Factors Affecting Natal Dispersal by Song Wrens (Cyphorhinus Phaeocephalus): Ecological Constraints and Demography

I studied the reproductive ecology and social organization of a forest-understory bird species, Song Wrens (Cyphorhinus phaeocephalus) of central Panama. First, I documented patterns of nest site selection and components of breeding productivity. I describe nest predation rates, between-brood intervals, timing and length of breeding season, clutch size, and annual rates of production of young. I then compared the components of breeding productivity of Song Wrens to six north-temperate and one Neotropical wren species and made preliminary tests of three hypotheses proposed to explain life-history evolution in tropical birds. Second, I documented patterns of delayed dispersal of Song Wren offspring. Song Wren males typically delay dispersal much longer than do females. Two hypotheses proposed to explain the evolution of delayed dispersal in birds were tested using data from both naturally-occurring and experimentally-created breeding vacancies. Song Wren behavior was not consistent with the predictions of either hypothesis, however. I then estimated dispersal mortality risk for male and female Song Wrens. My estimates revealed that males and females may suffer very different costs of dispersal. While such risks have often been proposed as important in the evolution of dispersal patterns, dispersal mortality risk had not been previously integrated as an explanation of age- and sex-specific biases in dispersal patterns.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Robinson, Tara Rodden

Contributors dc:contributor

• Robinson, Scott K.

• Biology, Ecology

Language dc:language

eng

Identifier

(MiAaPQ)AAI9971178

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85413