[CT Birds] Hawks and Bird Feeders

Dennis Varza dennisvz at optonline.net
Thu Jul 23 19:56:53 EDT 2009

I ran across this paper and thought some might be interested.

It is one of those papers that demonstrate the intuitively obvious.

Dennis Varza


Timothy C. Roth II and Steven L. Lima

Use of Prey Hotspots by an Avian Predator: Purposeful  

American Naturalist 169 (264-273)

The use of space by predators in relation to their prey is a poorly  
understood aspect of predator-prey interactions. Classic therory  
suggests that predators should focus their efforts on areas of  
abundant prey, that is, prey hotspots, wheras game-theory models of  
predator and prey movement suggest that the distribution of predators  
should match that of their prey’s resoureces. If, however prey are  
spatially anchored to one location and these prey have particularly  
strong antipredator response that make them difficult to capture with  
frequent attacks, then predators may be forced to adopt alternative  
movement strategies to hunt behaviorally responsive prey. We examined  
the movement patterns of bird-eating Sharp-shinned Hawks, in an  
attempt to shed light on hotspot use by predators. Our results  
suggest that the hawks. do not focus on prey hotspots such as bird  
feeders but instead maintain much spatial and temporal  
unpredictability in their movements. Hawks seldom revisited the same  
area, and the few frequently used areas were revisited in a manner  
consistent with unpredictable returns, giving prey little additional  
information about risk.

“In fact, during the winter, the most common species included in the  
diet of sharp-shinned hawks are those species most likely to visit  
House Sparrow Northern Cardinal Dark-eyed Junco

Terre Haute Indiana Radio telemetry
40 Sharp-shinned Hawks 58 Feeders

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