Bush selection along foraging pathways by sympatric impala and greater kudu
In order to identify the selection mechanism of two sympatric African browsers, we analysed encounter rates and selection of hushes along foraging pathways. We monitored the tracks, left overnight, by kudu and impala on an experimental plot of natural Acacia nilotica and Dichrostachys cinerea in the highveld of Zimbabwe, and recorded the number of bushes attacked in each category. Both ungulates were selective for the bush categories, but kudu were consistently more selective than impala, and showed a higher preference for the larger A. nilotica and D. cinerea bushes, which had a significantly greater number of bites which were not reachable by impala. For both kudu and impala, the probability of attacking larger bushes increased significantly with the proportion of large bushes encountered along the foraging pathways, whereas the consumption of smaller bushes was apparently unpredictable. For the most abundant food item (medium D. cinerea), the probability of attack by impala along a pathway decreased with increasing proportions of larger bushes in the experimental area, but was also dependent on impala group size and season. In addition, we found that encounter rates with larger bushes were significantly higher for kudu than for impala. Experimentally reducing the availability of the larger bushes had little effect on both impala and kudu during the following rainy season. However, during the following cool dry season, kudu showed an increased selectivity with a strong preference for the remaining large bushes (large A. nilotica), followed by a sharp decrease in selectivity in the hot dry season when they also fed from significant numbers of medium trees. Impala had little reaction to the experimental changes in the availability of bush categories in either season. We suggest that both kudu and impala selected bushes on the basis of the potential number of bites they can provide, and this resulted in different search strategies. Kudu focussed on the larger bushes which have a larger number of twigs which are out of reach of impala and kudu also probably directed their path preferentially towards the few larger bushes to maximize encounter rates with this favoured bush category. These differences in bush selection process lead to a low overlap in resource use between the two browsers in this type of savanna.
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Subjects: | L20 - Écologie animale, compétition animale, alimentation des animaux, parcours, espèce en danger, herbivore, http://aims.fao.org/aos/agrovoc/c_35268, http://aims.fao.org/aos/agrovoc/c_429, http://aims.fao.org/aos/agrovoc/c_6448, http://aims.fao.org/aos/agrovoc/c_2557, http://aims.fao.org/aos/agrovoc/c_3567, |
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dig-cirad-fr-5355182024-01-28T14:57:12Z http://agritrop.cirad.fr/535518/ http://agritrop.cirad.fr/535518/ Bush selection along foraging pathways by sympatric impala and greater kudu. De Garine-Wichatitsky Michel, Fritz Hervé, Gordon Iain J., Illius Andrew W.. 2004. Oecologia, 141 (1) : 66-75.https://doi.org/10.1007/s00442-004-1630-3 <https://doi.org/10.1007/s00442-004-1630-3> Bush selection along foraging pathways by sympatric impala and greater kudu De Garine-Wichatitsky, Michel Fritz, Hervé Gordon, Iain J. Illius, Andrew W. eng 2004 Oecologia L20 - Écologie animale compétition animale alimentation des animaux parcours espèce en danger herbivore http://aims.fao.org/aos/agrovoc/c_35268 http://aims.fao.org/aos/agrovoc/c_429 http://aims.fao.org/aos/agrovoc/c_6448 http://aims.fao.org/aos/agrovoc/c_2557 http://aims.fao.org/aos/agrovoc/c_3567 In order to identify the selection mechanism of two sympatric African browsers, we analysed encounter rates and selection of hushes along foraging pathways. We monitored the tracks, left overnight, by kudu and impala on an experimental plot of natural Acacia nilotica and Dichrostachys cinerea in the highveld of Zimbabwe, and recorded the number of bushes attacked in each category. Both ungulates were selective for the bush categories, but kudu were consistently more selective than impala, and showed a higher preference for the larger A. nilotica and D. cinerea bushes, which had a significantly greater number of bites which were not reachable by impala. For both kudu and impala, the probability of attacking larger bushes increased significantly with the proportion of large bushes encountered along the foraging pathways, whereas the consumption of smaller bushes was apparently unpredictable. For the most abundant food item (medium D. cinerea), the probability of attack by impala along a pathway decreased with increasing proportions of larger bushes in the experimental area, but was also dependent on impala group size and season. In addition, we found that encounter rates with larger bushes were significantly higher for kudu than for impala. Experimentally reducing the availability of the larger bushes had little effect on both impala and kudu during the following rainy season. However, during the following cool dry season, kudu showed an increased selectivity with a strong preference for the remaining large bushes (large A. nilotica), followed by a sharp decrease in selectivity in the hot dry season when they also fed from significant numbers of medium trees. Impala had little reaction to the experimental changes in the availability of bush categories in either season. We suggest that both kudu and impala selected bushes on the basis of the potential number of bites they can provide, and this resulted in different search strategies. Kudu focussed on the larger bushes which have a larger number of twigs which are out of reach of impala and kudu also probably directed their path preferentially towards the few larger bushes to maximize encounter rates with this favoured bush category. These differences in bush selection process lead to a low overlap in resource use between the two browsers in this type of savanna. article info:eu-repo/semantics/article Journal Article info:eu-repo/semantics/publishedVersion http://agritrop.cirad.fr/535518/1/document_535518.pdf application/pdf Cirad license info:eu-repo/semantics/restrictedAccess https://agritrop.cirad.fr/mention_legale.html https://doi.org/10.1007/s00442-004-1630-3 10.1007/s00442-004-1630-3 http://catalogue-bibliotheques.cirad.fr/cgi-bin/koha/opac-detail.pl?biblionumber=194308 info:eu-repo/semantics/altIdentifier/doi/10.1007/s00442-004-1630-3 info:eu-repo/semantics/altIdentifier/purl/https://doi.org/10.1007/s00442-004-1630-3 |
