TY - JOUR
T1 - Intra- and interspecific variation in vigilance and foraging of two gerbillid rodents, Rhombomys opimus and Psammomys obesus
T2 - The effect of social environment
AU - Tchabovsky, Andrei V.
AU - Popov, Sergei V.
AU - Krasnov, Boris R.
N1 - Funding Information:
We are grateful to Irina Khokhlova and Georgy Shenbrot for assistance in collecting field data. Allan Degen, Daniel Blumstein and two anonymous referees provided valuable comments on the manuscropt. This work was partly funded by the Blaustein Center for Scientific Cooperation at the Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Israel (for A.V.T.), Israel Ministry of Science and Local Council of Mizpe Ramon (for B.R.K.). This is publication no. 118 of the Ramon Science Center.
PY - 2001/1/1
Y1 - 2001/1/1
N2 - We studied time budgets in two closely related and ecologically similar gerbillids to test the effect of group size on vigilance and foraging in adult females. Psammomys obesus is strictly solitary, while Rhombomys opimus is mainly social. We compared time budgets of (1) solitary P. obesus females, (2) solitary R. opimus females and (3) R. opimus females living in male-female pairs. Solitary R. opimus females spent more time underground, more time in low-cost vigilant postures, moved more, hoarded food more and fed above ground less than paired females. However, females of both categories spent similar time in high-cost upright postures. These results conform mainly to the group size effect hypothesis, while the high level of high-cost vigilance in paired females can be attributed to within-group vigilance, masking the group size effect. Solitary females of P. obesus and R. opimus showed similar time budget patterns; however, P. obesus allocated more time to high-cost vigilance and less time to feeding. In general, differences in time budgets between heterospecific females of the same social status (solitary or paired) were less pronounced than differences between conspecifics of different status. Thus, variation in activity patterns of females can be largely explained by different social conditions rather than by species affiliation. We discuss the results in terms of predation avoidance strategies in solitary and social species.
AB - We studied time budgets in two closely related and ecologically similar gerbillids to test the effect of group size on vigilance and foraging in adult females. Psammomys obesus is strictly solitary, while Rhombomys opimus is mainly social. We compared time budgets of (1) solitary P. obesus females, (2) solitary R. opimus females and (3) R. opimus females living in male-female pairs. Solitary R. opimus females spent more time underground, more time in low-cost vigilant postures, moved more, hoarded food more and fed above ground less than paired females. However, females of both categories spent similar time in high-cost upright postures. These results conform mainly to the group size effect hypothesis, while the high level of high-cost vigilance in paired females can be attributed to within-group vigilance, masking the group size effect. Solitary females of P. obesus and R. opimus showed similar time budget patterns; however, P. obesus allocated more time to high-cost vigilance and less time to feeding. In general, differences in time budgets between heterospecific females of the same social status (solitary or paired) were less pronounced than differences between conspecifics of different status. Thus, variation in activity patterns of females can be largely explained by different social conditions rather than by species affiliation. We discuss the results in terms of predation avoidance strategies in solitary and social species.
UR - http://www.scopus.com/inward/record.url?scp=0035668266&partnerID=8YFLogxK
U2 - 10.1006/anbe.2001.1833
DO - 10.1006/anbe.2001.1833
M3 - Article
AN - SCOPUS:0035668266
SN - 0003-3472
VL - 62
SP - 965
EP - 972
JO - Animal Behaviour
JF - Animal Behaviour
IS - 5
ER -