Thesis (Ph.D.), Memorial University of Newfoundland, 2000. / Includes bibliographical references.

No description available.

In this thesis my initial goal was to use yellow warblers to examine the effect of paternal care on female mate choice. I first examined whether mate choice based on paternal care could be considered adaptive. Paternal care was variable among males and important to female fitness, but, contrary to a previous report, male chest striping could not be used to predict paternal care. Females did not compensate for reductions of male parental care, which resulted in significantly reduced nestling growth. In chapter two I tested the idea that monogamy in birds is maintained because of the need for biparental care. I reduced the need of strict biparental care by providing pairs at some nests with supplemental food, and found that the main effect of supplemental food was on maternal, not paternal behaviour. The first two chapters suggest that males and females provide for their brood independently from each other, which is in disagreement with current models on the maintenance of biparental care. These models assume that any given factor must affect maternal and paternal care equally for biparental care to be maintained. In Chapter three I showed that the effects of brood size and nestling age on parental care are similar for both sexes. In Chapter four I deal with age-related changes in reproductive success and the possible effects on female mate choice. Age affected the likelihood of breeding in females, but only the time of breeding in males. These changes were accompanied by age-related increases in size in both sexes. These results raise the possibility of age-related increases in parental ability, and female preference for older males.

Thesis (M.A.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 138-144).

Thesis (PH.D.)--Michigan State University. Zoology Ecology, Evolutionay Biology, and Behavior, 2008. / Title from PDF t.p. (viewed on Aug. 11, 2009) Includes bibliographical references (p. 64-72). Also issued in print.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2004. / Includes bibliographical references.

Thesis (Ph.D.) - University of St Andrews, March 2010.

No description available.

These studies examined the effects of altered developmental experience (rearing history) and altered behavioral context (testing environment) on the alarm call responsiveness of maternally naive, incubator-reared bobwhite quail chicks. Experiment 1 assessed alarm call responsiveness in socially-reared, socially-tested hatchlings across the first 96 hours following hatch. No significant age effects were revealed. Hatchlings tested at 24 hours did not differ significantly from birds tested at 48, 72, or 96 hours on the two principle behavioral measures (number of grid crossings and vocalizations per one-minute trials). Experiment 2 assessed whether hatchlings' alarm call responsiveness is at least partially dependent on the availability of cover (i.e., hiding sites) in the testing situation. No significant differences in responding were found in comparisons between hiding sites and social (non-hiding sites) testing conditions. However, behavioral observations did indicate that hatchlings in the hiding site condition utilized the hiding site as an attractor, in that chicks typically huddled and froze around the hiding site structure. Experiment 3 examined the relative effects of individual testing on socially-reared bobwhite quail hatchlings. Results revealed that individually tested hatchlings increased their locomotor activity following initial exposure to the maternal alarm call when compared to socially tested chicks. Vocalizations were significantly reduced in post-alarm call testing from pre-alarm call levels. However, hatchlings tested individually had higher levels of vocal activity when compared to socially tested chicks. In comparison with socially-reared/socially-tested subjects, socially-reared/individually tested subjects were more active following exposure to the maternal alarm call than they were prior to exposure to the call. Results from the three experiments are discussed in terms of species-typical experience and development. It is maintained that species-typical responding to the bobwhite maternal alarm call is partially influenced by social context. An argument for continued polythetic research on behavioral development in avian communication is also made. / Master of Science

Maternal performance of reciprocal two-breed cross cows between Angus, Herefords and Shorthorns was compared in 249 matings over a four year period. These cows were mated to bulls of the same three breeds to produce three-breed and baekcross calvea. Shorthorn x Angus cows (sire breed first) weaned l7.S~ fewer calve. and Hereford x Angus cows 10.31 fewer calves than their respective reciprocal crosses. Thete differencea while large were not statistically significant presumably due to the small numbers involved. There was little difference between Shorthorn x Hereford and Hereford x Shorthorn cows in percentage calf crop_ The calves from Shorthorn x Angua cows were significantly heavier at birth than the calves from their reciprocals. Birth weight differences of calves from the other two sets of rec1proc41 eros. cows were not significantly different. Differences in average daily gain from birth to weaning were highly significant in calves from Angus x Hereford cows over calves from Hereford x Angus cows as well as Shorthorn x Hereford over Hereford x Shorthorn. The third set of reCiprocal crossea, Angus x Shorthorn versus Shorthorn x Hereford, did not show significant differences in average daily gains. / Master of Science