C. Akaki et Ge. Duke, Apparent chitin digestibilities in the Eastern Screech Owl (Otus asio) andthe American Kestrel (Falco sparverius), J EXP ZOOL, 283(4-5), 1999, pp. 387-393
Chitin, which is found in arthropod exoskeletons as a structural and defens
ive material, is one of the most abundant carbohydrates in nature. Chitin d
igestibility was studied in two partially insectivorous raptors, Eastern Sc
reech Owls (Otus asio) and American Kestrels (Falco sparverius). When owls
were fed crab shell chitin (5% or 2% of total dried food, by weight), 10.6
+/- 7.1% (SD) to 30.4 +/- 7.8% was digested (species digestibility means we
re 26.2 +/- 4.4% and 18.6 +/- 6.6%). Kestrels consuming a 5% or 2% chitin d
iet had 15.7 +/- 3.9 to 25.7 +/- 5.3 percent digestibilities. The mean appa
rent digestibilities for kestrels were 18.5 +/- 2.5% and 22.3 +/- 3.0%, res
pectively, for the 5% and 2% chitin diets. In an effort to improve chitin d
igestibilities in owls and kestrels, chitin was added to daily meals for 3
or 6 weeks, but no statistically significant increase in digestibilities wa
s found. Relatively low apparent chitin digestibilities in those two raptor
ial species suggest that chitin is not an important energy source for rapto
rs. Further investigation is required to clarify the magnitude of potential
benefits. J. Exp. Zool. 283:387-393, 1999. (C) 1999 Wiley-Liss, Inc.