PARENT SESSION
Oral Session #64: Avian Ecology. Presiding: P. Warren.
Thursday, August 9, 2001. 8:00 AM to 12:00 PM. Hall of Ideas I.
Indirect effects of the chemical properties of plant leaves on tree use among tits.
PARK, CHAN-RYUL1, LEE, WOO-SHIN1, 1
ABSTRACT- This study was conducted to investigate the influence of the chemical properties of plant leaves on the populations and foraging niche of tits (Parus spp.) in a deciduous forest in Korea. Leaf toughness and tannin contents of spicebush (Lindera erythrocarpa) and oak (Quercus serrata) leaves were analyzed for two stands, spicebush-abundant and -nonabundant stands, respectively. Leaf toughness was higher in oak leaves than in spicebush leaves. Tannin content was higher in spicebush leaves than in oak leaves. Although diversity of lepidoptera larvae was higher in oaks (16 spp.) than in spicebush (4 spp.), the dry weight of the larvae was higher in spicebush than oaks. Tits visited oaks more frequently until April. Thirteen more individuals were found in the spicebush-abundant stands than in the spicebush-nonabundant stands. The socially dominant species, Great tit, used the leaves of spicebush with large size larvae more frequently. The results indicate that the differences in chemical properties between the leaves of spicebush and oaks resulted in the difference of dry weight of insects. This caused the differential use of tree species by tits. Also, chemical properties of plant leaves indirectly influenced the population density of tits and the plant use among tits.
KEY WORDS: Indirect effects, Parus species, Spicebush, Foraging niche