RESUMEN
At many beaver (Castor canadensis) sites at Allegany State Park in New York State, red maple (Acer rubrum) is the only or one of the few tree species left standing at the ponds' edges. The relative palatability of red maple (RM) was studied in three ways. (1) At seven beaver sites, the available and utilized trees were recorded and an electivity index (E) computed. Of 15 tree species, RM ranked second or fourth lowest. (2) In experiment I, RM, sugar maple (A. saccharum, SM), and quaking aspen (Populus tremuloides) logs were presented cafeteria style at 10 colonies. RM was the least preferred. (3) Bark of RM was extracted with solvents. Aspen logs were painted (experiment II) or soaked (experiment III) with this RM extract and presented to beaver cafeteria-style, along with aspen and RM controls. This treatment rendered aspen logs less palatable, indicating that a chemical factor had been transferred.
RESUMEN
White-tailed deer fawns continued to play despite an experimentally induced 33 percent milk shortage. They reduced play by 35 percent and general activity by 9 percent but increased grazing by 62 percent, resulting in virtually complete energetic compensation. This demonstrates the importance of play behavior in a mammal's activity budget.
RESUMEN
Male pronghorn (Antilocapra americana) mark vegetation by rubbing with their subauricular glands. Males respond to scent marks by sniffing, licking, thrashing, and marking. Hand-raised males were confronted with artificial scent marks consisting of whole extract of the subauricular gland or synthesized compounds corresponding to those identified from the extract. Of these, isovaleric acid released the strongest responses.