Nest predation study in Hampton Roads
Oleksii Dubovyk
Avian Ecology Lab
Department of Biological Sciences, Old Dominion University, Norfolk, VA, 23529
oadubovyk@gmail.com | odubovyk@odu.edu
Ongoing study, new participants are welcome
Last update 2025-02-18.
1 About
We all love birds in our backyards and parks. Yet, living in a city can be dangerous for birds. For example, some predators can eat birds’ eggs and chicks, which totally diminishes breeding effort of loving bird parents.
For my dissertation research, I want to take a look at the predators that are potentially threatening birds in different levels of urbanization, and how predators and birds coexist with humans in our cities. On the other hand, any manipulation with a real nest can attract predators to it, and I do not want to jeopardize wild birds’ nests with my study, so that I am trying to imitate the nests with artificial ones, accompanied by a motion-activated camera to observe the predators of a nest.
I am currently looking for property owners who would let me to install the artificial nests and cameras for 10 days on their properties next year (2025).
1.1 Where?
The area of interest is located near Norfolk, Virginia, mainly the following counties: Chesapeake, Norfolk, Portsmouth, Suffolk, and Virginia Beach (Fig. 1.1). Yet, if you live outside of these cities but are still nearby, I would still be happy to conduct the research on your property.
Figure 1.1: Area of the study.
1.2 When?
Interested homeowners are welcome to contact me or leave the contact information here at any time.
The experimental setups will be installed for 10 days between March and mid-June of 2025.
2 Experimental setups
Once we get in touch, I will visit the household and install an artificial nest on the property, of course, under guidance of the property owner. The motion-activated camera will be facing a nest and exclude the property from the field of view as much as possible. The camera and the nest will be there for 10 days, after which they will be collected1.
Over this 10-days period, there is no reason to expect that the setup will attract any vermin: the camera will only show what already occurs at the property. Of course, all observations will be provided to the property owners at request.
2.1 Artificial nests
The type of an artificial nest is defined randomly every time. There are three possible nest types: nest box, cup nest, or ground nest. There will be three quail eggs in any nest (Fig. 2.1).
Figure 2.1: Quail eggs in a nest box.
There will be no real birds in these nests. However, there is a chance that some animals will occupy the nest box during the 10 days while the setup is active. Every nest box will be checked with an endoscope camera to ensure that there are no wild animals inside before collection.
2.1.1 Nest box
If nest box is chosen as a nest type, a typical bluebird house will be used (Fig. 2.2).
Figure 2.2: Bluebird nestbox.
To install such nest box, there should be an appropriate and accessible tree on the property. However, if there is no such tree, an artificial platform will be installed to substitute a tree (Fig. 2.3).
Figure 2.3: Bluebird nestbox installed on a pole with weight on a property where there were no suitable trees.
A camera will be installed either on a pole attached to the nest box, or on a big trunk nearby, if possible (Fig. 2.4).
Figure 2.4: Two possible options for attaching a camera to the nest box.
2.1.2 Cup nest
The cup nest imitates a typical bird nest located on a fork of branches on a tree (Fig. 2.5).
Figure 2.5: Imitation of a cup nest with quail eggs.
Figure 2.6: Installing a cup nest means that I need to do a bit of climbing. This project is just an excuse to climb trees.
Similarly to nest boxes, cup nests require a suitable tree, but if there is none, an imitation of a tree will be installed (Fig. 2.7).
Figure 2.7: Imitation of a tree with a cup nest.
2.1.3 Ground nest
Finally, a ground nest is just a depression in soil or mulch with three eggs (Fig. 2.8), hidden in some vegetation.
Figure 2.8: A ground nest.
A camera will be installed next to a ground nest on trunks (Fig. 2.9) or, if there are none, on a small pole.
Figure 2.9: Camera next to a ground nest.
2.2 Motion-activated cameras
Motion-activated cameras are a common tool in wildlife monitoring. They are exactly what it sounds like: a small box with batteries, camera, infra-red flash (to take black-and-white pictures at night without scaring the animals), and motion detectors (Fig. 2.10). Every time the motion sensor detects any movement, it triggers a camera and a photo is taken.
Figure 2.10: Motion-activated camera. The motion sensor is partially covered to decrease false positive triggering by movement outside of an artificial nest.
After 10 full days in the field, the camera will be collected and the photos will be reviewed. If requested, the photos of the wildlife observed will be sent to the property owners.
