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Accueil du site → Master → Etats Unis → 2011 → FACTORS AFFECTING SURVIVAL AND CAUSE-SPECIFIC MORTALITY OF SAIGA CALVES (Saiga tatarica mongolica) IN MONGOLIA

University of Massachusetts Amherst (2011)

FACTORS AFFECTING SURVIVAL AND CAUSE-SPECIFIC MORTALITY OF SAIGA CALVES (Saiga tatarica mongolica) IN MONGOLIA

BAYARBAATAR BUUVEIBAATAR

Titre : FACTORS AFFECTING SURVIVAL AND CAUSE-SPECIFIC MORTALITY OF SAIGA CALVES (Saiga tatarica mongolica) IN MONGOLIA

Auteur : BAYARBAATAR BUUVEIBAATAR

Université de soutenance : University of Massachusetts Amherst

Grade : Master of Science (MS) 2011

Résumé
Factors affecting juvenile survival are poorly known in the world’s most northern antelope, the endangered saiga (Saiga tatarica), yet they are fundamental for understanding what drives population change. For saiga neonates monitored in Sharga Nature Reserve, western Mongolia, during 2008–2010, male and single calves were heavier than females and twins, respectively. However, there was no significant difference in seasonal and annual survival rates between males and females or singletons and twins. Litter size and birth mass varied among years, and there was a negative relationship between these variables. Multiple regression models suggest that summer precipitation in previous years and spring mean temperature explained inter-annual variations in twinning rates, and mortality was highest during summer. Covariates providing the best model fits included year, litter size, and body weight, suggesting that environmental conditions influence twinning rates and body mass may play a key role in neonate survival rate in the first year. We identified 3 sources of mortality by predation : raptors, foxes (red and corsac, Vulpes vulpes and V. corsac), and lynx (Lynx lynx). Most predation was by raptors, such as golden eagles (Aquila chrysaetos) and cinereous vulture (Aegypius monachus). Our results point to both environmental and biotic factors affecting juvenile survival.

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Page publiée le 22 octobre 2016, mise à jour le 19 septembre 2019