eWestern Birds

Hooded Oriole Nest Failure Associated with A Novel Nest Site

Kevin Ellison and Timothy Brush

ABSTRACT: Ecological traps occur where species are attracted to use a resource that exposes them to greater than normal risk of mortality or reproductive failure. We observed complete failure of Hooded Oriole (Icterus cucullatus) nests in streetlights in a south Texas suburb where use of such nest sites was relatively common. This is of concern as streetlights functioned essentially as traps: orioles built their nests within them but all these nests failed, evidently because the eggs were exposed to lethal temperatures. Moreover, Hooded Oriole nesting success on all other substrates in this area was low (31%, n = 69). Therefore, sufficient time for multiple nesting attempts is an important component of the oriole’s reproductive success, and time lost to nesting attempts in streetlights, with no chance for success, imparts reproductive costs beyond egg losses. Deterring orioles from nesting in streetlights may increase the potential for subsequent nest attempts on more productive substrates. A simple screen installed as a barrier blocking the opening in the shades beneath the lightbulbs eliminates this unnecessary source of nest failure.

Download—Hooded Oriole Nest Failure Associated with A Novel Nest Site