In a study of almost 16 000 nest records from seven swallow species across the entire Western Hemisphere, clutch sizes decline with relative laying date in each population, but the slope of this decline grows steeper with increasing distance from the equator. Late-laying birds at all latitudes lay clutches of similar sizes, suggesting that latitudinal differences may be driven primarily by earlier-laying birds. Focused comparisons of site-years in North America with qualitatively different food availability indicate that food supply significantly affects mean clutch size but not the clutch size-lay date regression. Other studies on the seasonality of swallow food also indicate that steeper clutch size-lay date declines in the North are not caused by steeper earlier food peaks there. The distribution of lay dates grows increasingly right-skewed with increasing latitude. This variation in lay-date distributions could be due to the predominance of higher quality, early-laying (and large-clutched) individuals among populations at higher latitudes, resulting from latitudinal variation in mortality rates and the intensity of sexual selection. Our results underscore the importance of studying clutch size and lay date in tandem and suggest new research into the causes of their joint geographic variation. © 2014 The Authors.
Documento: | Artículo |
Título: | Latitudinal variation in clutch size-lay date regressions in Tachycineta swallows: Effects of food supply or demography? |
Autor: | Winkler, D.W.; Ringelman, K.M.; Dunn, P.O.; Whittingham, L.; Hussell, D.J.T.; Clark, R.G.; Dawson, R.D.; Johnson, L.S.; Rose, A.; Austin, S.H.; Robinson, W.D.; Lombardo, M.P.; Thorpe, P.A.; Shutler, D.; Robertson, R.J.; Stager, M.; Leonard, M.; Horn, A.G.; Dickinson, J.; Ferretti, V.; Massoni, V.; Bulit, F.; Reboreda, J.C.; Liljesthröm, M.; Quiroga, M.; Rakhimberdiev, E.; Ardia, D.R. |
Filiación: | Dept of Ecology and Evolutionary Biology and Laboratory of Ornithology, Cornell Univ., Ithaca, NY 14853, United States Dept of Ecology and Evolutionary Biology, Cornell Univ., Ithaca, NY 14853, United States Dept of Entomology and Wildlife Ecology, Univ. of Delaware, Newark, DE 19716, United States Dept of Biological Sciences, Univ. of Wisconsin-Milwaukee, Milwaukee, WI 53201, United States Ontario Ministry of Natural Resources, 2140 East Bank Drive, Peterborough, ON K9J 7B8, Canada Environment Canada, 115 Perimeter Road, Saskatoon, SK S7N OX4, Canada Ecosystem Science and Management Program, Univ. of Northern British Columbia, University Way, Prince George, BC V2N 4Z9, Canada Dept of Biological Sciences, Towson Univ., Towson, MD 21252, United States Univ. of Colorado Museum of Natural History, Boulder, CO 80309, United States Dept of Fisheries and Wildlife, Oregon State Univ., 104 Nash Hall, Corvallis, OR 97331, United States Dept of Biology, Grand Valley State Univ., Allendale, MI 49401, United States Dept of Biology, Acadia Univ., Wolfville, NS B4P 2R6, Canada Dept of Biology, Queen's Univ., Kingston, ON K7L 3N6, Canada Dept of Animal Biology, Univ. of illinois, Urbana-Champaign, IL 61820, United States Dept of Biology, Dalhousie Univ., Halifax, NS B3H 4R2, Canada Cornell Laboratory of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, United States Cornell Lab of Ornithology, Ithaca, NY 14850, United States División Ornitología, Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Av. Ángel Gallardo 470, Buenos Aires, C 1405 DJR, Argentina Depto de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Univ. de Buenos Aires, Intendente Güiraldes 2160, Buenos Aires, C 1428 EHA, Argentina Depto de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Univ. de Buenos Aires, Intendente Güiraldes 2160, Buenos Aires, C 1428 EHA, Argentina Depto de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Univ. de Buenos Aires, Intendente Güiraldes 2160, Buenos Aires, C 1428 EHA, Argentina Depto de Ecología y Evolución, Facultad de Ciencias Exactas y Naturales, Univ. de Buenos Aires, Pabellón II, Ciudad Universitaria, Buenos Aires, C 1428 EHA, Argentina Centro Austral de Investigaciones Científicas, CADIC-CONICET, Bernardo Houssay 200, Ushuaia, Tierra del Fuego, V 9410 BFD, Argentina Aquatic Birds Lab, INALI-CONICET-UNL/UADER, Santa Fé, SF 3000, Argentina Dept of Marine Ecology, Royal Netherlands Inst. for Sea Research (NIOZ), PO Box 59, NL-1790 AB, Den Burg, Texel, Netherlands Dept of Vertebrate Zoology, Biological Faculty, Lomonosov Moscow State Univ., RU-119991, Moscow, Russian Federation Dept of Biology, Franklin and Marshall College, Lancaster, PA 17604, United States |
Palabras clave: | clutch size; demography; food availability; food supply; latitudinal gradient; mortality; passerine; regression analysis; sexual selection; Aves; Hirundinidae; Tachycineta |
Año: | 2014 |
Volumen: | 37 |
Número: | 7 |
Página de inicio: | 670 |
Página de fin: | 678 |
DOI: | http://dx.doi.org/10.1111/j.1600-0587.2013.00458.x |
Título revista: | Ecography |
Título revista abreviado: | Ecography |
ISSN: | 09067590 |
CODEN: | ECOGE |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09067590_v37_n7_p670_Winkler |