1
|
Bouwman H, Pieters R, Polder A, Quinn L. Ten Bird Species, Six Guilds, Three Habitats, and 59 Chlorinated and Brominated POPs: What do 64 Eggs from the Largest Economic Hub of Southern Africa tell us? ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 81:347-366. [PMID: 34480207 DOI: 10.1007/s00244-021-00882-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/21/2021] [Indexed: 06/13/2023]
Abstract
There is little information on how POPs in eggs of different terrestrial, wetland, and aquatic birds share a large urban and rural landscape relate. We collected and analysed 64 eggs belonging to ten species of six feeding guilds, and compared organic chlorinated pesticide (OCP), polychlorinated biphenyl (PCB), and brominated flame retardants (BFR) residue concentrations and compositions. The eggs were collected in the Gauteng and the northern part of the Free Sate provinces of South Africa, one of the largest economic hubs in Africa. White-breasted Cormorant and African Darter eggs (at the highest trophic level as large aquatic predators) had the highest ΣOCP and ΣPCB concentrations, and Cape Sparrow and Southern Masked Weaver (granivores) eggs had the lowest concentrations, corresponding to the lowest trophic level in our collection. The highest percentage p,p'-DDT were in eggs of the terrestrial insectivore Crowned Lapwing (24%) and the scavenging African Sacred Ibis (17%), and the lowest in African Darter (1.0%) and White-breasted Cormorant (0.9%) eggs, suggesting that recency of DDT releases in a region cannot be gauged by this metric. African Sacred Ibis and Southern Masked Weaver eggs had the highest ΣBFR concentrations, with Crowned Lapwing, Cattle Egret, and White-breasted Cormorant eggs the least. Based on feeding guilds, the mean ΣPOP concentrations increased from granivore, aquatic omnivore, scavenger, terrestrial insectivore, small aquatic predator, to large aquatic predator. Mean ΣPOP concentrations in eggs increased from terrestrial, to wetland, to aquatic habitat birds. Interesting patterns were observed with multivariate analyses. There were no significant regressions between egg size and any summed POP classes. ΣBFR concentrations were not correlated with ΣOCPs or ΣPCBs. Eggshell thinning of African Darter eggs was associated with p,p'-DDE and ΣPCB suggesting risk. Other metrics also suggest risk. Therefore, different species of terrestrial and aquatic birds from the same area acquire and deposit POPs in different proportions and quantities in their eggs. Trophic levels and habitat explain the overall patterns, but detailed differences were found, some of which we are unable to explain. Based on POPs residues in terrestrial, wetland, and aquatic bird eggs, different POPs classes behave differently in a shared large inland industrial area, complicating deductions about POPs and associated risks based on one or few species.
Collapse
Affiliation(s)
- Hindrik Bouwman
- Research Unit, Environmental Sciences and Management, North-West University, Potchefstroom, 2520, South Africa.
| | - R Pieters
- Research Unit, Environmental Sciences and Management, North-West University, Potchefstroom, 2520, South Africa
| | - A Polder
- Research Unit, Environmental Sciences and Management, North-West University, Potchefstroom, 2520, South Africa
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - L Quinn
- National Metrology Institute of South Africa, Pretoria, South Africa
| |
Collapse
|
2
|
Hidalgo CM, Mora MA, Sericano JL, Mutch BD, Juergens PW. Persistent organic pollutants in eggs from south Texas Aplomado falcons. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115685. [PMID: 33011574 DOI: 10.1016/j.envpol.2020.115685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/27/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
A program to reintroduce the Northern Aplomado falcon (Falco femoralis septentrionalis) in south Texas and the southwestern United States was initiated in the late 1970s. Fledgling Aplomado falcons were first released in the Laguna Atascosa National Wildlife Refuge in 1993 and the first nesting pair in the area was recorded by 1995. During 2004-2017 we collected addled eggs from nesting pairs in the Laguna Atascosa National Wildlife Refuge and Matagorda Island in south Texas, to determine if environmental contaminants in Aplomado falcon eggs had decreased over time and if eggshell thickness values were similar to those in the pre-DDT era. We analyzed organochlorine pesticides, PCBs, and PBDEs in 60 egg homogenates by gas chromatography-mass spectrometry. Eggshells were measured to determine thickness and to correlate with contaminant concentrations. Mean concentration in eggs were 244 ng/g ww for p,p'- DDE, 270 ng/g ww for PCBs and 10 ng/g ww for PBDEs. These values were lower than those reported in a previous study for eggs collected between 1999 and 2003, with a mean of 821 ng/g ww for p,p'-DDE and 1228 ng/g ww for total PCBs. Eggshell thickness ranged from 0.206 mm to 0.320 mm (n = 156). Overall, contaminant concentrations in eggs of Aplomado falcons were low, at levels not likely to impact the recovery of the species. Data from this and previous studies indicate that DDE has decreased significantly in eggs of Aplomado falcons over the last 25 years in south Texas. Breeding populations have been steady at over 30 breeding pairs in south Texas since 2011, although they decreased to 24 pairs in 2018 following Hurricane Harvey.
