Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
LITERATURE CITED ASCHOFF, ]., AND H. POHL. 1970. Der Ruheumsatz von Vogeln. als Funktion der Tageszeit und der Korpergrosse. ]. Orn. Berl. 111: 38-47. BARTHOLOMEW, G. A., T. R. HOWELL, AND T. ]. CADE. 1957. Torpidity in the White-throated swift, Anna humming bird, and Poor-Will. Condor 59: 145-155. HELDMAIER, G. 1975. Metabolic and thermoregulatory responses to heat and cold in the D j ungarian hamster, sungorus. ]. comp. Physiol. 102: 115-122. Phodopus LACK, D. 1976. Island Biology. Studies in Ecology, Vol. 3, Blackwell Scientific Publications. LASIEWSKI, R. C. 1963. Oxygen consumption of torpid, resting, active, and flying hummingbirds. Physiol. Zoo!. 122-140. 36: , AND R. ]. LASIEWSKI. 1967. Physiological responses of the Blue-throated and Rivolis hummingbirds. Auk 84: 34-48. --- PEARSON, 0. P. 1950. The metabolism of hummingbirds. Condor 52: 145-152. . 1953. The metabolism of hummingbirds. Scient. Am. 188: 69-72. --- ---. 1954. The daily energy requirements of a wild Anna Hummingbird. Condor 55: 17-20. ScHOLANDER, P. F., R. HOCK, v. WALTERS, F. JOHNSON, AND L. IRVING. 1950. Heat regulation in some arctic and tropical mammals and birds. Biol. Bull. mar. biol. Lab. 99: 23 7-258. WITHERS, P. C. 1977. Respiration, metabolism, and heat exchange of euthermic and torpid Poorwills and hummingbirds. Physiol. Rev. 57: 43-52. WOLF, L. L., AND F. R. HAINSWORTH. 1972. Environmental influence on regulated body temperature in torpid hum mingbirds. Comp. Biochem. Physiol. 4 lA: 167-173. WUNDER, B. A., D. S. D OBKIN, AND R. D. GETTINGER. 1977. ochrogaster). Oecologia 29: 11-26. Shifts of thermogensis in the Prairie vole (Microtus NOTE Protective Coloration of Young Leaves in Certain Malaysian Palms In Malaysia, understory palms play an important role. Some (Calamus, Daemonorops) may eventually leave ( Oncosperma, Orania). Still others remain permanently as comparatively short understory plants (Arenga hookeri, Nenga macrocarpa, Pinanga spp., lguanura geonomaeformis, etc.). Most of the last-mentioned species are unarmed, the understory by climbing; others grow up to assume a position very close to canopy level lacking spines or thorns. I have noticed on many occasions that the young developing leaves of some species of the last category, particularly Iguanura and Pinanga, are dull-colored because of the presence of both an thocyanins and chlorophyll, the reddish and green tints combining to form a dull brown. This color from a distance strikingly mimics the drab color of dying or w ithered dead leaves. Such new leaves fail to show dam age from animal predation (at least in intact environments). For animals which rely on eyesight for the rec ognition of suitable food plants, these palms may apppear unsuitable, being comprised only of "dead" and adult leaves. Is it possible that the young leaf coloration is adaptive in this regard, and therefore that the red pigment is playing at least a dual, perhaps a triple, role-as a lignin precursor, as a photosynthesis enhancer, and as a "dead-leaf color" mimic in conjunction with the green chlorophyll? Benjamin C. Stone Department of Botany University of Malaya Kuala Lumpur, Malaysia ------- ·--------- · ------ 126 Schuchmann and Schmidt-Marich