Honors College Theses

Publication Date



Biology (B.A.)

Document Type and Release Option

Thesis (open access)

Faculty Mentor

Aaron Schrey


Many Australian birds, including chestnut-crowned babblers, commonly use cooperative breeding. In these species, individuals may delay or refuse dispersal to provide care to the offspring of the others instead of producing their own. This system challenges natural selection evolution and postulates that reproductively advantage genes will be more favorable. One possibility that contributes to chestnut-crowned babblers’ dispersal behavior is the epigenetic modifications interacting between the genome and the environment during development. Chestnut-crowned babblers (Pomatostomus ruficeps) are usually found in arid and semi-arid zones, which are varied and poor-conditioned. In the undesired conditions, helpers are needed for breeding to occur successfully (Rubenstein and Lovette, 2017). Chestnut-crowned babblers breeding occurs between late winter and early summer. Clutch-size ranged from two to five, and one to five chicks fledged after 21-25 days of provisioning. I use the targeted enzymatic-methyl sequencing to measure DNA methylation on the promoters of specific genes in the genome of chestnut-crowned babblers. I analyze DNA methylation of chestnut-crowned babblers at hatching, before fledging, and adults to predict the pattern of their dispersal behavior. I found a correlation between the number of helpers and DNA methylation. Further, methylation patterns occur more frequently in dispersers than in natal individuals at hatchling and fledging stage; yet, it shows a lower pattern in adult dispersers. However, further work is required to determine whether the number of helpers could help predict the dispersal behaviors in chestnut-crown babblers.