Managing

Southeast Ohio:inForest Birds

A Guide forLand Managers

Ohio Bird

ConservationInitiative

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ContentsAcknowledgements 3

Summary of Management Recommendations 4

Chapter 1: The state of forest birds in Ohio 6

Chapter 2: Forest birds and succession 11

Chapter 3: Managing early-successional habitats for shrubland birds 13

Chapter 4: Managing mature forest for breeding birds 16

Chapter 5: Managing shelterwood harvests 19

Chapter 6: Managing landscape mosaics and structurally complex habitats for post-fledging and post-breeding birds 23

References 27

Appendix A: Metric conversions 28

Appendix B: Bird-habitat associations 29

Appendix C: Landscape design 32

Appendix D: Scientific names 33

About This GuideThis guide is written for land managers seeking to improve habitat conditions for forest birds. Recommendations are based on research conducted in the forested landscapes of southeast Ohio by The Ohio State University and Ohio Division of Wildlife. Although many of the patterns and general strategies may apply elsewhere, birds are known to show regional variation in habitat associations and responses to disturbance. Additional detail about study site locations, methodology, and results as well as site-specific data can be found in theses and dissertations of graduate students and published articles (see appendix for a list of these sources).

Photo credits for cover: Ohio Division of Wildlife and Andrew Vitz

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AcknowledgementsDevelopment of this publication has been supported by the Ohio Division of Wildlife through the Wildlife Diversity and Endangered Species Fund. This fund consists of donations through the state income tax check-off program, sales of the Ohio Wildlife Legacy Stamp, and the purchase of Cardinal license plates. Research discussed in this guide was supported by the Ohio Division of Wildlife and the U.S. Fish and Wildlife Service through the State Wildlife Grant program and the Federal Aid in Wildlife Restoration Program (W-134-P, Wildlife Management in Ohio), National Fish and Wildlife Foundation through National Council on Air and Stream Improvement Council, U.S. Fish and Wildlife Service, MeadWestvaco, The Nature Conservancy, Ohio Agricultural Research and Development Center (OARDC), the American Ornithologists’ Union, and The Ohio State University (School of Environment and Natural Resources, Terrestrial Wildlife Ecology Lab and SENR GradRoots). This research would not have been possible without the tireless work of the following graduate students: Marja Bakermans, Felicity Newell, Sarah Lehnen, and Andrew Vitz. Many individuals provided helpful advice, especially Paul Rodewald, Roger Williams, Stan Gehrt, Mike Reynolds, Steve Matthews, Lisa Petit, and Kim Brown. The research benefited from technical and logistical assistance from Jarel Bartig, Dave Minney, August Froehlich, Elaine Fujimara, and Deni Porej with The Nature Conservancy; Carolyn Caldwell, Dave Swanson, Mike Reynolds, Mike Tonkovich, and Dave Scott from the Ohio Division of Wildlife; Robert Boyles and Dick Lusk from Ohio Division of Forestry; Daniel Yaussy, David Hosack, from the Northern Research Station of the U.S. Forest Service, and Wayne Lashbrook and Patrick Keyser from MeadWestvaco. This research resulted from the hard efforts of dozens of field assistants and student volunteers, including Adam Anderson, Katie Anderson, Richard Aracil, Evelyn Astudillo-Sanchez, Anne Balogh, Edwin Blaha, Mike Boyd, Daniel Brown, Jeff Brown, Shannon Buckley, Alicia Byrd, Grace Cochran, Travis Collingsworth, Gabriel Colorado, Myles Falconer, Karla Falk, Julia Fromfeld, David Gagne, Michael Gerringer, Michael Gill, Aaron Haiman, Samuel Holcomb, Todd McCabe, Bill McFall, James Junda, Steve Jacquemin, Angela Johnson, Tennille Johnson, Elizabeth Kreakie, JoAnna Leachman, Seabrooke Leckie, Linda Daily Leonhard, Matt MacArthur, Julie Means, Mark Miller, Desirée Narango, Josh Pennington, Jennifer Philhower-Gillen, Lauren Pulliam, David Roth, Dan Small, and Ryan Trimbath. The following individuals provided helpful reviews for which I am grateful: David Apsley, Amanda Conover, Greg Guess, Cotton Randall, Mike Reynolds, and Dan Yaussy. Finally, a huge thank you goes to Amanda Conover for graciously designing and illustrating the publication.

Author: Amanda D. Rodewald, School of Environment and Natural Resources, The Ohio State UniversityDocument Design and Illustration: Amanda Conover, Ohio Bird Conservation Initiative

Printing made possible by The Nature Conservancy in Ohio.

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• Inharveststhatareregenerating,encouragegrowthofnativehardwoodvegetationratherthanplantingconifers.Allowdensewoodyvegetationtoregenerateinsomeareas,asdensityofshrublandbirdsincreaseswithwoodystemsduringthefirstseveralyearsofregenerationAlthoughnativeandnon-nativeplantsbothcontributetovegetativestructure,nativeplantsofferbetterfoodresourcestobirdsandtheirinsectprey.Becauseexoticplantscanquicklyinvadefollowingdisturbance,managersshouldusespecies-specificrecommendedtechniquestoremoveexoticplantsbothbeforeandafterharvest.

• Forsitespermanentlymanagedassuccessionalhabitats,introducedisturbanceat6-8yearintervals.Abundanceofshrublandspecialistsdeclinessharplyafter6yearspost-harvest.Indigo bunting. Photo by Ohio Division of Wildlife.

• Whenpossible,avoidcreatingsmall(<12acres;5ha),narrow(<300ftwide;100m),orirregularly-shapedshrublandpatches.Abetterstrategyistomanageforpatcheslargeenoughtoprovidehabitat>250ft(75m)fromedges.Smoothorstraightedgesofharvestsalsowillallowgreaternumbersofterritoriestobeaccommodated.Favoringsquareorcircularpatchesratherthanrectangularorirregularoneswillincreasetheinteriorhabitatofclearcutswithoutnecessarilyincreasingharvestarea.

• Whenpossible,clusterharvestsandshrublandpatcheswithinparticularmanagementareasorzones.Providingmultiplepatcheswithin0.3-0.6miles(0.5-1.0km)maypromotelandscapeconnectivityforshrublandbirds.

• Recognizethattheserecommendedstrategies(i.e.,creatinglargerandmoreregularlyshapedshrublandpatchesorclusteringofpatches)alsohavethepotentialtobenefitmatureforestdependentspeciesinmanagedforestlandscapesbyreducingtheamountofedgeandfragmentation.

• Engageinlandscape-scaleandlong-termplanningtoensurethattheneedsofearly-andlatesuccessionalwildlifearemet.SeeAppendixCforanexample.

Scarlet tanager. Photo by T. K. Tolford.

Early-successional habitats for shrubland birdsSummary of Management Recommendations

Mature Forests for Late-Successional Birds• Effortstomanagelocalhabitatfeatures,suchasforeststructure,areanimportantpieceofsustainingmature-forestbreeders.In

theforestedlandscapes(>70%forestcover)ofsoutheastOhio,structuralattributesofforest(i.e.,canopystructure,treesize,verticalcomplexity)hadstrongrelationshipswithdensityandnestsurvivalofsensitivespecies.

• Featuresgenerallyassociatedwitholderforestsmaybeimportanthabitatcomponentsformatureforestbreeders,suchasceruleanwarbler.Theseold-forestcharacteristicsincludeaheterogeneouscanopy,diverseunderstoryvegetation,grapevines,andemergentlargetrees.Thus,usinglongerrotationages(>100years),aswellasspecificharvestprescriptions(e.g.,singletreeandgroupselection)andtimberstandimprovementpractices(e.g.,thinningandcroptreerelease)arelikelytoencouragethedevelopmentofthesefeatures.

• Asdescribedinthesectionon“managingshelterwoodharvests”,whiteoakshouldbeemphasizedinmanagementbecauseitisafavorednestingtreeforceruleanwarblersandothercanopy-nestingbirds.(seeChapters4snd5foradditionaldetailsaboutfloristiccompositionofstands).

• Severalsensitivespeciesbreedinginmatureforestwouldbenefitfromcreatingcanopygaps(>430ft2,40m2)throughsingle-treeorgroupselectioncuts.

• BasedonresultsfromtheCooperativeCeruleanWarblerForestManagementProject(Boves2011),recommendationsforAppalachianforestedlandscapesspecifythatforestssupporting>2territoriesper10acres(>5territories/10ha)ofCeruleanWarblershouldbemanagedwithoutharvestingandinwaysthatminimizedisturbance.Onforeststandswithfewerterritories,managementshouldreducebasalareato56-78ft2/acre(13-18m2/ha)whileretaininglargeoverstorytrees(>16inchesdbh;>40cmdbh),especiallyofwhiteoak.Becauseidentifyingthebestmanagementcoursedependsuponbirddensities,coordinationandcooperationwithwildlifebiologistsmaybenecessary.

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Shelterwood Harvests for Early and Late-Successional Birds• Partialharvesting(~50%stockinglevel),suchastheshelterwood

technique,canbeusedtoprovidehabitattobothearly-successionalbirds(e.g.,prairiewarbler,Easterntowhee)andcanopy-nestingspeciesusuallyassociatedwithmatureforest(e.g.,yellow-throatedvireo,scarlettanager).InsouthernOhio,reducingbasalareafrom100-143ft2/acreto39-70ft2/acre(23-33m2/hato9-16m2/ha)supportedgreaternumbersofbothshrublandandcanopy-nestingspeciesthanunharvestedmatureforest.

• Recognizingthatoverstoryistypicallyremovedforoakregenerationwithin5-10years,shelterwoodprescriptionsneedtoensurethatnestinghabitatismaintainedacrossspaceandthroughtimewithinthelandscape.

Landscape Mosiacs and Structurally Complex Habitats for Post-Fledging and Post-Breeding Birds

• Favorwhiteoaksratherthanredoaksinshelterwoodharvests,aswhiteoaks(whiteandchestnutoaks)werestronglyfavoredfornestingandforagingbymostcanopynestingspecies.Redoaks(Northernred,Easternblack,andscarletoaks)alsomaydepressnestingsuccessofcanopynestingbirds.

• Whenpossible,retainlargediametertrees(>15inchesdbh;>38cmdbh),whicharemostheavilyusedfornestingbycanopybirds,includingceruleanwarbler.

• Incaseswherethereiswidelatitudeinchoiceofharvestlocation,avoidolderforestswithcanopygapsand/orthoseonnortheast-facingslope,becausethesetendtobemostheavilyusedbythedecliningceruleanwarbler.Instead,shelterwoodharvestsarebetterimplementedinareasthatlacksteepslopes(>approximately 15%) and/or have few canopy gaps, where they are more likely to create or improve habitat for species requiring heterogeneous canopies.

Eastern towhee. Photo by Ohio Division of Wildlife.

Ovenbird fledgling. Photo by Andrew Vitz.

• Managematureforestsinwaysthatpromotestructuralcomplexity,whichencouragesmicrohabitatsthatprovidedenseunderstoryvegetation.Examplesincludetreefallgaps,riparianthickets,andnaturalpatchesofshrubs.Becausesomeofthesefeaturesaretypicalcomponentsinold,uneven-agedforests,considerallowingstandstoreachagesgreaterthan100years.

• Allowroadsidesandotherhuman-associatededgestodevelopthethickvegetationthatisheavilyusedbypost-breedingbirds.Thereappeartobenostrongsizerequirementsforusebybirds.

• Whenconsistentwithothermanagementgoals(e.g.,oakregeneration),considerusingsilviculturaltechniquestocreateareaswithdensevegetation.Group-selectionharvestsandshelterwoodharvestsmaybegoodexamplesofthis.Althoughuseoftheseharvesttypeshasnotbeenspecificallystudiedduringthisstageintheannualcycle,changesinhabitatstructureassociatedwiththosesilviculturaltechniquesareconsistentwithfeaturespreferredbypost-breedingandpost-fledgingbirds.

