Preening and Associated Comfort Behavior in Birdsa

Abstract

41seem to be a kind of spare-time activity that is performed whenever there is nothing more important to do.Gulls in the wild, subject as they are to all kinds of selective pressures, spend less time preening than well-provided-for, aviary caged gulls (15070 versus 26% of their time, p < 0.01; own observations).In contexts that make little demand on the animals, and in an undisturbed environment, rhythmicities with periods on the order of several tens of minutes may be predominant in determining the occurrence of preening. 5Over and above these short cycles, a diurnal cycle is often very apparent" (but compare ref.3).It is not certain whether it is directly due to a central circadian rhythm, or secondary to the dark-light cycle.It is well documented that periodic external stimuli such as light pulses can entrain the short-term cyclic occurrence of preening. 7ome preening-related behavior can, however, become strongly stimulus dependent in particular situations.I have observed skylarks to respond forthwith with sunbathing behavior during prolonged cloudy-foggy weather spells whenever the sun managed to break through and to immediately begin with rainbathing behavior during extended hot-dry weather spells whenever it began to drizzle."Deprivation of the opportunity to dustbathe leads to a cumulating increase in the probability that chickens will show this behavior as soon as dust is made available.8 There are also, undoubtedly, events that require immediate preening attention by birds.This might be the case with the more offensive activities of integument parasites,9 disturbances due to feather loss and growth (molting seems to intensify preening in pigeons), and disturbances due to wind gusts or the behavioral activities of the bird itself or those of other birds.Particularly short duration bouts of preening are thought to be primarily elicited by such acute cutaneous, and sometimes visual, stimuli.to This evidence indicates that local somesthetic stimuli may, on the one hand, trigger and direct preening.On the other hand, they are probably not essential for preening to occur and to be structured.Lefebvre and Jolyl1 (see also ref. 5), for example, argue on the basis of a detailed analysis of extensive observational data that the longer preening bouts of kestrels are not initiated by any particular stimulus.They also conclude that