Cavity Nest Webs as a Template for Studying Non-trophic Interactions in Invasion Ecology

Authors

Joshua M. DiamondFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Earth Systems Science

First Advisor's Name

Michael S. Ross

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Joel T. Heinen

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Hong Liu

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Philip K. Stoddard

Fourth Advisor's Committee Title

Committee member

Keywords

Biodiversity, Ornithology, Other Forestry and Forest Sciences, Terrestrial and Aquatic Ecology

Date of Defense

6-7-2019

Abstract

Invasive exotic animals are considered destructive forces in cities for preying on and competing with native species. I examined an aspect of competition from a different perspective, focusing on the role of Miami’s rich exotic bird assemblage in its cavity nest web, where a supply of woodpecker-created cavity nests limited by urbanization is the focal point of competition. We located 967 nest trees with 1,864 cavities and determined that woodpeckers successfully nested in this tropical urban region by exploiting standing dead palms (snags). Native upland forests were the most important cover type for woodpeckers but planted landscapes like parks and botanical gardens supported a similar density of nests. Fluctuations in nest resource availability were studied following Hurricane Irma in 2017. After the storm, the proportion of nests in palm snags increased relative to other substrates. Compared to other substrates, palm snags persisted at intermediate rates after the hurricane but were the dominant type excavated by woodpeckers. I monitored 750 cavities to determine species occupancy and turnover. Of special interest were Miami’s many parrot species, which have been suspected of breeding in woodpecker nests. I determined that two exotic parrot species commonly use woodpecker nests but are far less abundant than the native birds or other exotic bird species in the cavity nest web. Geographic analysis of nests combined with citizen science data suggest the parrots are closely linked to urban areas, and do not pose a risk of invading the Florida Everglades. The parrots also do not disrupt the urban cavity nest web, despite sharing nest preferences with similarly large-bodied birds, because of an offset in breeding phenology; parrots breed months later than the native birds they would be competing with. Invasive European Starlings and Common Myna do pose a significant threat, usurping active nests from species with similar nest preferences. Starlings are a well-established invasive species, but a growing population of mynas would exert considerable pressure on the nest web based on their nest selection and phenology.

Identifier

FIDC007799

Recommended Citation

Diamond, Joshua M., "Cavity Nest Webs as a Template for Studying Non-trophic Interactions in Invasion Ecology" (2019). FIU Electronic Theses and Dissertations. 4234.
https://digitalcommons.fiu.edu/etd/4234