Collapse
Affiliation(s)
- Chelsea M Hidalgo
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, 77843-2258, USA.
| | - Miguel A Mora
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, 77843-2258, USA
| | - Jose L Sericano
- Geochemical and Environmental Research Group, Texas A&M University, College Station, TX, 77845, USA
| | | | | |
Collapse
|
3
|
Miller A, Elliott JE, Wilson LK, Elliott KH, Drouillard KG, Verreault J, Lee S, Idrissi A. Influence of overwinter distribution on exposure to persistent organic pollutants (POPs) in seabirds, ancient murrelets (Synthliboramphus antiquus), breeding on the Pacific coast of Canada. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 259:113842. [PMID: 31926389 DOI: 10.1016/j.envpol.2019.113842] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 12/12/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
Assessing the fate of both legacy and newer persistent organic pollutants (POPs) is an ongoing challenge. Top predators, including seabirds, are effective monitors of POPs because they forage over a range of marine habitats, integrating signals over space and time. However, migration patterns can make unravelling contaminant sources, and potentially assessments of the effectiveness of regulations, challenging if chemicals are acquired at distant sites. In 2014, we fitted geolocators on ancient murrelets (Synthliboramphus antiqueus) at four colonies on the Pacific Coast of Canada to obtain movement data throughout an annual cycle. All birds underwent a post-breeding moult in the Bering Sea. Around one-third then returned to overwinter on the British Columbia (BC) coast while the rest migrated to overwinter in waters along the north Asian coast. Such a stark difference in migration destination provided an opportunity to examine the influence of wintering location on contaminant signals. In summer 2015, we collected blood samples from returned geo-tagged birds and analyzed them for a suite of contaminants, including polybrominated diphenyl ethers (PBDEs), non-PBDE halogenated flame retardants, perfluoroalkyl substances (PFASs), organochlorines, and mercury. Feathers were also collected and analyzed for stable isotopes (δ13C, δ15N, and δ34S). We found no significant differences in blood concentrations of any contaminant between murrelets from the two different overwinter areas, a result that indicates relatively rapid clearance of POPs accumulated during winter. Spatial variation in diet (i.e., δ13C) was associated with both BDE-47 and -99 concentrations. However, individual variation in trophic level had little influence on concentrations of any other examined contaminants. Thus, blood from these murrelets is a good indicator of recent, local contaminants, as most signals appear independent of overwintering location.
Collapse
Affiliation(s)
- Aroha Miller
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Delta, BC, Canada
| | - John E Elliott
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Delta, BC, Canada.
| | - Laurie K Wilson
- Canadian Wildlife Service, Environment and Climate Change Canada, Delta, BC, Canada
| | | | | | - Jonathan Verreault
- Université du Québec à Montréal, P.O. Box 8888, Succursale Centre-ville, Montreal, QC, H3C 3P8, Canada
| | - Sandi Lee
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Delta, BC, Canada
| | - Abde Idrissi
- Ecotoxicology and Wildlife Health Directorate, Environment and Climate Change Canada, Ottawa, ON, Canada
| |
Collapse
|
4
|
Sandoval C, Mora MA, Sericano J, Rech RR. Persistent Organic Pollutants in Livers and Hg in Feathers of Neotropic Cormorants (Phalacrocorax brasilianus) from the Trinity River Watershed (Texas, USA). ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2019; 76:405-413. [PMID: 30623198 DOI: 10.1007/s00244-018-00596-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
The Trinity River (Texas, USA) has been historically known as a polluted river because of its proximity to the Dallas-Fort Worth area and because of known discharges of sewage and agricultural irrigation waters to the river. Surprisingly, there are no studies regarding the presence of legacy contaminants in the river and their impacts to wildlife. The objectives of this study were to determine accumulation and potential impacts of persistent organic pollutants, such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), on Neotropic cormorants (Phalacrocorax brasilianus) nesting along the Trinity River. Adult and first-year cormorants were collected from two sites on the Trinity River Watershed during 2014 and 2015. Tissue sections from liver, spleen, kidneys, and gonads were used for histopathology analysis, and a portion of the liver was analyzed for OCPs, PCBs, and PBDEs. Breast feathers were analyzed for Hg. Surprisingly, all the contaminants were present at low concentrations, p,p'-DDE (2-724 ng/g ww), PCBs (28-851 ng/g ww), PBDEs (1-85 ng/g ww), Hg (1.9-3.4 µg/g dw), and below those that could be associated with adverse effects. Also, histological analysis of liver and kidney samples did not reveal morphologic changes consistent with acute or chronic toxicosis. The majority of the histologic changes were inflammatory and were related to parasitic infestation. Our results suggest that aquatic birds using the Trinity River watershed are not at risk for adverse effects due to the contaminants studied. These results should be useful to wildlife managers regarding concerns over contaminant impacts on wildlife of the Trinity River.
