Supplementary feeding has limited impact on reproductive success in eastern screech owls Megascops asio

  • Published source details Gehlbach F.R. & Roberts J.C. (1997) Experimental feeding of suburban eastern screech-owls Otus asio has few effects on reproduction apart from non-experimental factors. Journal of Avian Biology, 28, 38-46


This study is summarised as evidence for the following.

Action Category

Provide supplementary food for owls to increase reproductive success

Action Link
Bird Conservation
  1. Provide supplementary food for owls to increase reproductive success

    A replicated, controlled and paired study at two suburban study sites in Texas, USA, in 1992-5 (Gehlbach & Roberts 1997), found that eastern screech owls Megascops asio (formerly Otus asio) nest in nest boxes provisioned with supplementary food (46% of nests in fed boxes vs. 53% in unfed boxes). First laying dates, clutch sizes and chick survival rates were no different between owls in 13 fed and 16 unfed boxes (fed nest boxes: first eggs laid on 22nd March, 3.0-4.5 eggs/clutch and 77% nestling survival; unfed nest boxes: first eggs laid on 20-22nd March, 3.0-4.5 eggs/clutch and 75% nesting success), but owls in fed boxes had higher fledging success than those in unfed boxes, due to greater hatching success (93% of eggs producing fledglings in 13 fed boxes vs. 74% in 16 unfed boxes). Food provided was either 9 g/day or 26 g/day of dead laboratory mice Mus musculus and began approximately 30 days before first laying date and continued through first laying.


Output references

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 17

Go to the CE Journal

Subscribe to our newsletter

Please add your details if you are interested in receiving updates from the Conservation Evidence team about new papers, synopses and opportunities.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust