Seasonal micro-migration in a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands
Open accessAbstract
The extent to which seasonal changes in food availability affect small-scale movements in free-ranging populations of birds of prey is relatively little studied. Here we describe a seasonal “micro-migration” of a farm-island population of striated caracaras ( Phalcoboenus australis ) in the Falkland Islands in response to seasonal changes in the availability of seabird carcasses. We banded more than 450 individuals on Saunders Island, deployed archival and satellite GPS data loggers on 17 individuals, and monitored movements within and between two feeding areas on Saunders Island, a “marine-subsidized” site near seabird colonies and an anthropogenic “human-subsidized” farm site 16 km to the southeast. During 67 observation days between 2010 and 2015, resightings of 312 banded caracaras were greater at the marine-subsidized site during austral summer than winter, and the total daily resightings varied significantly between spring versus summer, summer versus winter, autumn versus spring, and autumn versus winter. Resightings were higher at the human-subsidized site in austral winter than summer and the total daily resightings varied significantly across all bi-seasonal comparisons. Resightings indicated that at least 12 of 197 birds (6.1%) moved between the human- and marine-subsidized sites at least once during the same winter, 15 of 335 birds (4.5%) did so in spring, none of 164 birds did so in summer, and 16 of 297 birds (5.4%) did so in autumn. Individuals fitted with archival GPS data loggers at the marine-subsidized site in summer maintained highly localized 95% kernel core areas (0.55 ± 0.12 km 2 [mean ± SD]), whereas those at the human-subsidized site in winter maintained larger 95% kernel core areas (3.8 ± 4.6 km 2 ). Two of 6 satellite-tagged individuals that summered at known caracara breeding colonies 80 km WNW of Saunders Island were subsequently resighted in winter at the human-subsidized site. Our results suggest that seasonal shifts in food resource availability drive seasonal micro-migrations in a farm-island population of striated caracaras, and that farm sites can be critical in providing nutritional resources for caracaras when naturally occurring marine-subsidized resources become less available. Our results have important implications for striated caracara spatial ecology and conservation, as increased winter survival could improve the status of this globally Near-Threatened population.
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During austral winter, caracaras' diets include native upland geese, feces and carrion of resident southern fur seals, southern sea lions, and gentoo penguins, as well as beetles and subsidies provided by farms.
“During austral winter, when most seabirds migrate offshore, caracaras' diets include native upland geese (Chloephaga picta), the feces and carrion of resident southern fur seals (Arctocephalus australis), southern sea lions (Mirounga leonina) and gentoo penguins (Pygoscelis papua), as well as beetles and subsidies provided by farms [17,28,31].”
From Seasonal activity levels of a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands (2020) · cites this paper as [17]
The Discussion (page not provided) describes winter use of farm scraps and upland-goose carcasses, and the Background says some caracaras switch to invertebrates. But the Discussion places reliance on pinniped feces and carcasses historically, while the study-area passage mentions gentoo penguins in summer; the copy does not establish beetles or the named mammals and penguins as current winter foods. (LLM, conf=0.88)
Experimental — accuracy not yet measuredIt was not possible to trap at both sites during the same season because the birds seasonally migrate between the two sites.
“It was not possible to trap at both sites during the same season, because the birds seasonally migrate between the two sites [17].”
From Seasonal activity levels of a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands (2020) · cites this paper as [17]
The Results (page unavailable) show seasonal movement between the farm and seabird-colony sites, with more resightings at the colonies in summer and at the farm in winter. The paper does not say that trapping at both sites in the same season was impossible because of that movement; its Methods describe surveys at both sites in each season. (LLM, conf=0.85)
Experimental — accuracy not yet measuredThe seasonal daily ranges measured in this study were comparable to the multiday ranges reported in Harrington et al. (2018).
“Notably, the seasonal daily ranges we measured were comparable to the multiday ranges reported in Harrington et al. (2018), which tracked 6 birds with GPS dataloggers over 5-20 days during December 2010 and 5 birds over 3-9 days during July-August 2012 and 2017.”
From Seasonal activity levels of a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands (2020) · cites this paper as Harrington et al. (2018)
During austral winter, most seabirds migrate offshore.
