When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought
Arid environments remind one of the punctuated equilibriumtheory 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...
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Academy of Science of South Africa
2009-12-01
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doaj-2fee2c73289d4f03a237790a3348bc2e2021-04-06T13:39:37ZengAcademy of Science of South AfricaSouth African Journal of Science1996-74892009-12-011051/2When to stay, when to go: trade-offs for southern African arid-zone birds in times of droughtW.R.J. DeanP. BarnardM.D. AndersonArid environments remind one of the punctuated equilibriumtheory 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.http://192.168.0.121/index.php/sajs/article/view/10060 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
W.R.J. Dean P. Barnard M.D. Anderson |
spellingShingle |
W.R.J. Dean P. Barnard M.D. Anderson When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought South African Journal of Science |
author_facet |
W.R.J. Dean P. Barnard M.D. Anderson |
author_sort |
W.R.J. Dean |
title |
When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought |
title_short |
When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought |
title_full |
When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought |
title_fullStr |
When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought |
title_full_unstemmed |
When to stay, when to go: trade-offs for southern African arid-zone birds in times of drought |
title_sort |
when to stay, when to go: trade-offs for southern african arid-zone birds in times of drought |
publisher |
Academy of Science of South Africa |
series |
South African Journal of Science |
issn |
1996-7489 |
publishDate |
2009-12-01 |
description |
Arid environments remind one of the punctuated equilibriumtheory 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. |
url |
http://192.168.0.121/index.php/sajs/article/view/10060 |
work_keys_str_mv |
AT wrjdean whentostaywhentogotradeoffsforsouthernafricanaridzonebirdsintimesofdrought AT pbarnard whentostaywhentogotradeoffsforsouthernafricanaridzonebirdsintimesofdrought AT mdanderson whentostaywhentogotradeoffsforsouthernafricanaridzonebirdsintimesofdrought |
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