Collapse
Affiliation(s)
- Christopher Sandoval
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA
| | - Miguel A Mora
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA.
| | - Jose Sericano
- Geochemical and Environmental Research Group, Texas A&M University, College Station, TX, USA
| | - Raquel R Rech
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| |
Collapse
|
5
|
Mo L, Zheng X, Sun Y, Yu L, Luo X, Xu X, Qin X, Gao Y, Mai B. Selection of passerine birds as bio-sentinel of persistent organic pollutants in terrestrial environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 633:1237-1244. [PMID: 29758876 DOI: 10.1016/j.scitotenv.2018.03.311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 03/25/2018] [Accepted: 03/25/2018] [Indexed: 06/08/2023]
Abstract
A broad suite of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dichlorodiphenyltrichloroethane (DDT) and its metabolites, were analyzed in pectoral muscle of eight terrestrial passerine bird species from an extensive e-waste recycling site in South China. Concentrations of PCBs, PBDEs, and DDTs in bird samples ranged from 1260-279,000, 121-14,200, and 31-7910ng/g lipid weight, respectively. Insectivorous birds had significantly higher levels of PCBs, PBDEs, and DDTs than those in granivorous birds. Concentrations of POPs in resident insectivorous birds were significantly greater than those in migrant insectivorous birds. PCBs were the predominant pollutants in all bird species from the e-waste site, followed by PBDEs and DDTs, indicating that PCBs were mainly derived from e-wastes. The granivorous birds had higher proportions of hepta-CBs in total PCBs and higher proportions of octa- to deca-BDEs in total PBDEs compared with the insectivorous birds. The various dietary sources, migration behavior, and possible biotransformation were suspected as reasons of the distinct profiles of POPs in different bird species. The δ15N values were significantly and positively correlated with concentrations of POPs in resident insectivorous birds, but not in other passerine bird species, suggesting the influence of trophic levels on bioaccumulation of POPs in resident insectivorous birds. The resident insectivorous birds seem to be promising bio-sentinel of POPs in terrestrial environment around the e-waste sites.
Collapse
Affiliation(s)
- Ling Mo
- Hainan Research Academy of Environmental Sciences, Haikou 510100, China; CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Xiaobo Zheng
- College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
| | - Yuxin Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Lehuan Yu
- School of Biology and Food Engineering, Guangdong University of Education, Guangzhou 510303, China
| | - Xiaojun Luo
- State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Xiangrong Xu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoquan Qin
- College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Yongli Gao
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Equipment Public Service Center, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Bixian Mai
- State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| |
Collapse
|
6
|
Schmitt CJ, Echols KR, Peterman PH, Orazio CE, Grim KC, Tan S, Diggs NE, Marra PP. Correction to: Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 101:294. [PMID: 29971608 DOI: 10.1007/s00128-018-2383-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The original version of this article contained a mistake. Author name in the text citation and reference in section should be Maldonado et al (2016), it was incorrectly spelled as Maldinado et al (2015).