• Regardingharvestsize,beattentivetoneedsofotherspeciesandduringotherstagesoftheannualcycle.Post-fledgingbirdsdonotseemtorequirelargepatchesofsuccessionalhabitatandcanusedensevegetationwithinmatureforests.Consequentlyshrublandhabitatsareprobablybestmanagedaccordingtorecommendationsforearly-successionalbreeders.

• Engageinlandscape-scaleplanningtoensurethatsufficientforestisretainedtopermitmovementthroughthelandscape(seeAppendixC).Notonlyareindependentjuvenilesknowntomakeextensivemovements,butnumbersofpost-breedingbirdsusingharvestswaspositivelyrelatedtoforestcoverwithin0.62miles(1km).

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Figure 1. Percentage of Ohio species among habitat guilds that have significantly declined since 1966. Data based on Breeding Bird Survey (1966-2009). Sauer et al. 2011.

Box 1. Forest birds showing significant population declines in Ohio, 1966-2009.

Mature or late-successional

Whip-poor-will Cerulean Warbler Least Flycatcher Eastern Wood-Pewee Great Crested Flycatcher Tufted Titmouse

Shrubland or early- successional

Northern Bobwhite Field Sparrow Prairie Warbler Yellow-breasted Chat Brown Thrasher Song Sparrow

Box 2. Forest birds showing significant population increases in Ohio, 1966-2009.

Mature or late-successional

Wood Thrush Red-eyed Vireo Scarlet Tanager Yellow-throated Vireo Downy Woodpecker Carolina Chickadee Rose-breasted Grosbeak Red-bellied Woodpecker Ruby-thr. Hummingbird Black-capped Chickadee Black-and-white Warbler Pileated Woodpecker Ovenbird White-breasted Nuthatch Broad-winged Hawk Yellow-throated Warbler Worm-eating Warbler Red-shouldered Hawk Cooper’s Hawk Hooded Warbler Northern Parula Wild Turkey

Shrubland or early- successional

Northern Cardinal House Wren Gray Catbird White-eyed Vireo Carolina Wren

Chapter 1:The state of forest birds in Ohio

Ohio’sforestshaveseenremarkablechangeoverthelasttwocenturies.Afterwidespreadclearinginthe1800s,forestcoverplummetedtoapproximately10%ofthestate.However,forestregenerationoverthelast80-100yearshasresultedinroughlyone-thirdofOhiobeingclassifiedasforested.Whilespeakinggenerallyabouttrendsinforestcoveriseasy,generalizingpopulationtrendsandconservationthreatsacrossbirdspeciesisdecidedlymoredifficult.

Althoughforestbirdsremainalegitimateconservationconcern,datafromtheBreedingBirdSurveyinOhioshowthatwoodland-breedingspeciesinOhiofaredreasonablywellasagroup,withonly14%showingsignificantnegativepopulationtrendsand51%withsignificantpositivetrendsbetween1966-2009(Saueretal.2011;Figs1and2).Speciesthatuseshrublandsandothersuccessionalhabitatsfaredworsewith32%decliningand26%increasingsince1966(Boxes1and2).Thosetrendscontrastwiththe83%ofgrasslandbirdspeciesthatsignificantlydeclinedinabundanceinOhio.AmongthemostseverelydecliningbirdsarespeciesthatoccupyreclaimedstripminesandothergrasslandhabitatinsoutheastOhio:grasshoppersparrow,bobolink,Easternmeadowlark,savannahsparrow,andHenslow’ssparrow.ThoughsoutheastOhioisnotthoughttohavehistoricallysupportedlargenumbersofgrasslandspecies,theirglobalpopulationdeclinesmaywarrantmanagementwherelocalpopulationsexist,suchasonreclaimedstripmines.Recentinitiativestoreforeststripmines(e.g.,AppalachianReforestationInitiative;website)arenowstimulatingdialoguesaboutconservationprioritiesandlong-termandlandscape-scaleplanningefforts.

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Figure 2. Population trends from Breeding Bird Survey (BBS) data for two early-successional (yellow-breasted chat and field sparrow) and two late-successional (Eastern wood-pewee and cerulean warbler) species, 1966-2009 (Sauer et al. 2011). BBS abundance indices are shown on the y-axes.

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High Continental Concern + High Regional Responsibility (only those for OH)

Cerulean WarblerHenslow’s SparrowPrairie WarblerKentucky WarblerWorm-eating WarblerBlue-winged WarblerAmerican WoodcockWood Thrush

High Continental ConcernLouisiana WaterthrushAcadian FlycatcherField SparrowYellow-breasted ChatBlack-billed CuckooEastern TowheeIndigo Bunting

High Regional ResponsibilityScarlet TanagerYellow-throated VireoHooded WarblerYellow-throated WarblerChimney Swift

Kentucky warbler. Photo by T. K. Tolford.

How does Ohio contribute to regional conservation initiatives for forest birds?

BecausemostwoodlandinOhioisprivatelyowned,thesoutheasternregionofthestatestandsoutinitsrelativelyhighproportionofpubliclymanagedforest,forestedlandscapes,and,consequentlyimportanceforforestbirds.Publicownershipfacilitateslandscape-scaleandlong-termplanningandmanagement,aswellasprovidesoneofthestate’sbestopportunitiestoretainlargeblocksofcontiguousforest.Indeed,someoftheregion’smostsensitivespeciesreachtheirhighestdensitiesinthispartofthestate.Notsurprisinglythen,southeastOhiofeaturesprominentlyinregionalconservationinitiatives.

AcadianFlycatcherBlack-and-whiteWarblerBlack-billedCuckooBlue-wingedWarblerBroad-wingedHawk*BrownThrasher*CanadaWarblerCeruleanWarblerChimneySwiftChuck-will’s-widowEasternMeadowlarkEasternTowhee

EasternWood-PeweeFieldSparrowGrasshopperSparrowHenslow’sSparrowHoodedWarblerIndigoBuntingKentuckyWarblerLarkSparrowLoggerheadShrikeLouisianaWaterthrushMarshWrenNorthernBobwhite

NorthernFlickerNorthernHarrierNorthernParula*NorthernSaw-whetOwlPeregrineFalconPrairieWarblerProthonotaryWarblerPurpleMartinRed-headedWoodpeckerRuffedGrouseScarletTanagerSedgeWren

Sharp-shinnedHawk*Short-earedOwlSummerTanager*Whip-poor-willWillowFlycatcherWoodThrushWorm-eatingWarblerYellow-breastedChatYellow-throatedVireo

Yellow-throatedWarbler*

Partners-in-Flight:PlanforOhioHills

SoutheasternOhiofallswithintheOhioHillsPhysiographicProvinceorEcoregionforthenationalplanningeffortsofPartners-In-Flight,whichisapublic-privatepartnershipforbirdconservationintheWesternHemisphere.TheOhioHillsplanidentifiespriorityspeciesandhabitatsthatoccurinsoutheasternOhio.Inmaturedeciduousforest,thefollowingspeciesareconsideredtobemanagementpriorities:ceruleanwarbler,Louisianawaterthrush,worm-eatingwarbler,Acadianflycatcher,Kentuckywarbler,andwoodthrush.Inearlysuccessionalshrub,golden-wingedwarbler(notcurrentlydocumentedasbreedinginsoutheasternOhio),prairiewarbler,andfieldsparrowarethepriorities.Inaddition,Henslow’ssparrowislistedasapriorityforgrasslandhabitats,whichprimarilyoccuronreclaimedminesinsoutheastOhiolandscapes.TheOhioHillsplanfurtheridentifiesboththelevelofcontinentalconcern

(i.e.,large-scalepopulationdeclines)andregionalresponsibility(i.e.,highproportionoftheglobalpopulationresidinginaparticularecoregion;Box3).

AppalachianMountainsJointVenture:PlanForTheAppalachianMountainsBirdConservationRegion

SoutheasternOhiofallswithintheboundariesoftheAppalachianMountainsJointVenture(AMJV),whichisoneof18habitatJointVenturepartnershipsintheUS.TheAMJVrepresentsapublic-privatepartnershipofagencies,organizations,andindustriesthatworktogethertosupportthelong-termviabilityofnativebirdsthatbreedintheAppalachianMountains.

ThefollowinglandbirdsarethosethatregularlybreedinsoutheasternOhioandarelistedaspriorityspeciesforAMJVandintheOhioDivisionofWildlife’sOhio’sWildlifeActionPlan(speciesmarkedwith*areonlyinAMJVplan).

Box 3. Priority species in Partners-in-Flight plan for Ohio Hills based on continental concern and regional responsibility.

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OhioBirdConservationInitiative:All-BirdConservationPlanforOhio

TheOhioBirdConservationInitiative(OBCI)isacoalitionofover90memberorganizationsthatsupportbirdconservation,birdrecreation,educationandoutreach.Aspartofitsplanningefforts,OBCIdevelopedastatewidebirdconservationplanthatidentifiespriorityspeciesandhabitatsaswellastargetpopulationobjectives.IntheOBCIplan,thehighestprioritydeciduousormixedforestbirdsarewoodthrush,worm-eatingwarbler,andceruleanwarbler,whereasthehighestpriorityspeciesassociatedwithearly-successionalhabitatsareAmericanwoodcockandblue-wingedwarbler.Otherspeciesarelistedaccordingtohighandmoderateprioritylevels(Table1).

Table 1. Ohio’s Priority birds associated with Deciduous, Mixed, or Successional Forest.

Highest Priority High Priority Moderate PriorityWood Thrush Whip-poor-will Ruffed Grouse VeeryWorm-eating Warbler Black-billed Cuckoo Yellow-billed Cuckoo Canada WarblerCerulean Warbler Hooded Warbler Northern Saw-whet Owl American RedstartAmerican Woodcock Kentucky Warbler Eastern Screech-Owl Black-and-white WarblerBlue-winged Warbler Red-headed Woodpecker Chuck-will’s-widow Scarlet Tanager

Northern Bobwhite Northern Flicker Willow FlycatcherLoggerhead Shrike Eastern Wood-Pewee Brown ThrasherBell’s Vireo Great Crested Flycatcher Yellow-breasted ChatPrairie Warbler Yellow-throated Vireo Eastern Towhee Field Sparrow Golden-crowned Kinglet Indigo Bunting

Blue-gray Gnatcatcher Orchard Oriole

Bothfromstatewideandregionalperspectives,theforestsofsoutheasternOhioareimportantfocalareasforbirdconservationandmanagementifwearetoachievepopulationgoals.Notonlydidadecision-supporttooldevelopedbyJointVenturesidentifytheregionasthehighestconservationvalueinthestate(Fig.3),buttherealsoarespecificfocalareasidentifiedbyOBCI(Fig.4).

Figure 3. Areas of high priority for woodland breeding bird conservation in Ohio. From: Ohio Bird Conservation Initiative. 2010. Ohio All-bird Conservation Plan. Unpublished report to the Ohio Department of Natural Resources-Division of Wildlife. 106 pp.

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Figure 4. Map showing Ohio Bird Conservation Initiative Focus Areas (blue counties) in relation to Ohio DNR lands (pink areas), Wayne National Forest lands (green), and Bird Conservation Regions. From Ohio Bird Conservation Initiative Plan. 2010.

