Which Factors Influence Oʻahu ʻElepaio (Chasiempis ibidis) Nesting Success in Rodent-Controlled and Uncontrolled Areas?
| dc.contributor | Taylor, Phillip | |
| dc.contributor.advisor | Price, Melissa | |
| dc.contributor.author | Preston, Nicole | |
| dc.contributor.instructor | Litton, Creighton M. | |
| dc.date.accessioned | 2023-07-27T23:05:39Z | |
| dc.date.available | 2023-07-27T23:05:39Z | |
| dc.date.issued | 2023-05 | |
| dc.description.course | Master’s of Environmental Management (MEM) Capstone Reports | |
| dc.format | dissertation or thesis | |
| dc.identifier.uri | https://hdl.handle.net/10125/105180 | |
| dc.subject | predator control | |
| dc.subject | breeding biology | |
| dc.subject | passerine | |
| dc.subject | management decisions | |
| dc.subject | novel threats | |
| dc.subject | habitat characteristics | |
| dc.subject | nest-site-selection | |
| dc.subject | Predatory animals--Control-- | |
| dc.subject | Environmental management--Decision making | |
| dc.subject | Nest building | |
| dc.subject | Passeriformes | |
| dc.subject | Wildlife recovery | |
| dc.subject | Endangered species--Management | |
| dc.subject | Endangered species--Habitat | |
| dc.subject | Animals--Habitat selection | |
| dc.subject | Birds--Habitat-- | |
| dc.subject | Monarchs (Birds) | |
| dc.title | Which Factors Influence Oʻahu ʻElepaio (Chasiempis ibidis) Nesting Success in Rodent-Controlled and Uncontrolled Areas? | |
| dc.type | text | |
| dcterms.abstract | Reducing invasive rat populations is a common approach when protecting endangered birds globally, but as populations recover following conservation actions, they may expand into nearby areas without rat control and experience higher mortality in these unprotected areas, developing a ‘source-sink’ dynamic. Nesting success of breeding populations of O’ahu ‘Elepaio (Chasiempis ibidis) has increased following rat control over the last decade, and dispersing individuals are now establishing breeding territories in nearby areas without rat control. This may leave ‘Elepaio nests in newly-occupied areas vulnerable to rat predation. The objective of this study was to compare the nesting success and nest-site characteristics of ‘Elepaio between sites with and without rodent control. A total of 48 nests were monitored, 29 at the site with rodent control and 19 at the site without rodent control. Nesting success and potential causes of nest failure were determined using motion-activated game cameras placed near ‘Elepaio nests, as well as direct observations. Rat tracking tunnels were utilized to evaluate rodent presence. Logistic exposure models were used to investigate the relationship between survival probability and nest-site characteristics (tree height, nest height, tree species relative dominance, and rodent abundance). Rat activity was significantly lower at the site with rat control, consistent with expectations (p<0.01, t=4.8). Between sites, a total of 27 nests hatched chicks and only 2 nests failed due to depredation. There was no difference in nesting success between sites (p=0.96; X2= 0.002). The site without rodent control produced 18 chicks, and the site with rat control produced 15 chicks. The top logistic exposure model predicted that nest survival is highest when the nest is positioned at the highest point in the tree. Vegetation composition was similar between sites and did not influence nesting success. Our results suggest that expanding populations of ‘Elepaio in areas without rat control are able to nest successfully. Nesting habitats should be managed for optimum tree heights to support the persistence and expansion of O’ahu ‘Elepaio populations. Further, ground-based rat control may not adequately protect tree-nesting birds from rats with arboreal tendencies, and future studies should explore alternatives that better remove arboreal rats. | |
| dcterms.extent | 23 pages | |
| dcterms.rightsHolder | Preston, Nicole | |
| dcterms.spatial | Hawaii-Oahu |