Metal Birds
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Transcript of Metal Birds
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7/29/2019 Metal Birds
1/1
Oksana Lane1, Oscar Brenes2, Peter Doherty3 , Pablo Elizondo4, and Robert Taylor5, Bruce Rinker1*1 Biodiversity Research Institute, Gorham, Maine, USA; 2 Reserva Playa Tortuga, Ojochal, Costa Rica; 3 Virginia, USA; 4 INBioparque, San Jose, Costa Rica; 5 Trace Element Research Laboratory,
Texas A&M, College Station, Texas, USA
*Presenter
Heavy metals screening in feathers of resident birds and neotropical migrants at
selected sites in Costa Rica and Panama
Metales pesados en las plumas de aves residentes y migratorias neotropicales, en
sitios selectos de Costa Rica y Panam
ABSTRACT: We non-lethally collected feather samples from resident and migrant birds from
several sites representing different habitats in Costa Rica and Panama to assess if exposure to
mercury (Hg) and/or other heavy metals are of concern at these sites. Of 43 species sampled
in Costa Rica and nine in Panama, mercury exposure was in generally low at all sites. The
American pygmy kingfisher (Chloroceryle aenea) had the highest mercury levels of all birds
sampled, ranging from 2.8 to 5.7 ppm (parts per million) in Panama to 11 ppm at Cao Palma
Research Station in Barra del Colorado Wildlife Refuge, Costa Rica. Feather mercury
concentrations over 4.6 ppm are considered elevated in songbirds (Jackson et al. 2011) and
over 40 ppm in fish-eating birds (Evers et al. 2008). Invertivorous neotropical migrantssuch
as the northern waterthrush (Seiurus noveboracencis), spotted sandpiper (Actitis macularius)
and piscivorous species such as resident kingfishers foraging in aquatic habitats (ie. streams
and mangroves) tended to have higher feather mercury concentrations than other species.
A subset of feather samples (n = 39) were analyzed for other metals including several
essential elements. Here we focus on selected metals that were elevated in sampled birds:
aluminum (Al), barium (Ba), copper (Cu), iron (Fe), manganese (Mn), strontium (Sr), tin (Sn)
and zinc (Zn).
ACKNOWLEDGEMENTS
We are grateful to Alejandra Martinez and the staff from CATIE, Todd Lewis fromCao Palma Biostation, Costa Rica, biologists Jon Van Dort and Evelyn Paola
Thibodeau, and the staff of the Center for Caribbean Conservation and Reserva
Playa Tortuga all helped with bird capture and banding. We thank Kevin Regan at
BRI for Hg analysis.
American Pygmy Kingfisher (Chloroceryle aenea), resident in Costa Rica and Panama
Figure 1. Study sites in Costa Rica and Panama
INTRODUCTIONHeavy metals are among the most toxic poisons known with the nervous system often being the principal
target. We are unaware of any published studies that address heavy metal exposure to the resident birds
and neotropical migrants of Mesoamerica. Most of the toxicity information available focus on aquatic
organisms, particularly fish, but little has been published on metal toxicity in other vertebrates including
birds.Elevated exposure to Al can be toxic to fish and cause pulmonary and developmental problems. Barium
does not bioaccumulate but at high exposures can induce gastrointestinal distress, muscular paralysis, and
cardiovascular problems at concentrations exceeding 10 ppm (Moore 1991). Toxic effects to birds from
exposure to Cu include reduced growth rates, lowered egg production, and developmental abnormalities
(US EPA 2008). Elevated concentrations of Mn in birds have been known to cause decreased hemoglobin,
anemia, and reduced growth (ATSDR 1991). Elevated levels of Zn can cause mortality, pancreatic
degradation, reduced growth, and decreased weight gain in birds (Eisler 1993, NAS 1980). And mercury, in
its methylated form, is a well known neurotoxin and has been shown to affect reproductive success in birds
(Evers et al. 2008, Jackson et al. in press).
Many studies have surveyed for heavy metals in pelagic sea birds, but fewif anyhave assessed heavy
metal exposure to the resident and migrant birds of Mesoamerica. This study provides an initial survey of
heavy metal concentrations for the region.
METHODSAND STUDY AREAOuter tail feathers (R6) were pulled from birds
captured using mistnets. Birds were released
following sampling at the site of capture. Sampling
was completed between November 15, 2010 and
April 19, 2011. Mercury analysis in feathers wasdone using a Direct Mercury Analyzer (DMA-80) by
Millestone Inc. at Biodiversity Research Institute
Wildlife Mercury Research Lab in Maine, USA.
Trace metal scan was done using ICP-MS at the
Trace Element Research Lab at Texas A&M
University, Texas, USA.
In Costa Rica we sampled 2 sites in the lowlands
on the Caribbean Coast near Tortuguero (Cao
Palma and Tortuguero), one site in a cacao
plantation near Volcan Turrialbo (CATIE), one site in
San Jose (INBio Parque) and one site on the Pacific
Coast in the wetlands of Ojochal (Reserva Playa
Tortuga). In Panama three mangrove sites were
sampled on the Atlantic coast (Playa Bonita,
Panama Vieja and Juan Diaz; Figure 1).
RESULTSSee table 1 for metal concentrations by site
and individuals, and figures 2 and 3 for
summary of selected heavy metals by site
and species. Due to lack of funding only a
few samples were screened for heavy
metals. This study serves as a pilot
screening to determine if further sampling is
necessary to assess contaminant exposure to
birds and other wildlife in Central America
and to locate sources of contamination.
Table 1. Concentrations of heavy metals in bird feathers (ppm or mg/kg) from Costa Rica and Panama (numbers in re
we consider high or elevated; species in bold are considered residents).
