scent lures. (A) Paste lure applied directly to a branch (photo by F. Schlexer). (B) Perforatedfilm canister containing cotton balls saturated with liquid lure and suspended from a branch using monofilament fishing line(photo by F. Schlexer). (C) Gauze pad saturated with liquid lure and suspended from a branch using monofilament fishing line(photo by F. Schlexer). Scent lures in figures 10.4B and 10.4C should be hung out of reach of the target species and potentialscavengers.

A

B C

necessary to saturate the bark. In some cases, over-application of lures may have a repellent effect(Carman 1975; Dobbins 2004).

Visual Lures

The most important factor to consider when in-stalling visual lures is sight distance. Vegetation mayhinder both the visibility of the lure and breezes toprovide motion. The lure should thus be suspended(with string or monofilament fishing line) from abranch in an opening above the detection device, ata height of 1–3 m. If string or twine is used, laid(twisted) line provides more motion than braidedline. Attaching the line to a tree limb via heavy gaugewire and a fishing swivel can help to maximize luremovement and minimize twisting and entanglementwith tree limbs (figure 10.1D; Weaver et al. 2005).Scent lures can be used to draw an animal withinrange of the visual lure and the detection device.This may not be effective or necessary for felids,however, which primarily rely on vision during for-aging (Kitchener 1991) and can be readily attractedto visual lures without additional scent lures (Mowatet al. 1999). In areas of high human use, care shouldbe taken to conceal visual lures from human view inorder to minimize vandalism or theft of detectiondevices.

Acquisition and Storage

Baits and lures can be an expensive component of acarnivore survey. Thus, it is important to seek outlow-cost sources and to employ effective storagemethods. Appendix 10.4 provides cost informationfor some commercial baits and lures.

Baits

Chicken is a good choice of bait because it is readilyavailable, relatively inexpensive, and can be obtainedin convenient sizes (Zielinski 1995). Chicken necks,backs, and wings, and other types of bait (e.g.,canned meat or fish) can usually be purchased inbulk at a discount. Grocery stores or butcher shopscan be excellent sources of free meat or fish that is

outdated or spoiled. Butcher shops and meat pack-ing plants may also be able to supply meat scraps ororgans that can’t be sold for human consumption,and slaughterhouses can provide livestock bloodthat would otherwise be discarded. Similarly, fishmarkets and fish packing plants will often providefree trimmings, fish heads, viscera, or rancid wholefish. These can either be used as is or rendered intofish oil. Whole fish are sometimes available from fishhatcheries or commercial fishermen. Nonmeat baits,such as rotten fruit or vegetables and stale bakedgoods, are often available at no charge.

Many carnivores are opportunistic and can be at-tracted with ungulate carcasses (Hornocker andHash 1981) or those of other species, such as beaver.Two potential sources of carcasses are trappers/hunters and road-killed animals. Deer (Odocoileussp.) are the most commonly available roadkill, butelk (Cervus elaphus) and moose (Alces alces) are ob-tainable in some areas. As it is often illegal to handleor transport road-killed game without permission, itis important to contact the local game agency beforepursuing this type of bait. Trappers may be able toprovide carcasses representing the target species’typical prey (note that trappers are occasionally paida small fee for this service). Kucera et al. (1995a) rec-ommend using whole carcasses when available, buthindquarters can be more manageable. Whole car-casses can also be cut into smaller pieces and frozenfor future use.

Researchers should be prepared to take advantageof opportunistic sources of large amounts of bait,particularly outside of the field season (e.g., roadkill,meat sales at the local market). If storage space islimited, it may be cost-effective to rent freezer space.Bait should be cut into single-use portions and indi-vidually wrapped before freezing, thus allowing theappropriate amount of bait to be removed duringthe survey with minimal handling.

Whether fresh or rancid bait is ultimately chosen,storage and disposal methods should be carefullyconsidered in advance. Meat, blood, and fish baitsrequire refrigeration or freezing. If appropriate facil-ities are not available or convenient, canned baits


should be explored as alternatives. Provisions shouldbe made to safely and lawfully dispose of unusedbait. To avoid confounding survey results, uneatenor nonreward baits should be removed from the sur-vey area and discarded in a manner compliant withlocal waste-disposal laws.

Scent Lures

Although certain scent lures, such as fish emulsionand cod-liver oil, can be obtained from a variety ofsources (e.g., garden and farm supply stores), someresearchers prefer to use commercial products or tomix their own lures using ingredients available fromtrapping supply companies (appendices 10.2, 10.3).Lure recipes and manufacturing methods are avail-able from traditional trapping sources (e.g., Carman1975; Hanson 1989), and descriptions of how to pre-pare livestock blood and fish oil for use as lures canalso be readily found (e.g., Wyshinski 2001; USDI2003). A few substances used in lures, such as honeyand molasses, are available in bulk from discountgrocery stores, canned food warehouses, and bakerysuppliers—in quantities ranging from 1 gal. bottlesto 55 gal. drums. Matrix lures can be acquired fromtrapping suppliers, and potentially from hunters,zoos, or game ranches. FAS and catnip oil can be ac-quired from the USDA Pocatello Supply Depot (ap-pendix 10.2).

Given that scent lures contain volatile com-pounds, they should be stored in airtight containersin a dark, dry place. Sealed bottles should be storedat room temperature and can have a shelf life of upto two years (Wyshinski 2001). Opened bottlesshould be frozen for long-term storage but may bekept at room temperature when use is pending.

Health Concerns

Baits have the potential to cause disease—not onlyin wildlife, but in researchers conducting surveys.The possibility of infection in both humans andwildlife can be mitigated by the careful selection ofattractants and safe handling methods. Some meth-

ods of bait presentation may also put animals at riskand should be avoided.

Safe Handling of Baits and Scent Lures

The potential risks of handling raw or rotted meat orfish are a legitimate concern, and all survey protocolsinvolving bait should include instructions for safebait handling. Table 10.3 lists the most commonpathogens that can cause illness in humans whohandle contaminated meat or fish. Some of theseagents are found in the intestines of animals, butothers are ubiquitous in the environment and cancontaminate fresh bait after it has been deployed atthe survey station, particularly in warm weather. In-deed, bait can become contaminated in as little asfour hours at 20°C (USDA 2005). In a volunteerstudy with humans (Black et al. 1988), Campylobac-ter infection occurred in subjects who ingested asfew as 800 organisms—an amount that can be pres-ent in just one drop of juice from raw chicken.

