Further Assessment of Environmental Contaminants in Avian Prey of the Peregrine Falcon in Big Bend National Park, Texas

Mora, Miguel A.; Skiles, Raymond; Paredes, Marcos

doi:10.1894/0038-4909(2007)52[54:faoeci]2.0.co;2

Cited by 4 publications

(5 citation statements)

References 21 publications

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“…This agrees with field data suggesting a much larger breeding population size [13] , [31] . Reducing organochlorine pesticides and other contaminants (e.g., mercury; [140] , [141] ) in their environment is of greater importance for securing the long-term viability of peregrine falcon populations, and recent results from Henny et al [125] suggest that these conditions are improving. Consequences of the illegal take of peregrine falcons in their wintering distribution in South America [142] also deserves more attention, and certainly, local monitoring of specific areas within the species' breeding distribution should continue.…”

Section: Discussionmentioning

confidence: 99%

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

et al. 2010

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BackgroundOur ability to monitor populations or species that were once threatened or endangered and in the process of recovery is enhanced by using genetic methods to assess overall population stability and size over time. This can be accomplished most directly by obtaining genetic measures from temporally-spaced samples that reflect the overall stability of the population as given by changes in genetic diversity levels (allelic richness and heterozygosity), degree of population differentiation (F ST and D EST), and effective population size (N e). The primary goal of any recovery effort is to produce a long-term self-sustaining population, and these genetic measures provide a metric by which we can gauge our progress and help make important management decisions.Methodology/Principal FindingsThe peregrine falcon in North America (Falco peregrinus tundrius and anatum) was delisted in 1994 and 1999, respectively, and its abundance will be monitored by the species Recovery Team every three years until 2015. Although the United States Fish and Wildlife Service makes a distinction between tundrius and anatum subspecies, our genetic results based on eleven microsatellite loci suggest limited differentiation that can be attributed to an isolation by distance relationship and warrant no delineation of these two subspecies in its northern latitudinal distribution from Alaska through Canada into Greenland. Using temporal samples collected at Padre Island, Texas during migration (seven temporal time periods between 1985–2007), no significant differences in genetic diversity or significant population differentiation in allele frequencies between time periods were observed and were indistinguishable from those obtained from tundrius/anatum breeding locations throughout their northern distribution. Estimates of harmonic mean N e were variable and imprecise, but always greater than 500 when employing multiple temporal genetic methods.Conclusions/SignificanceThese results, including those from simulations to assess the power of each method to estimate N e, suggest a stable or growing population, which is consistent with ongoing field-based monitoring surveys. Therefore, historic and continuing efforts to prevent the extinction of the peregrine falcon in North America appear successful with no indication of recent decline, at least from the northern latitude range-wide perspective. The results also further highlight the importance of archiving samples and their use for continual assessment of population recovery and long-term viability.

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Section: Discussionmentioning

confidence: 99%

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

et al. 2010

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“…Furthermore, the DDE values observed in all neotropical migrants from Illinois (Klemens et al 2000) were within the range of those observed in resident and migrant birds in Michoacán. OCs in resident and migrant birds from Michoacán also were similar to those of insectivorous passerine birds from Arizona (Mora et al 2003) but were much lower than those observed in passerine birds from the Texas-Mexico border over the last few years (Mora et al 2002(Mora et al , 2006(Mora et al , 2007. There are, however, some inconsistencies with the general observed trend of no accumulation of OCs during the winter in Michoacán.…”

Section: Discussionmentioning

confidence: 63%

“…Two to five grams of homogenate was used for each analysis. The carcass homogenates were analyzed for persistent OCs, including polychlorinated biphenyls (PCBs), at the Geochemical and Environmental Research Group, Texas A&M University, under procedures described previously (Brooks et al 1989;Mora et al 2007;Sericano et al 1990). Carcass homogenates were mixed with sodium sulfate and extracted with hexane.…”

Section: Organochlorine Analysismentioning

confidence: 99%

Organochlorine Pollutants and Stable Isotopes in Resident and Migrant Passerine Birds from Northwest Michoacán, Mexico

