Abstract:

 

Potential access to females is the key factor that influences where and how big of an area subordinate male white rhinos call home

 

Robyn E Khoury, Adrian M Shrader

 

School of Life Sciences, University of KwaZulu Natal, Pietermaritzburg, Private Bag X01, Scottsville, 3209 South Africa

 

As adults, male white rhinos can either hold territories or live as subordinate males. Territory holders are generally in their prime and defend territories to secure access to potential mates. In contrast, subordinate males are either pre- or post- their prime, and are either tolerated within another male’s territory or establish a separate home range. In this study we asked two questions: 1) Where do subordinate males settle within the Ithala Game Reserve? and 2) What influences how large of an area they live within? Using rhino sighting data, we determined the location and size of the annual home ranges of 10 subordinate white rhino males. By using seasonal changes in crude protein of the different habitat types comprising the home ranges, we were able to generate a measure of overall seasonal quality for each home range. In addition, we determined how many female home ranges overlapped each male home range. Finally, we generated a measure of male density surrounding each home range. When we overlaid the subordinate home ranges on the reserve map, we found that subordinates established home ranges throughout the reserve. Of the factors tested, we found that subordinate males preferred to settle in areas with the highest number of females. However, the size of this area was reduced as the density of surrounding males increased. Finally, food quality played a role in that lower crude protein levels during the dry season resulted in larger home ranges.Ultimately, our results suggest that females are the key factor determining where and how big of an area subordinate males settle. This is surprising as only territorial males are supposed to have access to females. However, a recent study indicates that subordinate males can breed with females. Thus, we suggest that a subordinate male’s choice of where to live is likely driven by potential sneaky breeding opportunities.

 

Presentation Topic

 

Potential access to females is the key factor that influences where and how big of an area subordinate male white rhinos call home

 

 

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