The cameras are installed in such a way as not to look at the buildings or areas where some activities are possible, to minimize any potential invasion of privacy. If, by any chance, there are people on the photos taken, such photos will be permanently deleted.
3 Join
I am currently seeking more locations for this study. Please feel free to fill in the form with your contact information here, and I will reach out back to you as soon as I have a free camera to install.
3.1 Eligibility
Anyone can participate.
All kinds of property are interesting for this research: it can be a residence, local business, warehouse, forest, farm, etc. Moreover, the property owners do not need to physically present in Hampton Roads from March to June – I just need 10 days within the study period.
3.2 Contacts
Please feel free to reach out to me with any question through email:
or text:
757-355-3036
You can learn more about me and my work on the website:
4 Results
Because the cameras and the experimental setups required additional testing, the study has started with a delay in late April of 2023. I have now collected the data from the first two years of the project.
4.1 Completeness
For proper statistical analysis, I need at least 144 repetitions of the experiment. If all three nest types are tested at the same location, there should be at least 48 locations.
Figure 4.1: Completeness of the study.
4.2 Preliminary results
Despite the attempts to stratify 47 locations by level of urbanization, most locations were in areas with low or medium levels of urbanization (10–40% impervious area – concrete, asphalt, etc.) (Fig. 4.2).
Figure 4.2: Density distribution of urbanization levels at study locations quantified as percent of impervious area within 500 m of the location, according to the USGS National Land Cover Database. The gray outline corresponds to all data combined from 2023 and 2024.
It seems that the probability of a nest being depredated over 10 days slightly increases with urbanization level, but this relationship depends on the nest type. Cup nests have the steepest response to urbanization, ground nests also get depredated often but the effect of urbanization is slightly less rapid, while nestboxes have the lowest predator pressure (Fig. 4.3).
Figure 4.3: Logistic regression plots of probability of experimental nests (nestbox, cup nest, or ground nest) being depredated as a function of level of urbanization for each nest type, as well as for all nest types combined with dashed lines representing 95% CI.
Overall, 17 species of mammals, 42 species of birds, and one reptile species (unidentified skink) were detected. Out of these species, six mammalian and three avian species were observed consuming eggs: American/Fish Crow (16 events), Eastern Gray Squirrel (15), North American Raccoon (14), Southern Flying Squirrel (12), Virginia Opossum (10), Blue Jay (9), Black Rat (4), Red-bellied Woodpecker (1), and Gray Fox (1).
Four other species were associated with damaging the eggs. There was one case wherein adult Gray Catbirds were observed repeatedly attempting to peck the quail eggs in a ground nest while juveniles stayed nearby and observed. In another case, Eastern Bluebirds were observed removing the egg shell from the nest box, however, it was unclear whether those individuals caused the damage to the egg, or if it was due to other species that had visited the nest previously (e.g., House Wren, House Sparrow). Unfortunately, the details are unable to be determined since the motion-activated camera was located outside of the nest. In two other cases, a Great Crested Flycatcher and Eastern Kingbird damaged the eggs unintentionally while collecting nest material from artificial nests.
Nestboxes were visited mostly by Southern Flying Squirrels, Eastern Gray Squirrels, with occasional interest from Black Rats, North American Raccoons, Red-bellied Woodpeckers, and Blue Jays. The Southern Flying Squirrel was the only species that was directly observed consuming the eggs. Eastern Gray Squirrels were primary visitors of cup nests, followed by Black Rats, Blue Jays, Southern Flying Squirrels, Fish/American Crows, and North American Raccoons, while eggs were consumed mostly by crows, Blue Jays, Eastern Gray Squirrels, Southern Flying Squirrels, Black Rats, and North American Raccoons. Finally, ground nests were visited mostly by North American Raccoons, Eastern Gray Squirrels, Virginia Opossums, Black Rats, with several visits by corvids and Gray Foxes, while eggs were consumed most commonly by North American Raccoons, Eastern Gray Squirrels, Virginia Opossums, followed by crows, Blue Jays, and Gray Foxes.
Figure 4.4: Proportions of detected visits of artificial nests by species that have been observed consuming the eggs (left) and proportion of actual predation events by predator identity (right).
4.3 Nestbox camera
In 2023, all nestboxes were monitored with a camera outside aimed at the entrance. This created several issues: first, in a case when a House Wren would decide to build a nest, real or dummy, the bird would fly in and out of the box pretty often, so that by the end of the 10-day monitoring period there would be thousands of pictures like Fig. 4.6. Another problem was related to the fact that it was impossible to say what has happened inside of the nestbox and if the quail eggs were damaged, it was impossible to say when they got damaged exactly. In one case, the nestbox has been visited by House Wrens, Carolina Chickadees, House Sparrows, and Eastern Bluebird, until one picture showed an Eastern Bluebird pushing an eggshell out of the box (Fig. 4.7). Having the photos from outside of the nestbox does not allow us to guess who exactly from among the visitors damaged the egg, but we only can say that the Eastern Bluebird was cleaning up.
After learning this lesson, all nestbox experimental setups in 2024 had two cameras: one outside of the box, pointing at the entrance, and another at the nestbox roof, pointing inside of the box through a hole in the roof panel (see Fig. 4.5). Although this setup might be somewhat chunky and creates gaps in the roof, the wildlife didn’t seem to mind it (Figs. 4.18, 4.19).
Figure 4.5: Trail cameras were fitted to look inside of the experimental nestboxes in 2024.
4.4 Gallery
Figure 4.6: It took this House Wren only four days to start building a nest in the experimental nest box. The camera was collected, but the box has been left alone.
Figure 4.7: A controversial photo of an Eastern Bluebird pushing an eggshell out of the nestbox. It is unclear who exactly from all the prior nestbox vistors damaged the quail eggs in that artificial nest.
Figure 4.8: Carolina Wren checks out the nest box.
Figure 4.9: A fragment of video featuring a crow eating the quail egg from an artificial cup nest.
Figure 4.10: Virginia Opossum has been finally caught on camera checking the ground nest, but the eggs, apparently, were not too interesting.
Figure 4.11: Common Grackle found out that the nest material of the fake nest (coconut fiber and Spanish moss) can turn out handy.
Figure 4.12: This Virginia Opossum was checking for the eggs. Luckily for it, the Eastern Gray Squirrel was trying to hide a newly found egg right under the nest material earlier!
Figure 4.13: The Gray Fox found the experimental ground nest on right on its everynight trail.
Figure 4.14: North American Raccoons are common guests of the ground nests.
Figure 4.15: One of the most interesting observations – Coyote in the middle of Norfolk.
Figure 4.16: Also an interesting observation from 2023 – the Southern Flying Squirrel spent a few night in the nestbox, eating one of the eggs.
Figure 4.17: Installing the artificial ground nest in a middle of a raccoon trail guarantees that the eggs are getting eaten.
Figure 4.18: One of the nestbox pictures from 2024 showing an early stage of the Eastern Bluebird nest building. Experimental quail eggs get buried under a nest in cases like this.
Figure 4.19: Southern Flying Squirrels also did not mind a camera in the nestbox and readily used them for roosting.
Figure 4.20: A Black Bear caught on camera in Chesapeake in 2024.
5 Acknowledgments
Special thanks to Ella DiPetto and Chi Wei for all the help with building the nest boxes and preparing the experimental setups, to Rich Hardison, Nicholas Flanders, and Norfolk Botanical Gardens for assisting with the outreach to the property owners.
The project would be impossible without the numerous property owners who are interested in the wildlife and are granting access to their properties: A.J.H., A.P., B&M.Z., C.A., C.I., C.L., C.W., E.D., G.C., J.M., J.T., K.C., K.F., K.M., L.O., M.B., M.H., M.S., N.F., P.S., R.A., R.H., S., S.E., and many more people who reached out to me. The agencies that allowed the data collection also include Blackwater Ecological Preserve (Old Dominion University); Department of Recreation, Parks, & Open Space (The City of Norfolk); Fire Station 10 (Chesapeake Fire Department); First Landing State Park (Virginia Department of Conservation and Recreation); Hoffler Creek Wildlife Preserve; Money Point Conservation Area (Kinder Morgan); Weyanoke Bird and Wildflower Sanctuary (Cape Henry Audubon Society).
The study protocol has been approved by Old Dominion University Institutional Animal Care and Use Committee (#23-004). The approval to conduct the activities has been waived by the Institutional Review Board at Old Dominion University and Virginia Department of Wildlife Resources.
in a case if the nest box becomes occupied by some wildlife (e.g., Carolina Wren, European Starling, etc.), it will be checked with an endoscope and left alone until the end of the season; the property owners will be welcome to retain the nest box.↩︎