LITERATURECITED
Evers, D. C., L. Savoy, C. DeSorbo, D. Yates, W. Hanson, K. Taylor, L. Siegel,J. Cooley, M. Bank, A. Major, K. Munney, B. Mower, H. Vogel, N.
Schoch, M. Pokras, M. Goodale, and J. Fair. 2008. Adverse effects
from environmental mercury loads on breeding common loons.
Ecotoxicology 17:69-81.
Jackson, A. K., D. C. Evers, M. A. Etterson, A. M. Condon, S. B. Folsom, J.
Detweiler, J. Schmerfeld, D. A. Cristol. 2011. Mercury exposure
affects the reproductive success of a free-living terrestrial songbird,
the Carolina wren (Thryothorus l udovicianus). The Auk. In press.
DISCUSSIONCertain species, such as the spotted
sandpiper, appear to have elevated levels of
several toxic elements including copper (Cu),
manganese (Mn), Tin (Sn) and mercury (Hg).
In addition to exposure through diet,
shorebirds may ingest a portion of the
metals by consuming contaminated
sediment while foraging. Many heavy metals
are also used in pesticides and
manufacturing and birds may occupy
agricultural habitats or areas downstream
from polluted areas allowing for exposure to
many contaminants.
It appears that further investigation into
contaminant exposure to birds in Central
America is warranted based on these
preliminary data.
Figure 2. Concentrations of trace elements in tail feathers of
individual spotted sandpipers in Costa Rica and Panama.
Figure 3. Mercury concentrations in feathers of kingfishers from Costa
Rica and Panama.
RESUMEN: no letales recogieron muestras de plumas de aves residentes y migratorias de varios sitios que
representan los diferentes hbitats en Costa Rica y Panam para evaluar si la exposicin al mercurio (Hg) y
/ u otros metales pesados son motivo de preocupacin en estos sitios. De 43 especies muestreadas en
Costa Rica y nueve en Panam, la exposicin al mercurio fue en general baja en todos los sitios. El martn
pescador estadounidense enano (Chloroceryle aenea) tenan los niveles ms altos de mercurio de todas
lasaves objeto de muestreo, que van desde 2,8 hasta 5,7 ppm (partes por milln)en Panam a 11 ppm en
Cao Palma Estacin de Investigacin en Barra del Colorado Wildlife Refuge, Costa Rica. Concentraciones
de mercurio en plumas de ms de 4,6 ppm se consideran elevadas en aves cantoras (Jackson et al. 2011) y
ms de 40 ppm en aves piscvoras (Evers et al. 2008). Invertivorous migrantes neotropicales, tales como
el waterthrush norte (Seiurus noveboracencis), playero manchado (Actitis macularius) y las especies se
alimentan de peces como el martn pescador residente de alimentacin en los hbitats acuticos (ros y
manglares es decir), tendan a tener mayores concentraciones de mercurio que otras especies de
plumas. Un subconjunto de muestras de plumas (n = 39) fueron analizadas por otros metales incluyendo
varios elementos esenciales. Aqu nos centramos en los metales seleccionados que fueron elevados
en aves objeto de muestreo: de aluminio (Al), bario (Ba), cobre (Cu), hierro (Fe), manganeso (Mn),
estroncio (Sr), estao (Sn) y zinc (Zn).
0
2
4
6
8
10
12
American Pygmy Kingfisher
(Chloroceryle aenea)
Green and Rufous
Kingfisher (Chloroceryle
inda)
Green Kingfisher
(Chloroceryle americana)
Juan Diaz, Panama (3; 1)
Cao Palma, Costa Rica (1)
Rio Balso, Ojochal, Costa Rica (1)
Feather
Mercury(ppmf
w)
Site Species Al Ba Cu Hg Mn Sn Sr Zn
Cao Palma, CR American Pygmy kingfisher 9.5 0.81 9.87 11.29 2.98 3.62 2.29 141
Northern waterthrush 10.7 1.96 5.62 2.20 14.9 1.29 1.43 119
Red-capped manakin 90.6 3.39 7.9 0.50 24.2 3.91 2.73 106
S ummer t an ager 3 1. 7 4. 41 5.9 7 0. 09 13. 5 3.6 5 1 .31 1 04
Swainson's thrush 13.1 2.09 6.57 0.50 8.86 3.85 1.25 97.7
Swainson's thrush 52.2 2.35 6.68 0.19 12.8 2.28 1.57 93.7
White-collared manakin 50.2 4.83 6.36 0.35 8.67 3.3 2.76 109
Wood thrush 260 7.86 7.92 1.89 47.8 2.22 4.62 96.1
Wood thrush 342 9.01 6.53 1.67 37.9 2.15 4.1 95.2Tortuguero, CR Swainson's thrush 36.3 3.9 9.58 1.02 9.98 3.36 1.51 102
Yellow bell ied flycatcher 10.6 3.83 6.2 1.26 40 3.31 2.02 96.6
CATIE, CR Baltimore oriole 288 6.34 8.34 0.27 15.3 2.06 4.61 61.2
Chesnut-sided warbler 21.8 2.83 6.66 12.4 4.18 1.23 110
Passarin's tanager 458 25.5 7.33 0.08 52.9 2.1 5 1 1 10 3
Yellow-throated euphonia 61 31.9 5.3 0.06 8.87 4.24 8.63 100
In Bi o, S an Jose, CR N ort hern wa tert hru sh 3 1. 8 2. 03 1 9. 6 1. 24 1 7. 5 2.5 7 2.58 9 6. 8
Philadelphia v ireo 56.3 1.56 6.59 0.21 1.43 4.32 1.12 90.2
Reserva Play Tortuga, Ojochal, CR Black-hooded antshrike 20.1 4.25 7.43 0.03 19.6 5.13 5.28 154
Blue-grey tanager 34.2 7.19 7.14