ForestPlanforWayneNationalForest

AspartoftheNationalForestManagementAct,theWayneNationalForestismandatedtomaintainviablepopulationsofallwildlifeonNationalForestlands.Tohelpachievethisgoal,biologists,managers,andotherexpertsidentifiedseveral“ManagementIndicatorSpecies”intherecentlyrevisedWayneNationalForestPlan(2006).Abundancesofthefollowingspeciesareusedtoindicatethesuitabilityoftheforestforotherspecieswithinthesamehabitatguilds:

•Pinewarbler–maturepineandpinehardwoodcommunities

•Pileatedwoodpecker–maturehardwoodforestwithsnagsandcoarsewoodydebris

•Ceruleanwarbler–matureinteriorhardwoodforestswithaheterogeneouscanopy

•Worm-eatingwarbler–matureinteriorhardwoodorpine-hardwoodforestonhillsideswithadenseunderstoryandcoarsewoodydebris

•Louisianawaterthrush–matureriparianforestcorridorsalongheadwaterstreams

•Ruffedgrouse–mosaicofsuccessionalforeststages

•Yellow-breastedchat–earlysuccessionalforest

•Henslow’ssparrow–extensivegrasslands

Yellow-breasted chat. Photo by Sarah Lehnen.

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Chapter 2Forest birds and succession

Forestsuccessionisthechangeinthestructureandcompositionofforestsovertime.Understandinghowsuccessioninfluencesaviancommunitiesisessentialtoeffectivelymanageforestsforbirdsandotherwildlife.Becausemanybirdspeciesrequirespecifichabitatattributes,forestsatdifferentsuccessionalstagesfavordifferentbirdspeciesbyvirtueoftheresourcestheyprovide(Box4).Forexample,certainbirds,suchasprairiewarblerandyellow-breastedchat,specializeonthedenseandshrubbyhabitatprovidedbyearly-successionalstands.Others,liketheceruleanwarbler,favorlate-successionalforestswithlargetreesanddiversecanopyforbreeding.Thus,nomatterhowaforestismanaged,whetheractivelyorpassively,certainspecieswillbefavoredandothersdiscouraged.Thebeststrategydependsuponthemanagementgoal.

Althoughmanymembersofthegeneralpublicmightjudgeconservationvaluebyforestage,biologistsrecognizethatallsuccessionalstageshavetheabilitytosupportbirdsofhighconservationvalue.ThereisagrowingrecognitionthatthroughoutmuchofeasternNorthAmerica,availabilityofearly-successionalhabitatshasdeclinedsincethe1950swithchangingdisturbanceregimes(e.g.,firesuppression)andhumanactivities(e.g.,changingagriculturalpracticesandfarmlandabandonment).Concomitantly,numbersofshrub-successionalbirdshavedeclinedsoseverelyinsomecasesthatearly-successionalbirdsarenowincludedaspriorityspeciesinmanyregionalconservationplans.Estimatesoftheamountofearly-successionalhabitatinpre-settlementNorthAmericanlandscapesvariesamongstudies,buttheyareconsistentintheviewthattherewereavarietyofnatural(e.g.,fire,storms,beaveractivity)andanthropogenicdisturbances(e.g.,burningwasusedamanagementtoolbyNativeAmericans)thatmadesuccessionalhabitatmorecommononthelandscapethanitisnow.Evenmatureforestswerelikelydifferentfromtoday’ssecondgrowthduetotheirolderandunevenagestructurethatresultedinlargertreesandmorenumerouscanopygaps.

Box 4. Abundant breeding bird species detected in different forest stands in Athens, Vinton, Gallia, and Jackson counties. Birds are listed in order of declining abundance.

Regenerating clearcuts (4-7 years post-harvest)

1. Blue-winged warbler2. Yellow-breasted chat3. White-eyed vireo4. Gray catbird5. Prairie warbler6. Indigo bunting7. Eastern towhee8. Common yellowthroat9. Baltimore oriole10. Field sparrow

Shelterwood harvests (50% stocking, 2-5 years post harvest)

1. Red-eyed vireo 2. Hooded warbler 3. Brown-headed cowbird4. Scarlet tanager 5. Black-and-white warbler 6. Ovenbird 7. Indigo bunting 8. Eastern towhee9. Prairie warbler 10. Wood thrush

Mature, unharvested oak-hickory forest:

1. Ovenbird 2. Red-eyed vireo 3. Hooded warbler 4. Wood thrush 5. Scarlet tanager 6. Black-and-white warbler 7. Worm-eating warbler8. Brown-headed cowbird 9. Eastern wood-pewee 10. Blue jay

Scarlet tanager. Photo by Marja Bakermans.

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Figure 4. Numbers of captures for early-successional (light bars) and late-successional (dark bars) forest breeding birds in regenerating clearcuts (4-7 years post-harvest) in southeast Ohio, 2002-2003 (Vitz and Rodewald 2006).

Box 5. Mature-forest breeding species using regenerating clearcuts in post-breeding season (in order of decreasing abundance)

1. Ovenbird2. Worm-eating warbler3. Red-eyed vireo4. Hooded warbler5. Scarlet tanager6. Wood thrush7. Ruby-throated hummingbird8. Black-and-white warbler9. Carolina chickadee10. Tufted titmouse

Hooded warbler. Photo by T.K. Tolford.

Anotherissuethataddstothecomplexityofunderstandingrelationshipsbetweenbirdsandforestsuccessionisthatbirdscandifferintheirneedsacrosstheannualcycle.Weoftencategorizespeciesaccordingtotheirbreedinghabitats,butpatternsofhabitatuseshiftacrosslifestages.Thepost-breedingstage,whichextendsfromtheendofnestingtothestartofmigration,providesoneexcellentillustrationofsuchshiftsinhabitatuse.Duringthisperiod,adultbirdsaremoltingfeathersandgainingmassastheyprepareformigration,whilejuvenilebirdscontinuetolearnhowtoforageeffectivelyandevadepredators.Oneespeciallycriticaltimeduringthepost-breedingwindowisthepost-fledgingstage,whichrepresentsthefirstfewweeksafterayoungbirdhasleftthenest.Duringthepost-fledgingperiod,birdsmayfacethegreatestriskofmortality,oftenduetopredation.StudiesconductedinOhioandelsewhereintheUSindicatethatmanybirdsthatbreedinmatureforestactivelyseekdensevegetation,includingbutnotexclusivetosuccessionalhabitat,duringthisperiodoftheannualcycle.Forexample,inregeneratingclearcuts(4-7yearspost-harvest)insoutheastOhio,VitzandRodewald(2006)captured32species,whichrepresentsnearlyallmature-forestbreedingspecies.Moreover,mature-forest birds rivaled successional breeders in abundance (Box 5, Fig. 4).

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EdgeandareasensitivityResearchinsoutheasternOhiohasconsistentlyshownthatmanyshrublandbirdsoccupyedgesofharvestsinlowerdensitiesthaninteriors.Inonestudy,birdswerecapturedandbandedatdistancesof60,150,and240ft(20,50,and80m)frommature-forestedgesat6small(1-15acres;4–8ha)and6large(32-40acres;13–16ha)regeneratingclearcuts.Resultssuggestedthatmanyshrublandspecialistbirdsavoidedtheedgeswheretheshrubbyhabitatabuttedthematureforest(Fig.6,RodewaldandVitz2005).Sevenof8shrublandspecialists,particularlyblue-wingedwarbler,prairiewarbler,yellow-breastedchat,indigobunting,andfieldsparrow,avoidedmature-forestedges(Table2).Thereasonsthatbirdsavoidededgesremainunclearbecausewefoundnorelationshipbetweendistancetoedgeandvegetation,insectbiomass,orfruitabundance.Likewise,nestsurvivalandplacementdidnotchangewithdistancetoedge(Lehnen2008).

Intheirinitialwork,RodewaldandVitz(2005)foundnostrongevidencethatshrub-successionalbirdspreferlargerthansmallerharvests(Fig.6,Table3).Subsequently,LehnenandRodewald(2009)alsoexamineddensity,annualsurvival,andproductivitybyexaminingcapturerates,apparentannualsurvivalestimates,andjuvenile-to-adult-femaleratiosinsmallandlargeharvests.Capture

Figure 5. Capture rates by harvest age for songbird species in 13 shrubland patches in Ohio during the late- and post-breeding period (15 June to 17 August). Songbirds classified into for three categories: shrubland specialists, forest specialists, and shrubland generalists. Bars show +1 standard error. From Lehnen (2008).

Chapter 3Managing early-successional habitats for shrubland birds

Shrub-successionalbreedersSuccessionalhabitatscansupportanimpressivediversityofbirds,someofwhicharehabitatspecialistsandofhighconservationimportance.Aswithotherhabitatguilds,shrublandbirdsaresensitivetohabitatattributesacrossmultiplespatialscales,fromlocaltolandscape.LocalhabitatandsuccessionalstageAwiderangeofnaturalandanthropogenicdisturbancescreateandmaintainshrub-successionalhabitats.Theprocessofforestsuccessioneventuallychangeslocalattributestothepointwheretheynolongerareattractivetomanyshrublandspecialists.Thoughshrublandbirdsbecomemoreabundantwithincreasingdensityofwoodystems,thisoccursonlyuptoapoint.Researchatregeneratingclearcutsaged4to10yearspost-harvestindicatedthatabundanceofshrublandgeneralists(i.e.,speciesthatusemultipletypesofhabitat)andspecialists(i.e.,speciesrestrictedtoonlyonetypeofhabitatorrequirespecialfeatures)weregreatestattheearliestsuccessionalstagesstudied(Fig.5,Lehnen2008).Numbersofshrublandspecialistsdeclinedstronglyafter6yearspost-harvest.Likewise,whenweightingabundancesbypriorityranksassignedtoeachspeciesbyPartners-in-Flight,theconservationvalueofstandsalsowasgreatestfour-to-fiveyearsafterharvest.Thesefindingssuggestashortharvestrotationscheduleappliedtocertainsitesorconcentratedinspecificregionsmightmostbenefitshrublandbirds.

Indigo bunting. Photo by Marja Bakermans.

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ratesforsixfocalshrublandbirdsincreasedwithpatchareaandwereupto44%higherinlargestthansmallestpatch.However,thisareaeffectwasonlysignificantfortheyellow-breastedchatandthecommonyellowthroatandwaslesspronouncedafterdatawereadjustedforprobabilityofcapturebasedonbirdmovements.Patchareawasnotagoodpredictorofapparentannualsurvivalorjuvenile-to-adult-femaleratiosforanyspecies,suggestingthatareadidnotaffectreproductiverates(LehnenandRodewald2009a).Thus,therewasnoevidencethatannualsurvivalorproductivitydifferedbypatchareainregeneratingclearcutsinsoutheasternOhio.

SubsequentresearchtounderstandthepatternofapparentedgeavoidancefocusedonYellow-breastedchats,astheyshowedthemostconsistentrelationshipswithbothedgeandarea.Basedon37malechatsthatwereradio-tracked,estimatedhomerangesizewas8acres(3.3ha)withbirdsmostheavilyusingareasof1.7acres(0.68ha)withinthathomerange(Lehnen2008).Detailedstudyofthemovement,homerangesize,andnestsuccessofchatssuggestedthatbirdsdidnotactivelyavoidedgesofregeneratingharvests.Instead,wesuspectthattheshapeandsizeofsmalleroredge-dominatedharvestslimitthenumberofterritories(Fig.7).

Figure 6. Capture rates of shrubland specialist birds of hatch-year (juveniles) and after-hatch-year (>1 year old) ages at varying distances from edges of regenerating harvests and different stand sizes.

Table 2. Mean capture rates for every 100 hours of netting (+SE) of juvenile (hatch-year) and adult (after-hatch-year) birds at varying distances from edge in 12 regenerating clearcuts in southern Ohio that were 4-6 years post-harvest from June-August 2002 and 2003.

