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Accueil du site → Master → Etats Unis → 2009 → Diversity and Abundance of the Dark Kangaroo Mouse, Microdipodops megacephalus, in Communities of Nocturnal Granivorous Rodents in Western North America

Brigham Young University (2009)

Diversity and Abundance of the Dark Kangaroo Mouse, Microdipodops megacephalus, in Communities of Nocturnal Granivorous Rodents in Western North America

Haug Ashley S.

Titre : Diversity and Abundance of the Dark Kangaroo Mouse, Microdipodops megacephalus, in Communities of Nocturnal Granivorous Rodents in Western North America

Auteur : Haug Ashley S.

Université de soutenance : Brigham Young University

Grade : Master of Science 2009

Résumé
The dark kangaroo mouse, Microdipodops megacephalus, is a sensitive species in the Great Basin Desert. This thesis explores the structure of desert rodent communities of the Great Basin to better understand M. megacephalus’ place in the community and the conditions that promote large and stable populations. To determine community structure, I used nestedness analysis to evaluate 99 communities of nocturnal granivorous rodents. I found that the community structure was non-random, indicating the existence of assembly rules and ecological constraints. I also found that M. megacephalus was the second most vulnerable species in the community. To explore the correlation between species diversity and relative abundance, I performed regression analyses on M. megacephalus and five commonly co-occurring species of the nocturnal granivore guild : Perognathus longimembris (little pocket mouse), Perognathus parvus (Great Basin pocket mouse), Dipodomys ordii (Ord’s kangaroo rat), Dipodomys microps (chisel-toothed kangaroo rat), and Peromyscus maniculatus (deer mouse). Results showed a positive correlation between rodent species diversity and relative abundance for M. megacephalus, P. longimembris, P. parvus, and D. microps, and a negative correlation for D. ordii and P. maniculatus. To further understand community composition, I ran interspecific association analyses based on presence-absence data for the six species using chi-square to determine strength of interspecific associations. I found positive interspecific associations between M. megacephalus and P. parvus, between P. longimembris and P. parvus, between P. longimembris and D. microps, and between D. microps and P. maniculatus, and a negative association between P. longimembris and P. maniculatus. A species cluster dendogram with respect to sites in common further supports the interspecific association results. A site cluster dendogram with respect to species abundances implies that dune habitat promotes diversity but not uniformity. All results indicate that M. megacephalus is more abundant and stable at sites with high species richness. The results also provide evidence for the existence of assembly rules, competition, and niche partitioning in desert rodent communities.

Mots Clés : Microdipodops megacephalus, nocturnal granivore guild, assembly rules, community structure, nestedness, species diversity, relative abundance, regression, interspecific associations, competition, cluster analyses, conservation, Great Basin Desert

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Page publiée le 9 novembre 2012, mise à jour le 10 novembre 2018