Bait should be carried into the field in containersto protect researchers from contamination. One safetransport method is to place individual pieces of baitin plastic Ziplock bags and freeze them until needed.To further prevent infection, personal protectiveequipment such as latex gloves or kitchen tongsshould be used when handling fresh, old, or rancidbait. Hands should always be washed with soap and(preferably warm) water after handling bait, particu-larly before touching one’s face or consuming food.If hands are not visibly soiled, disposable antisepticwipes or waterless disinfectant may be liberally ap-plied as an alternative. These alcohol-based handsanitizers should contain at least 60% alcohol to beeffective (Reynolds et al. 2006). Researchers with re-cent skin abrasions should avoid direct contact withbait. Finally, to prevent cross-contamination, cloth-ing or other gear should not come into contact withhands or gloves used to handle bait.

In study areas where bears occur, researchersshould exercise caution when carrying and handlingbait to reduce the likelihood of human-bear interac-tions. Bait containers should be completely sealed to


minimize external odor. In brown bear habitat, fieldpersonnel should never hike alone, be aware of theirsurroundings, and make noise to alert bears of theirpresence—particularly in dense brush. Researchersshould also be prepared to quickly surrender the baitcontainer if a bear charges. Additional safety tips areavailable from the American Bear Association (ABA2006).

Due to the potency and disagreeable odor ofmany scent lures—and in order to avoid attractinganimals to anything but the detection device—careshould be taken to prevent contamination of field

personnel (i.e., skin and clothing), gear, and vehicles.This can be accomplished by sealing the lure in aplastic Ziplock bag or container (e.g., Loukmas et al.2003). Military surplus ammunition cans, 5 gal.plastic tubs, or airtight plastic or aluminum cameracases are ideal for transporting both scent lures andbaits—as long as they don’t need to be carried a longdistance.

Wildlife Health and Safety

Given that rotten meat is commonly used to attractcarnivores (Bullard 1982), questions sometimes


Table 10.3. Common pathogens that may contaminate meat or fish baits used in noninvasive surveys

Pathogenic agent Source Potential bait reservoirs Method of transmission Infective dose*

Brucella spp. Urine, blood, and tis- Ruminantsa, swineb, canids Aspiration, ingestion, Very smallsues of infected animals mucosal contact,

dermal abrasions

Campylobacter jejuni Feces and intestinal Ruminants, swine, fowlc, Aspiration, ingestion Smalltracts of animals and rodentsbirds

Campylobacter coli Feces and intestinal Ruminants, swine, fowl, Aspiration, ingestion Smalltracts of animals and rodentsbirds

Clostridium perfringens Soil, feces, and intestinal Ruminants, swine, fowl, Aspiration, ingestion, Very largetracts of animals fish dermal abrasions

Escherichia coli O157:H7 Water, feces, and intes- Any domestic or wild Aspiration, ingestion, Unknown, but assumed tinal tracts of mammals mammal dermal abrasions to be very small

Francisella tularensis Soil, water, blood, and Many domestic and wild Aspiration, ingestion, Aspiration—very small, tissues of infected mammals and birds dermal contact ingestion and dermal animals contact—very large

Leptospira interrogans Urine, blood, and tis- Ruminants, swine, rodents, Aspiration, ingestion, Very smallsues of infected animals reptiles, amphibians dermal abrasions

Listeria monocytogenes Soil, water, blood, feces Any domestic or wild Aspiration, ingestion, Unknown, but assumed and intestinal tracts of mammal or bird dermal abrasions to be smallanimals

Salmonella spp. Water, feces and intes- Ruminants, swine, fowl, Aspiration, ingestion Very small(over 2,300 species) tinal tracts of animals rodents, reptiles, fish

and fish

Source: USDA 2005; FDA 2006; PHAC 2006.*Infective dose is the number of organisms needed to cause disease in average healthy individuals. Very small indicates as few as 10–100 organ-isms; Small indicates 500–1,000 organisms; Very large indicates ≥ 108 organisms.aRuminants include deer, elk, moose, caribou, wild sheep and goats, and domestic livestock (i.e., cattle, sheep, goats, horses).bSwine include wild and domestic pigs.cFowl include wild birds and domestic poultry.

arise regarding the potential effects of such baits onthe health of target species. Many carnivores regu-larly consume carrion or are at least occasional scav-engers; most can safely tolerate the high bacterialload in rotten meat due to having short digestivetracts and appropriate digestive enzymes and acids(DeVault et al. 2003). Harrison et al. (2006) testedfor bacterial contamination of carcass meat (includ-ing deer and elk) donated to a zoo and concludedthat such meat appears to be reasonably safe for carnivores.

A more serious health threat for some carnivoresoccurs when raw fish is used as bait. Salmon poison-ing disease (SPD) and Elokomin fluke fever (EFF)are acute, infectious diseases, primarily affectingcanids. Animals become infected by ingesting sal -mon, steelhead, or trout that contain a rickettsia- infected fluke. SPD can kill up to 90% of infected an-imals, while EFF usually manifests in a milder form(Aiello 1998). SPD has been commonly seen in coy-otes (Foreyt et al. 1987), foxes (Cordy and Gorham1950), and gray wolves (Canis lupus; Darimont et al.2003), and has been reported in cougars (Puma con-color; Kistner et al. 1979) and American black bears(Farrell et al. 1973) as well. SPD microorganisms arealso transmittable to domestic animals and humans(Aiello 1998). EFF has been reported in canids, ur-sids, procyonids, and mustelids (Aiello 1998). In-fected fish are found along the northern Pacific coastand in rivers used for migration. Because the en-cysted flukes are resistant to freezing (Aiello 1998),fresh or frozen salmonids should only be used as baitif they are cooked or canned, or if they originatefrom outside infected areas.

An additional safety consideration for wildlife liesin bait presentation. For some survey methods (e.g.,remote cameras), nonreward meat baits are rou-tinely wrapped and fastened to trees in woven wiremesh (e.g., chicken wire) or hardware cloth to in-crease the duration of attractiveness. There is in-creasing concern among researchers that portions ofwire could be incidentally consumed with the bait,posing a health risk from metal poisoning or intes-

tinal perforation. This method of bait presentation,therefore, should be avoided. The preferred alterna-tive is to nail small frozen bait directly to a tree (fig-ure 10.2B)—or to wrap large bait to a tree with thin-gauge wire (figure 10.2C)—within the target area ofthe detection device.