Juveniles AdultsSpecies 60 ft 150ft 240 ft 60 ft 150ft 240 ftWhite-eyed vireo 1.1 (0.21) 1.7 (0.27) 1.3 (0.22) 1.3 (0.26) 1.5 (0.26) 1.2 (0.23)Blue-winged warbler 1.0 (0.19) 1.7 (0.35) 1.4 (0.24) 1.0 (0.19) 1.3 (0.31) 2.3 (0.44)Prairie warbler 0.7 (0.20) 1.3 (0.22) 1.9 (0.38) 0.5 (0.13) 0.8 (0.13) 1.1 (0.22)Yellow-breasted chat 1.5 (0.14) 2.1 (0.28) 2.7 (0.32) 1.0 (0.16) 1.2 (0.25) 1.8 (0.30)Common yellowthroat 0.4 (0.08) 0.7 (0.26) 0.7 (0.21) 0.5 (0.12) 0.7 (0.30) 0.7 (0.26)Eastern towhee 0.3 (0.11) 0.3 (0.14) 0.4 (0.09) 0.6 (0.23) 0.7 (0.17) 0.8 (0.18)Field sparrow 0.2 (0.08) 0.5 (0.14) 1.0 (0.24) 0.1 (0.04) 0.3 (0.11) 0.7 (0.23)Indigo bunting 0.8 (0.18) 1.4 (0.27) 1.3 (0.28) 0.4 (0.13) 0.8 (0.14) 1.1 (0.20)

Table 3. Mean capture rates for every 100 hours of netting (+SE) of juvenile (hatch-year) and adult (after-hatch-year) birds 6 small (1—15 acres; 4–8 ha) and 6 large (32-40 acres; 13–16 ha) regenerating clearcuts that were 4-6 years post-harvest from June-August 2002 and 2003.

Juveniles AdultsSpecies Small Large Small LargeWhite-eyed vireo 3.3 (0.67) 4.7 (0.63) 3.1 (0.72) 4.7 (0.78)Blue-winged warbler 3.9 (0.88) 4.3 (1.12) 3.8 (0.96) 5.5 (1.01)Prairie warbler 3.5 (1.25) 4.2 (0.57) 2.1 (0.56) 2.7 (0.31)Yellow-breasted chat 5.0 (0.61) 7.4 (0.77) 2.6 (0.73) 5.2 (0.67)Common yellowthroat 0.9 (0.34) 2.4 (0.77) 1.2 (0.49) 2.4 (1.12)Eastern towhee 1.0 (0.57) 0.9 (0.43) 2.8 (0.63) 1.5 (0.41)Field sparrow 1.3 (0.59) 2.0 (0.16) 0.8 (0.43) 1.3 (0.48)Indigo bunting 2.8 (0.64) 4.3 (0.79) 2.2 (0.37) 2.5 (0.56)

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Thefindingthatchatsdidnotactivelyavoidedgesbecausetheyofferedsuboptimalhabitatprovidesanimportantcautionarytaletomanagers.Basedonspatialpatternsalone,onemightquicklyconcludethatedgesprovidedlow-qualityhabitat.However,itseemsmorelikelythatbirdsweredisplacednearedgessimplyduetogeometry.Althoughtheoutcomeofreduceddensitiesnearedgesisthesame,themostrecentworksuggeststhatsmallorirregularlyshapedpatchesarenoless“preferred”andarenotdetrimentaltobirdnestingsuccessorsurvival.Despitehavinganidenticalpattern,thealternatemechanismsleadtodifferentmanagementimplications.Thus,managersshouldreduceedgesinorderaccommodategreaterdensitiesofshrublandbirds(i.e.,duetogeometry),buttheyhavelessreasontoworrythatedge-dominatedharvestswillbeactivelyavoidedorwillfunctionaspopulationsinks.Landscape-scalesensitivityAswithbirdsdependentuponlargeblocksofcontiguousmatureforest,shrublandbirdsalsomaybesensitivetolandscapecontext.LehnenandRodewaldevaluatedtheimportanceoflandscapecompositiontoshrublandbirdsbycomparingtherelativeimportanceofplot,patch,andlandscapecharacteristicstoexplaincaptureratesofshrublandbirdsinregeneratingclearcuts(Lehnen2008).Numbersofshrublandbirdswithinaregeneratingharvestincreasedwiththeamountofshrublandhabitatwithin0.62miles(1km;LehnenandRodewald2009b).Overall,theworksuggeststhatamountofshrublandhabitatinthelandscapeismoreimportantthanthesizeofharvest.Thus,clusteringpatchesmaybeaneffectivestrategyformanagingsuccessionalhabitats.Clusteringpatchesalsohastheadditionalbenefitofconcentratingdisturbanceandedge,whichhasthepotentialtonegativelyaffectspeciesusinglatesuccessionalhabitats.

Dataondispersalandmovementsalsoareconsistentwiththepossibilitythathavingmultiplepatchesofearly-successionalhabitatwithinthesamelandscapeisimportantforsomeshrublandbirds.Afteraccountingforprobabilityofdetection,21%ofbirdsbandedasjuvenilesandrecapturedasadultsreturnedtothepatcheswheretheywerehatchedand78%ofadultbirdsreturnedtothesamepatchtobreedinsuccessiveyears(Lehnenand

Figure 7. Shape of a harvest can limit the number of territories that can be accommodated even in the absence of true edge avoidance. In this example, a greater number of fixed-size territories can be accommodated in one contiguous harvest patch versus several smaller patches of equal total area.

Rodewald2009b).Thetendencyofbirdstoreturntopreviouslyusedpatches,coupledwiththefactthatthepatchesareshort-livedsuccessionalstages,suggeststhatshrublandbirdsmaycolonizenewbreedingareasthatarerelativelyclosetopreviouslyoccupiedsites.Indeed,dataondispersingindividualsshowedthatyoungbirdsmovedapproximately1mileandadultsonlyone-tenthofamiletonewpatches.Movementamongpatcheswascommon,with35%ofourradio-markedmaleyellow-breastedchatsmovingamongnearbypatcheswithinthebreedingseason.Ourstudyprovidesevidencethatshrublandbirds,especiallychats,moveamongpatchesduringthebreedingseason,averagingmovementsof0.3mile.Basedonourresults,birdsseemedtofrequentlymoveamongpatchesseparatedby0.3milesorlesswithoccasionalvisitstopatcheslocatedmorethanahalf-mileaway.Hereagain,clusteringpatchesofshrublandhabitatmayreducerisksposedbymovementamongpatchesandminimizedisturbancetomatureforesthabitat.

Management Recommendations1.Inharveststhatareregenerating,encouragegrowthofnativehardwoodvegetationratherthanplantingconifers.Allowdensewoodyvegetationtoregenerateinsomeareas,asdensityofshrublandbirdsincreaseswithwoodystemsduringthefirstseveralyearsofregeneration.Althoughnativeandnon-nativeplantsbothcontributetovegetativestructure,nativeplantsofferbetterfoodresourcestobirdsandtheirinsectprey.Forthisreason,managersshouldalsobepreparedtocontrolexoticplantsthatcanquicklyinvadefollowingdisturbance.

2.Forsitespermanentlymanagedassuccessionalhabitats,introducedisturbanceat6-8yearintervals.Abundanceofshrublandspecialistsdeclinessharplyafter6yearspost-harvest.

3.Whenpossible,avoidcreatingsmall(<12acres;5ha),narrow(<300ftwide;100m),orirregularly-shapedshrublandpatches.Abetterstrategyistomanageforpatcheslargeenoughtoprovidehabitat>250ft(75m)fromedges.Smoothorstraightedgesofharvestsalsowillallowgreaternumbersofterritoriestobeaccommodated.Favoringsquareorcircularpatchesratherthanrectangularorirregularoneswillincreasetheinteriorhabitatofclearcutswithoutnecessarilyincreasingharvestarea.

4.Whenpossible,clusterharvestsandshrublandpatcheswithinparticularmanagementareasorzones.Providingmultiplepatcheswithin0.3-0.6miles(0.5-1.0km)maypromotelandscapeconnectivityforshrublandbirds.

5.Recognizethattheserecommendedstrategies(i.e.,creatinglargerandmoreregularlyshapedshrublandpatchesorclusteringofpatches)alsohavethepotentialtobenefitmatureforestdependentspeciesinmanagedforestlandscapesbyreducingtheamountofedgeandfragmentation.

6.Engageinlandscape-scaleandlong-termplanningtoensurethattheneedsofearly-andlatesuccessionalwildlifearemet.SeeAppendixCforanexample.

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Chapter 4Managing mature forest for breeding birds

Asiconicsymbolsofforestconservation,manybirdsthatbreedinmatureforestarearea-sensitiveandneedlargepatchesofforestinordertomeethabitatrequirements.Assuch,conservationeffortshaveemphasizedtheamountofforestwithinlandscapesandbeenlesssensitivetolocalforestconditions.Overrecentdecades,wehavelearnedthatmanagementforthissuiteofbirdsismorenuancedthanoriginallythought.Notonlycansensitivitytoareaandedgesvaryacrosslandscapes,butstudieshaveshownthatmanymature-forestbirdsarealsodisturbance-dependentandmaybehighlysensitivetosubtlefeaturesoftheforest.Withinthiscontext,effectivemanagementrequiresattentiontoattributeswithin(i.e.,local)andsurrounding(i.e.,landscape)foresttractsusedforbreeding.

LocalhabitatmanagementEcologistshavelearnedthatthematureforestsoftodayareverydifferentfrompresettlementforests,whichgenerallywereolderandwithgreaterstructuraldiversity.Forexample,oldforestsareinfluencedbycanopygapformationprocessesthatcreatetreefallgaps,highstructuralcomplexity,standinganddowneddeadtrees,widely-spacedlargetrees,andathickbutpatchyherbaceouslayer.Thus,evenwithinlate-successionalforests,specifichabitatattributescanvaryremarkablydependinguponforestage,topography,floristics,disturbancehistory,previousmanagementactivities,andpressurefromherbivoresandpests.SuchdifferenceslikelycontributetothewidevariationindensitiesofforestbirdsbreedingamongmatureforeststandsinsoutheastOhio(Bakermansetal.,2012.Table4).

Species Mean density (SE) Range (mix – max)Wood thrush 7.25 (0.57) 4.50 – 10.50Ovenbird 8.75 (0.35) 7.00 – 11.30Worm-eating warbler 3.46 (0.44) 0.00 – 5.33Kentucky warbler 0.63 (0.24) 0.00 – 2.25Hooded warbler 3.19 (0.57) 1.00 – 7.25Cerulean warbler 1.97 (0.69) 0.00 – 7.47Scarlet tanager 4.46 (0.18) 3.50 – 5.50

Inmatureforeststands(80-120yearsold)insoutheastOhio,densitiesofbreedingbirdswererelatedtoforeststructure,especiallycanopygaps(Bakermansetal.2012).Densityofceruleanwarblerwaspositivelyrelatedtocanopyopenness,densityofvegetationintheunderstory,andslopebutnegativelyrelatedtothenumberofsmallandlargetrees.Densityofscarlettanagerwasincreasedwithheightoftheforestcanopy,densityofvegetationintheunderstory,slope,andcanopyopenness.Densityofovenbirdswaspositivelyassociatedwithcanopyopennessandslopebutwasnegativelyrelatedtocanopyheight.Woodthrushdensitieswerepositivelyassociatedwithnumbersofsmallandlargetreesbutnegativelyassociatedwithslope,canopyopenness,andunderstorydensity.Worm-eating,hooded,andKentuckywarblerdensitieswerepositivelyrelatedtocanopyheightandunderstorydensity.Recentworkalsosuggeststhatcanopyopennessmightinfluencenestsurvivalaswellasdensity(Bakermansetal.2012).

