An experimental approach to the brood reduction hypothesis in Magellanic penguins

Autor:	Melina Barrionuevo, Esteban Frere
Rok vydání:	2017
Předmět:	0106 biological sciences Range (biology) Otras Ciencias Biológicas media_common.quotation_subject Zoology Spheniscus magellanicus 010603 evolutionary biology 01 natural sciences Ciencias Biológicas Brood reduction Abundance (ecology) Magellanic penguin Hatching asynchrony Ecology Evolution Behavior and Systematics media_common Facultative biology Ecology Hatching 010604 marine biology & hydrobiology Fledge biology.organism_classification Nestling survival Brood Animal Science and Zoology Reproduction CIENCIAS NATURALES Y EXACTAS
Zdroj:	Journal of Avian Biology. 48:1077-1086
ISSN:	0908-8857
Popis:	In many bird species, eggs in a brood hatch within days of each other, leading to a size asymmetry detrimental to younger siblings. Hatching asynchrony is often thought of as an adaptive strategy, and the most widely studied hypothesis in relation to this is the ‘brood reduction hypothesis’. This hypothesis states that when food resources are unpredictable, hatching asynchrony will allow the adjustment of the brood size maximizing fledging success and benefitting parents. The Magellanic penguin Spheniscus magellanicus is an appropriate species to test this hypothesis because it has a 2-egg clutch that hatches over a 2-d interval with a broad range of variation (–1 to 4 d), it shows facultative brood reduction, and food abundance between breeding seasons is variable. We performed a manipulative study at Isla Quiroga, Argentina, during three breeding seasons (2010–2012) by forcing broods to hatch synchronously (0 d) or asynchronously (2 or 4 d). Years were categorized based on estimated food abundance. Our study provided mixed results because in the low estimated food abundance year asynchronous broods did not have higher nestling survival than synchronous broods, and the second-hatchling in asynchronous broods did not die more often than those in synchronous broods. On the other hand, younger siblings of 4-d asynchronous broods starved earlier than those of synchronous broods, and 2-d asynchronous broods fledged heavier young than synchronous broods. Asynchronous hatching would seem to benefit reproduction in this species, not with respect to survival, but in terms of the advantages it can accord to nestlings and, in terms of lower costs, for parents raising nestlings. Fil: Barrionuevo, Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina Fil: Frere, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Wildlife Conservation Society; Estados Unidos
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0cca6f5f3edc78d5694bf77d110a1cfd https://doi.org/10.1111/jav.01200 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
Nepřihlášeným uživatelům se plný text nezobrazuje	K zobrazení výsledku je třeba se přihlásit.