Collapse
Affiliation(s)
- Christopher J Schmitt
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA.
| | - Kathy R Echols
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA
| | - Paul H Peterman
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA
| | - Carl E Orazio
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA
| | - K Christiana Grim
- Center for Species Survival, Smithsonian National Zoological Park, Front Royal, VA, USA
| | - Shirlee Tan
- Center for Species Survival, Smithsonian National Zoological Park, Front Royal, VA, USA
- Public Health Seattle and King County, 401 5th Ave., Seattle, WA, 98104, USA
| | - Nora E Diggs
- Smithsonian Migratory Bird Center, National Zoological Park, 3001 Connecticut Avenue NW, Washington, DC, 20008, USA
| | - Peter P Marra
- Smithsonian Migratory Bird Center, National Zoological Park, 3001 Connecticut Avenue NW, Washington, DC, 20008, USA
| |
Collapse
|
7
|
Schmitt CJ, Echols KR, Peterman PH, Orazio CE, Grim KC, Tan S, Diggs NE, Marra PP. Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 100:741-747. [PMID: 29796875 DOI: 10.1007/s00128-018-2357-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 05/11/2018] [Indexed: 06/08/2023]
Abstract
Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,p'-DDE) was detected in all neighborhoods. p,p'-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (< 0.1 ng/g) in more rural areas; however, p,p'-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,p'-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was < 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor localized contamination.
Collapse
Affiliation(s)
- Christopher J Schmitt
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA.
| | - Kathy R Echols
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA
| | - Paul H Peterman
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA
| | - Carl E Orazio
- Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Road, Columbia, MO, 652011, USA
| | - K Christiana Grim
- Center for Species Survival, Smithsonian National Zoological Park, Front Royal, VA, USA
| | - Shirlee Tan
- Center for Species Survival, Smithsonian National Zoological Park, Front Royal, VA, USA
- Public Health Seattle and King County, 401 5th Ave., Seattle, WA, 98104, USA
| | - Nora E Diggs
- Smithsonian Migratory Bird Center, National Zoological Park, 3001 Connecticut Avenue NW, Washington, DC, 20008, USA
| | - Peter P Marra
- Smithsonian Migratory Bird Center, National Zoological Park, 3001 Connecticut Avenue NW, Washington, DC, 20008, USA
| |
Collapse
|
8
|
Eng ML, Winter V, Elliott JE, MacDougall-Shackleton SA, Williams TD. Embryonic exposure to environmentally relevant concentrations of a brominated flame retardant reduces the size of song-control nuclei in a songbird. Dev Neurobiol 2018; 78:799-806. [PMID: 29786974 DOI: 10.1002/dneu.22604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 04/12/2018] [Accepted: 05/01/2018] [Indexed: 02/28/2024]
Abstract
Environmental contaminants have the potential to act as developmental stressors and impair development of song and the brain of songbirds, but they have been largely unstudied in this context. 2,2',4,4',5-Pentabromodiphenyl ether (BDE-99) is a brominated flame retardant congener that has demonstrated endocrine disrupting effects, and has pervaded the global environment. We assessed the effects of in ovo exposure to environmentally relevant levels of BDE-99 on the neuroanatomy of the song-control system in a model songbird species, the zebra finch (Taeniopygia guttata). Embryos were exposed via egg injection to a vehicle control (DMSO), 10, 100, or 1000 ng BDE-99/g egg on the day the egg was laid. Chicks were raised to sexual maturity to investigate long-term effects of BDE-99 on the adult male brain. Three key song-control nuclei (Area X, HVC, RA) all showed a dose-dependent trend toward decreasing volume as BDE-99 concentration increased, and birds exposed to 1000 ng/g in ovo BDE-99 had significantly smaller song-control nuclei volume compared to control birds. High environmental concentrations of BDE-99 in avian tissues can be within that range and thus could affect development of the song-control system in birds, and potentially other processes. We previously found that BDE-99 exposure during the nestling period had no effect of on the song-control system, although it did have significant effects on some behaviural endpoints. Taken together, these results suggest that exposure to polybrominated diphenyl ether (PBDEs) during critical developmental windows can significantly alter neurological development. © 2018 Wiley Periodicals, Inc. Develop Neurobiol, 2018.
Collapse
Affiliation(s)
- Margaret L Eng
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - Viktoria Winter
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - John E Elliott
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
- Environment and Climate Change Canada, Pacific Wildlife Research Centre, Delta, British Columbia, V4K 3N2, Canada
| | - Scott A MacDougall-Shackleton
- Department of Psychology and Advanced Facility for Avian Research, Western University, London, Ontario, N6A 5C2, Canada
| | - Tony D Williams
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| |
Collapse
|