Response of Vegetation and Endangered Waterbirds to Habitat Management Techniques at Kealia Pond National Wildlife Refuge

<p>Habitat selection, reproductive effort, and habitat utilization of Hawai’ian stilts (Himantopus mexicanus knudseni) and Hawai’ian coots (Fulica alai) was studied on Kealia Pond National Wildlife Refuge in Mau’i, Hawai’i. Nesting behavior was confirmed following management treatments on the northern shore of Kealia Pond. Nests were dispersed or randomly spaced within vegetation patches or newly created mudflat habitat. Pickleweed and makai were the dominant vegetation surrounding the nest setting and utilized for nest substrate by Hawai’ian stilts and Hawai’ian coots respectively. Mechanical control treatments were implemented through monotypic stands of pickleweed to increase interspersion of open water and promote native vegetation. Changes in habitat conditions increased nesting for both species of endangered Hawai’ian waterbirds. In 2003, habitat conditions on the northern shore prevented nesting. In 2004, 32 stilt nests and 69 coot nests were found compared to no nests in previous years. Mass loss of 123 stilt and 320 coot eggs were monitored during incubation in 2004. A constant rate of mean mass loss accounted for approximately 14.32% and 9.07% of the mean fresh egg mass loss for stilts and coots respectively. The Mayfield nest success in 2004 for stilts was 0.38 and 0.36 for coots. Habitat utilization of both endangered waterbirds was examined in 2003 and 2004. Hawai’ian waterbirds highly selected newly created habitats over other habitats of similar water depths. Hawai’ian coot utilization of water depths were dominated in depths that required swimming. Hawai’ian stilts were most often observed in water depths in relation to their bodies ranging from foot to body. Hawai’ian coots were predominately observed feeding and in locomotion while stilts were predominately observed feeding in treated habitats. The abundance of habitat utilization through the course of this study allowed for conjecture on management strategies and demographics of breeding populations. Endangered Hawai’ian waterbirds depend on early successional habitat for nesting and foraging. Vegetation resulting from seasonally-flooded management strategies may increase nesting activities by these birds by increasing the proportion of native vegetation on treated sites. Further research is needed to understand vegetation characteristics resulting from habitat manipulations and the life history strategies employed by these birds during the breeding season.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Wildlife and Fisheries Science

Year

2005

Author dc:creator

• Rader, James Andrew

Contributors dc:contributor

• Leigh H. Fredrickson

• endangered waterbirds
• habitat
• wildlife management
• wetlands
• hawaii
• kealia pond
• vegetation
• Natural Resources and Conservation

Statement dc:rights

• Copyright © 2005 James Andrew Rader. All rights reserved.

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/368

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1368