Predators of artificial nests in grasslands of east-central Kansas.

Abstract

Grassland birds have declined faster than any other avian guild in North America during recent decades. The decline has been attributed to increased fragmentation of the grassland biome by anthropocentric activities. The area near the edge has been shown to have a lower nesting success for grassland birds in the most heavily fragmented areas. However, a study conducted in east-central Kansas and in other less fragmented areas have not shown a clear edge effect. Edge effects occur when predators use the ecotonal boundaries as travel lanes and are more successful at finding avian nests. Geographic variability in predator occurrence and abundance seems to have a large effect on the presence/absence of an edge effect. I Llsed artificial nests to determine nest success and predator type along a distance gradient extending perpendicular to the habitat edge. Additionally, I used various monitoring techniques to identify characteristics of habitat used by potential predators within prairie fragments of east-central Kansas. I did not find an edge effect for artificial nests in my study. Small mammals belonging to the genus Peromyscus were the most common predator of artificial nests and the deer mouse (P. maniculatus) was the most common potential predator caught in the prairie fragments. Additionally, Peromyscus depredated nests and deer mouse was caught equally across the entire distance from the habitat edge. The cotton rat (Sigmodon hispidus) did show an affinity for the habitat edge in occurrence and when depredating artificial nests. Other predators of artificial nests in my study were Elliot's short-tailed shrew (Blarina hylophaga), prairie vole (Microtus ochrogaster), raccoon (Procyon lotor), striped skunk (Mephitis mephitis), and birds. Further research should focus on identifying what the egg shape limitations are for small predators of grassland birds. Additionally, more research should be conducted on the effects of haying on grassland birds and their predator community.