Mora

2008

Arch Environ Contam Toxicol

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Although concentrations of organochlorine compounds (OCs) in birds from most of the United States and Canada have decreased over the last 30 years, there is still concern that migrant birds might be exposed to elevated concentrations of OCs during migration in Latin America. The Lerma-Chapala Basin in west-central Mexico is an important migration corridor and wintering area for many species. The objectives of this study were to assess if resident and migrant birds wintering in western Michoacán, Mexico accumulated elevated concentrations of OCs during fall and spring and to determine if the stable isotopes d 15 N, d 13 C, and dD could be used to predict burdens and origins of DDE accumulation. Resident and migrant passerine insectivorous birds were collected during fall and spring (2001)(2002) in northwest Michoacán, near Chapala Lake, Mexico. The carcasses were analyzed for OCs and tail feathers were analyzed for stable isotopes d 15 N, d 13 C, and dD. The OCs detected in more than 50% of the samples were: oxychlordane (79%), p,p'-DDE (100%), p,p 0 -DDT (57%), and total PCBs (100%). p,p 0 -DDE was the OC detected at the highest concentrations, whereas residues of other OCs were near or below detection limits. Overall, there were no significant differences in concentrations of OCs between seasons or between resident and migrant birds. Concentrations of DDE and oxychlordane were somewhat higher in migrant and resident birds during spring than in fall; however, concentrations were significantly different only for oxychlordane. Two resident birds collected in fall and spring had DDE residues [10 lg/g wet weight in carcass. There were no significant differences in d 13 C and d 15 N values among species, between seasons, or between migrant and resident birds. However, dD values were clearly different between species and helped differentiate migrant from resident birds. dD values also were negatively and significantly correlated with DDE concentrations in carcass. Birds with more depleted dD values in feathers tended to have higher DDE concentrations than those with less depleted dD values, suggesting a potential latitudinal accumulation of DDE. Overall, our results suggest that during fall and spring, there is not a significant buildup of persistent OCs in migrant and resident passerine insectivorous birds in northwest Michoacán, Mexico.

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“…We hypothesized that these effects could be associated with high concentrations of DDE; however, swallows from El Paso also had high concentrations of copper and selenium (Mora et al 2006). Swallows are known to be prey of different raptor species (Enderson et al 1982;Mora et al 2007); thus, they could be a significant source of contaminants for their predators. Potential avian prey (insects and passerine birds) of the northern aplomado falcon (Falco femoralis septentrionalis) collected in the Laguna Atascosa National Wildlife Refuge during 1994 had low levels of DDE (mean range 10 to 250 ng/g ww) (Mora et al 1997).…”

Section: Discussionmentioning

confidence: 99%

“…Northern rough-winged swallows (Stelgidopteryx serripennis) from the Big Bend region in 1997 had mean DDE concentrations in carcass of 5140 ng/g ww (Mora et al 2002). Repeated sampling during 2001 also provided low DDE concentrations in potential prey (mostly passerine birds, mean 2 to 216 ng/g ww) of the peregrine falcon in Big Bend National Park (Mora et al 2007).…”

Section: Discussionmentioning

confidence: 99%

Swallows as Indicators of Environmental Pollution of the Rio Grande/Rio Bravo Basin: Are Persistent Organic Pollutants a Concern?

Mora

Sericano

Baxter

2011

Arch Environ Contam Toxicol

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Swallows from two locations in the Rio Grande/Rio Bravo Basin and one reference site located 500 km away were analyzed for organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Of the OC pesticides, only p,p'-DDE was observed at levels of concern (carcass geometric mean range 642 to 8511 ng/g wet weight [ww]). DDE residues in carcass were significantly greater at El Paso than at other locations. PCBs were relatively low compared with locations in the northeastern United States and the Great Lakes. Geometric mean PBDE concentrations ranged from 18 to 258 ng/g ww (280 to 3395 ng/g lipid weight). PBDE congeners 47 and 99 comprised approximately 60% of total PBDEs. Concentrations of DDE measured in swallows from El Paso in 2000 and 2005 are among the highest observed in the last 20 years along the United States-Mexico border. The results from this study indicated that swallows are still being exposed to high concentrations of DDE, which could have adverse effects on reproduction or on predators that feed on swallows.

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Further Assessment of Environmental Contaminants in Avian Prey of the Peregrine Falcon in Big Bend National Park, Texas

Cited by 4 publications

References 21 publications

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

Organochlorine Pollutants and Stable Isotopes in Resident and Migrant Passerine Birds from Northwest Michoacán, Mexico

Swallows as Indicators of Environmental Pollution of the Rio Grande/Rio Bravo Basin: Are Persistent Organic Pollutants a Concern?

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