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Accueil du site → Master → Etats Unis → 2014 → Body condition and survival of desert bighorn sheep in relation to habitat and precipitation on the Kofa National Wildlife Refuge, Arizona

New Mexico State University (2014)

Body condition and survival of desert bighorn sheep in relation to habitat and precipitation on the Kofa National Wildlife Refuge, Arizona

Overstreet Matthew W

Titre : Body condition and survival of desert bighorn sheep in relation to habitat and precipitation on the Kofa National Wildlife Refuge, Arizona

Auteur : Overstreet Matthew W

Université de soutenance : New Mexico State University

Grade : Master of Science (MS) 2014

Résumé
To assess the influence of potential limiting factors on female desert bighorn sheep (Ovis canadensis mexicana) on the Kofa National Wildlife Refuge (KNWR), I modeled percent body fat of adult females as a function of previous year’s reproductive effort, age class, and forage conditions (i.e., seasonal NDVI and seasonal precipitation). In addition, I assessed the relative influence of the body condition of adult females, precipitation, and forage conditions (NDVI) on number of days a lamb was observed at heel. I assessed the relationship between adult body fat and the previous year’s home range size (95% kernel and 50% core use home range km²). I monitored 34 female sheep from November 2009 to November 2010. I used an information-theoretic approach to evaluate support for my a priori models. Models containing the previous year’s reproductive effort and spring NDVI best approximated my data. The second best model included the previous year’s reproductive effort and spring precipitation. I monitored 41 females from November 2010-2011. The highest-ranking model included the previous year’s reproductive effort and winter NDVI. The second-ranked model include previous year’s reproductive effort, and winter and spring NDVI. Home-range models were evaluated based on east and west sides of the refuge due to an elevation gradient that had the potential to influence forage production for bighorn sheep. Adult females on the west side of the refuge (n = 33) had a positive association between percent body fat and the size of the core areas during spring. Adult females on the east side of the refuge (n = 12) had a negative association between percent body fat and home range and core area size during spring

Mots Clés : Desert bighorn sheep — Health — Arizona — Climatic factors — Nutrition — Kofa National Wildlife Refuge.

Annonce (WorldCat)

Présentation (NMSU Library)

Page publiée le 13 mars 2015, mise à jour le 23 décembre 2019