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Choy ES, Blight LK, Elliott JE, Hobson KA, Zanuttig M, Elliott KH. Stable Mercury Trends Support a Long-Term Diet Shift Away from Marine Foraging in Salish Sea Glaucous-Winged Gulls over the Last Century. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:12097-12105. [PMID: 35946869 DOI: 10.1021/acs.est.1c03760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Marine predators are monitored as indicators of pollution, but such trends can be complicated by variation in diet. Glaucous-winged gulls (Larus glaucescens) have experienced a dietary shift over the past century, from mainly marine to including more terrestrial/freshwater inputs, with unknown impacts on mercury (Hg) trends. We examined 109-year trends in total mercury (THg) and methylmercury (MeHg) concentrations in glaucous-winged gull feathers (1887-1996) from the Salish Sea. Adult flank feathers had higher MeHg concentrations than immature feathers, and males head feathers had higher THg concentrations than females. Overall, we found no evidence of a trend in feather MeHg or THg concentrations over time from 1887 to 1996. In the same individuals, δ15N, δ13C, and δ34S declined over time in gull feathers. In comparison, egg THg concentrations declined from 1970 to 2019 in two species of cormorants, likely reflecting decreases in local Hg sources. We conclude that diet shifts through time may have countered increased Hg deposition from long-range transport in glaucous-winged gulls. The lack of Hg trends over time in glaucous-winged gull feathers provides additional support that these gulls have decreased the amount of marine forage fish in their diet.
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Affiliation(s)
- Emily S Choy
- Department of Natural Resource Sciences, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada
| | - Louise K Blight
- School of Environmental Studies, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
- Procellaria Research & Consulting, Victoria, British Columbia V9A 5C3, Canada
| | - John E Elliott
- Environment and Climate Change Canada, Pacific Wildlife Research Centre, Delta, British Columbia V4K 3N2, Canada
| | - Keith A Hobson
- Department of Biology, University of Western Ontario, London, Ontario N6A5B7, Canada
- Environment and Climate Change Canada, Saskatoon, Saskatchewan S7N 3H5, Canada
| | - Michelle Zanuttig
- National Wildlife Research Centre, Environment and Climate Change Canada, 1125 Colonel By Dr, Ottawa, Ontario K1S 5B6, Canada
| | - Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada
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Cushing JM, Henson SM. Periodic matrix models for seasonal dynamics of structured populations with application to a seabird population. J Math Biol 2018; 77:1689-1720. [PMID: 29397422 DOI: 10.1007/s00285-018-1211-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 01/06/2018] [Indexed: 11/29/2022]
Abstract
For structured populations with an annual breeding season, life-stage interactions and behavioral tactics may occur on a faster time scale than that of population dynamics. Motivated by recent field studies of the effect of rising sea surface temperature (SST) on within-breeding-season behaviors in colonial seabirds, we formulate and analyze a general class of discrete-time matrix models designed to account for changes in behavioral tactics within the breeding season and their dynamic consequences at the population level across breeding seasons. As a specific example, we focus on egg cannibalism and the daily reproductive synchrony observed in seabirds. Using the model, we investigate circumstances under which these life history tactics can be beneficial or non-beneficial at the population level in light of the expected continued rise in SST. Using bifurcation theoretic techniques, we study the nature of non-extinction, seasonal cycles as a function of environmental resource availability as they are created upon destabilization of the extinction state. Of particular interest are backward bifurcations in that they typically create strong Allee effects in population models which, in turn, lead to the benefit of possible (initial condition dependent) survival in adverse environments. We find that positive density effects (component Allee effects) due to increased adult survival from cannibalism and the propensity of females to synchronize daily egg laying can produce a strong Allee effect due to a backward bifurcation.
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Affiliation(s)
- J M Cushing
- Department of Mathematics and Interdisciplinary Program in Applied Mathematics, University of Arizona, 617 N Santa Rita, Tucson, AZ, 84721, USA.
| | - Shandelle M Henson
- Department of Mathematics, Andrews University, 4260 Administration Drive, Berrien Springs, MI, 49104, USA.,Department of Biology, Andrews University, 4280 Administration Drive, Berrien Springs, MI, 49104, USA
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Quinn J, Hamilton D, Hebert C. Fatty acid composition and concentration of alternative food of Semipalmated Sandpipers (Calidris pusilla) in the upper Bay of Fundy, Canada. CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0246] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Semipalmated Sandpipers (Calidris pusilla (L., 1766)) that migrate through the upper Bay of Fundy, Canada, depend on a rich food supply to fuel their continued migration. Although past studies have reported a diet dominated by the amphipod Corophium volutator (Pallas, 1766), an animal rich in n–3 polyunsaturated fatty acids (PUFAs), recent evidence suggests that sandpiper diets are broad. This is beneficial in that it allows Semipalmated Sandpipers to respond to a changing food base, but quality of food is also important. PUFAs are important in providing the energy required by migrating birds and may play a role in migratory preparation. We assessed fatty acid (FA) concentrations and proportions in three common food items. We found that polychaetes should adequately meet the needs of migrating sandpipers in terms of FA composition. Concentrations of FAs in biofilm were low, but proportionally, n–3 PUFAs were well represented, particularly in biofilm collected in Shepody Bay, where it forms a substantial part of the sandpiper diet. Therefore, provided that birds can consume a sufficient volume of biofilm, it is also probably a suitable source of essential FAs. Our results suggest that Semipalmated Sandpipers in the Bay of Fundy can meet their FA needs with a variety of dietary options.
