Connecticut Audbon Society

A Good Year for Ospreys In Connecticut but Trouble Looms to the South

Record numbers of nests & fledglings

Osprey Nation steward Joseph Szalay photographed these Ospreys on their nest in Ashford, one of the most northerly nesting sites in the state.

November 18, 2024—Ospreys in Connecticut flourished in 2024. The successful nesting season shows that the local revival of these previously imperiled hawks continues, although with concerns about a more difficult season to the south.

Volunteers for Connecticut Audubon’s Osprey Nation project kept track of 726 active Osprey nests this year. Those nests produced 1,077 fledglings.

That’s the highest number of nests and fledglings in the history of the project, which started in 2014. The average number of fledglings per nest was a strong 1.48.

The details and an analysis are contained in the just-released “Osprey Nation 2024 Season Report,” written by Scott Kruitbosch, who oversaw the project this year.

Click HERE for a PDF of the report.

Connecticut Audubon started Osprey Nation in 2024 to provide data that would show not only the health of the bird population but also the health of the state’s waters, following the near-collapse of the Osprey population in the mid 20th century because of DDT.

Ospreys serve as an indicator of environmental health. Because Ospreys’ diet consists almost entirely of fish, the health of their population can be used to understand the health of fish populations and the ecosystems they rely on. The success of Ospreys can be attributed, at least in part, to abundant fish populations and clean water sources.

That continues to be the case. But the 2024 report also includes a discussion of Chesapeake Bay, where a scarcity of fish, particularly Atlantic menhaden, led to widespread nest failures in some areas that might threaten the Bay’s success in the near future.

The report states: “As was seen in the Chesapeake Bay, prey levels can fluctuate and plummet rapidly as well, starving young. While Connecticut may have a more diverse population of forage species and harvesting is managed differently than other regions, even slight changes can dramatically impact the Osprey population immediately.

“Monitoring the seas, keeping littering at a minimum, expanding education and public outreach in sensitive areas, continuing to promote the erection of new [nest] platforms, and widening the volunteer base should all continue to be priorities to provide a buffer against losses and encourage the Osprey population to grow ….”

Among the many encouraging signs in Connecticut were the number of volunteers—420, including 112 people who were new to the program. That shows a remarkable dedication to the protection of Connecticut’s birds and its environment in general. Over the project’s history, well over 1,200 people have volunteered to track the status of the state’s Ospreys.

The volunteers sign up in spring to observe nests, and then visit the nests several times a month into August and September, to watch for signs that the birds are nesting and raising young. They submit information about what they’ve seen for the Osprey Nation map.

Ospreys are so abundant that one pair nested successfully on a rock in Norwalk. Photo by Robin Horgen.

It shows that Long Island Sound and the state’s rivers continue to be the Ospreys’ strongholds. But the volunteers documented that Ospreys are continuing to expand their nesting range, with new nests identified in inland areas, including Torrington, Cornwall, Salem, and Simsbury.

This expansion reflects both a growing population and increased public awareness leading to more nest discoveries.

The report also identifies potential challenges. These include the possibility that the Osprey population will exceed the carrying capacity of some areas. Ospreys have already expanded beyond marshes and river edges to occupy utility poles, communications towers, buoys, and rocks. The increased nesting near human activity might lead to conflicts in the future.

Climate change and prey fluctuations also pose threats to the long-term health of the Osprey population.

The Osprey Nation report concludes, “The species may move near or beyond the carrying capacity in Connecticut, at least in some regions, as birds more frequently choose nesting locations in closer proximity to human activity. Climate change and more severe weather events can take a future toll as well, from wild spring temperature swings to more prolonged summer heat waves hurting young in nests.”

Connecticut Audubon emphasizes the importance of the Osprey Nation project to monitor the future well-being of these birds. To learn more about volunteering for the 2025 season, email osprey@ctaudubon.org.

 

 

Key Takeaways from the 2024 Report

  • Record-breaking Numbers: The 2024 Osprey Nation season was highly successful, with record-breaking numbers of volunteers (420), nests with data (973), active nests (726), and fledglings (1,077).
  • Strong Productivity: The 2024 productivity rate remained strong at 1.48 fledglings per active nest, the fourth highest in 10 years of the project. 
  • Expanding Osprey Population: The map of Osprey nest sites in Connecticut is expanding, with new nest sites being added in inland areas. This expansion is attributed to both increased awareness and reporting of nests, and a growing Osprey population.
  • Favorable Weather Conditions: While the early part of the season saw challenging weather, including severe winds that damaged or destroyed nests, the remainder of the season saw favorable weather conditions. This contributed to successful incubation, foraging, and feeding, ultimately leading to a high number of fledglings.
  • Ample Prey: Connecticut’s Ospreys were able to find plenty of fish to eat, contributing to the successful breeding season. This contrasts with the Chesapeake Bay region, which experienced high nest failure rates attributed to a lack of Atlantic Menhaden, a primary food source for Ospreys in that area.
  • Potential Challenges: The report suggests that the Osprey population in Connecticut may be approaching or exceeding its carrying capacity in some areas, leading to increased nesting near human activity. This, coupled with potential future threats such as climate change and prey fluctuations, highlights the need for continued conservation and monitoring efforts.

The Chesapeake Bay Osprey Crisis

Osprey in Connecticut. Photo by Joseph Szalay.

The 2024 Osprey Nation report highlights a contrasting situation in the Chesapeake Bay region, where Ospreys experienced a challenging breeding season and the nest success rate fell below the level necessary for the population to sustain itself.

The report cites data from the Center for Conservation Biology, which monitored 571 Osprey pairs in 12 study areas within the Chesapeake Bay. The Center found a high percentage of single-chick broods and nest failures, attributing this to starvation caused by limited prey availability.

The Center’s study linked the lack of menhaden to the harvest practices of industrial fishing companies, raising concerns about the impact of these practices on the Bay’s ecosystem.

Osprey Productivity
The lack of menhaden resulted in a significant drop in the Osprey productivity rate in the Chesapeake Bay, falling below the level necessary for the population to sustain itself. This decline raises concerns about the future of the Osprey population in the Bay region.

Regional Variations
The report also notes that Osprey nesting success varied within the Chesapeake Bay region. Osprey located in freshwater areas of the Bay had higher survival rates because they could forage on other fish species like catfish and gizzard shad. This highlights the importance of habitat diversity and the availability of alternative prey sources for Osprey populations.

Implications for Connecticut
The report emphasizes that while Connecticut’s Osprey population thrived in 2024, the situation in the Chesapeake Bay serves as a cautionary tale. The report stresses the importance of continued monitoring of prey levels in Long Island Sound and managing harvesting practices to prevent a similar crisis in Connecticut waters.

 

 2015201620172018201920202021202220232024

Stewards

146

224

287

314

342

231

342

385

411

420

Active nests

250

337

394

416

501

510

558

606

688

726

Fledglings

356

490

607

725

650

549/
744*

858

835

881

1077

Fledglings per nest

1.42

1.45

1.54

1.74

1.3

1.08/
1.46

1.54

1.37

1.28

1.48

*observed/estimated

 

 

 

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