Survey Design Issues

Survey objectives may constrain attractant selection.Detection-nondetection surveys might require aspecific scent lure to attract a target species within asample unit. Other types of surveys, such as those fo-cusing on foraging behavior or habitat use, might beconfounded by a strong lure if the effective samplingdistance is great and animals deviate from their nat-ural paths to investigate (Zielinski et al. 2005).Hence, the use of strong scent lures in such situa-tions is not recommended (Gese 2001). Cautionshould also be applied in scat-based diet studies,which may yield unreliable results if commercialfoods or atypical bait items are consumed.

Habituation and Avoidance

Some canids—particularly coyotes—are susceptibleto trap-shyness and learn to recognize and avoidtraps and associated attractants (Conner et al. 1998).Coyotes that have been trapped appear to make fewervisits to noninvasive scent stations (Andelt et al.1985). Reciprocally, recent or nearby trapping efforts(either for recreational, control, or research pur-poses) may inflate survey detection rates if animalsbecome conditioned to bait as a food source (Brongoet al. 2005). The use of novel attractants (i.e., thosenot widely used by trappers or animal control per-sonnel) can potentially mitigate these problems. Reward-based attractants (e.g., the coyote lure opera-tive device or CLOD; Marsh et al. 1982) can be usedto attract trap-shy animals (Berentsen et al. 2006).

Reward baits can have both ethical and samplingimplications. In terms of the former, some animals


become reliant on the food value of bait, potentiallyresulting in a caloric deficit when the survey stationis removed (Brongo et al. 2005). Sampling bias isalso a concern in this situation. Habituated animalsmay remove bait early in the sampling occasion, re-ducing the attractiveness of the device and thuscausing undersampling. Conversely, a habituated in-dividual can cause oversampling by repeatedly visit-ing the same device in hopes of obtaining food.Nonreward baits likely reduce return visits by thesame individual, but can attract nontarget scavengerspecies when baits decompose. Bait presentationshould strive to maximize the probability of detect-ing the target species while simultaneously minimiz-ing multiple detections of the same individual(Zielinski et al. 1995b).

Attractant effectiveness can vary with survey du-ration. Martin and Fagre (1988) determined thatcoyote visitation rates at scented track stations weresignificantly lower at the end of a six-day survey pe-riod than at the beginning. In contrast, Stapper et al.(1992) found that visitation rates did not changeover the course of three-day surveys, suggesting thatsome carnivores neither avoided nor were attractedback to a lure after their initial visit when the surveyperiod was relatively short.

Results from studies of captive animals (Harri-son 1997) and repeated scent surveys conductedover a short period (Robson and Humphrey 1985)suggest that a given population’s response to scent-based attractants may decline over time. Free- ranging carnivores, however, are less likely to be-come accustomed to scents that they encounteronly a few times each year. The concern of habitua-tion should thus not deter the use of scent lures forlong-term monitoring of carnivore populations(Harrison 1997).

Standardization of Attractants

Switching attractant types, or employing multipleattractant types, during a survey can create attrac-tion biases, including variations in effective sam-

pling distance, unequal detection probability, andlack of spatial independence (see chapter 2). For ex-ample, sampling distance might change dependingon the strength of the odor associated with a scentlure, and switching to a bait that is less attractive tothe target species could violate the assumption ofequal detection probability. To minimize such issues,attractant type and quantity, and the protocol fordeploying attractants, should be standardized formost surveys, particularly those comparing esti-mates of absolute abundance (Buckland et al. 2006)or relative abundance (Romain-Bondi et al. 2004;Gompper et al. 2006) over geographic areas oramong years (Raphael 1994).

The use of standardized attractants for relativeabundance surveys increases the probability that ob-served detection rates reflect differences in popula-tion size versus differences in methodology (Raphael1994). Even species presence cannot be reliably in-ferred using nonuniform methods (McKelvey et al.1999). A standardized, reliable set of attractants ap-plied with consistent protocols will help to generatestatistically valid data and facilitate repeatability.Standardized attractants were used in the NationalLynx Detection Protocol, for example (McKelvey etal. 1999; see chapter 6). This rigorous protocol stipu-lated the type, proportions, and placement of luresused to attract Canada lynx (Lynx canadensis), al-lowing the pooling of data collected by a large num-ber of agencies and administrative jurisdictions overa broad geographic area.

Attempts have been made to develop standard-ized attractants for particular species. The develop-ment of FAS arose from the testing and field evalua-tion of standardized lures intended to attractdepredating coyotes (Roughton and Bowden 1979),and standardized attractants have also been pro-posed for some species of felids (Clapperton et al.1994a; McDaniel et al. 2000), foxes (Steelman et al.1998), mustelids (Clapperton et al. 1994b; Zielinskiet al. 2005), and ursids (Mowat and Strobeck 2000).Attractant standardization methods for remotecamera and track station surveys are respectively


recommended by Kucera et al. (1995a) and Zielinski(1995).

Seasonal Issues

Baits and lures can be used in any season, but re-searchers should select attractants and associatedprotocols based on the expected temperature andhumidity during the survey season (see Frequency ofReapplication). The effective sampling distance willtypically be greater in warm versus cold weather.Large baits, which resist decay and desiccation, maybe more appropriate in warm weather. Wind andtemperature not only affect scent dispersion but caninfluence animal behavior as well. In general, carni-vores are more likely to investigate baits and scentsduring winter when prey availability is more limitedand less diverse (Carman 1975). Conducting surveysin winter also prevents conflicts with bears, whichcan inflict damage to equipment (see Safe Handlingof Baits and Scent Lures) and alter the behavior of thetarget species.

Some attractants are limited by seasonal availabil-ity. Whole fish or road-killed carcasses may be spo-radically accessible, for example, and certain lures(e.g., cow blood) need to be aged or premixed underspecific environmental conditions. Most liquid scentlures require the addition of an antifreeze agent ifthey are to be used in below-freezing temperatures(table 10.2). Finally, commercial trapping lures maybe in high demand and difficult to obtain in quan-tity immediately before a trapping season.

Frequency of Reapplication

Weather conditions dictate how often bait must bereplenished. Baits can be washed out by rain or des-iccated by heat, leaving them odorless and ineffec-tive. Given that baits decompose most rapidly inwarm weather, summer field personnel should carryextra bait during station checks in case replacementis warranted. Zielinski (1995) recommends that re-ward baits be replaced at enclosed track plates everyvisit (i.e., every two days), although detections may

occur as long as some bait remains (Raphael 1994).Frozen baits deployed in subfreezing conditions areresistant to decomposition and therefore require lessfrequent replacement. Such baits, however, may notbe as effective as a distance lure due to the reducedrelease of aromatic compounds. Thus, under theseconditions, rotted bait is preferred to fresh bait.