Table 4. Mean densities/10 ha and range of densities of common breeding birds across all 12 mature forest study sites in southeast Ohio, USA, 2004 – 2006. (Bakermans et al. 2012.)

Cerulean warbler. Photo by Marja Bakermans.

Special Focus on Cerulean WarblerPerhapsmoresothanmostothermature-forestbreedingbirds,ceruleanwarblersseemparticularlysensitivetoforeststructure.Ceruleanwarbler,aNeotropicalmigratoryspecies,isreceivingtremendousattentionfromconservationandmanagementgroupsbecauseitshowsoneofthefastestandsteepestdeclinesamongNorthAmericanbreedingbirds.From1966-2003,populationsdeclinedat3.2%peryear,increasingto-4.6%/yearbetween2003-2008(Ziolkowskietal.2010).Assuch,ceruleanwarblersarelistedas“vulnerabletoextinction”byBirdlifeInternational,aspeciesofconservationconcernbytheU.S.FishandWildlifeService,andapriorityspeciesinOhioandotherregionalbirdconservationplans.TheOhioHillsisanimportantfocalareabecauseitsupportsamongthehighestbreedingdensitiesforthespecies.

Overthelastseveralyears,anumberofresearchprojectshaveexaminedhowforestmanagementmayaffectbreedingpopulationsofceruleanwarblersinsoutheastOhio.Althoughthespeciesonlybreedsinrelativelyforestedlandscapes(often>60%forestcover),thepresenceofscatteredregeneratingclearcutsandinterioredges(e.g.,edgeswithinlargerexpansesofmatureforest)doesnotappeartoaffecteitherdensityornestingsuccess.Tothecontrary,thereissomeevidencethatceruleanwarblerspreferentiallylocateterritoriesnearsmall-scaledisturbances.Moreover,studiesindicatethatdensityandnestingsuccessmaybebestexplainedbylocal

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habitatfeaturesandtendtobepositivelyassociatedwithstandshavingrelativelyopenstructure,intermsoftreedensityandcanopy(BakermansandRodewald2009,Bakermansetal.2012).Thesestructuralfeaturescorrespondwelltostockinglevelsbetween60-70%comparedtostandswithstockinglevelsrangingfrom70-85%.Numbersofceruleanwarblershaveindeedbeenshowntodeclinewithincreasingbasalarea(BakermansandRodewald2009,NewellandRodewald2011,Bakermansetal.2012).Likewise,inarecentmulti-statecooperativeexperimentofcanopymanipulation,densitiesincreasedwithreductionsincanopycoverthatwereconsistentwithheavythinning(Boves2011).Thus,improvedmanagementforceruleanwarblersmayrequirecreatingfeaturesthatmimicold-growthforests.

Patternsofnestsurvivalforceruleanwarblerspresentamorecomplicatedpicture.Whilenestsurvivalratesarelowoverallcomparedtoothercanopy-nestingspecies,thereisevidenceofreducedsurvivalonharvestedstands,despitehigherdensities(Boves2011).Withinmatureforests,structuralattributeswererelatedtonestsurvival.Grapevinesseemtobeimportantfornest-siteselection(Fig.8)andnestsurvival.Forexample,numberofgrapevineswaspositivelyassociatedwithnestsurvivalofceruleanwarblers,perhapsbecausebeingclosetograpevines,whichareusedinnestconstruction,reducedtheconspicuousnessoffemalemovementsorconcealsnests(BakermansandRodewald2009).Ceruleanneststhatweresurroundedbylargeamountsofgrapevine(i.e.,upto23vines>5cmdbhwithin11.3mofthenest)weremorelikelytofledgeyoungthanthosenestswithfewgrapevines.Eveninsituationswheregrapevinesmustberemovedpriortoharvest,managersmighttrytopreservegrapevinesinsmall(>40ftradius)patcheswhereoverstorytreesareretained,thoughtheeffectivenessofthatapproachhasnotbeenexplicitlytested.

Floristiccompositionalsomaybeimportant.InsoutheastOhio,ceruleanwarblersshowedapreferenceforwhiteoaksandanavoidanceofredoaksfornesting(Bakermans2008,NewellandRodewald2011).SimilarpatternswerereportedthroughouttheAppalachiansaspartofthecooperativeexperiment,with

whiteoaksbeingthemostpreferrednesttrees,andredoaksandredmaplesbeingavoided(Boves2011).

Landscapesensitivity(edge,adjacencytoharvests)Matureforestbreedersarewidelyrecognizedasbeingsensitivetothecompositionandconfigurationofthelandscape.Probablythemostcommonmanagementrecommendationformature-forestbirdsistoretainlargehabitatpatchestoreduceedgeeffectsandaccommodatearea-sensitivespecies.Althoughthisisagoodgeneralstrategy,researchshowsthatedgeandareaeffectsarestronglylinkedtothelandscapecontext.Increasingfragmentationinthelandscapewilltendtomagnifytheeffectsofedge,area,andisolation,whereastheireffectsmaynotbedetectedatallinforestedlandscapes.Indeed,minimumpatchsizescanrangefrom25-2500acresforsomespecies,witharearequirementsincreasingwithdecliningforestcover.Oneexplanationfortheabsenceofareaandedgeeffectsinforestedlandscapesisthatpopulationsofgeneralistpredatorsoftenassociatedwithincreasedpredationnearedgesdonotsubstantiallyincreaseuntilthelandscapehasbecomequitefragmented.Thus,apatchofdisturbance,suchasaclearcut,withinheavilyforestedlandscapesseemsnottobeasdetrimentaltobirdsusingmatureforestsasthesamedisturbanceinafragmentedlandscape.Thismeansthatmanagersconcernedwithedgeeffectsmustbekeenlyawareoflandscapecontext.

Todate,researchinsoutheastOhiohasbeenconsistentwiththisideaoflandscape-dependentedgeeffects.Forexample,neitheradjacencynordistancetoharvestwassignificantrelatedtodensityofseveralfocalspecies,includingceruleanwarbler,ovenbird,andworm-eatingwarbler(Table5;Bakermansetal.2012).Likewise,therewasnoapparentrelationshipwithnestsurvival(Bakermansetal.2012).Thekeypointtorememberhereisthatduringtheperiodofresearch,forestcoverwithinthestudyareacountiesexceeded70%.Withlandusechange,lossofforestcover,orchangesinforestpatchageandsize,theremaybeincreasedpresenceofedgeandareaeffects.

Fig. 8. Cerulean warblers nested in areas with greater numbers of grapevines than randomly-located plots. In addition, Cerulean warblers are known to prefer northeast-facing slopes, which also have higher numbers of grapevines than southwest-facing slopes (Bakermans and Rodewald 2009).

Table 5. Mean densities/25 acres (10 ha) at different distances from the edge of regenerating clearcuts, and densities by harvest context of common breeding birds across all 12 mature forest study sites in southeast Ohio, USA, 2004 – 2006. (Bakermans et al. 2012)

Species <600ftfromedge >600ftfromedge Borderingharvest SurroundedbyforestWoodthrush 6.67 7.75 7.21 7.29Ovenbird 8.61 9.53 9.07 8.35Worm-eatingwarbler 3.33 4.11 3.72 3.19Kentuckywarbler 1.00 0.75 0.88 0.38Hoodedwarbler 3.92 3.17 3.54 2.83Ceruleanwarbler 1.03 1.72 1.31 2.62Scarlettanager 4.00 4.42 4.21 4.71

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Managementrecommendations1.Effortstomanagelocalhabitatfeatures,suchasforeststructure,areanimportantpieceofsustainingmature-forestbreeders.Intheforestedlandscapes(>70%forestcover)ofsoutheastOhio,structuralattributesofforest(i.e.,canopystructure,treesize,verticalcomplexity)hadstrongrelationshipswithdensityandnestsurvivalofsensitivespecies.

2.Featuresgenerallyassociatedwitholderforestsmaybeimportanthabitatcomponentsformatureforestbreeders,suchasceruleanwarbler.Theseold-forestcharacteristicsincludeaheterogeneouscanopy,diverseunderstoryvegetation,grapevines,andemergentlargetrees.Thus,usinglongerrotationages(>100years),aswellasspecificharvestprescriptions(e.g.,singletreeandgroupselection)andtimberstandimprovementpractices(e.g.,thinningandcroptreerelease)arelikelytoencouragethedevelopmentofthesefeatures.

3.Asdescribedinthesectionon“managingshelterwoodharvests”,whiteoakshouldbeemphasizedinmanagementbecauseitisafavorednestingtreeforceruleanwarblersandothercanopy-nestingbirds.(seenextchapterforadditionaldetailsaboutfloristiccompositionofstands).

4.Severalsensitivespeciesbreedinginmatureforestwouldbenefitfromcreatingcanopygaps(>430ft2,40m2)throughsingle-treeorgroupselectioncuts.

5.BasedonresultsfromtheCooperativeCeruleanWarblerForestManagementProject(Boves2011),recommendationsforAppalachianforestedlandscapesspecifythatforestssupporting>2territoriesper10acres(>5territories/10ha)ofCeruleanWarblershouldbemanagedwithoutharvestingandinwaysthatminimizedisturbance.Onforeststandswithfewerterritories,managementshouldreducebasalareato56-78ft2/acre(13-18m2/ha)whileretaininglargeoverstorytrees(>16inchesdbh;>40cmdbh),especiallyofwhiteoak.Becauseidentifyingthebestmanagementcoursedependsuponbirddensities,coordinationandcooperationwithwildlifebiologistsmaybenecessary.

Oak leaves. Photo by Amanda Rodewald.

Grapevines. Photo by Marja Bakermans.

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Chapter 5:Managing shelterwood harvests

Oaks(Quercusspp.)havedominatedmanyeasternforestsforatleast10,000years,resultingfromclimaticconditions,periodicfires,landpracticesofNativeAmericans(includingburning),andrepeatedcuttingfollowedbyfireandgrazingafterEuropeansettlement.However,changesindisturbanceregimeshavemadeitdifficultforoakstoregenerate.Nowshadetolerantspecies,suchas,redmaple(Acer rubrum),sugarmaple(A. saccharum),andblackgum(Nyssa sylvatica)dominatetheunderstoryandmidstorylayersofmanyoakforests.

Fireplayedanimportantroleinthehistoricdominanceofoak-hickoryineasterndeciduousforestsforthelast10,000years.Becauseoaksaretoleranttofire,periodicfiresfavoroakstootherspecies,likemapleandtulip.Forthisreason,prescribedburningisanincreasinglycommonmanagementtoolusedtoimproveoakregeneration.Inthesamestudyareaastheotherresearchhighlightedinthisguide,Artmanetal.(2001)investigatedtheshort-termconsequencesofprescribedburning(62-146°Ctemperaturefires)onbirds.Of30birdspeciesmonitored,densitiesofonlysixchangedinresponsetoburning.Fourspecies,ovenbirds,worm-eatingwarbler,hoodedwarbler,andnortherncardinaldeclinedinnumber,whereasAmericanrobinandEasternwood-peweeincreasedinresponsetoburning.Asawhole,ground-andlow-shrubnestingbirdsexperiencedthemostadverseeffects,buttherewerenooverallchangesinthebirdcommunity.

Changingforestcompositionimpactsbirdcommunitiesbyaffectingfoodandnestingresources.Consequently,agenciesarenowimplementingforestmanagementspecificallyintendedtoimproveoakregeneration.Oneexampleisthatoak

regenerationisamajorcomponentoftherevisedForestPlanforWayneNationalForest(inthe“HistoricOldForest”managementunits).Silviculturaltechniques,suchasshelterwoodharvests,alsoareusedtoincreaseoakregenerationandrecruitment.Duetotheiropencanopystructure,abundantunderstoryvegetation,andmaturetrees,standsmanagedforoakregenerationcanhavetheuniqueabilitytosupportadiverseassemblageofearly-andlate-successionalforestbirdsforthefirst5-10yearsuntilretainedtreesareremoved.