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Affiliation(s)
- J.T. Quinn
- Department of Biology, Mount Allison University, 63B York Street, Sackville, NB E4L 1G7, Canada
| | - D.J. Hamilton
- Department of Biology, Mount Allison University, 63B York Street, Sackville, NB E4L 1G7, Canada
| | - C.E. Hebert
- Environment and Climate Change Canada, Science and Technology Branch, National Wildlife Research Centre, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
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Olin JA, Bergeon Burns CM, Woltmann S, Taylor SS, Stouffer PC, Bam W, Hooper-Bui L, Turner RE. Seaside Sparrows reveal contrasting food web responses to large-scale stressors in coastal Louisiana saltmarshes. Ecosphere 2017. [DOI: 10.1002/ecs2.1878] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Jill A. Olin
- Department of Oceanography and Coastal Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
| | - Christine M. Bergeon Burns
- School of Renewable Natural Resources; Louisiana State University AgCenter; Baton Rouge Louisiana 70803 USA
| | - Stefan Woltmann
- Department of Biology and Center of Excellence for Field Biology; Austin Peay State University; Clarksville Tennessee 37044 USA
| | - Sabrina S. Taylor
- School of Renewable Natural Resources; Louisiana State University AgCenter; Baton Rouge Louisiana 70803 USA
| | - Philip C. Stouffer
- School of Renewable Natural Resources; Louisiana State University AgCenter; Baton Rouge Louisiana 70803 USA
| | - Wokil Bam
- Department of Oceanography and Coastal Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
| | - Linda Hooper-Bui
- Department of Environmental Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
| | - R. Eugene Turner
- Department of Oceanography and Coastal Sciences; Louisiana State University; Baton Rouge Louisiana 70803 USA
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Kitowski I, Indykiewicz P, Wiącek D, Jakubas D. Intra-clutch and inter-colony variability in element concentrations in eggshells of the black-headed gull, Chroicocephalus ridibundus, in northern Poland. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:10341-10353. [PMID: 28275970 PMCID: PMC5389991 DOI: 10.1007/s11356-017-8635-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 02/13/2017] [Indexed: 05/06/2023]
Abstract
Eggshells are good bioindicators of environmental contamination, and therefore, the concentrations of 17 trace elements in 87 eggshells of black-headed gulls, Chroicocephalus ridibundus, were determined in five breeding colonies in an area dominated by farmland in northern Poland. The intra-clutch variability in the eggshell concentrations of heavy metals and other elements was also investigated, and the concentrations of the elements showed the following pattern: Ca > Mg > Sr > Fe > Zn > Al > Cr > Se > Mn > Cu > Pb > As > Ni > Mo = V > Sc > Cd. The concentrations of Fe, Al, and Mn decreased with the order in which the eggs were laid, but Sr concentrations increased. In contrast, the concentration of Cu significantly increased with the laying date. The concentrations of all elements significantly differed among the studied colonies; the highest concentration of eight elements was found in the eggshells from the Kusowo colony, which may have resulted from the intensive use of fertilizers, manure, and slurry in the surrounding agricultural region. The concentrations of Mg, Sr, and Zn in the eggshells from Skoki Duże were higher than those of the other studied colonies, which may have occurred because the gulls were nesting in a functioning gravel pit; soil and the parent rock are natural reservoirs of these elements. The observed element levels indicate that the environment where the black-headed gull eggs were formed, i.e., primarily near the breeding colonies, remains in a relatively unpolluted state, which was reflected by the low levels of Cd, Ni, and Pb and the lack of measurable levels of Hg.