Researchers should not rely on their own sense ofsmell to determine if scent lures are in need of reap-plication. A lure reapplication schedule should bebased on scientific literature or on experimentaltesting and should address environmental variablessuch as topography, climate, and season. The relur-ing interval can vary from several days to severalweeks (Dobbins 2004), depending on survey dura-tion, lure type, and weather conditions. Zielinski(1995) recommends that scent lures be applied atenclosed track plates at least twice during a twelve-day survey period. As many scent lures are oil-basedand therefore are not seriously diluted by rain orsnow, reapplication after every weather event is un-necessary. Lures with a skunk-based scent are moreeffective at low temperatures (Carman 1975), butsome scent lure base materials (e.g., lanolin) becomeunusable at temperatures below freezing.

Evaluating the Effectiveness ofBaits and Lures

The majority of baits and lures used by commercialand recreational trappers and hunters are foundedon tradition and time-tested success. Many of theseattractants may be valid for noninvasive carnivoresurveys as well and should be scientifically evaluatedusing rigorous, repeatable protocols. Researchershave generally used attractants based on their his-tory of effectiveness (appendix 10.1), and the scien-tific testing of attractants didn’t begin until the lastfew decades (e.g., Linhart and Knowlton 1975).Some such testing continues today, following thesystematic approach of separating out the compo-nents of a given attractant and assessing each com-ponent individually (e.g., Kimball et al. 2000)—


often in collaboration with local trappers, animalcontrol agents, or analytical chemists (Turkowski etal. 1979; Wood et al. 2005).

One common testing method involves presentinga captive animal with a variety of attractants andmeasuring its relative interest by recording behav-ioral responses. This method can quantitatively eval-uate such behaviors as sniffing, scent-marking,scraping, rubbing/rolling, licking/biting, and defe-cating, as well as response enthusiasm (Fagre et al.1981, Harrison 1997). Various attractants can thusbe ranked according to behavioral response.

Field testing is more appropriate for assessing theeffectiveness of attractants in wildlife research, as itincorporates environmental factors and populationdensity. In such tests, visitation rate (or detectionrate)—as opposed to behavioral response—is oftenused as a means of evaluation (Graves and Bod-dicker 1987). Scent stations provide an effectivevenue for assessing visitation. Bullard et al. (1983),for example, found that free-ranging coyote visits in-creased with lure type and intensity, and that widelydifferent odors elicited similar visitation rates. An-delt and Woolly (1996) used experimental manipu-lation to determine the responses of urban carni-vores to a variety of natural and proprietary lures atscent stations (see appendix 10.1). The randomiza-tion of attractants and the rotation of lures at a givenlocation allow for statistical comparison with a con-trol lure (e.g., water). Combining captive animal be-havioral trials and field evaluations is another suc-cessful approach to assessing baits (e.g., Fowler andGolightly 1993).

When evaluating attractants for a noninvasivesurvey, it is important to consider a number of fac-tors beyond attractiveness. These include, for in-stance, the survey season, study area, target species,and duration. Martin and Fagre (1988) found thatsuch variables significantly affected outcome whentesting natural and synthetic lures.

Clapperton et al. (1994a) assessed the effect of avariety of odors on captive wild and domestic cats(Felis spp.) and on feral cats (Felis catus) in field tri-als. These researchers identified catnip and matatabi

(Actinidia polygama, otherwise known as Japanesecatnip) as the most successful candidate lures for at-tracting cats. Scent station visits and behavioral re-sponses to scent lures in captive and free-rangingCentral American felids were evaluated by Harrison(1997), who found that behavioral scores were moreeffective at evaluating lures than were investigationtimes. A randomized test of natural and proprietarylures found that beaver castorium and catnip oil weremost effective at attracting Canada lynx (McDaniel etal. 2000). And the USDA Forest Service is evaluating abroad spectrum of scent lures to assess their potentialfor attracting wolverines (Gulo gulo; Copeland et al.2004). Nearly thirty individual compounds havebeen tested, and wolverine urine and anal gland se-cretions show promise (Wood et al. 2005).

Much effort has been expended to develop palat-able baits for delivering poison or fertility controldrugs to “pest” (e.g., coyotes; Robinson 1962) andnonnative species (e.g., stoats [Mustela erminea];Clapperton et al. 1994b). Similar research has beenaimed at developing bait-based methods for admin-istering rabies vaccines to Arctic foxes (Vulpes lago-pus; Follmann 1988), gray foxes (Urocyon cinereoar-genteus; Steelman et al. 1998), and raccoons (Wolf etal. 2003). This category of research has employedrigorous methods for testing the efficacy of baits andlures (see also Turkowski et al. 1979; Graves andBoddicker 1987; Mason et al. 1999).

Advanced statistical methods can validate experi-mental manipulations of attractants. Stanley andRoyle (2005) used Poisson and negative binomialmodels to evaluate retrospective data quantifyingthe effect of bait supplementation at scent stations(Hein and Andelt 1994). Both studies showed thatcoyotes used scent stations baited with a supplemen-tal deer carcass more often than stations withoutsupplemental bait.

Among the many salient questions pertaining tothe use and evaluation of attractants for noninvasivesurveys, three stand out: Why are such a wide varietyof carnivores attracted to skunk-based scent lures?Which species prefer rotten bait to fresh bait? Whatis the sampling radius (effective distance) over


which specific lures are able to attract particular spe-cies?

Addressing these questions would do much to en-hance the reliability and repeatability of carnivoresurvey efforts. Meanwhile, the studies presented hereillustrate how carnivore surveys can benefit from thesystematic testing of attractants. Although folk tra-dition should not be ignored, this field will be hand-icapped until quantifiable and repeatable testing oftraditional attractants supplants anecdotal conjec-ture. The identification of scientifically valid and ef-fective baits and lures will conserve scarce researchfunds and provide standardized and defensible re-

sults for surveys designed to inform the conserva-tion of carnivores in a changing world.

Acknowledgments

I thank the USDA Forest Service Pacific SouthwestResearch Station for supporting this work. Russ Car-man and Paul J. Dobbins assisted with research andshared some “inside secrets” from the lure business. Iam also grateful to Roland Kays and the late EricYork for providing helpful reviews of early drafts ofthis chapter.


Bait or lure by species Reference

CoyoteBaits

unplucked chickens Aubry et al. 1997fish (salmon and

steelhead) Aubry et al. 1997deer carcasses Aubry et al. 1997black-tailed prairie dogs Kamler et al. 2002black-tailed jackrabbits Kamler et al. 2002cottontail rabbits Kamler et al. 2002; Way et al.

