Details

Autor(en) / Beteiligte

• Kemp, Alan C.

Titel

A COMPARISON OF HUNTING BEHAVIOUR BY EACH SEX OF ADULT GREATER KESTRELS FALCO RUPICOLOIDES RESIDENT NEAR PRETORIA, SOUTH AFRICA

Ist Teil von

• Ostrich, 1995-03, Vol.66 (1), p.21-33

Ort / Verlag

Taylor & Francis Group

Erscheinungsjahr

1995

Beschreibungen/Notizen

• Kemp, A. C. 1995. A comparison of hunting behaviour by each sex of adult Greater Kestrels Falco rupicoloides resident near Pretoria, South Africa. Ostrich 66:21-33. During 1975-79,I observed the hunting behaviour of territorial, colour-marked, adult Falco rupicoloides that were resident on grass and croplands near Pretoria, South Africa. I recorded 686 strikes by males and 796 by females. Both sexes mainly hunted from perches or hovers and captured invertebrates <2 g or vertebrates > 10 g. In monthly comparisons, both sexes made more and shorter strikes from perches when moulting and not breeding (December-May). They made more and longer strikes at vertebrate prey during courtship (June-August). When breeding (September-November), hunting success of males was highest when feeding the incubating female. It remained high for both sexes when feeding nestlings and both made more strikes from hovers when breeding, especially females that also increased the number of bouts of hovering preceding a strike. Differences between individuals, in the proportion of perch and hover-hunting and the size of prey, were only significant during courtship and incubation. Overall, both sexes were 98-99 % successful at invertebrates. Males made more strikes than females into tall grasslands (30 % vs 14 %), more from perches (77% vs 49 %), and more (23% vs 6%) but with lower success (31% vs 66 %) at vertebrates due to more misses at birds. Females made more strikes into short grasslands, more at invertebrates, and with more success from hovers (96 % vs 66 %). There were also sexual differences in perch heights and in hunting behaviour at different times of the day. Sexual differences in hunting behaviour may correlate, not only with different sexroles during breeding and reversed size dimorphism, but also with differences in body proportions, hunting habitat, prey selection or hunting time. I propose an epigamic role for energetic pursuit of avian prey and a test of this hypothesis.