An observation of the foraging behavior of a great horned owl (Bubo virginianus) feeding on field crickets (Gryllus)

摘要

The great horned owl (Bubo vi,ginianus) is distributed throughout the Americas and is a major avian predator in many ecosystems (Johnsgard, 1988). Although lagomorphs and other small- to medium-sized mammals compose the majority of the great horned owl's diet, the range of food items taken is very broad and includes birds, reptiles, and amphibians (Schenmitz and Ables, 1962; Johnsgard, 1988; Pulich, 1988; Donazar et al., 1997; Houston et al., 1998). Some authors (Stoner, 1931; Houston et al., 1998) have noted arthropods, including Orthopterans, in the diet of great horned owls; however, little information exists regarding actual foraging behavior of owls in regards to invertebrates. On 14 September 1999, at approximately 2300 h, I observed a great horned owl feeding on the ground beneath a security light in the parking area of Mason Mountain Wildlife Management Area, Mason Co., Texas. The bird was hopping about on the ground and pecking, ignoring 3 observers standing within 50 m. The owl occasionally flew 10 to 15 m to a different location and resumed the behavior. When I approached the bird, it flew to the top of a nearby tree. Upon inspection, I found the feeding site to be teeming with field crickets (Gryllus), apparently attracted to the light. Evidently, the owl had been feeding on the crickets, as no other potential prey species were present. The owl returned to teeding <5 min after I left the feeding site. The owl was still feeding when I departed at approximately 0130 h. I saw the owl in the same location on 2 subsequent nights, but made no lengthy observations of its activity.