2002gray squirrels Way et al. 2002woodchucks Way et al. 2002supermarket meat scraps Way et al. 2002lamb meat Shivik et al. 2005jackrabbit meat Shivik et al. 2005deer meat Shivik et al. 2005raw chicken Way et al. 2002; Gompper et al.

2006deer meat (2–5 kg) Gompper et al. 2006beaver meat (2–5 kg) Aubry et al. 1997; Gompper et

al. 2006Scent lures

FASa Harrison 1997*; Sargeant et al. 1998

catnipb oil Harrison 1997*bobcat urine Harrison 1997*commercial lurec Harrison 1997*wool Shivik et al. 2005unspecified commercial

lure Shivik et al. 2005commercial lured Gompper et al. 2006

Sound luresvocalization recordings Knowlton and Stoddart 1984

Gray wolf Baits

meat Van Ballenberghe 1984Scent lures

wolf urine Van Ballenberghe 1984unspecified commercial

lure Van Ballenberghe 1984FASa Sargeant et al. 1998

Gray fox Baits

raisins and other fruits Fuller 1978; Trapp 1978; Hallberg and Trapp 1984

honey-based commercial bait Berchielli and Leubner 1981

fish Smith and Brisbin 1984dog food Weston and Brisbin 2003raw chicken Zielinski et al. 2005; Gompper

et al. 2006deer meat (2–5 kg) Gompper et al. 2006beaver meat (2–5 kg) Smith and Brisbin 1984;

Gompper et al. 2006Scent lures

fox gland lure Berchielli and Leubner 1981fox urine Berchielli and Leubner 1981FASa Harrison 1997*catnipb oil Harrison 1997*bobcat urine Conner et al. 1983; Harrison

1997*commercial lurec Harrison 1997*commercial luree Weston and Brisbin 2003commercial lured Zielinski et al. 2005; Gompper

et al. 2006

Island fox Baits

dry cat food Kohlmann et al. 2005canned cat food Kohlmann et al. 2005

Scent luresloganberry paste com-

mercial lure Kohlmann et al. 2005

Arctic foxBaits

fish Garrott and Eberhardt 1987

Kit fox Baits

carrion (especially lagomorphs) O’Farrell 1987

birdsf O’Farrell 1987small mammalsf O’Farrell 1987sardines O’Farrell 1987cooked chicken parts O’Farrell 1987cheese O’Farrell 1987canned mackerel O’Farrell 1987; Cypher and

Spencer 1998; Koopman et al. 2000; Warrick and Harris 2001

black-tailed jackrabbits Zoellick and Smith 1992leporids Cypher and Spencer 1998;

Koopman et al. 2000Scent lures

FASa Warrick and Harris 2001


Appendix 10.1

Baits and lures (scent, visual, and sound) that have been used in carnivore surveys, by target species

Bait or lure by species Reference

Swift fox Baits

chicksf Scott-Brown et al. 1987rabbitsf Scott-Brown et al. 1987deer Scott-Brown et al. 1987raw chicken Covell 1992beef scraps Harrison et al. 2002black-tailed prairie dogs Kamler et al. 2002black-tailed jackrabbits Kamler et al. 2002desert cottontails Kamler et al. 2002canned mackerel in oil Uresk et al. 2003

Scent lurescod-liver oil-mackerel Harrison et al. 2002; Harrison

commercial lureg 2003

Red fox Baits

honey-based commercial bait Berchielli and Leubner 1981

raw chicken Zielinski et al. 2005; Gompper et al. 2006

deer meat (2–5 kg) Gompper et al. 2006beaver meat (2–5 kg) Gompper et al. 2006

Scent luresfox gland lure Berchielli and Leubner 1981fox urine Berchielli and Leubner 1981FASa Sargeant et al. 1998commercial lured Gompper et al. 2006

Ocelot Baits

live chickens or chicks Tewes 1986; Emmons 1988; Crawshaw and Quigley 1989; Laack 1991; Caso 1994; Horne 1998; Harve-son et al. 2004; Dillon 2005

live rabbits Tewes 1986; Caso 1994live quail Caso 1994live pigeons Horne 1998sardines in oil Trolle 2003; Trolle and Kery

2003; Dillon 2005chicken parts Dillon 2005

Scent luresocelot, bobcat, and fox

urine Laack 1991FASa Harrison 1997*commercial lureh Boddicker et al. 2002catnipb Shinn 2002; Weaver et al. 2005cod-liver oil Trolle 2003commercial lurej Shinn 2002; Weaver et al. 2003;

Weaver et al. 2005commercial lurei Dillon 2005

Visual lurespie plate flasher Shinn 2002; Weaver et al. 2005

Margay Scent lures

FASa Harrison 1997*catnipb oil Harrison 1997*bobcat urine Harrison 1997*commercial lurec Harrison 1997*commercial lureh Boddicker et al. 2002

Canada lynx Baits

chicken Zielinski 1995carrion Kucera et al. 1995adeer (> 5 kg) Kucera et al. 1995afish Kucera et al. 1995arabbit Shenk 2001

Scent luresunspecified commercial Zielinski 1995; Kucera et al.

lure 1995askunk musk/essence/

tincture Kucera et al. 1995abeaver castoreum McDaniel et al. 2000*catnipb oil McDaniel et al. 2000*

Visual luresflasher Young 1958; Baker and Dwyer

1987; Zielinski 1995; Kucera et al. 1995a

Bobcat Baits

fresh meat Kitchings and Story 1979; Zezulak and Schwab 1979; Smith and Brisbin 1984

live chickens Kitchings and Story 1979; Zezulak and Schwab 1979; Fischer 1998; Horne 1998

live rabbits Kitchings and Story 1979; Zezulak and Schwab 1979

fish Smith and Brisbin 1984unplucked chickens Aubry et al. 1997fish (salmon and

steelhead) Aubry et al. 1997beaver meat Aubry et al. 1997deer carcasses Aubry et al. 1997live pigeons Horne 1998raw chicken Long et al. 2007bcommercial lurej Long et al. 2007b

Scent luresFASa Roughton 1979*; Diefenbach

et al. 1994; Sargeant et al. 1998

bobcat urine Morrison et al. 1981; Conner et al. 1983

commercial lurej Shinn 2002commercial lured Long et al. 2007b


Bait or lure by species Reference Bait or lure by species Reference

Visual luresflasher Young 1958; Baker and Dwyer

1987; Shinn 2002

Jaguar Baits

sardines in oil Trolle 2003Scent lures

catnipb Kitchener 1991commercial lureh Boddicker et al. 2002cod-liver oil Trolle 2003

Cougar Baits


steelhead) Aubry et al. 1997beaver meat Aubry et al. 1997deer carcasses Aubry et al. 1997sardines in oil Trolle 2003

Scent lurescod-liver oil Trolle 2003

Jaguarundi Baits

live chickens Caso 1994live rabbits Caso 1994live quail Caso 1994

Scent luresFASa Harrison 1997*bobcat urine Harrison 1997*commercial lurec Harrison 1997*

Striped skunk Baits

smoked herring Bailey 1971fish Smith and Brisbin 1984;

Greenwood et al. 1997deer carcasses Smith and Brisbin 1984; Aubry

et al. 1997sardines Rosatte 1987; Bartelt et al.