“During austral winter, when most seabirds migrate offshore, caracaras' diets include native upland geese (Chloephaga picta), the feces and carrion of resident southern fur seals (Arctocephalus australis), southern sea lions (Mirounga leonina) and gentoo penguins (Pygoscelis papua), as well as beetles and subsidies provided by farms [17,28,31].”
From Seasonal activity levels of a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands (2020) · cites this paper as [17]
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Cites
Density Estimation for Statistics and Data Analysis
Silverman, B. W. (2018) · Routledge eBooks · doi:10.1201/9781315140919 · Cited by 15,938 · see citing works
Density Estimation for Statistics and Data Analysis
(1986) · Springer eBooks · doi:10.1007/978-1-4899-3324-9 · Cited by 8,478 · see citing works
Optimal foraging, the marginal value theorem
Charnov, E. L. (1976) · Theoretical Population Biology · doi:10.1016/0040-5809(76)90040-x · Cited by 5,374 · see citing works
A movement ecology paradigm for unifying organismal movement research
Nathan, R., Getz, W. M., Revilla, E., Holyoak, M., Kadmon, R., Saltz, D., & Smouse, P. E. (2008) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0800375105 · Cited by 2,979 · see citing works
Handbook of the Birds of the World
del Hoyo, J., Elliott, A., Vicens, J. S. I., & Christie, D. G. S. (2010) · Medical Entomology and Zoology · Cited by 2,893 · see citing works
Polis, G. A., Anderson, W. B., & Holt, R. D. (1997) · Annual Review of Ecology and Systematics · doi:10.1146/annurev.ecolsys.28.1.289 · Cited by 2,364 · see citing works
Dingle, H., & Drake, V. A. (2007) · BioScience · doi:10.1641/b570206 · Cited by 1,176 · see citing works
Migration: the biology of life on the move
(2015) · Choice Reviews Online · doi:10.5860/choice.187908 · Cited by 959 · see citing works
Polis, G. A., & Hurd, S. D. (1996) · The American Naturalist · doi:10.1086/285858 · Cited by 832 · see citing works
Bird Migration: A General Survey
(2002) · The Auk · doi:10.1642/0004-8038(2002)119[0874:bmags]2.0.co;2 · Cited by 661 · see citing works
Berthold, P. R. (2001) · doi:10.1093/oso/9780198507864.001.0001 · Cited by 596 · see citing works
SEARCH STRATEGIES FOR LANDSCAPE-LEVEL INTERPATCH MOVEMENTS
Zollner, P. A., & Lima, S. L. (1999) · Ecology · doi:10.1890/0012-9658(1999)080[1019:ssflli]2.0.co;2 · Cited by 469 · see citing works
Dingle, H. (2014) · doi:10.1093/acprof:oso/9780199640386.001.0001 · Cited by 457 · see citing works
THE DISTRIBUTION AND ABUNDANCE OF COYOTES: THE EFFECTS OF ALLOCHTHONOUS FOOD SUBSIDIES FROM THE SEA
Rose, M. D., & Polis, G. A. (1998) · Ecology · doi:10.1890/0012-9658(1998)079[0998:tdaaoc]2.0.co;2 · Cited by 259 · see citing works
Cagnacci, F., Focardi, S., Heurich, M., Stache, A., Hewison, A. J. M., Morellet, N., Kjellander, P., Linnell, J. D. C., Mysterud, A., Neteler, M., et al. (2011) · Oikos · doi:10.1111/j.1600-0706.2011.19441.x · Cited by 250 · see citing works
Gilbert, N. I., Correia, R. A., Silva, J. P., Pacheco, C., Catry, I., Atkinson, P. W., Gill, J. A., & Franco, A. M. A. (2016) · Movement Ecology · doi:10.1186/s40462-016-0070-0 · Cited by 217 · see citing works
Monsarrat, S., Benhamou, S., Sarrazin, F., Bessa‐Gomes, C., Bouten, W., & Duriez, O. (2013) · PLoS ONE · doi:10.1371/journal.pone.0053077 · Cited by 206 · see citing works
Migrating raptors of the world: their ecology and conservation
(2007) · Choice Reviews Online · doi:10.5860/choice.44-3867 · Cited by 196 · see citing works
Ball, J. P., Nordengren, C., & Wallin, K. (2001) · Wildlife Biology · doi:10.2981/wlb.2001.007 · Cited by 191 · see citing works
Optimal Foraging on Arbitrary Food Distributions and the Definition of Habitat Patches
Arditi, R., & Dacorogna, B. (1988) · The American Naturalist · doi:10.1086/284825 · Cited by 143 · see citing works
Effects of Radiomarking on Prairie Falcons: Attachment Failures Provide Insights About Survival
Steenhof, K., Bates, K. K., Fuller, M. R., et al. (2006) · Wildlife Society Bulletin · doi:10.2193/0091-7648(2006)34[116:eoropf]2.0.co;2 · Cited by 94 · see citing works
Obligate versus rich patch opportunism: Evolution and endocrine mechanisms
Cornelius, J. M., Watts, H. E., Dingle, H., et al. (2013) · General and Comparative Endocrinology · doi:10.1016/j.ygcen.2013.04.003 · Cited by 39 · see citing works
Catry, P., Lecoq, M., & Strange, I. J. (2008) · Polar Biology · doi:10.1007/s00300-008-0454-8 · Cited by 38 · see citing works
Migrating Raptors of the World: Their Ecology and Conservation
Martell, M. S. (2007) · Ornithological Applications · doi:10.1650/0010-5422(2007)109[481:mrotwt]2.0.co;2 · Cited by 34 · see citing works
Rexer-Huber, K., & Bildstein, K. L. (2013) · Polar Biology · doi:10.1007/s00300-012-1266-4 · Cited by 28 · see citing works
Self-citationBildstein, K. L. (2017) · Cornell University Press eBooks · doi:10.7591/9781501707865 · Cited by 23 · see citing works
Self-citationSocial Hierarchy of Scavenging Raptors on the Falkland Islands, Malvinas
Dwyer, J. F., & Cockwell, S. G. (2011) · Journal of Raptor Research · doi:10.3356/jrr-10-75.1 · Cited by 21 · see citing works
Raptors: The Curious Nature of Diurnal Birds of Prey
Bildstein, K. L. (2017) · Project Muse (Johns Hopkins University) · Cited by 13 · see citing works
Self-citationMarín, M., Kusch, A., Oehler, D. A., et al. (2006) · Anales del Instituto de la Patagonia · Cited by 9 · see citing works
Ordeal by Ice: Ships of the Antarctic
Bryan, R. B. (2011) · Cited by 5 · see citing works
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Research works printed but not linked: 1
- [28]Williams T The penguins 1995 Oxford Oxford University Press
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Harrington, K. J., Fahlbusch, J. A., Langrock, R., Therrien, J.-F., Houtz, J. L., & McDonald, B. I. (2020) · Animal Biotelemetry · doi:10.1186/s40317-020-00214-y · Cited by 7 · see citing works
Self-citation
- Authors
- Harrington, K. J., Pole-Evans, S., Reeves, M., Bechard, M., Bobowski, M., Barber, D. R., Rexer-Huber, K., Lecomte, N., & Bildstein, K. L.
- Affiliations
- Hawk Mountain Sanctuary (US)
- Falklands Conservation (GB)
- Boise State University (US)
- Université de Moncton (CA)
- Corresponding author
- Harrington, Katie J.
- Venue
- Movement Ecology
- Published
- 2018-03-30
- Volume
- 6
- Issue
- 1
- Pages
- 4-4
- ISSN
- 2051-3933 (ISSN-L)
- PMC
- PMC5878424
- OpenAlex
- W2795015964
- Cited by
- 13
- References
- 30
- Citations by year
- 2026: 1 · 2025: 3 · 2024: 2 · 2023: 1 · 2021: 2 · 2020: 2 · 2019: 2
- FWCI
- 1.13
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Movement Ecology (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Funders
- Hawk Mountain Sanctuary Association
- Topics
- Physical Sciences › Environmental Science › Ecology › Avian ecology and behavior
- Physical Sciences › Environmental Science › Ecology › Animal Ecology and Behavior Studies
- Physical Sciences › Environmental Science › Ecology › Wildlife Ecology and Conservation
- Keywords
- food availability, home range size, GPS tracking, satellite telemetry, Falkland Islands, anthropogenic food
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