This study investigates the colonization of Barbados, the seasonality of breeding, and the function of breeding plumes in the cattle egret Bubulcus ibis ibis. Colonization occurred around 1956, and the island now has 4 colonies. Numbers of birds at each colony are still increasing. Colonies are evenly spaced around the island. Plumage scores varied seasonally, and males had higher scores than females. Breeding activity peaked in July-August and November-March. Conspecific interference may force poorly plumed birds to breed when environmental conditions are poor. Chick mortality was primarily from starvation during periods of low breeding activity, and primarily from conspecific attack during high breeding activity. Fledging success did not increase with breeding activity. Plumage scores correlated positively in breeding pairs. Well-plumed males fed chicks more often than poorly plumed males and had the higher fledging success. Males contributed more to nest and nestling attendance when their mates were well plumed. Plumes appear to indicate the potential paternal care and the genetic quality of a mate.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.60507 |
| Date | January 1991 |
| Creators | Krebs, Elizabeth Ann |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001256012, proquestno: AAIMM72073, Theses scanned by UMI/ProQuest. |
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