Figure 9. Densities per 10 acres for avian nesting guilds in shelterwood and unharvested stands in southern Ohio (Newell & Rodewald 2012).

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Canopy nesters.Forexample,in18standsacross4stateforestsinsoutheasternOhio,NewellandRodewald(2012)foundthatdensitiesofcanopy-nestingspeciesthataretypicallyassociatedwithmatureforest(i.e.,ceruleanwarbler,yellow-throatedvireo,scarlettanager,blue-graygnatcatcher)were31-98%higherinshelterwoodthanunharvestedreferencestands(Fig.9,Table6).Densityofceruleanwarblerswashighlyvariableamongforests.AtZaleskiStateForest,densityofceruleanswas>200%higherinshelterwoodthanreferencesstands,whereasfewterritorieswerepresentatRichlandFurnaceStateForest.Thevariationinresponsetoshelterwoodharvestingmightbeduetodifferencesamongforestsinslopeandaspect,giventhatceruleanswerepositivelyassociatedwithnortheast-facingslopes.

Midstory and ground nesters.Incontrasttocanopynesters,late-successionalmidstoryandground-nestingspecieswerenegativelyassociatedwithshelterwoodharvesting,andoccupiedshelterwoodsat33%and46%lowerdensities,respectivelyforthesegroups.Atthelevelofindividualspecies,red-eyedvireos,woodthrush,andworm-eatingwarblerswere26–38%lessabundantwhileAcadianflycatchersandovenbirdswere67%lessabundantinshelterwoodsthanreferencestands(Table6).

Understory-nesters.Becauseshelterwoodharvestingstimulatesunderstorygrowth,shrub-nestingspecieswerepositivelyassociatedwithshelterwoodstands,withdensitiesreaching155%higherthaninreferencestands.DensityofEasterntowheeswas300%higherinshelterwoodsthreeyearspost-harvesting.Kentuckywarblers,indigobuntings,andprairiewarblersallbeganbreedinginshelterwoodstandswithintwoorthreeyearsofharvesting.

Species Unharvested ShelterwoodCanopy-nesting guild 2.7 3.9

Eastern wood-pewee 0.5 0.8Yellow-throated vireo 0.2 0.4Blue-gray gnatcatcher 0.2 0.4Cerulean warbler 0.4 0.6Scarlet tanager 1.0 1.3

Midstory-nesting guild 5.7 3.8Acadian flycatcher 0.4 0.1Red-eyed vireo 3.0 2.3Wood thrush 1.3 0.9American redstart 0.4 0.5

Shrub-nesting guild 2.3 5.8Carolina wren 0.2 0.4Prairie warbler 0.0 0.9Kentucky warbler 0.0 0.6Hooded warbler 1.8 2.2Eastern towhee 0.4 0.9Indigo bunting 0.0 1.0

Ground-nesting guild 5.2 2.8Black-and-white warbler 0.9 1.1Worm-eating warbler 0.9 0.6Ovenbird 3.3 1.1

Cavity-nesting guild 0.8 0.9Red-bellied woodpecker 0.1 0.2Eastern tufted titmouse 0.3 0.3White-breasted nuthatch 0.2 0.2

Avian predators and brood parasite 0.7 0.7Blue jay 0.5 0.6American crow 0.1 0.2Brown-headed cowbird 0.6 1.3

Table 6. Mean density per 10 acres in recent shelterwood harvests and unharvested forest in southeastern Ohio, USA, 2007–2008. Adapted from Newell and Rodewald (2012).

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HabitatuseversussuitabilityAlthoughshelterwoodstandswereusedheavilybymanybirdswithinthefirstfewyearsofharvest,managersmustbecautiousaboutthepossibilityofcreatinganecologicaltrap.Anecologicaltrapoccurswhenacuethatoncecouldbereliablyusedtoindicatequalityofahabitat,resource,ormatenolongerconveysthecorrectinformationandorganismsusingthecuehavelowerperformance,reproduction,orsurvival.Animalsarethereforeattractedtoorpreferahabitatfeaturethatresultsinlowersurvivalorreproductivesuccess.Inthesecases,abundancedoesnotindicatehabitatqualityandmayevenbegreatestattheworstsites.Othermetricsmayserveasbetterindicatorsofquality,includingagedistribution,reproductivesuccess,andsitefidelity.

InthesoutheastOhiostudy,NewellandRodewaldfoundthatshelterwoodstandshadovertwiceasmanyyoungfirst-timebreedersofcanopynesters,includingbothceruleanwarblersandscarlettanagers,thanreferencestands.Althoughthismightsuggestalowerpreferenceforharvestedstands,thepatternalsomightbeaconsequenceofyoungbirdscolonizingnewlycreatedorimprovedhabitat.Sitefidelity(i.e.,returningtobreedatthesamesiteacrossyears)wassimilarat~50%inunharvestedandshelterwoodstands.

Basedonover700nests,nestsurvivaldidnotdifferbetweenshelterwoodandunharvestedstands,possiblybecausenumbersofavianpredatorsdidnotchangewithharvesting.Despiteincreasednumbersofbrown-headedcowbirdsinshelterwoods,only2%ofcanopynestsinwhichyoungcouldbeidentifiedwereparasitized.Nodifferencesinbroodsizewerefoundbetweenstandtypeseither.Oneworrisomepatternwasthat,despitethelackofaharvesteffect,nestingsuccesswaslow,rangingfrom15–19%foryellow-throatedvireosandceruleanwarblers,to27–36%forscarlettanagers,blue-graygnatcatchersandEasternwood-pewees,whichislowerthanreportedforotherAppalachianforests.

Asawhole,theresearchsuggeststhatshelterwoodharvestscontainingabundantoverstorytrees(~32overstorytrees/acreor80trees/ha)canprovideshort-termbreedinghabitatforcanopysongbirds.However,recognizingthatoverstoryistypicallyremovedforoakregenerationwithin5-10years,shelterwoodprescriptionsneedtoensurethatnestinghabitatismaintainedinspaceandthroughtimewithinthelandscape.

Long-termresponsesofbirdstopartialharvestingmaydiffergiventhatmanagementforoakregenerationwilltypicallyremovealloverstorytreeslaterinthecuttingcycle,whichshouldinitiallyeliminatebreedinghabitatfor canopy songbirds.

Theimportanceoftreespecies,treesize,andmicrohabitats.NewellandRodewald(2011)foundthatfactorssuchastopography,canopystructure,andfloristicsmaybeimportantinhabitatselectionandnestingsuccessforcanopysongbirds.Canopy-nestingbirdsselectedlargetreesinhigherproportionthanavailable(i.e.,66–75%ofnestsinlargetreescomparedtoimportancevaluesof47%)andselectedareaswithfewermedium-sizedtrees(9-15inchesdbh;23–38cmdbh).TheEasternwood-peweefavoredplacingnestsalongridgesandopencanopiescreatedbypartialharvesting,whereasceruleanwarblersfavoredproductivenortheast-facingslopeswithabundantgrapevines.

Althoughimportanceofoakstobirdsisoftengeneralizedacrossoaks,NewellandRodewald(2011)foundstrongdifferencesamongoakgroups(i.e.,white[whiteandchestnutoaks]andred[Northernred,Easternblack,andscarletoaks]).Almostallcanopyspeciesfavoredwhiteoakasanestsubstrate,whichissimilartoworkbyBakermansandRodewald(2008).Redoakwasavoidedfornestingbyblue-graygnatcatchers,ceruleanwarblersandscarlettanagers,andEasternwood-peweesavoidedtulippoplar(Fig.10).Mostspeciesalsoavoidedredmaple.Forthecanopy-nestingguildandseveralindividualspecies,nestingsuccesswasnegativelyassociatedwithredoaksaroundthenest.

Brown-headed cowbird. Photo by Ohio Division of Wildlife.

Southeast Ohio forest. Photo by Andrew Vitz.

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Prairie warbler. Photo by T. K. Tolford.

Figure 10. Tree species preferences for nesting for canopy-nesting species in southern Ohio. Importance values indicate the relative availability of each tree species. Adapted from Newell and Rodewald 2011.

Managementrecommendations1.Partialharvesting(~50%stockinglevel),suchastheshelterwoodtechnique,canbeusedtoprovidehabitattobothearly-successionalbirds(e.g.,prairiewarbler,Easterntowhee)andcanopy-nestingspeciesusuallyassociatedwithmatureforest(e.g.,yellow-throatedvireo,scarlettanager).InsouthernOhio,reducingbasalareafrom100-143ft2/acreto39-70ft2/acre(23-33m2/hato9-16m2/ha)supportedgreaternumbersofbothshrublandandcanopy-nestingspeciesthanunharvestedmatureforest.

2.Recognizingthatoverstoryistypicallyremovedforoakregenerationwithin5-10years,shelterwoodprescriptionsneedtoensurethatnestinghabitatismaintainedacrossspaceandthroughtimewithinthelandscape.

3.Favorwhiteoaksratherthanredoaksinshelterwoodharvests,aswhiteoaks(whiteandchestnutoaks)werestronglyfavoredfornestingandforagingbymostcanopynestingspecies.Redoaks(Northernred,Easternblack,andscarletoaks)alsomaydepressnestingsuccessofcanopynestingbirds.

4.Whenpossible,retainlargediametertrees(>15inchesdbh;>38cmdbh),whicharemostheavilyusedfornestingbycanopybirds,includingceruleanwarbler.

5.Incaseswherethereiswidelatitudeinchoiceofharvestlocation,avoidolderforestswithcanopygapsand/orthoseonnortheast-facingslope,becausethesetendtobemostheavilyusedbythedecliningceruleanwarbler.Instead,shelterwoodharvestsarebetterimplementedinareasthatlacksteepslopesand/orhavefewcanopygaps,wheretheyaremorelikelytocreateorimprovehabitatforspeciesrequiringheterogeneouscanopies.

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Chapter 6:Managing landscape mosaics and structurally complex

habitats for post-fledging and post-breeding birdsOneofthemostsurprisingfindingstoemergefromstudiesofforestwildlifeoverthelastdecadeisthatmanyspecieswidelyconsideredtobeobligatelate-successionalspeciesare,infact,disturbancedependentinoneormoreperiodsoftheirannualorlifecycles.Duringtheseperiods,speciesmayusehabitatsthatdifferwidelyfromthoseusedforreproduction.Suchisthecasewithmanybirdsthatbreedinmatureforestastheymoveintopost-breedingandpost-fledgingperiodsthatextendfromthecompletionofbreedingactivities(orleavingthenest)untiltheonsetofmigration.Forexample,mature-forestbreeders,suchasovenbirdsandworm-eatingwarblers,aredetectedinlargenumbersinhabitatswithdenseunderstoryvegetation,early-successionalforests,andevenregeneratingclearcuts.Becausepost-breedingbirdstendtobelessmaneuverableduetomoltingorinexperienceandhavehighenergeticdemands,theyhaveahighriskofmortality.Differencesinhabitatusebetweenbirdsduringbreedingandpost-breedingseasonsarethoughttoreflectanattractionofpost-breedingbirdsto(1)densecovertoreduceriskofpredation,and(2)abundantfruitresourcestofacilitateforaging.Althoughthereasonsdrivinghabitatselectionremainunclearformanyspecies,providingqualityhabitattopost-breedingandpost-fledgingbirdsisnowrecognizedasanimportantcomponentofanycomprehensiveapproachtomanagingforestbirds.

