Response of vegetation and breeding birds to the removal of cattle on the San Pedro River, Arizona, USA

  • Published source details Krueper D., Bart J. & Rich T.D. (2003) Response of vegetation and breeding birds to the removal of cattle on the San Pedro River, Arizona, USA. Conservation Biology, 17, 607-615.


This study is summarised as evidence for the following.

Action Category

Exclude grazers from semi-natural habitats

Action Link
Bird Conservation
  1. Exclude grazers from semi-natural habitats

    A before-and-after study from 1986-1990 (Krueper et al. 2003) found that more birds were detected in an area of riparian, mesquite and Chihuahuan desert-scrub in Arizona, USA, after the removal of cattle and the onset of a grazing moratorium in 1988 (average of 221 birds detected/km of transect in 1990 vs. 103 birds/km for 1986). Detections increased for 42 species, 26 significantly, and decreased for 19 species, eight significantly.  Only four species in the study showed similar trends in regional Breeding Bird Surveys.  Insectivores, granivores, midstory species, upperstory species and riparian species were most likely to increase, and migrants tended to show greater increases than residents. Chihuahuan desert-scrub species showed the smallest increases and were most likely to decline, possibly because the Chihuahuan scrub changed the least with the grazing moratorium. Surveys were conducted three times a month, every month over the study period.


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