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Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts

SIMPLE SUMMARY: Rodents in Australia’s central deserts face highly unpredictable climatic conditions, with long dry ‘bust’ periods, when resources are sparse, punctuated by brief ‘boom’ periods, after heavy rainfall, when resources are abundant. We studied the diet of an Australian desert-dwelling r...

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Autores principales: Yip, Stephanie J. S., Dickman, Christopher R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10215460/
https://www.ncbi.nlm.nih.gov/pubmed/37238132
http://dx.doi.org/10.3390/ani13101702
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author Yip, Stephanie J. S.
Dickman, Christopher R.
author_facet Yip, Stephanie J. S.
Dickman, Christopher R.
author_sort Yip, Stephanie J. S.
collection PubMed
description SIMPLE SUMMARY: Rodents in Australia’s central deserts face highly unpredictable climatic conditions, with long dry ‘bust’ periods, when resources are sparse, punctuated by brief ‘boom’ periods, after heavy rainfall, when resources are abundant. We studied the diet of an Australian desert-dwelling rodent species, the sandy inland mouse Pseudomys hermannsburgensis, by watching what animals ate in the field and by analysing the stomach contents of preserved specimens collected opportunistically over 24 years. Both techniques showed that seeds were the most important component of the diet, and that invertebrates and green plant material were also consumed. Although there were no seasonal or sex-based differences in diet, invertebrates were consumed more frequently during bust periods compared to booms, perhaps suggesting that animals switch to invertebrates at times when seeds are scarce. We drew two main conclusions. Firstly, sandy inland mice are omnivorous. This contrasts with a common view that seeds generally are the mainstay of desert rodents but supports some previous research on Australian desert species. Secondly, in environments with unpredictable climatic conditions where food resources are likely to be unreliable, dietary flexibility is important in allowing animals to exploit different food groups as these become available at different times. ABSTRACT: Seeds are commonly viewed as the mainstay of the diet of desert rodents. We describe the diet of a common Australian desert rodent, the sandy inland mouse Pseudomys hermannsburgensis, using direct observations of free-living animals and analysis of the stomach contents of preserved specimens. Direct observations showed that animals forage mostly on the ground surface and eat seeds from a wide range of plant species, as well as invertebrates and occasional green plant material. Stomach content analysis revealed no differences in the presence or absence of these three major food groups between seasons or the sexes. However, invertebrates were more prominent in the diet of mice during prolonged, dry, population ‘bust’ periods compared with post-rain population ‘boom’ periods, with this dietary shift probably reflecting a scarcity of seeds during the busts. The results confirm that seed is an important component of the diet of P. hermannsburgensis, with 92% of stomachs containing seed. The results also support the classification of the species as omnivorous rather than granivorous, with 70% of stomachs containing invertebrates and over half the specimens analysed containing both seeds and invertebrates. We suggest that dietary flexibility is important for rodent persistence in Australia’s climatically unpredictable arid regions.
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spelling pubmed-102154602023-05-27 Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts Yip, Stephanie J. S. Dickman, Christopher R. Animals (Basel) Article SIMPLE SUMMARY: Rodents in Australia’s central deserts face highly unpredictable climatic conditions, with long dry ‘bust’ periods, when resources are sparse, punctuated by brief ‘boom’ periods, after heavy rainfall, when resources are abundant. We studied the diet of an Australian desert-dwelling rodent species, the sandy inland mouse Pseudomys hermannsburgensis, by watching what animals ate in the field and by analysing the stomach contents of preserved specimens collected opportunistically over 24 years. Both techniques showed that seeds were the most important component of the diet, and that invertebrates and green plant material were also consumed. Although there were no seasonal or sex-based differences in diet, invertebrates were consumed more frequently during bust periods compared to booms, perhaps suggesting that animals switch to invertebrates at times when seeds are scarce. We drew two main conclusions. Firstly, sandy inland mice are omnivorous. This contrasts with a common view that seeds generally are the mainstay of desert rodents but supports some previous research on Australian desert species. Secondly, in environments with unpredictable climatic conditions where food resources are likely to be unreliable, dietary flexibility is important in allowing animals to exploit different food groups as these become available at different times. ABSTRACT: Seeds are commonly viewed as the mainstay of the diet of desert rodents. We describe the diet of a common Australian desert rodent, the sandy inland mouse Pseudomys hermannsburgensis, using direct observations of free-living animals and analysis of the stomach contents of preserved specimens. Direct observations showed that animals forage mostly on the ground surface and eat seeds from a wide range of plant species, as well as invertebrates and occasional green plant material. Stomach content analysis revealed no differences in the presence or absence of these three major food groups between seasons or the sexes. However, invertebrates were more prominent in the diet of mice during prolonged, dry, population ‘bust’ periods compared with post-rain population ‘boom’ periods, with this dietary shift probably reflecting a scarcity of seeds during the busts. The results confirm that seed is an important component of the diet of P. hermannsburgensis, with 92% of stomachs containing seed. The results also support the classification of the species as omnivorous rather than granivorous, with 70% of stomachs containing invertebrates and over half the specimens analysed containing both seeds and invertebrates. We suggest that dietary flexibility is important for rodent persistence in Australia’s climatically unpredictable arid regions. MDPI 2023-05-20 /pmc/articles/PMC10215460/ /pubmed/37238132 http://dx.doi.org/10.3390/ani13101702 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Yip, Stephanie J. S.
Dickman, Christopher R.
Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts
title Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts
title_full Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts
title_fullStr Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts
title_full_unstemmed Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts
title_short Foraging and Food Selection in a Desert Rodent: Diet Shifts of the Sandy Inland Mouse between Population Booms and Busts
title_sort foraging and food selection in a desert rodent: diet shifts of the sandy inland mouse between population booms and busts
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10215460/
https://www.ncbi.nlm.nih.gov/pubmed/37238132
http://dx.doi.org/10.3390/ani13101702
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