Response of great horned owls to experimental ‘hot spots’ of snowshoe hare density

  • Published source details Rohner C. & Krebs C.J. (1998) Response of great horned owls to experimental ‘hot spots’ of snowshoe hare density. The Auk, 115, 694-705.


This study is summarised as evidence for the following.

Action Category

Provide supplementary food through the establishment of food populations

Action Link
Bird Conservation
  1. Provide supplementary food through the establishment of food populations

    A replicated, controlled study from 1989-1992 in 3 experimental blocks and 5 control blocks (all 1 km2) within a forest region in the Yukon, Canada (Rohner & Krebs 1998), found that artificially increasing the density of prey did not alter the territorial or social structure of great horned owls Bubo virginianus. Experimental owls on food-enriched territories did not show a difference in home-range size and patchiness of spatial use compared with control owls. However, the distances of owl locations to treatment blocks were significantly closer to experimental centre-points than expected by chance (on average, 0.6 km closer). At a larger scale, no owls vacated their territories to use experimental plots and no owls switched to a nomadic strategy. The authors speculate that territorial behaviour prevents large aggregations of predators at an intermediate spatial scale. Experimental blocks were provided with commercial rabbit chow added weekly all year; snowshoe hare Lepus americanus densities were 2.8-10.3 times higher than in control blocks.


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