Nest Monitoring Guidelines
Following the life of a nest is an enriching time of discovery. At the same time, nest monitoring should strictly adhere to basic guidelines. The guiding principle to responsible nest monitoring is conducting observations with as little disturbance as possible. Some questions can be answered far from the nest; for example, whether the nest is still being built, if it is still active, if eggs have hatched (i.e. if adults are carrying food to nestlings). But e most data rely on quick and careful nest visits at close-range.
If conducted under appropriate protocols, nest monitoring also gives the observer a chance to make important scientific contributions. During the course of monitoring, several kinds of scientific data are recorded on a nest data form. The form serves as a guide leading you through a timeline of a nest attempt. Depending on when the nest was found within the cycle and whether the nest failed will determine how much of the timeline is monitored. Your records will include dates corresponding to numbers of eggs, nestlings, and fledglings up until the fate of the nest is known. To help us determine how well bird populations are surviving, it is essential that a nest be monitored until its final outcome - whether it was successful, predated, abandoned, or otherwise.
The information below provides the guidance necessary to monitor nests successfully and gather data for scientific purposes. After review you may proceed to the brief nest monitoring quiz then be on your way as a contributor to the exciting world of citizen science!
The Nesting Season
Neighborhood Nestwatch will accept nest data on any bird breeding within a 75-mile radius of Washington, D.C. Resident birds living in the Washington, DC area year-round (e.g. Carolina Chickadees, Northern Cardinals, Carolina Wrens) will begin nesting as early as the beginning of March and will nest as late as the end of July. Migratory birds (e.g. Gray Catbirds, House Wrens) will nest between late April and mid-July. It's important to keep in mind that the majority of nesting species in our region will attempt more than one nest per breeding season, particularly if earlier nest attempts fail. So it's possible to make observations on more than one nest attempt for an individual bird.
The Nesting Cycle
Generally, nests are built very quickly within two to three days. Eggs are then laid at the rate of one per day. Beginning the day before the last egg is laid, most songbirds in our region spend 11-14 days incubating. Most songbird eggs hatch within 24-48 hours of each other. Once hatching occurs, 10-18 days are needed depending on the species for nestlings to develop sufficiently before they can fledge. A nest is considered successful if it fledges at least one young.
Number of Observations During the Nesting Cycle
A nest can be found at any point during the nesting cycle. It is OK if monitoring begins at any point beyond nest building. Be mindful that nest building, egg-laying, and incubation are the most sensitive stages of the nesting cycle. During these periods, adult birds will be most prone to abandon nests if disturbed. Depending on the nest stage, visits should occur at the following frequency:
Nest-building, Egg-laying, Incubation stages: at least 3 days apart.
Nestling stage: at least 2 days apart.
Fledging stage: 1 "visit".
Although fledging can be difficult to witness, try to anticipate this glorious day. Note that nests can fail as late as the day of fledging. If you find an empty nest, try to confirm success or failure. Does the nest look predated (failure)? Do you see or hear young around your property (successful)? Reminder: this is the most important determination of the nesting cycle!
Gather as much data as you can. If time is limited, try hard to make at least 3 observations on a nest including the final one that determines nest fate.
Nest Fate and Predation
The final and most important piece of information recorded on the nest data form is the final outcome, or fate, of a nest. Listed below are the various nest fates we can expect:
- nest produced at least one fledged young.
- Successful but parasitized:
- produced at one fledged young along with at least one egg, nestling, or fledgling from a brown-headed cowbird
- Failed - predated:
- nests which don't produce any fledglings due to destruction of nest and/or consumption of contents by predators
- Failed - weather-related:
- nests destroyed or critically weakened by weather events. (Careful not to confuse with predation.)
- Failed - human activity related:
- Examples-abandonment due to lawn mowing or hedge trimming; frequent activity around nest site.
- Failed - parasitized:
- nests which do not produce any young of host species due to raising brown-headed cowbird eggs and young.
- Failed - unknown:
- nest abandoned by adults for unknown reason.
Avoid nests during nest building and the first few days of incubation. Use binoculars from a distance or check the nest when adults are not present, e.g., when the female occasionally leaves the nest to feed.
Do not check in the early morning. Check nests in the afternoon, since most females lay their eggs in the morning. Eggs and young nestlings get cold quickly if left alone in the morning.
Do not check nests at or after dusk. Females may be returning to the nest for the night.
Do not approach nests when young are close to fledging. When the young are disturbed during this stage, they may leave the nest prematurely. Young that fledge prematurely usually do not return to the nest leaving them with little chance of survival. Don't check the nest once the young are fully feathered. You can check the nest from a distance with binoculars to determine if the parents are still actively feeding the young.
Avoid nests during bad weather. If the weather is cold, damp, or rainy, postpone checking the nest until another day. Checking nests during this time can be very stressful for birds.
Be wary of nest predators. Be sure dogs, cats, crows, or jays are not following you or watching you. Nest predators are everywhere. If predation has occurred, look for hints as to what may have depredated the nest and keep watching the adults for a second nest attempt.
Do not leave a dead-end trail during nest-checking. Whenever possible, take a different route away from the nest site than the route you took to reach it. Walking a back-and forth route to the nest leaves a dead-end trail at the nest that can lead predators with a heightened sense of smell directly to the nest. Instead, make a loop to and from the nest, if possible.
Minimize disturbance at the nest. The ideal time to quickly check a nest is when parents are absent. Sometimes waiting a short period of time for parents to leave is all it takes. Do not startle parents on your approach to the nest as this may cause eggs or young to get knocked out.
Nest boxes should be lightly tapped first to allow the parent to slip away before you stare directly into the box. Use small mirrors attached to poles for nests that are out of reach. Avoid touching nests, eggs and young. Upon return, wait until you are at least 10 meters away before recording data.
Be mindful of the number of days since the last visit. Follow the suggested visit frequency rigorously and remember to make at least three observations per nest including the final one that determines nest fate.
Missing a day. If you miss a day or can't determine the exact day of egg-laying, or if you even make a mistake, it's OK. Indicate this on the data form. This is a learning process. If you have to be gone for an extended period, ask a friend for help or contact us.
Understand the Migratory Bird Treaty Act. Under the Migratory Bird Treaty Act it is illegal to take, possess, import, export, transport, sell, purchase, barter, or offer for sale, any migratory bird, or the parts, nests, or eggs of such a bird except under the terms of a valid permit issued by federal and, in some cases, state agencies.
Record your data. All observations should be recorded on the nest data form with the corresponding date. Use a new data sheet for each new nest.
Report your data. Completed nest data forms can sent in by regular mail or the data can entered online through the website.
→ At-Large Participants click here to take quiz