Browsing by Author "Holmern, Tomas"

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    Human habituation reduces hyrax flight initiation distance in Serengeti
    (John Wiley & Sons, Inc., 2019) Mbise, Franco P.; Fredriksen, Kari-Elise; Ranke, Peter S.; Jackson, Craig; Fyumagwa, Robert; Holmern, Tomas; Fossøy, Frode; Røskaft, Eivin
    Many animal populations are exposed to disturbance originating from human ac‐ tivities. In response to human disturbance, certain animals display a variety of po‐ tentially costly behavioural responses, such as increased antipredator behaviour or relocation to new areas. In contrast, other animals seemingly thrive in the presence of humans and benefit from human‐derived resources. Flight initiation distance (FID: the distance between predator and prey when prey starts to flee) is a measure com‐ monly used to assess animals’ tolerance to humans. In this study, we tested how FID changes in relation to human presence in two hyrax species in Serengeti National Park. Hyraxes living on kopjes (rock outcrops) among human settlements showed a significantly shorter FID than hyraxes living on kopjes without human settlements. In addition, we found that hyraxes feeding before the experiment had shorter FID than hyraxes resting or being vigilant, and hyraxes disturbed during the early morn‐ ing had shorter FID than hyraxes disturbed during late morning. We did not find any significant effects of group size or species composition on FID. Our results suggest that hyraxes living in the presence of humans are habituated and are not adversely affected by human settlements
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    Livestock loss caused by predators outside the Serengeti National Park, Tanzania
    (Elsevier Ltd, 2007) Holmern, Tomas; Nyahongo, Julius; Røskaft, Eivin
    Human–carnivore conflict is a serious management issue often causing opposition towards conservation efforts. In a survey of 481 households in seven different villages outside the Serengeti National Park in Tanzania, 67.4% of respondents owned livestock and 27.4% of all the households surveyed reported losses of a total of 4.5% of their livestock to wild predators over 12 months. This loss equated to an average annual financial loss of 19.2% (US $26.8) of their cash income. Livestock depredation was reported to be caused most often by spotted hyena (Crocuta crocuta) (97.7%), leopard (Panthera pardus) (1.6%), baboon (Papio cynocephalus) (0.4%), lion (Panthera leo) (0.1%) and lastly black-backed jackal (Canis mesomelas) (0.1%). Total reported losses during 2003 amounted to US $12,846 of which spotted hyena kills were reported to account for 98.2%. The mean annual livestock loss per household (of those that reported loss) was 5.3 head of stock, which represents more than two-thirds of the local average annual cash income. Depredation by large felids occurred only in a narrow zone along the protected area (<3 km), whereas spotted hyenas killed livestock even in households located far away (>30 km). Tolerance of livestock depredation among the respondents was low. Logistic regression models indicated that education improved tolerance, while for livestock owners higher depredation rates was linked to approval of lethal retaliation and effective protection measures was associated with a reduced desire of retaliation. We recommend that further research should identify the precise causes of livestock loss and which protection measures that can reduce depredation.