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A comparative study of the breeding behaviour of the Augur Buzzard, <i>Buteo augur</i>, in two different land-use areas in southern Lake Naivasha, Kenya
Abstract
A comparative study of the
breeding behaviour of the Augur Buzzard Buteo augur was made in two
contrasting areas on the southern side of Lake Naivasha, Kenya. Hell's Gate National Park represented a natural site, and the lake environs an agricultural
site. Locations of adult birds and their activity time budget during the
breeding cycle were studied from April to October 1995. Factors influencing
prey delivery and nestling feeding rates, and intra-/inter-specific
interactions were given special attention. Augur Buzzard pairs in the lake
environs spent more time caring for chicks than their counterparts in Hell's
Gate. This was apparent in the increased maternal care and paternal foraging
which resulted in larger broods and more prey deliveries to nests respectively.
Prey and biomass delivery rates to nests showed an increasing trend as the
nestling period progressed. This was significant in the lake environs where
brood sizes were larger than in Hell's Gate. Overall nestling feeding rates
were also significantly greater in the lake environs than in Hell's Gate. Augur
Buzzards in Hell's Gate spent significantly more time interacting with
conspecifics and other species compared to those in the lake environs. We
suggest that reduced predation pressure from conspecifics and other raptors in
the lake environs as a result of lower inter-/intra-specific interactions
enabled Augur Buzzards to maximise provisioning of their young hence
potentially increasing productivity.
Ostrich 2004, 75(1&2): 11–19
breeding behaviour of the Augur Buzzard Buteo augur was made in two
contrasting areas on the southern side of Lake Naivasha, Kenya. Hell's Gate National Park represented a natural site, and the lake environs an agricultural
site. Locations of adult birds and their activity time budget during the
breeding cycle were studied from April to October 1995. Factors influencing
prey delivery and nestling feeding rates, and intra-/inter-specific
interactions were given special attention. Augur Buzzard pairs in the lake
environs spent more time caring for chicks than their counterparts in Hell's
Gate. This was apparent in the increased maternal care and paternal foraging
which resulted in larger broods and more prey deliveries to nests respectively.
Prey and biomass delivery rates to nests showed an increasing trend as the
nestling period progressed. This was significant in the lake environs where
brood sizes were larger than in Hell's Gate. Overall nestling feeding rates
were also significantly greater in the lake environs than in Hell's Gate. Augur
Buzzards in Hell's Gate spent significantly more time interacting with
conspecifics and other species compared to those in the lake environs. We
suggest that reduced predation pressure from conspecifics and other raptors in
the lake environs as a result of lower inter-/intra-specific interactions
enabled Augur Buzzards to maximise provisioning of their young hence
potentially increasing productivity.
Ostrich 2004, 75(1&2): 11–19
