The Birds of Sasmeer Township, Retreat

Winterbottom, J. M.

doi:10.1080/00306525.1962.9633434

Cited by 9 publications

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most frequently measured responses by birds in arid regions to above average rainfall or isolated rainfall events are breeding out of season, breeding in large numbers, and increases in clutch size or number of young produced. For example, 'heavy rains' following a five-year drought in the western Karoo stimulated bird breeding activity, with a number of species recorded with eggs and young, and all collected specimens in breeding condition 31 . Similarly, 170 mm of rain between January and March 1985, following a severe drought in the central Karoo, was believed to have stimulated breeding in 27 species of birds 32 .…”

Section: The Influence Of Rainfall On Population Dynamicsmentioning

confidence: 99%

When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought

Dean

Barnard

2009

S. Afr. J. Sci

View full text Add to dashboard Cite

Arid environments remind one of the punctuated equilibrium theory of evolution: they experience long periods of stasis and low productivity, interrupted with episodic rainfall which spurs reproduction and movement. Birds, as highly dispersive organisms, are among the most dramatic indicators of these fluctuations. Here we review birds' two main strategies, residency and nomadism, and the trade-offs faced by individuals in uncertain times. In general, wet years stimulate higher densities of nests (i.e. smaller territories), larger clutch sizes, unseasonal breeding, and at some times of year, higher breeding success. Rainfall above a certain threshold triggers breeding in resident species and an influx of nomadic species which breed and then move on. The environmental cues which trigger nomadism are sometimes poorly understood, but include distant thunderstorms for aquatic species, and perhaps for insectivores. Environmental cues that draw nomadic granivores to areas that have had recent rain are not known.

show abstract

Section: The Influence Of Rainfall On Population Dynamicsmentioning

confidence: 99%