NestWatch is a nest-monitoring project launched in 2008 by the Cornell Lab of Ornithology. By building upon previous regional nest-monitoring programs, such as The Birdhouse Network and the Cornell Nest Record Card Program, NestWatch aims to provide a unified nest-monitoring scheme to track reproductive success for all breeding birds in the United States. This effort is designed to generate a broad temporal and geographic data set in order to better understand and manage the impacts of environmental change on bird populations. The project also seeks to engage the public to connect with nature and science in their backyards. Volunteers collect information on nests during the egg-laying, incubation, hatching, nestling, and fledging periods. Data collected include the species, location, habitat and other variables relating to nest placement and configuration; reproductive data including estimates of egg-laying, hatching and fledging dates, as well as number of eggs and number of young; and data on nest parasitism and predation. Data collection is focused on species commonly found in rural, suburban and urban areas, which are accessible for nest monitoring. However, nesting data for any North American species is accepted. Data are entered by observers into a centralized online database.


Current data are publicly available through the NestWatch website.  Future incorporation of decades of historic Nest Record Card data will make  the NestWatch database one of the largest repositories of avian reproductive data in North America; the database will house nearly 400,000 nest records spanning over four decades and 500 species.


As with any monitoring program that relies on citizen scientists, there is the potential for inaccuracy, although the database filtering system was built to avoid mistakes in data entry. There is a bias in the NestWatch database toward species that use nest boxes, and toward nests located in habitat easily accessible to humans.  Very few of the commonly monitored species are high priorities for conservation.  

Examples of use

The following journal articles utilize data from NestWatch’s predecessors; The Birdhouse Network and the Cornell Nest Record Card Program.  Similar application of NestWatch data is expected.

Cooper, C.B., W.M. Hochachka, T.B. Phillips, and A.A. Dhondt. 2006. Geographic and seasonal gradients in hatching failure in Eastern Bluebirds reinforce clutch size trends. Ibis 148:221-230.

Cooper, C.B., W.M. Hochachka, and A.A. Dhondt. 2005. Latitudinal trends in within-year reoccupation of nest boxes and their implications. Journal of Avian Biology 36:31-39.

Winkler, D.W., P.O. Dunn, and C.E. McCulloch. 2002. Predicting the effects of climate change on avian life-history traits. Proceedings of the National Academy of Sciences 99:13595-13599.

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