Foraging behaviour in Alpine ibex (Capra ibex): consequences of reproductive status, body size, age and sex
Abstract
The ibex (Capra ibex) is a mountain ungulate that lives most of the year in sexually segregated groups. With females weighing about half as much as males, ibex are one of the most sexually dimorphic ungulate species. Time budgets and bite rates of different age, sex, and reproductive condition classes as well as of animals in different reproductive condition were compared to evaluate how sexual differences in body size and differences in energetic needs of lactating and non-lactating females affects these measures. Adult males spent more time lying, standing and walking and less time grazing than adult females. Non-lactating females spent more time lying and walking and less time grazing than lactating females. Lactating females took the most bites per minute and adult males the fewest, while non-lactating females showed intermediate bite rates. Lactating females fed less on bushes and more on graminoids than non-lactating females or males. While the mean lengths of activity bouts did not differ between lactating and non-lactating females, males grazed on average for a shorter period of time, stood and walked for longer than adult females. We concluded that differences in body size and in reproductive expenditures lead to differences in behaviour, probably leading to sexual segregation.
- Publication:
-
Ethology Ecology & Evolution
- Pub Date:
- October 2002
- DOI:
- Bibcode:
- 2002EtEcE..14..373N
- Keywords:
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- Alpine ibex;
- Capra ibex;
- feeding ecology;
- bite rates;
- sexual dimorphism;
- cost of reproduction