2001chicken entrails Rosatte 1987dog food Rosatte 1987unplucked chickens Aubry et al. 1997fish (salmon and

steelhead) Aubry et al. 1997beaver meat Aubry et al. 1997chicken eggs Greenwood et al. 1997dry dog food Greenwood et al. 1997sunflower seeds Greenwood et al. 1997canned cat food Baldwin et al. 2004raw chicken Zielinski et al. 2005

Scent luresvarious chemical

attractants Rosatte 1987FASa Greenwood et al. 1997;

Sargeant et al. 1998mink gland and salmon

oil (1:1) Loukmas et al. 2003commercial lured Zielinski et al. 2005

Western spotted skunk Baits


steelhead) Aubry et al. 1997beaver meat Aubry et al. 1997deer carcasses Aubry et al. 1997raw chicken Zielinski et al. 2005

Scent luresFASa Sargeant et al. 1998commercial lured Zielinski et al. 2005

Wolverine Baits

fresh meat (1 kg) Hash and Hornocker 1980carrion Kucera et al. 1995adeer (> 5 kg) Kucera et al. 1995a; Copeland

et al. 1995fish Kucera et al. 1995a; Copeland

et al. 1995chicken Zielinski 1995beaver carcasses Copeland 1996; Fisher 2005rotten meat Mowat 2001

Scent luresfish oil Mowat 2001beaver castor Mowat 2001unspecified commercial Zielinski 1995; Kucera et al.

lure 1995acommercial lurek Fisher 2005

Visual lurescloth flasher Hash and Hornocker 1980flasher Zielinski 1995; Kucera et al.

1995a

North American river otter Baits

whole fish Melquist and Dronkert 1987

American marten Baits

beaver carcasses Strickland and Douglas 1987canned sardines Strickland and Douglas 1987;

Gosse et al. 2005strawberry or raspberry

jam Strickland and Douglas 1987



beaver meat (2–5 kg) Baker and Dwyer 1987; Aubry et al. 1997; Gompper et al. 2006

carrion Kucera et al. 1995afish Kucera et al. 1995adeer (> 5 kg) Kucera et al. 1995a; Aubry et

al. 1997raw chicken Zielinski 1995; Zielinski et al.

2005; Gompper et al. 2006unplucked chickens Aubry et al. 1997fish (salmon and

steelhead) Aubry et al. 1997partially decomposed

chicken wings Mowat et al. 2001deer meat (2–5 kg) Gompper et al. 2006

Scent luresbeaver fat Baker and Dwyer 1987anise oil Strickland and Douglas 1987fish oil Strickland and Douglas 1987unspecified commercial Zielinski 1995; Kucera et al.

lure 1995a; Mowat et al. 2001rendered fish oil Mowat et al. 2001skunk scent commercial

lure Gosse et al. 2005commercial lured Zielinski et al. 2005; Gompper

et al. 2006Visual lures

flasher Zielinski 1995; Kucera et al. 1995a

Fisher Baits

beaver carcasses Douglas and Strickland 1987canned sardines Douglas and Strickland 1987beaver meat Baker and Dwyer 1987; Aubry

et al. 1997meat scraps Jones and Garton 1994carrion Kucera et al. 1995adeer (> 5 kg) Kucera et al. 1995a; Aubry et

al. 1997fish Kucera et al. 1995achicken Zielinski 1995unplucked chickens Aubry et al. 1997fish (salmon and steelhead)Aubry et al. 1997raw chicken Zielinski et al. 2005; Long et al.

2007b; Gompper et al. 2006deer meat (2–5 kg) Gompper et al. 2006beaver meat (2–5 kg) Gompper et al. 2006

Scent luresbeaver fat Baker and Dwyer 1987anise oil Douglas and Strickland 1987unspecified commercial Jones and Garton 1994;

lure Zielinski 1995; Kucera et al. 1995a

mink gland and salmon oil (1:1) Loukmas et al. 2003

commercial lured Zielinski et al. 2005; Long et al. 2007b; Gompper et al. 2006

Visual luresflasher Zielinski 1995; Kucera et al.

1995a

Ermine Baits


steelhead) Aubry et al. 1997deer carcasses Aubry et al. 1997beaver meat (2–5 kg) Aubry et al. 1997; Gompper et

al. 2006fresh meat Gonzales 1997partially decomposed

chicken wings Mowat et al. 2001raw chicken Gompper et al. 2006deer meat (2–5 kg) Gompper et al. 2006

Scent luresrendered fish oil Mowat et al. 2001unspecified commercial

lure Mowat et al. 2001mink gland and salmon

oil (1:1) Loukmas et al. 2003commercial lured Gompper et al. 2006

Long-tailed weasel Baits

dead domestic mice DeVan 1982; Gehring and Swihart 2004



al. 2006fresh meat Gonzales 1997raw chicken Zielinski et al. 2005; Gompper

et al. 2006deer meat (2–5 kg) Gompper et al. 2006

Scent luresmink gland and salmon

oil (1:1) Loukmas et al. 2003unspecified commercial Gehring and Swihart

lure 2004commercial lured Gompper et al. 2006

Least weasel Baits

live mice Fagerstone 1987



fresh meat Henderson 1994; Gonzales 1997

American mink Baits

fresh rabbit, muskrat, birds NDFA 1997

fresh fish NDFA 1997Scent lures

fish oil NDFA 1997mink glands and urine NDFA 1997unspecified commercial

mink lure Loukmas and Halbrook 2001ranch mink scat Loukmas and Halbrook 2001mink gland and salmon

oil (1:1) Loukmas et al. 2003

American badger Baits

raw chicken Minta and Marsh 1988; Zielinski et al. 2005

chicken carcass Gonzales 1997ground squirrels Newhouse and Kinley 2000;

