Record Details
Behavioral patterns and their temporal organization in breeding American Avocets
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Behavioral patterns and their temporal organization in breeding American Avocets |
| Names |
Gibson, Flash
(creator) Wiens, John A. (advisor) |
| Date Issued | 1971-05-06 (iso8601) |
| Note | Graduation date: 1971 |
| Abstract | The organization of behavioral activities in time is important to a bird's survival and reproduction. To be successful, either proximately or ultimately, a bird must apportion its behavior in time so that it may obtain sufficient energy for maintenance activities and for such activities as migration and reproduction. The organization of behavioral activities in time can be expressed as a time budget. I have described the action patterns and displays of breeding American Avocets (Recurvirostra americana) and have examined the budgeting of time among these behaviors and its possible adaptiveness. Particular consideration is given to patterns of seasonal, diurnal and sexual variations. The study area was located within an alkaline marsh at Summer Lake, Oregon. The time budget data were collected by recording at 10 sec. intervals the amount of time spent in 12 categories of behavior. During the 1969 breeding season (April-July) 422 hrs. of data were taken on 36 individuals. The breeding season was divided into four stages ; prenesting, incubation, parental care and post breeding. Seasonally, all maintenance activities combined took 67% of the avocet's time, and reproductive activities took 26%. Of all activities, feeding took the largest portion of time (36%). Feeding, because of its close relationship to bioenergetics, is probably one of the most important aspects of the time budget. Through the breeding season energy requirements change, and this is reflected in a seasonal flux in time spent feeding. I suggest that seasonal variation in temperature, activity levels, prey abundance, and such energetically expensive processes as egg production, molting and premigratory fat deposition may determine the amount of time spent foraging. There was little seasonal fluctuation in the amount of time spent in resting, preening, or in aggressive activities. Incubation and caring for the young required similar amounts of time. Diurnally, several categories of behavior, such as feeding, preening and nest building, exhibited morning and afternoon peaks of activity, separated by a period of inactivity at midmorning. This pattern held when all "active" action patterns were combined. I concluded that foraging patterns largely dictate the form of the diurnal activity pattern. The morning feeding peak may be related to a need to feed after the night-long fast, while the afternoon peak is perhaps associated with optimum environmental conditions for feeding, such as maximum insect availability. Avocet males and females exhibited few significant differences in either the seasonal or diurnal time budgets. However, males appeared to be more aggressive while females spent more time incubating. The general similarities of morphology, behavior, and temporal organization of behavior, indicate that the sexes have similar roles in the social system, and may be ecologically similar as well. |
| Genre | Thesis/Dissertation |
| Topic | Avocets |
| Identifier | http://hdl.handle.net/1957/46388 |