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Affiliation(s)
- Ignacy Kitowski
- State School of Higher Education in Chełm, Pocztowa 54, 22-100, Chełm, Poland.
| | - Piotr Indykiewicz
- Department of Zoology and Landscaping, University of Sciences and Technology, Kordeckiego 20, 85-225, Bydgoszcz, Poland
| | - Dariusz Wiącek
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290, Lublin, Poland
| | - Dariusz Jakubas
- Department of Vertebrate Ecology and Zoology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
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Blight LK, Hobson KA, Kyser TK, Arcese P. Changing gull diet in a changing world: a 150-year stable isotope (δ13C, δ15N) record from feathers collected in the Pacific Northwest of North America. GLOBAL CHANGE BIOLOGY 2015; 21:1497-507. [PMID: 25369474 DOI: 10.1111/gcb.12796] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 09/24/2014] [Indexed: 05/06/2023]
Abstract
The world's oceans have undergone significant ecological changes following European colonial expansion and associated industrialization. Seabirds are useful indicators of marine food web structure and can be used to track multidecadal environmental change, potentially reflecting long-term human impacts. We used stable isotope (δ(13)C, δ(15)N) analysis of feathers from glaucous-winged gulls (Larus glaucescens) in a heavily disturbed region of the northeast Pacific to ask whether diets of this generalist forager changed in response to shifts in food availability over 150 years, and whether any detected change might explain long-term trends in gull abundance. Sampled feathers came from birds collected between 1860 and 2009 at nesting colonies in the Salish Sea, a transboundary marine system adjacent to Washington, USA and British Columbia, Canada. To determine whether temporal trends in stable isotope ratios might simply reflect changes to baseline environmental values, we also analysed muscle tissue from forage fishes collected in the same region over a multidecadal timeframe. Values of δ(13)C and δ(15)N declined since 1860 in both subadult and adult gulls (δ(13)C, ~ 2-6‰; δ(15)N, ~4-5‰), indicating that their diet has become less marine over time, and that birds now feed at a lower trophic level than previously. Conversely, forage fish δ(13)C and δ(15)N values showed no trends, supporting our conclusion that gull feather values were indicative of declines in marine food availability rather than of baseline environmental change. Gradual declines in feather isotope values are consistent with trends predicted had gulls consumed less fish over time, but were equivocal with respect to whether gulls had switched to a more garbage-based diet, or one comprising marine invertebrates. Nevertheless, our results suggest a long-term decrease in diet quality linked to declining fish abundance or other anthropogenic influences, and may help to explain regional population declines in this species and other piscivores.
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Affiliation(s)
- Louise K Blight
- Centre for Applied Conservation Research, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada; Procellaria Research & Consulting, 944 Dunsmuir Road, Victoria, BC, V9A 5C3, Canada
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Climate driven life histories: the case of the Mediterranean storm petrel. PLoS One 2014; 9:e94526. [PMID: 24728099 PMCID: PMC3984163 DOI: 10.1371/journal.pone.0094526] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 03/18/2014] [Indexed: 11/19/2022] Open
Abstract
Seabirds are affected by changes in the marine ecosystem. The influence of climatic factors on marine food webs can be reflected in long-term seabird population changes. We modelled the survival and recruitment of the Mediterranean storm petrel (Hydrobates pelagicus melitensis) using a 21-year mark-recapture dataset involving almost 5000 birds. We demonstrated a strong influence of prebreeding climatic conditions on recruitment age and of rainfall and breeding period conditions on juvenile survival. The results suggest that the juvenile survival rate of the Mediterranean subspecies may not be negatively affected by the predicted features of climate change, i.e., warmer summers and lower rainfall. Based on considerations of winter conditions in different parts of the Mediterranean, we were able to draw inferences about the wintering areas of the species for the first time.
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Winter V, Williams TD, Elliott JE. A three-generational study of In ovo exposure to PBDE-99 in the zebra finch. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:562-568. [PMID: 23258742 DOI: 10.1002/etc.2102] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 08/27/2012] [Accepted: 10/29/2012] [Indexed: 06/01/2023]
Abstract
Based on a literature review of avian data for polybrominated diphenyl ethers (PBDEs), ecologically relevant doses, low (10 ng/egg), medium (100 ng/egg), and high (1,000 ng/egg) of the 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) congener along with dimethylsulfoxide (DMSO) control were injected into the yolk sac of un-incubated eggs of zebra finch, Taeniopygia guttata. Offspring development and adult phenotype were followed over three generations. No effects of in ovo PBDE exposure on hatching success, chick growth, thyroid hormone levels, or hematological traits were measured at sexual maturity (90 d posthatching). However, the authors did detect significant effects of BDE-99 treatment on adult phenotype of in ovo-exposed birds by breeding observations, in which clutch size was significantly smaller in all PBDE-dosed birds (low, medium, and high) compared with controls. A trend was also seen for longer laying intervals in PBDE-dosed birds (13-14 d) compared with control birds (8 d). In addition, a significant effect of PBDE was found on growth of the second-generation offspring of in ovo-treated females; body mass was significantly lower in the high-PBDE dosed birds compared with controls from hatch through to fledging (day 30). The authors found no evidence of effects over the longer term and in successive generations, whether in adult, reproductive phenotype of the second-generation offspring of in ovo-treated birds, or in the growth of their (third-generation) offspring. Their results suggest that egg levels as low as 10 ng/g BDE-99 may affect reproduction in small passerines by reducing clutch size.
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Affiliation(s)
- Viktoria Winter
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
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