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Accueil du site → Doctorat → Australie → 2018 → Understanding the characteristics and role of refuges in the persistence of the plains mouse (Pseudomys australis) in arid landscapes

University of Sydney (2018)

Understanding the characteristics and role of refuges in the persistence of the plains mouse (Pseudomys australis) in arid landscapes

Young, Lauren Ivy

Titre : Understanding the characteristics and role of refuges in the persistence of the plains mouse (Pseudomys australis) in arid landscapes

Auteur : Young, Lauren Ivy

Université de soutenance : University of Sydney

Grade : Doctor of Philosophy (PhD) 2018

Résumé
Many desert-swelling small mammals increase in abundance in response to rainfall driven resource pulses and decline as the landscape dries. While the response of species to resource pulses is widely studied, less is known about how they persist through the dry periods. My research focused on drought refuges ; one strategy by which small mammal populations persist throughout the long dry periods. Refuges have a more consistent supply of resources than the surrounding landscape, respite from threatening processes, or a combination of these, and promote the persistence of species through dry periods. I studied the refuge-use of the plains mouse, Pseudomys australis. I aimed to gain insight into the temporal dynamics and spatial ecology of P. australis during a time when populations were confined to refuge habitat, and how resources influence the occurrence of P. australis in the landscape. The capture rate of P. australis was related positively to antecedent rainfall. Density-dependent habitat selection was apparent, whereby P. australis favours areas of cracking clay until densities increase, subsequent to which individuals occupy the stony plain more frequently. Radiotracked P. australis had small short-term home ranges that were entirely within the cracking clay. All individuals had a core area of use, centred on frequently used burrows. Soil cracks were used less frequently than burrows. The occurrence of P. australis in the landscape was consistently and most strongly influenced by the presence of cracks. Food resources were also important, but the strength of influence varied temporally. Species distribution modelling using remotely-sensed mineral indices was useful for mapping the potential occurrence of P. australis. Model predictions corresponded well with the known distribution of P. australis across the study area, and provide a means to focus management efforts to areas where populations have the best chance of persistence when they are most vulnerable.

Mots clés : arid rodent refuge Pseudomys resource irruptive

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Page publiée le 27 décembre 2018