Apps et al. 2002rabbitsf Newhouse and Kinley 2000;

Apps et al. 2002beef liver Newhouse and Kinley 2000;

Apps et al. 2002Scent lures

commercial lurel Newhouse and Kinley 2000unspecified commercial

lure Apps et al. 2002commercial lured Zielinski et al. 2005

Ringtail Baits

raisins Hallberg and Trapp 1984; Kaufmann 1987

fruit jam Kaufmann 1987fish Kaufmann 1987unplucked chickens Aubry et al. 1997fish (salmon and

steelhead) Aubry et al. 1997beaver meat Aubry et al. 1997deer carcasses Aubry et al. 1997raw chicken Zielinski et al. 2005

Scent luresringtail urine Kaufmann 1987ringtail musk Kaufmann 1987commercial lured Zielinski et al. 2005

White-nosed coati Baits

bananas Kaufmann 1987

marshmallows Kaufmann 1987canned and dry pet food Kaufmann 1987live chickens Caso 1994live rabbits Caso 1994live quail Caso 1994sardines Valenzuela and Ceballos 2000

Scent lurescommercial lureh Boddicker et al. 2002

Raccoon Baits

fresh fish Smith and Brisbin 1984; Sanderson 1987

deer meat (2–5 kg) Smith and Brisbin 1984; Gompper et al. 2006

dry, chunk-style dog food Sanderson 1987canned fish Sanderson 1987unplucked chickens Aubry et al. 1997fish (salmon and


al. 2006sardines Bartelt et al. 2001marshmallows Bartelt et al. 2001strawberry jam Bartelt et al. 2001raw chicken Zielinski et al. 2005; Gompper

et al. 2006Scent lures

bobcat urine Conner et al. 1983; Rucker 1983; Leberg and Kennedy 1987

FASa Smith et al. 1994; Sargeant et al. 1998

mink gland and salmon oil (1:1) Loukmas et al. 2003

commercial lured Zielinski et al. 2005; Gompper et al. 2006

American black bear Baits

apples Baker and Dwyer 1987fish Baker and Dwyer 1987rotten meat (2 kg) Woods et al. 1999corn Brown 2004honey (diluted with

water) Brown 2004maple syrup (diluted

with water) Brown 2004stale pastries (e.g., ba-

gels, donuts, cookies) Brown 2004; Knorr 2004canned sardines Brongo et al. 2005raw chicken Zielinski et al. 2005; Long et al.

2007b; Gompper et al. 2006



fish food pellets Long et al. 2007bmolasses Long et al. 2007bdeer meat (2–5 kg) Gompper et al. 2006beaver meat (2–5 kg) Gompper et al. 2006

Scent luresliquid fish fertilizer Woods et al. 1999commercial lured Zielinski et al. 2005; Long et al.

2007b; Gompper et al. 2006

Grizzly bear Baits

raw meat (wild ungu-late, domestic livestock) Mace et al. 1994

livestock blood Mace et al. 1994; Boulanger et al. 2004c; Proctor et al. 2004; Romain-Bondi et al. 2004

rotten meat (2 kg) Woods et al. 1999; Proctor et al. 2004; Romain-Bondi et al. 2004

Scent lurescanned blueberries Mace et al. 1994anise extract Mace et al. 1994vanilla extract Mace et al. 1994commercial skunk scent Mace et al. 1994

liquid fish fertilizer Woods et al. 1999; Proctor et al. 2004; Romain-Bondi et al. 2004

fish oil Boulanger et al. 2004c

Note: Asterisk (*) indicates studies that have empirically tested andevaluated specific lures for the target species. † Lures available from multiple trapping supply distributors. See ap-pendix 10.2 for names and addresses.aSynthetic fatty-acid tablets (USDA, Pocatello Supply Depot, Poca -tello, ID).bNepeta cataria (fresh and dried catnip leaves are available from petstores and multiple trapping supply distributors; catnip oil is avail-able from USDA, Pocatello Supply Depot, Pocatello, ID).cHawbaker’s Wildcat #2 †. dCaven’s Gusto †. eLiquid Fox and Coyote Lure, Fox Gland Lure (On Target A.D.C.,Cortland, IL); Caven’s Fox #1, Caven’s Fox #2, Caven’s Canine Force†.fBait is presumed to be dead (author did not state)gTrailing Scent (On Target A.D.C., Cortland, IL).hCarman’s Canine Call, Pro’s Choice, Bobcat Gland Lure, TrophyDeer Lure, and Mega Musk †.iMarak’s Bobcat Lure, Marak’s Coyote Lure, Marak’s Gray Fox Lure,Marak’s Raccoon Lure †.jWeaver’s Cat Call (John L. Weaver, Wildlife Conservation Society,St. Ignatius, MT).kO’Gorman’s LDC Extra †. lCarman’s Canine Call †.



Item Supplier

FAS (fatty acid scent) USDA, APHIS, WSPlaster predator survey Pocatello Supply Depot

disks 238 East Dillon StreetCatnip oil Pocatello, ID 83201

[email protected]

Carnivore urines AllPredatorCalls.comGlands, musks, and PO Box 90163

proprietary lures Tucson, AZ 85752 Botanical oils and 520-293-2972

extracts www.allpredatorcalls.com/Vocalization recordings

Adirondack Outdoor CompanyPO Box 86Elizabethtown, NY 12932518-873-6806www.adirondackoutdoor.com/

trapping.htm

Cumberland’s Northwest Trappers Supply

PO Box 408Owatonna, MN 55060507-451-7607www.nwtrappers.com/default.asp

Dobbins’ Products208 Earl DriveGoldsboro, NC 27530919-580-0621www.trapperman.com/catalog.html

Funke Trap Tags & Supplies2151 Eastman Ave.State Center, IA 50247641-483-2597www.funketraptags.com/

S. Stanley Hawbaker & SonsPO Box 309Fort Louden, PA 17224

Kishel’s Quality Animal Scents & Lures, Inc.

c/o Rettig’s Outdoor Supplies107 Harvey LaneSaxonburg, PA 16056724-352-7121www.kishelscents.com/index.asp

Knob Mountain Fur Company430 Monroe StreetBerwick, PA 18603 570-759-7035www.knobmountainfur.com/

index.php

M & M Furs, Inc.PO Box 1526445 435th AvenueBridgewater, SD 57319-0015605-729-2535www.mandmfurs.com/

Minnesota Trapline Products6699 156th Avenue N.W.Pennock, MN 56279320-599-4176www.minntrapprod.com/