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L20 - Écologie animale compétition animale alimentation des animaux parcours espèce en danger herbivore http://aims.fao.org/aos/agrovoc/c_35268 http://aims.fao.org/aos/agrovoc/c_429 http://aims.fao.org/aos/agrovoc/c_6448 http://aims.fao.org/aos/agrovoc/c_2557 http://aims.fao.org/aos/agrovoc/c_3567 L20 - Écologie animale compétition animale alimentation des animaux parcours espèce en danger herbivore http://aims.fao.org/aos/agrovoc/c_35268 http://aims.fao.org/aos/agrovoc/c_429 http://aims.fao.org/aos/agrovoc/c_6448 http://aims.fao.org/aos/agrovoc/c_2557 http://aims.fao.org/aos/agrovoc/c_3567 |
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L20 - Écologie animale compétition animale alimentation des animaux parcours espèce en danger herbivore http://aims.fao.org/aos/agrovoc/c_35268 http://aims.fao.org/aos/agrovoc/c_429 http://aims.fao.org/aos/agrovoc/c_6448 http://aims.fao.org/aos/agrovoc/c_2557 http://aims.fao.org/aos/agrovoc/c_3567 L20 - Écologie animale compétition animale alimentation des animaux parcours espèce en danger herbivore http://aims.fao.org/aos/agrovoc/c_35268 http://aims.fao.org/aos/agrovoc/c_429 http://aims.fao.org/aos/agrovoc/c_6448 http://aims.fao.org/aos/agrovoc/c_2557 http://aims.fao.org/aos/agrovoc/c_3567 De Garine-Wichatitsky, Michel Fritz, Hervé Gordon, Iain J. Illius, Andrew W. Bush selection along foraging pathways by sympatric impala and greater kudu |
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In order to identify the selection mechanism of two sympatric African browsers, we analysed encounter rates and selection of hushes along foraging pathways. We monitored the tracks, left overnight, by kudu and impala on an experimental plot of natural Acacia nilotica and Dichrostachys cinerea in the highveld of Zimbabwe, and recorded the number of bushes attacked in each category. Both ungulates were selective for the bush categories, but kudu were consistently more selective than impala, and showed a higher preference for the larger A. nilotica and D. cinerea bushes, which had a significantly greater number of bites which were not reachable by impala. For both kudu and impala, the probability of attacking larger bushes increased significantly with the proportion of large bushes encountered along the foraging pathways, whereas the consumption of smaller bushes was apparently unpredictable. For the most abundant food item (medium D. cinerea), the probability of attack by impala along a pathway decreased with increasing proportions of larger bushes in the experimental area, but was also dependent on impala group size and season. In addition, we found that encounter rates with larger bushes were significantly higher for kudu than for impala. Experimentally reducing the availability of the larger bushes had little effect on both impala and kudu during the following rainy season. However, during the following cool dry season, kudu showed an increased selectivity with a strong preference for the remaining large bushes (large A. nilotica), followed by a sharp decrease in selectivity in the hot dry season when they also fed from significant numbers of medium trees. Impala had little reaction to the experimental changes in the availability of bush categories in either season. We suggest that both kudu and impala selected bushes on the basis of the potential number of bites they can provide, and this resulted in different search strategies. Kudu focussed on the larger bushes which have a larger number of twigs which are out of reach of impala and kudu also probably directed their path preferentially towards the few larger bushes to maximize encounter rates with this favoured bush category. These differences in bush selection process lead to a low overlap in resource use between the two browsers in this type of savanna. |
format |
article |
topic_facet |
L20 - Écologie animale compétition animale alimentation des animaux parcours espèce en danger herbivore http://aims.fao.org/aos/agrovoc/c_35268 http://aims.fao.org/aos/agrovoc/c_429 http://aims.fao.org/aos/agrovoc/c_6448 http://aims.fao.org/aos/agrovoc/c_2557 http://aims.fao.org/aos/agrovoc/c_3567 |
author |
De Garine-Wichatitsky, Michel Fritz, Hervé Gordon, Iain J. Illius, Andrew W. |
author_facet |
De Garine-Wichatitsky, Michel Fritz, Hervé Gordon, Iain J. Illius, Andrew W. |
author_sort |
De Garine-Wichatitsky, Michel |
title |
Bush selection along foraging pathways by sympatric impala and greater kudu |
title_short |
Bush selection along foraging pathways by sympatric impala and greater kudu |
title_full |
Bush selection along foraging pathways by sympatric impala and greater kudu |
title_fullStr |
Bush selection along foraging pathways by sympatric impala and greater kudu |
title_full_unstemmed |
Bush selection along foraging pathways by sympatric impala and greater kudu |
title_sort |
bush selection along foraging pathways by sympatric impala and greater kudu |
url |
http://agritrop.cirad.fr/535518/ http://agritrop.cirad.fr/535518/1/document_535518.pdf |
work_keys_str_mv |
AT degarinewichatitskymichel bushselectionalongforagingpathwaysbysympatricimpalaandgreaterkudu AT fritzherve bushselectionalongforagingpathwaysbysympatricimpalaandgreaterkudu AT gordoniainj bushselectionalongforagingpathwaysbysympatricimpalaandgreaterkudu AT illiusandreww bushselectionalongforagingpathwaysbysympatricimpalaandgreaterkudu |
_version_ |
1792496581069504512 |