LocalhabitatfeaturesHabitat Use.Asacomplementarystudytotheirresearchonshrublandbirds,VitzandRodewald(2007)examinedpost-breedinguseofregeneratinghardwoodclearcuts(3-7yearsold)insoutheastOhio.Vegetationstructurewasthemostimportantfactorassociatedwithpost-breedingbirduseofregeneratingclearcutsinsoutheasternOhio.Thegreatestnumberofbirdswascapturedinthemostheterogeneousareaswithinclearcutsandspecificallyareaswithopenstructureclosetotheground(VitzandRodewald2007).Extremelydensepatchesofvegetationnearthegroundmaymakeitdifficultforbirdstoforageandprovideareaswherepredators,suchassnakes,canhide.

Atthesametime,numbersofpost-breedingbirdswerepositivelyrelatedtovegetationheightanddensitywithintheclearcuts(VitzandRodewald2007).Forinstance,nearlytwiceasmanyovenbirdsand6xasmanywoodthrushwerecapturedwhenthecanopywas>12ftthan<8fttall.Tallcanopies(shrub-saplingcanopy)notonlyprovideadditionalstructuralresources,butalsomayprotectbirdsfromaerialpredatorssuchasCooper’sorbroad-wingedhawks,commonraptorsatsites.Abundanceofmostmature-forestjuvenilesandpost-breedingadultswasbestexplainedbyvegetationstructure.However,fruitwasthemostimportantvariablewhenexplainingcapturesofscarlettanager,whichareknowntoconsumelargeamountsoffruitoutsidethebreedingperiod(VitzandRodewald2007).

Thefindingthatvegetationplaysthemostimportantroleinhabitatselectionduringthepost-breedingperiodisconsistentwithworkdonebyVitzandRodewald(2012)thatexaminedstableisotopecomposition(δ15Nandδ13C)inretricesandbasicplumagebodyfeathersofjuvenileScarletTanagers,WoodThrush,andOvenbirdscapturedinregeneratingclearcutsinsoutheasternOhio,2005-2006.Stableisotopescanbeusedtoidentifythedietofindividuals.Isotopicratiossuggestedthatindependentjuvenilesdidnotheavilyconsumefruitsandratherprimarilyconsumedbothlepidopteranandpredatoryarthropodsratherthanprimarilylepidopteranlarvae.Thus,matureforestbirdsduringthepost-fledgingperioddidnotseemtospecificallyuseregeneratingclearcutsforfruitresources.

HabitatselectionandsurvivalEventhoughtheirinitialworkshowedhighuseofearly-successionalhabitat,therelationshipbetweenhabitatselectionandsurvivalhadnotbeenstudied.Twosubsequentstudiesusedradio-telemetrytoidentifypatternsofhabitatselection,notonlyuse,andtestassociationsbetweenselectionandsurvival(Vitz2008,VitzandRodewald2010,VitzandRodewald2011).

Fromamanagementperspective,thisinformationiscriticalbecausetheideathatmature-forestbreedersmightrequirelargepatchesofsuccessionalhabitatduringthepost-breedingperiodcouldconceivablygiverisetoascenariowhereonehastoask,“Doweharvestpartoftheremainingsmallpatchofforesttoimprovepost-fledginghabitat,ordowekeeptheforestinamaturestatetoimprovenestinghabitat?”Consequently,managersneedtoknowwhichfeaturesandhabitatspromotehighsurvivalofbirdssoonaftertheyleavethenest.

From2004-2007,VitzandRodewaldradio-taggedandrecordeddailylocationsof51ovenbirdsand60worm-eatingwarblerfledglingsinsoutheastOhio.Survivalratesweresimilarforthetwospeciesandestimatedtobe65%forovenbirdsand67%forworm-eatingwarblers,whicharehigherratesthanreportedforotherspeciesandregions.Overall,fledglingsofbothspeciesactivelyselecteddenselyvegetatedhabitatsthatcontained40-60%morewoodystemsintheunderstorythanrandomlocations(Fig11).

Ovenbird. Photo by Marja Bakermans.

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Useofdensevegetationpromotedsurvival.Survivingindividualsofbothspeciesusedareaswithapproximately20%morewoodystemsthannon-survivingindividuals(Fig.12).Importantly,survivalwasnotlinkedspecificallytouseoflargepatchesofearly-successionalhabitat.Birdsthatfledgednestsnearclearcutsandthosefarfromclearcutssurvivedatsimilarrates.

Moreover,nearlyallbirdsuseddensevegetationwithintheforestoralongedges(e.g.,riparianhabitats,roadedges,treefallgaps)andfewusedclearcuts.Thesefindingssuggestthatspecifichabitatfeatures(i.e.,densewoodyvegetation)ratherthanhabitattypes(i.e.,shrublandhabitat)arekeytoprovidingqualitypost-fledginghabitat.Giventhatdenseunderstoryvegetationpromotessurvivaloffledgingbirds,providingsuchvegetativelydensehabitatwithinaforestedlandscapemayimprovejuvenilesurvivorshipandincreaserecruitmentintothepopulation.

TwofindingsofVitzandRodewaldalsosuggestthatthequalityofnestinghabitatmightinfluencesurvivalofjuvenilesduringthepost-fledgingperiod.First,bodyconditionofnestlingswaspositivelyrelatedtosurvivalduringthepost-fledgingperiod.Thus,individualsfledgedfromnestsinthehighestqualitybreedinghabitatsarelikelytohavethegreatestsurvivalratesduetotheirpresumablygreateraccesstofoodresources.Second,ovenbirdsfledgingearlierintheseasonsurvivedatahigherratethanthoseleavingthenestlaterintheseason,potentiallyduetochangesinfoodresourcesacrosstheseason.Decliningsurvivaloffledglingsacrossthebreedingseasondemonstratesanadditionalcostofhighratesofnestpredation.Ifearlynestingattemptsfail,evenasuccessfulrenestingattemptmayincursubstantialfitnessconsequencesfromhigherpost-fledgingmortality.Hereagain,providingthehighestqualitynestinghabitatmaypositivelyaffectpost-fledgingsurvival.

Becauseobservationalstudieshaveimportantlimitations,VitzandRodewaldalsoexperimentallytestedhowaccesstoanduseoflargepatchesofsuccessionalhabitat(i.e.,regeneratingclearcuts)influencedsurvivalandbehaviorofjuvenileOvenbirdsthatwereindependent(i.e.,~3weeksofage).Between2004and2006theycapturedandradio-tagged85Ovenbirdsandrandomlyassignedindividualstooneofthreeexperimentalgroupsthatwerereleasedin1)theoriginalclearcutofcapture,2)adifferentclearcutofsimilarage,and3)amatureforest.Acrossa52-dayperiod,survivalofindependentjuvenileswas83%andwassimilaracrossthethreeexperimentaltreatments.Juvenilesurvivalwasbestexplainedbyandpositivelyrelatedtobothvegetationdensityandindividualenergeticcondition.Aswiththeyoungerfledglings,juvenilesselecteddenseunderstoryvegetationthatpromoted

Figure 11. Mean number (+ SE bars) of woody stems (left) and canopy cover (right) at fledgling, random, and nest locations for worm-eating warblers and ovenbirds in southern Ohio. From Vitz and Rodewald 2011.

Figure 12. Mean number (+ SE bars) of woody stems at ovenbird and worm-eating warbler locations of individuals that survived and died during the post-fledging period in southern Ohio. From Vitz and Rodewald 2011. Photo by Andrew Vitz.

Worm-eating warbler nest.

25

survival.Theseresultsareimportantfromamanagementperspectivebecausetheyshowthatwhiledensevegetationisselectedbyandpromotesjuvenilesurvival,birdsapparentlydonotapparentlyrequirelargepatchesofsuccessionalhabitat.Rather,juvenilesseemabletouseawiderangeofsuccessionalhabitatsandpatchesofdensevegetation(e.g.,treefallgaps,roadedges)thatoccurwithinmatureforests.

Collectively,thesefindingsshowthatduringthepost-breedingandpost-fledgingperiods,birdsactivelyselectareaswithdenseunderstoryvegetation,whichmayoccureitherwithinmatureforest,alongedges,orindifferenthabitats(e.g.,riparianorsuccessionalhabitats).Theyalsoprovidestrongevidencethatshiftsinmicrohabitatspromotesurvival.

Edge,area,andlandscapesensitivityThesensitivityofmature-forestbirdstoedgeandareaduringthebreedingseasoniswellestablishedinmanystudiesandavarietyofregions.However,researchonpost-breedingbirdssuggeststhattheymayactuallyfavoredgehabitatsduetopreferencesforthickvegetation.VitzandRodewald(2006)testedforattractionoraversiontoedgesofregeneratingclearcutsandforsensitivitytoharvestsize.Surprisingly,theyfoundthatmostpost-breedingindividualsavoidedareasclosesttothemature-forestedgeofclearcuts,andinsteadheavilyusedtheclearcutinteriors.

Paradoxically,juvenilesandpost-breedingadultsalsoavoidedlargeclearcuts(whichshouldhavemore“interior”),andcapturerateswereupto4timesgreaterinsmallthanlargeregeneratingclearcuts(Fig13).Captureratesforfiveofthesixspeciesofmature-forestbirdswere10-380%greaterinsmallthanlargecuts;aninterestingparadoxwiththepatternofedgeavoidance.Theydetectednodifferenceinhabitatstructureorfoodresourcestoexplainthispattern,butseveralpossibleexplanationsexist,includingavoidanceofpredatorsalongedges,reducingcompetitiveinteractionswithindividualsstillbreedinginmatureforest,ordifferencesinfoodavailability.Post-breedingbirdsmaydiscriminateamongregeneratingclearcutsbasedonsize,shape,oredge.Forsomespecies,highercaptureratesinsmallstandsalsomaybearesultofaconcentrationeffect.Asafunctionofclearcutsize,smallclearcutswithinaforestedlandscape

generallyhavemorematureforesthabitat(andpresumablymoremature-forestbirds)intheimmediatelandscapecomparedtolargecuts.Consequently,ifmature-forestbirdsselectregeneratingclearcutsduringthepost-breedingperiodonewouldexpectgreaternumbersofthembeingconcentratedinthesmallregeneratingclearcuts.

OtherworkconductedbyVitzandRodewald(2010)onmovementsalsoprovidesinsightsintopotentialarearequirementsofpost-fledgingbirds.Natalhomerangesizesforovenbirdandworm-eatingwarblerfarexceededthesizeofbreedingterritories,withnatalhomerangesizeofworm-eatingwarblers(25acres;10ha)beingtwiceaslargeasthatforovenbirds(12acres;5ha).Fledglingsalsomadesurprisinglylongdispersalmovementsfromnatalareas-oftentimesmorethan600ftwithinonlytwoweeksofleavingthenest.Birdsinbetterconditionmadelongermovements.Useoflargeareasafterfledgingmaycontributetopatternsofareasensitivity,atleastinfragmentssmallerthanthenatalhomerangesize.Onceapatchexceedsthissize,theseeffectswouldlikelybereducedbecausefamilygroupsmayhaveoverlappingnatalhomeranges.Ifareasensitivityispartiallyexplainedbynatalhomerangesize,thenspeciesexhibitinglargenatalhomerangesshoulddemonstrateahigherdegreeofareasensitivity.Indeed,worm-eatingwarblers,whichutilizednatalhomerangesthatwerenearlytwicetheareaasthoseforovenbirds,aremoresensitivetofragmentationthanovenbirds.

Anotherinterestingconnectionbetweenmovementandarearequirementscomesfromtheexperimentalstudywithindependentjuvenilesdescribedpreviously(Vitz2008).Ovenbirdsreleasedintomatureforesthabitattraveledfartherfromtheirreleaselocationafterboth7and14dayscomparedtobirdsreleasedintobothclearcuttreatments.Thehighermovementratesofindividualsrelocatedinmatureforesthabitatsmightindicatethatifbirdsaretorelyuponmatureforesttoprovidepost-breedingandpost-fledginghabitat,thattheymustmoveoverlargerareastolocatesuitablemicrohabitats(Figs.14,15).Thus,maintaininglargepatchesmaybeimportantinlandscapesdominatedbylate-successionalforest.

