Preferred nest site characteristics reduce predator-specific predation risk in a canopy-nesting raptor

• Published in: The Journal of wildlife management 2014-08, Vol.78 (6), p.1022-1032
• Main Authors: Chiavacci, Scott J., Bader, Troy J., Bednarz, James C.
• Format: Article
• Language: English
• Subjects: Animal behavior; Animal nesting; Bird nesting; Birds; bottomland forest; Canopies; Floodplains; Forest canopy; Forest habitats; Habitat conservation; Habitat Relations; Habitats; Ictinia mississippiensis; Mississippi kite; nest predation; nest site habitat; Nesting; Nesting sites; Nests; Overstory; Owls; Predation; Predators; Reproduction; Strigidae; time-lapse video; Trees; Wildlife; Wildlife management
• ISSN: 0022-541X; 1937-2817
• DOI: 10.1002/jwmg.746

Habitat features influence nest survival and, as a result, identifying relationships between habitat characteristics and nest survival remains a central focus among studies of avian reproduction. In cases where nest prédation is the main cause of failure, knowing how the habitat affects prédation risk may provide managers with a tangible means by which to improve reproductive success. The Mississippi kite (Ictinia mississippiensis) is a species of regional conservation concern due to small population sizes and high rates of nest failure. We monitored Mississippi kite nests, documented causes of nest failure, and examined relationships between habitat features and predator-specific patterns in nest prédation in a floodplain forest in east-central Arkansas. We identified Texas ratsnakes (Pantherophis obsoletus) and owls (Strigidae) as dominant nest predators and predation by each was influenced by different habitat features. Ratsnake predation was greater in areas with fewer overstory trees and when kite nests were positioned farther above the tree canopy. Owls were more likely to depredate nests farther from the forest edge and nests that had less canopy coverage around them. Our results illustrate that the nest site characteristics preferred by kites reduce nest prédation risk, indicating most of the management actions proposed to promote kite nesting are likely to create or maintain quality habitat for this species in the Mississippi Alluvial Valley. Beyond knowing the main causes of nest failure in kites, our results may also provide a glimpse into threats faced by mid-story and other canopy-nesting birds, a guild for which very little information exists regarding causes of nesting failure.