On Target A.D.C.PO Box 480Cortland, IL 60112815286-3073www.wctech.com/ontarget/

The Snare Shop858 East U.S. Highway 30Carroll, IA 51401712-792-0601

Sterling Fur and Tool Company11268 Frick RoadSterling, OH 44276330-939-3763

Sullivan’s Scents and Supplies429 Upper TwinBlue Creek, OH 45616740-858-4416www.sullivansline.com/sline/

slhome.htm

Wasatch Wildlife ProductsPO Box 753Magna, UT 84044801-250-9308www.wasatchwild.com


Appendix 10.2

Select commercial suppliers of baits and scent lures, lure ingredients, and other attractants

Item Supplier

Target family

Scent Use Characteristic Canidae Felidae Mephitidae Mustelidae Procyonidae Ursidae

Acorn oil attractant herbal xAlmond extract attractant sweet x x x xAmbergris oil

(synthetic) fixative musky x x x x xAmber oil fixative minty x xAmbrette musk attractant musky, sweet x x x xAnise oil attractant sweet, licorice x x x x xApple oil attractant sweet x xAsafoetida gum attractant pungent x xAsfoetida tincture attractant pungent x xBanana essence oil attractant, additive floral x x xBergamot oil attractant, additive minty x x x xBalsam oil attractant, additive herbal xBirch oil attractant, additive sweet xBlack prune oil additive fruity xBleach additive pungent xBlue cheese oil attractant sharp x x xBlueberry essence attractant fruity x x x x xCalamus oil attractant sweet x xCalamus powder attractant sweet x xCatnip oil attractant herbal x x xCatnip, dried attractant herbal x x xCatnip, fresh attractant herbal x x xCaramel essence additive sweet xCanton musk fixative musky x xChenopodium oil fixative musky xCherry oil attractant, additive sweet xCheese essence attractant pungent x x xCivet oil attractant musky xCod liver oil attractant fishy x xCumin fixative pungent xFAS (fatty acid scent) attractant pungent x x x xFennel oil attractant herbal xFig extract oil additive sweet xFish oil attractant fishy x x x xFish extract attractant fishy x x x xGarlic essence attractant pungent x x x xGrape essence attractant fruity x xHoney essence oil attractant, additive sweet x x xHoneysuckle oil attractant sweet, floral x xLavender oil attractant floral xLiquid smoke attractant pungent x x xLoganberry oil attractant fruity x x x xLovage oil attractant herbal xLovage root powder attractant herbal xMelon oil attractant fruity x xMuscaro musk attractant musky x xOrange oil attractant citrus x


Appendix 10.3

Scents and oils used in traditional and commercial lure manufacture

Pennyroyal oil attractant minty xPeppermint oil attractant minty xPersimmon oil attractant, additive fruity x xPhenyl acetic,

crystals attractant, additive sweet xPhenyl acetic, liquid attractant, additive sweet xPrune oil attractant sweet x xRaspberry oil attractant fruity x x xRhodium oil attractant minty xRue oil attractant, fixative herbal xSalmon oil attractant fishy x x x xSpearmint oil attractant, additive sweet, minty x xShellfish oil attractant fishy x x x xShrimp essence attractant fishy x x xStrawberry oil attractant fruity x x x xSweetcorn oil attractant, additive herbal x x xSynthetic fermented

egg attractant pungent x x x xTabasco attractant pungent xTonka bean extract additive vanilla x xTonquin musk,

synthetic attractant musky xTrout oil attractant fishy x x xValerian root extract attractant pungent x x xVanilla oil additive vanilla x xWatermelon oil attractant fruity xWhite thyme oil additive, fixative minty xWintergreen oil attractant, additive sweet, minty xYlang ylang oil attractant, additive floral, sweet x x x x x

Note: Musk tibetine and musk ketone, synthetic substances with a typical musky scent that are widely used as fixatives in lure manu-facture and in the cosmetics industry, are priority-listed Persistent, Bioaccumulative and Toxic (PBT) chemicals (OSPAR 2004) andalso cannot be recommended due to their potential carcinogenic effects (Schmeiser et al. 2001; Apostolidis et al. 2002).Source: Trapping supply catalogs; see appendix 10.2 for names and addresses of commercial lure suppliers.


Target family

Scent Use Characteristic Canidae Felidae Mephitidae Mustelidae Procyonidae Ursidae

Appendix 10.4

Approximate cost of select baits, lures, and lure bases

Approximate cost* Item and units

Baits Per poundChicken, whole, fresh or frozen $0.50–$1.50Chicken quarters, fresh or frozen $0.80–$1.30Chicken thighs, frozen (4 lb. bag) $0.70– $0.90Chicken legs, frozen (4 lb. bag) $0.70– $0.90Chicken drumettes (wings), frozen (4 lb. bag) $0.70–$0.90Beef liver, heart, or other organ meat $0.50– $1.50Canned fish (mackerel, sardines, salmon, tuna) $2.00–$3.00Canned pet food (cat or dog) $0.60–$0.80Dry pet food (cat or dog) $0.20–$0.40Proprietary baits (ground animal meat) $10.00–$20.00

Lures Per fluid ounceBeaver castor $3.50–$5.00Botanical oils $3.00–$5.00Carnivore glands $3.50–$4.50Carnivore urine $0.10–$0.25Catnip, dried $2.00–$4.00Catnip, oil $4.00–$23.50Cod-liver oil $1.30–$1.50Fatty acid scent (FAS), diluted $9.00Fatty acid scent (FAS), undiluted $5.25Fish fertilizer, liquid $0.10– $0.20Fish oil $0.15–$0.30Musk oils, natural or synthetic $4.00–$18.00Proprietary scent lures $3.50–$5.00Skunk scent, tincture $3.50–$5.50Skunk scent, pure $18.00–$20.00

Lure bases Various unitsGlycerine $22–$35/gal.Honey $25–$30/gal.Lanolin, anhydrous $10–$15/pt.Molasses $35–$40/gal.Predator survey disks, scented with FAS $0.43 ea.Predator survey disks, unscented $0.21 ea.Propylene glycol $20–$30/gal.Sodium benzoate, powder $35–$40/gal.Sodium citrate $0.30– $0.40/oz.Vegetable oil $5–$6/gal.Zinc valerate, powder $7–$15/oz.

*U.S. dollars as of July 2006. Prices may be lower if bought in quantity.


Attracting Animals to Detection Devices - Gwern.net266 NONINVASIVE SURVEY METHODS FOR CARNIVORES...

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