caa a22 4500 469096667 CHVBK 20180323133033.0 cr unu---uuuuu 170328e19920101xx s 000 0 eng 10.1007/BF00319020 doi (NATIONALLICENCE)springer-10.1007/BF00319020 Numerical and functional response of predators to a long-term decline in mammalian prey at a semi-arid Neotropical site [Elektronische Daten] [F. Jaksié, J. Jiménez, S. Castro, P. Feinsinger] Summary: Occurrence and diet of ten carnivorous predators (four falconiforms, four owls, and two foxes), and population levels of their mammalian prey, were monitored over 45 months at a semi-arid site in north-central Chile. Early in this period, small mammals irrupted and then declined markedly to a density 7% of that at peak. All four falconiforms (Buteo polyosoma, Falco sparverius, Geranoaetus melanoleucus, Parabuteo unicinctus) and one owl (Tyto alba) responded numerically to the decline in mammalian prey by virtually abandoning the study site. The three other owls (Athene cunicularia, Bubo virginianus, Glaucidium nanum) and the two foxes (Pseudalopex culpaeus and P. griseus) remained. With few exceptions, throughout the study predators maintained species-specific preferences among small mammal species regardless of the absolute and proportional abundance of these prev. At no time did the two prey species most responsible for the irruption (the rodents Phyllotis darwini and Akodon olivaceus) occur in predators' diets out of proportion to their estimated relative abundance in the field. Predators were clearly unable to prevent the irruption from occurring. Given the absence of a clear functional response to the most irruptive species, predators seemed unlikely to have been responsible for the observed crash. At present, however, predators may be prolonging the crash and delaying the return of small-mammal populations to typical densities. Springer-Verlag, 1992 Functional response nationallicence Numerical response nationallicence Vertebrate predators nationallicence Mammalian decline nationallicence Chile nationallicence Jaksié F. Departamento de Ecología, Universidad Católica de Chile, Casilla 114-D, Santiago, Chile aut Jiménez J. Departamento de Ecología, Universidad Católica de Chile, Casilla 114-D, Santiago, Chile aut Castro S. Departamento de Ecología, Universidad Católica de Chile, Casilla 114-D, Santiago, Chile aut Feinsinger P. Department of Zoology, University of Florida, 32611, Gainesville, FL, USA aut Oecologia Springer-Verlag 89/1(1992-01-01), 90-101 0029-8549 89:1<90 1992 89 442 https://doi.org/10.1007/BF00319020 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00319020 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Jaksié F. Departamento de Ecología, Universidad Católica de Chile, Casilla 114-D, Santiago, Chile aut NATIONALLICENCE 700 1- Jiménez J. Departamento de Ecología, Universidad Católica de Chile, Casilla 114-D, Santiago, Chile aut NATIONALLICENCE 700 1- Castro S. Departamento de Ecología, Universidad Católica de Chile, Casilla 114-D, Santiago, Chile aut NATIONALLICENCE 700 1- Feinsinger P. Department of Zoology, University of Florida, 32611, Gainesville, FL, USA aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 89/1(1992-01-01), 90-101 0029-8549 89:1<90 1992 89 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer