The Osprey is one of our most recognizable and popular raptors. Like the Bald Eagle, it is a charismatic bird of conservation concern strongly associated with aquatic habitats. Yet often it is found near humans. Unique in appearance, it is truly the “people’s fish hawk.” This year, the Game Commission is performing an extensive statewide survey of osprey nests. It is an initiative that’s not possible without the help of volunteers. Those who are interested in taking part can learn more at the Game Commission’s website,(www.pgc.pa.gov). Information on the nest survey is available on the Bird Conservation part of the Birding and Bird Conservation section under the Wildlife tab. Just download the Osprey Nest Survey Form along with the Nest Observation Protocol, and submit it to firstname.lastname@example.org.
There is an Osprey nest survey web page on the Game Commission website that has more information about this survey, including a link to the survey form. For the specific page on the website, please see: www.pgc.pa.gov/InformationResources/GetInvolved/Pages/OspreyNestSurvey.aspx
There also is a comprehensive description of the species in the state in the agency’s Wildlife Section under Endangered species. The survey seeks to determine the location of each active nest. If you know about a pair of ospreys, we would appreciate hearing from you. Please do not assume that a nest that you know about is covered by somebody else. The coordinates of the nest support structure is very important information to include in any report. This is easily achieved information with an on-line mapping program. For us to better understand Osprey management, it also is very helpful to know what kind of structure the nest is built on and what type of water body is nearby and used by the Ospreys for foraging. And, if possible, the number of chicks in each nest is great to know. The form asks for the data by August 31, but we would appreciate reports of active nests long before then (the productivity information can come later). We did a statewide Osprey survey in 2010 and found at least 115 nests, but missed several nests found later that were known to the birding community and were not reported. Since then, Ospreys have continued to expand slightly into new areas and have been recorded in a few more places. We would like to learn of these new nests.
The Pennsylvania Game Commission is changing its emphasis with Osprey management to watershed-based clusters rather than the Breeding Bird Atlas regions, so information about the known watershed also is appreciated. The information will be used to update the Pennsylvania Natural Heritage Program database and also enable us to better understand the status of this state-threatened species and its management potential. We intend to find at least 10 active nesting pairs in at least four different watershed clusters. That is a modest goal that we are confident that we can achieve with your assistance. Thank you in advance for your willingness to help us with this important survey.
The Game Commission has written a recovery and management plan for the Pennsylvania Osprey breeding population that can be found on the agency website in the Wildlife section. There are at least 100 nesting pairs in the state, but we do not receive information about all nests each year.
Most of these nests can be found in six distinct geographic clusters based on watersheds: the Upper Delaware River basin including the Poconos region; the Lower Delaware River basin; the Lower Susquehanna River basin; the Upper North Branch Susquehanna basin, mostly the Tioga-Hammond Reservoirs; the Upper Ohio – Beaver Watershed including Lake Arthur and the Northwestern wetlands; and the Allegheny River watershed including Kinzua Reservoir and Lake Wilhelm. There also are some Osprey nests in the watersheds of the West Branch Susquehanna River and the Monongahela River.
With the exception of the lower Delaware River and the Ohio River, the majority of the state’s Osprey nests are associated with reservoirs or impounded sections of rivers that are a lot like lakes. Most Osprey nests in Pennsylvania are built on human-made structures such as communication towers, transmission towers or nest platforms. And many of the Osprey clusters are near power stations where there is an abundance of artificial perching and nest sites as well as fish. Ospreys are often displaced by Bald Eagles but can coexist under certain conditions and do better than eagles in highly human-modified landscapes where there is a lot of human activity. So, in this way Osprey recovery can co-occur with the successful Bald Eagle recovery.
The Osprey population has grown steadily since its reintroduction in the 1980s. Although we have located more than 100 nests in recent years, we know that some nests have been overlooked. We also do not know if Ospreys are consistently using all sites, but we suspect that they are in most cases. In the 2010 survey, there was a clustered distribution with the top four counties accounting for 66 percent of the total number of nests. So, the distribution of this species is quite different from the much more widely distributed Bald Eagle or other raptors. It is almost colonial in its pattern. Of course, the places where you can find Ospreys are often good birding spots worth eBirding. So, we also urge birders to submit observations to eBird for those interesting places.
Thanks in advance for your cooperation with the statewide Osprey survey, our agency bird surveys, and eBird!
Doug Gross, Pennsylvania Game Commission Ornithologist, and the PGC Wildlife Diversity team