Wildlife Habitat Council- Nest Monitoring

Monitoring is a crucial part of any nest box, nesting platform, or ground nesting area program. It enables you to track the success of your program as well as identify potential problems such as predation, bad weather, parasites, and undesirable introduced species. Monitoring allows you to measure the effectiveness of the program and avoid problems. It also allows your site to receive public recognition as the benefits to wildlife can be clearly demonstrated.

Placing boxes or platforms along a trail allows a systematic review and facilitates monitoring. Generally, nesting structures should be accessible with a ladder or placed at a level where the monitor can easily look inside. Nest monitors need not be experts at bird identification, they simply walk along the trail and check the assigned nests. To be a monitor you should enjoy observing birds and be willing to devote some time to the wildlife project.

Nests should be monitored once a week during the breeding season. The season will vary from species to species: great-horned owls begin nesting in January in the Northeast, while wrens nest from late April through August in the same region. It is only with regular monitoring that problems can be identified and minimized, and the success of your program documented. Not monitoring leaves your program vulnerable to criticism of being a public image activity lacking credibility.

Nest boxes come in many shapes and sizes, and choosing which nest box to build or buy can be overwhelming. To help you sort through your choices, The Birdhouse Network staff is offering a crash course in the anatomy of a good nest box. Whether you plan to build a box or buy a box, your birdhouse should contain the features listed below. Use these guidelines to choose a nest box that works best for you.
Use a box that was built for the birds
Make sure that it is well constructed and made with the birds and nest-box monitoring in mind; it should be durable, easy to check, and clean. Features of a good nest box:
untreated wood (pine, cedar, or fir)
thick walls (at least 3/4 inches)
extended, sloped roof
rough or grooved interior walls
recessed floor
drainage holes
ventilation holes
easy access for monitoring and cleaning
sturdy construction
no outside perches

Please refer to the Nest Box Reference page for additional information on specific bird and box requirements. To see images of different types of boxes, click here.

Cavity-nesting birds are model species for studies in population ecology, conservation biology, behavioral ecology, and population genetics. Birds in nest boxes can be observed closely without harm to the birds or to the humans watching them. Therefore, it is relatively easy to collect large amounts of data on a wide range of important topics.

Because there is intense competition among cavity-nesting birds for a limited number of breeding sites, many of these species are decreasing in population. Most people, when they think of forests, imagine tall, healthy trees. But forests also have decaying and dead trees, or snags. Although seemingly unimportant snags are valuable to many birds species that depend on them for breeding sites. These dead and decaying trees contain natural cavities in which birds can raise young. As forests are cleared to make way for development, habitats essential to the survival of many birds are being destroyed. Not only is there a reduction in the number of live trees, but dead and decaying trees are being lost as well.

Non-native, or "exotic," cavity-nesting birds such as the House Sparrow and European Starling compete with native species for cavities in which to nest. These two species, introduced to North America in the 1800s, have easily adapted to many types of habitats and often out-compete native species for nesting cavities. And all cavity nesters must compete with other animals, including squirrels, mice, bees, and wasps, which also rely on natural cavities for their existence.

Human intervention may prevent population numbers of these birds from further decline, despite the destruction of their natural habitat. For some time, people with an interest in the plight of cavity-nesting birds have been building and putting up nest boxes. Because many species readily use these nest boxes, people who provide them are creating nesting opportunities for these birds.

Participants who monitor, record, and submit their observations are contributing valuable information to an ever-expanding body of knowledge about cavity-nesting birds. By sharing what they find, nest box monitors help answer questions and increase our overall knowledge and understanding of nature and the world around us. To accurately capture the details of bird biology and behavior on a broad scale, the scientific community needs the input of citizen monitors and amateur birders. Scientific inquiry can be carried out by people of all ages, from preschoolers to senior citizens. And when scientific inquiry is encouraged at an early age, youth are primed for a lifetime of scientific literacy.