Article Title

Diet and Seed Dispersal Efficiency of the Gray Fox (Urocyon cinereoargenteus) in Chaparral





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The frequency of occurrence of prey items in the diet of gray foxes {Urocyon cinereoargenteus) in the chaparral of Southern California was deter- mined from scat analysis. Fruit occurred in 70% of scats (n = 106) analyzed and consisted of coffeeberry (Rhamnus californica), eastwood manzanita (Arctostaph- ylos glandulosa), toyon (Heteromeles arbutifolia), and hollyleaf redberry (Rham- nus illicifolia). Mammalian prey included white-footed mice (Peromyscus sp., 7%), wood rats (Neotoma fuscipes, 4%), and meadow voles (Microtus californi- cus, 1%). Insects, including grasshoppers (Orthoptera, 66%) and Jerusalem crick- ets (Stenopelmatus sp., 54%) composed 14% of prey occurrences. There was only one occurrence of reptilian prey (0.94%), a western fence lizard (Sceloporus oc- cidentalis). Seeds passing through the fox's gut were tested to determine germi- nation period. Coffeeberry and redberry ingested by foxes germinated signifi- cantly sooner than seeds from fresh fruit (p = 0.0005 and 0.03), while toyon germination rates did not differ between fresh and ingested seeds. Days to ger- mination for fresh seeds and seeds from scat averaged 94.6 ± 37.2 and 48.2 ± 25.4 for coffeeberry, 68.9 ± 15.2 and 52.0 ± 8.2 for redberry, and 14.0 ± 2.3 and 22.2 ± 9.0 for toyon.