Do gerbils care more about competition or predation?

We used trained barn owls to introduce a controlled predation threat to two species of gerbil, Gerbillus allenbyi and G. pyramidum in a system of 2-ha, sandy-substrate field enclosures in the Negev Desert, Israel. Using the principles of optimal density-dependent habitat selection, we estimated seve...

Full description

Saved in:

Bibliographic Details
Published in:	Oikos Vol. 83; no. 1; pp. 75 - 84
Main Authors:	Abramsky, Z, Rosenweig, M.L, Subach, A
Format:	Journal Article
Language:	English
Published:	Oxford Munksgaard International Publishers, Ltd 01-10-1998 Blackwell
Subjects:	Animal and plant ecology Animal, plant and microbial ecology Animals Autoecology Biological and medical sciences BIOLOGICAL COMPETITION COMPETENCIA BIOLOGICA COMPETITION BIOLOGIQUE Ecological competition Ecology EXPERIMENTACION EXPERIMENTATION Foraging Fundamental and applied biological sciences. Psychology GERBILLE Gerbillus GERBILS GERBO HABITAT HABITATS HIBOU Interspecific competition Isoclines ISRAEL LECHUZA Mammalia OWLS Population ecology Predation PREDATOR PREY RELATIONS Predators RELACIONES PREDATOR PRESA RELATION PREDATEUR PROIE Vertebrata Asia Israel Costs Rodentia Risk Raptor Vertebrata Mammalia Interspecific competition Intraspecific competition Gerbillus pyramidum Tyto alba Desert Predation Negev Aves Gerbillus allenbyi
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	We used trained barn owls to introduce a controlled predation threat to two species of gerbil, Gerbillus allenbyi and G. pyramidum in a system of 2-ha, sandy-substrate field enclosures in the Negev Desert, Israel. Using the principles of optimal density-dependent habitat selection, we estimated several coefficients of population interaction focusing on G. allenbyi. G. allenbyi exhibits strong intraspecific competition. In the absence of owls, G. pyramidum competes with it (α = - 0.35). We estimated the slope of the G. allenbyi victim isocline to be - 0.60. The competitive effect of G. pyramidum disappeared in the presence of owl, although the intraspecific competition remained. Our results indicated that in the presence of owls, the threat of predation overwhelms the cost of interspecific competition.
Bibliography:	P01 1998021780 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23
ISSN:	0030-1299 1600-0706
DOI:	10.2307/3546548