Lehnen(2008)foundthatcapturesofpost-breedingforestspecialistswerebestexplainedbythecombinationofbothlocalhabitatvariablesandamountofmatureforestwithin0.62mile(1km).Thus,maintainingforestedlandscapesthathaveabundantlate-successionalforestisanimportantcomponentofprovidinghabitattopost-breedingandpost-fledgingbirds.

Figure 13. Total number of captures of mature-forest birds during the post-breeding period with respect to distance and stand size in regenerating clearcuts in southeast Ohio, 2002 and 2003. From Vitz and Rodewald 2006.

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Managementrecommendations1.Managematureforestsinwaysthatpromotestructuralcomplexity,whichencouragesmicrohabitatsthatprovidedenseunderstoryvegetation.Examplesincludetreefallgaps,riparianthickets,andnaturalpatchesofshrubs.Becausesomeofthesefeaturesaretypicalcomponentsinold,uneven-agedforests,considerallowingstandstoreachagesgreaterthan100years.

2.Allowroadsidesandotherhuman-associatededgestodevelopthethickvegetationthatisheavilyusedbypost-breedingbirds.Thereappeartobenostrongsizerequirementsforusebybirds.

3.Whenconsistentwithothermanagementgoals(e.g.,oakregeneration),considerusingsilviculturaltechniquestocreateareaswithdensevegetation.Group-selectionharvestsandshelterwoodharvestsmaybegoodexamplesofthis.Althoughuseoftheseharvesttypeshasnotbeenspecificallystudiedduringthisstageintheannualcycle,changesinhabitatstructureassociatedwiththosesilviculturaltechniquesareconsistentwithfeaturespreferredbypost-breedingandpost-fledgingbirds.

4.Regardingharvestsize,beattentivetoneedsofotherspeciesandduringotherstagesoftheannualcycle.Post-fledgingbirdsdonotseemtorequirelargepatchesofsuccessionalhabitatandcanusedensevegetationwithinmatureforests.Consequentlyshrublandhabitatsareprobablybestmanagedaccordingtorecommendationsforearly-successionalbreeders.

5.Engageinlandscape-scaleplanningtoensurethatsufficientforestisretainedtopermitmovementthroughthelandscape(seeAppendixC).Notonlyareindependentjuvenilesknowntomakeextensivemovements,butnumbersofpost-breedingbirdsusingharvestswaspositivelyrelatedtoforestcoverwithin0.62mile(1km).

Figure 14. The mean distance moved from the release location for independent juvenile Ovenbirds for each of the three treatment groups (mf = mature forest, cc-diff = released in a different clearcut, cc-same = released in original clearcut of capture). From Vitz 2008, Vitz and Rodewald 2013.

Figure 15. Daily locations of an independent juvenile ovenbird in southeastern Ohio (Vitz 2008).

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ReferencesArtman,V.L.,E.K.Sutherland,andJ.F.Downhower.2001.Prescribedburningtorestoremixed-oakcommunitiesinsouthernOhio:

effectsonbreedingbirdpopulations.ConservationBiology15:1423-1434.Bakermans,M.H.,A.D.Rodewald,andA.C.Vitz.2012.Influenceofforeststructureondensityandnestingsuccessofmatureforest

birdsinmanagedlandscapes.JournalofWildlifeManagement76:1225-1234.Bakermans,M.H.andA.DRodewald.2009.Thinkglobally,managelocally:theimportanceofsteadystateforestfeaturesfora

decliningsongbird.ForestEcologyandManagement258:224-232.Bakermans,M.H.2008.DemographyandhabitatuseofCeruleanWarblersonbreedingandwinteringgrounds.Ph.D.dissertation,

TheOhioStateUniversity,Columbus,OH.Boves,T.J.2011.MultipleresponsesofCeruleanWarblerstoexperimentalforestdisturbanceintheAppalachianMountains.PhD

Dissertation.CollegeofNaturalResources.UniversityofTennessee,Knoxville,TN.Lehnen,S.E.andA.D.Rodewald.2009a.Investigatingarea-sensitivityinshrublandbirds:responsestoapatchylandscape.Forest

EcologyandManagement257:2308-2316.Lehnen,S.E.andA.D.Rodewald.2009b.Dispersal,inter-patchmovements,andsurvivalinashrublandbreedingbirdcommunity.

JournalofFieldOrnithology80:242-252.Lehnen,S.E.2008.Anevaluationofsurvivorshipandhabitatuseofearly-successionalbirdsduringthebreedingseason:

implicationsforconservation.Ph.D.dissertation,TheOhioStateUniversity.Newell,F.L.andA.D.Rodewald.2012.Managementforoakregeneration:Short-termeffectsonthebirdcommunityand

suitabilityofshelterwoodharvestsforcanopysongbirds.JournalofWildlifeManagement76:.683-693.Newell,F.L.andA.D.Rodewald.2011.Roleoftopography,canopystructure,andfloristicsinnest-siteselectionandnesting

successofcanopysongbirds.ForestEcologyandManagement262:739-749.Rodewald,A.D.andA.C.Vitz.2005.Edgeandarea-sensitivityofshrublandbirds.JournalofWildlifeManagement69:681-688.Sauer,J.R.,J.E.Hines,J.E.Fallon,K.L.Pardieck,D.J.Ziolkowski,Jr.,andW.A.Link.2011.TheNorthAmericanBreedingBird

Survey,ResultsandAnalysis1966-2009.Version3.23.2011USGSPatuxentWildlifeResearchCenter,Laurel,MDVitz,A.C.andA.D.Rodewald.2013.Behavioralanddemographicconsequencesofaccesstoearly-successionalhabitatby

juvenileovenbirds:anexperimentalapproach.Auk130:21-29.Vitz,A.C.andA.D.Rodewald.2012.Usingstableisotopestoinvestigatethedietarytrophicleveloffledglingsongbirds.Journal

ofFieldOrnithology83:73-84.Vitz,A.C.andA.D.Rodewald.2011.Survivalinthethicket:Densevegetationpromotessurvivalofpost-fledgingsongbirds.

Condor113:400-411.Vitz,A.C.andA.D.Rodewald.2010.Fledglingsongbirdmovementswithinandbeyondthenatalhomerange.TheAuk127:364-

371.Vitz,A.C.andA.D.Rodewald.2007.Vegetativeandfruitresourcesasdeterminantsofhabitatusebymature-forestbirdsduring

thepost-breedingperiod.Auk124:494-507.Vitz,A.C.andA.D.Rodewald.2006.Canregeneratingclearcutsbenefitmature-forestbirds?Anexaminationofpost-breeding

ecology.BiologicalConservation127:477-486.Vitz,A.C.2008.Survivorship,habitatuse,andmovementsfortwospeciesofmatureforestbirdsduringthepost-fledgingperiod.

Ph.D.dissertation,TheOhioStateUniversity.Ziolkowski,D.J.,Jr.K.L.Pardieck,andJ.R.Sauer.2010.TheS2003-2008summaryoftheNorthAmericanbreedingbirdsurvey.

BirdPopulations10:90-109.

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Appendix A. Common metric conversions.

Metric English conversion1meter x3.28=ft1cm x0.394=inches1m2 x10.76=ft2

1hectare x2.471=acresTreesperhectare x0.4047=treesperacrem2perhectare x4.356=ft2peracrecmdbh X0.3939=inchesdbh

29

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31

32

Appendix C. Two hypothetical managed forest landscapes. Green indicates mature or late-successional forest, and yellow colors indicate various stages of early-successional forest. Because landscape A has clustered early-successional habitats to retain large contiguous mature forest, it is expected to better support populations of early and late successional birds. With widely distributed early-successional habitats, landscape B is less suitable for edge and area-sensitive species.

33

Appendix D. Common and scientific names of bird species included in this guide.

Common Name Scientific NameAcadianflycatcher Empidonax virescensAmericancrow Corvus brachyrhynchosAmericanredstart Setophaga ruticillaAmericanwoodcock Scolopax minorBaltimoreoriole Icterus galbulaBell’svireo Vireo belliiBlack-and-whitewarbler Mniotilta variaBlack-billedcuckoo Coccyzus erythropthalmusBlack-cappedchickadee Poecile atricapillusBluejay Cyanocitta cristataBlue-graygnatcatcher Polioptila caeruleaBlue-wingedwarbler Vermivora cyanopteraBroad-wingedhawk Buteo platypterusBrowncreeper Certhia americanaBrownthrasher Toxostoma rufumBrown-headedcowbird Molothrus aterCanadawarbler Cardellina canadensisCarolinachickadee Poecile carolinensisCarolinawren Thryothorus ludovicianusCeruleanwarbler Setophaga ceruleaChimneyswift Chaetura pelagicaChuck-will’s-widow Caprimulgus carolinensisCommonyellowthroat Geothlypis trichasCooper’shawk Accipiter cooperiiDownywoodpecker Picoides pubescensEasternmeadowlark Sturnella magnaEasternscreech-owl Megascops asioEasterntowhee Pipilo erythrophthalmusEasternwood-pewee Contopus virensFieldsparrow Spizella pusillaGolden-crownedkinglet Regulus satrapaGolden-wingedwarbler Vermivora chrysopteraGrasshoppersparrow Ammodramus savannarumGraycatbird Dumetella carolinensisGreatcrestedflycatcher Myiarchus crinitusHairywoodpecker Picoides villosusHenslow’ssparrow Ammodramus henslowiiHoodedwarbler Setophaga citrinaHousewren Troglodytes aedonIndigobunting Passerina cyaneaKentuckywarbler Geothlypis formosaLarksparrow Chondestes grammacusLeastflycatcher Empidonax minimusLoggerheadshrike Lanius ludovicianusLouisianawaterthrush Parkesia motacilla

Common Name Scientific NameMarshwren Cistothorus palustrisNorthernbobwhite Colinus virginianusNortherncardinal Cardinalis cardinalisNorthernflicker Colaptes auratusNorthernharrier Circus cyaneusNorthernparula Setophaga americanaNorthernsaw-whetowl Aegolius acadicusOrchardoriole Icterus spuriusOvenbird Seiurus aurocapillaPeregrinefalcon Falco peregrinusPileatedwoodpecker Dryocopus pileatusPinewarbler Setophaga pinusPrairiewarbler Setophaga discolorProthonotarywarbler Protonotaria citreaPurplemartin Progne subisRed-belliedwoodpecker Melanerpes carolinusRed-eyedvireo Vireo olivaceusRed-headedwoodpecker Melanerpes erythrocephalusRed-shoulderedhawk Buteo lineatusRose-breastedgrosbeak Pheucticus ludovicianusRuby-throatedhummingbird Archilochus colubrisRuffedgrouse Bonasa umbellusScarlettanager Piranga olivaceaSedgewren Cistothorus platensisSharp-shinnedhawk Accipiter striatusShort-earedowl Asio flammeusSongsparrow Melospiza melodiaSummertanager Piranga rubraTuftedtitmouse Baeolophus bicolorVeery Catharus fuscescensWhip-poor-will Caprimulgus vociferusWhite-breastednuthatch Sitta carolinensisWhite-eyedvireo Vireo griseusWildturkey Meleagris gallopavoWillowflycatcher Empidonax trailliiWoodthrush Hylocichla mustelinaWorm-eatingwarbler Helmitheros vermivorumYellow-billedcuckoo Coccyzus americanusYellow-breastedchat Icteria virensYellow-throatedvireo Vireo flavifronsYellow-throatedwarbler Setophaga dominica