New Jersey Osprey Project // Nest Monitoring Portal

Introduction + Background

From the 1970s through 2009, New Jersey osprey populations were monitored using standardized aerial surveys conducted twice each breeding season—during incubation in mid-May and again in mid-June when young were visible in nests. Surveys were initially flown using fixed-wing aircraft and later helicopters, covering major coastal colonies from northern Barnegat Bay south to Cape May and along the Delaware Bayshore. These surveys, supplemented by ground checks by staff and volunteers, were used to estimate population size, distribution, nest success, and productivity. Since 2009, aerial surveys have been replaced by ground-based monitoring and online reporting through Osprey-Watch.org, where staff, partners, and citizen scientists document nesting activity statewide. Today, most colonies are surveyed by boat in late June and early July, when nestlings are old enough to observe and band. Surveyors assess occupancy and nesting outcome through behavioral observations and direct nest inspections using ladders, cameras, poles, mirrors, GoPros, or permitted drones. Multiple surveys conducted throughout the nesting season help improve the accuracy of determining nest success and failure.

With your help, we aim to continue these efforts to ensure that this vital indicator species remains stable. On this page, which is devoted to providing information and updates to our NJ Osprey Watchers, you will find a map of osprey nests in New Jersey, guidelines for monitoring nests, past recordings from virtual info and training sessions, a PDF handbook and important links.

Important Links + Resources

Osprey Watch, Global Osprey Watching Community: osprey-watch.org

Link to custom google map with all known osprey nests.

Report Environmental Crimes (24/7): https://dep.nj.gov/warndep/ or 1877-WARN-DEP

Download the NJ OSPREY WATCH / Monitoring Guide 2026

Nest Monitoring Protocol

How to survey osprey nests

Equipment needed

• Binoculars, spotting scope, digital camera with telephoto lens
• Field datasheet and/or notebook and writing tool
• Smartphone/computer to enter data and view nest locations

Desired data

• Status of nest structure — Does the structure still exist? If so, is the nest occupied by a pair of ospreys?
• # ospreys on the nest (male/female present?)
• Nesting behavior to determine the status of nest (occupied, active – with eggs or young, failed nest, unoccupied nest, gone nest)
• Fledgling status
• Visible presence of plastic in nest

Survey methods

Using your own vehicle, you will drive to a known osprey nest. You can use Osprey-Watch.org or a shared map on this page to locate nests and plan your route. When arriving at the site, identify a location where you have a clear view of the nest. For taller structures, you may need to be positioned further from the nest, to see activity. Please make sure that you park in an area that does not put you in danger. Often times, you may be able to remain in your vehicle to observe the nest at a distance and use it  as a blind. Make sure that you do not trespass or walk onto private property without permission from the landowner. You may find it necessary to talk to people to let them know what you are doing, so they can be reassured that you are only there to observe wildlife. We can mail you small brochures that you can use to handout to people in these circumstances (reach out to Ben if you would like some).

Using a visual aid, like binoculars, a spotting scope or a digital camera with a telephoto lens, you look at the nest for signs of activity. Plan to watch the nest for as long as 30 minutes to confirm the nest activity. Given the time of year, less time may be adequate to determine nest status, especially if you have surveyed it multiple times. During incubation, the incubating adult often sits very low, with a flat back, 24/7. They do move or adjust sitting position depending on wind direction and other factors. They can be observed enfluffing eggs (shifting them to ensure proper development) and the pair performing incubation exchanges, often after the male delivers food, which the female takes to a perch nearby to eat away from the nest (to not attract predators).

Once the eggs start to hatch, you will see the female body position change, with her front lifted more. You may see feeding behavior and eventually the heads of the nestlings, especially once they get larger (at around 2 weeks old) This is more difficult when looking at a very tall structure (communications tower). In these situations you may observe more food deliveries, which is a sign of young present. If you cannot actually see young or determine how many, please record as unknown (UNK). It is very important that the data you collect is accurate. We never want to assume there is young in the nest when there is not. NOTE: Around 25% of nests surveyed annually are reported as occupied and the outcome was unable to be determined.

If a nest that you observed was active, with eggs (incubation observed), and later inactive (no young), this means that the nest attempt failed. There are many factors that could cause a nest to fail, including predation by ground/aerial predators, nest structure failure, weather/storms, entanglement/suffocation from plastic marine debris, adult experience, and food stress. A nest is only considered to be failed when it did have eggs or young and lost them.

In recent years, we have been seeing more signs of food stress in coastal colonies and if this appears earlier in the season, some females have not been laying eggs, laying reduced or late clutches, as they are not able to get into egg laying condition. This is more difficult to determine unless observations have been conducted throughout the spring to document whether the nesting female did or did not actually lay eggs.

Another important behavior to watch for is sibling aggression. This is where the older, often larger nestling outcompetes its younger siblings for food. It is most often observed when prey is brought into the nest but can also be observed at other times. This is where the older nestling will repeatedly peck or “bonk” the other nestling(s) into submission. This is another sign of food stress when this is observed at nests.

Later on in the nesting season, watching or counting the young produced is important. With food stress, we see brood reduction. This is where the younger nestlings perish from starvation. In times when there is more food scarcity, all young may not survive and the adults may abandon the nest entirely. In recent years, this has even been observed during the incubation period, as incubating females often have to leave their nest with eggs to try and find food, if the male is unable to find prey.

Otherwise, young are mostly downy until they get to around 3 weeks or 21 days in age. After that then they appear more buff colored, with body and flight feathers emerging and orange eyes.

Observation timeline

• One survey once a week (four times a month), if possible. At a minimum, once every two weeks.

• April 1 through September 1

Late March – April — Adult arrival. Nest construction and courtship displays occur. Egg laying begins.

May — Incubation underway. Hatching begins towards end of month. Earlier at inland locations. Record presence of adults and whether incubation behavior is observed. Watch for food delivery and incubation exchange. *difficult on very tall structures as adults may not be visible sitting low.

June — nestlings present. Note # observed of both young and adults. If unknown, record as observation until known. Do not guess. Behavior to watch for and record include food/fish deliveries, feeding of young. Chicks become visible when around two weeks old.

July — young are close to full grown but still unable to fly until later in the month. Note # observed of both young and adults. If unknown, record as UNK. Continue to watch for fish deliveries and feedings. Watch for nestling heads moving. Wings stretching and muscles strengthened by flapping, jumping on nest.

August — young fledge. Note # young observed on the nest. Some young may not be visible on nest after they fledge. Females begin fall migration. Young disperse and often continue resting on nest. Male supplements diet of young as they gain experience foraging.

September – some young remain on nests while adult male provides supplemental food.

Thank you for your dedication and contributions to monitoring New Jersey’s ospreys.

If you ever have any questions about a nest or ospreys in general. Contact Ben Wurst via email at ben.wurst@conservewildlifenj.org or call/text: 609-713-4464.