For almost 10 years, the Hog Island Osprey cam followed the lives of Rachel and Steve, a dedicated Osprey pair who experienced no shortage of drama. Now a new female Osprey, Lady, has taken Rachel's place. Join along as cam fans watch her and Steve take on life and raise a family together. Oh, and even though it's billed as an Osprey cam, occasionally other species stop by for their 15 minutes of fame.
Windows on Wildlife: Hog Island's Intervention Policy
Now that Ospreys have returned to Hog Island, the Explore.org cameras are providing bird enthusiasts with amazing views of their day-to-day life. Like most Explore.org nest cams, the primary purpose of these Osprey cams is to provide viewers with an enthralling and educational “Window on Wildlife” experience that enlightens viewers about osprey family life. Nest cams help us to connect with wildlife at an amazingly intimate level, glimpsing the most detailed moments of their lives. Our Osprey cams also help to reveal new Osprey behaviors, details about the kinds and amounts of fish required to raise chicks, and the challengesOosprey face in life. It is our intention that the lessons we learn from the osprey at Hog Island help Osprey in many other places as well.
Those that have watched osprey nests previously know that that they may also show high drama from predatory eagles and owls and other surprises at the nest that can threaten the chicks and parents. These interactions are also an important part of learning about osprey and their lives. A question naturally follows: When is it appropriate to intervene to reduce the risk of chick predation or other threatening events? We hope that the thoughts that follow will help to explain what Audubon is prepared to do under some of the situations that might occur.
Because the Audubon Osprey nests are built on platforms on or near buildings, the nesting situation is an artificial setting. Osprey are remarkably adaptable, and nest in settings with a range of human influence throughout their range. Because these platforms are in a location of our choosing, for the purposes of our enjoyment, education, and study, we feel some human effort to help these Ospreys succeed in rearing young can be appropriate. For example, we believe it is sometimes OK to deter predators from taking Osprey chicks or attacking the adults, if done in a passive or indirect way. We do not believe it is appropriate to harm, capture, or remove predators that may come to these nests. Hog Island is a sanctuary for all wildlife, including eagles and owls, both of which are likely to be nesting on the island with young of their own to feed. We believe that predators are neither good nor bad, right or wrong, but simply doing what they and their ancestors have done for eons--working hard for their next meal. Learning about eagles and owls, and how ospreys have adapted to live with them, are vital lessons from the osprey cams.
For example, we see that defense of the nest is a central feature of the division of parental responsibilities. This did not come to happen overnight, but evolved in response to predation. We see this in the behavior of the parents – osprey Steve spends much of his summer patrolling the skies near his nest. He perches nearby, watching vigilantly, and chases predators such as eagles and ravens from the vicinity. Through the cam, we have also seen osprey behavior change in response to predation. For example, in past years Rachael modified her nighttime behavior from perching far from the chicks to sitting right on the nest cup.
In previous years, we have put metal sheathing around the Hog Island nest pole to deter raccoons from climbing into the nest. This is an example of a passive deterrent that has no impact on the predator other than eliminating a particular opportunity to pursue a meal. Two summers ago we experimented with a “teenager” mannequin and spotlights at night to provide some possible deterrence to owls—interventions that again had no direct impact on the predator. Last year we expanded this experiment by using a mannequin “family” along with the spotlights, and after an owl attacked, we even added the additional deterrence of playing recorded human conversations. These methods may have helped deter the owl, or at least owl attacks were less of a problem following each added intervention. The outcomes we observed suggest a couple important lessons. The first is perhaps not surprising: Human presence at night may deter an owl from entering the area around an Osprey nest. We have long suspected that our daytime activity on Hog Island has deterred Bald Eagles from bothering the Ospreys. A similar effect at night on owls seems reasonable. The second lesson may also be predictable: Owls and other predators may quickly acclimate to static or unchanging deterrents. This is consistent with other efforts to deter wildlife; for example, owl decoys are often successful at keeping pigeons and other birds off buildings and other structures, but lose their effectiveness over time.
Our experiments with mannequins, light, and sound have been informative, and appear to have benefitted the efforts of Steve and Rachel to raise young. They are actions that require maintenance and likely the regular addition of new effects, however. That makes them difficult to implement over time and limits their potential use in other places to benefit other Osprey.
Besides measured interventions to harmlessly deter predators, we also believe intervention is appropriate if an Osprey chick or adult becomes entangled in plastic or fishing line, because these are human-created threats. We would attempt to remove the entangling material where possible, but only when it is safe for the birds and our staff. Likewise, if a chick falls or jumps from a nest, managers would attempt to replace the chick in the nest or place it in a nearby location for the parents to attend. We would do the same for any other nestling bird. As a last resort, we might take an injured chick or fledgling to an avian rehabilitation center. If the nest was invaded by stinging insects (as happened in one recent year), we would not use pesticides to reduce the stinging insects because, like predators, these are naturally occurring environmental challenges to ospreys and pesticides can be toxic to birds. We also would not provide supplemental feedings at these nests. We will assess new situations as they arise on a case-by-case approach, usually favoring a “hands-off” approach.
The 2020 Breeding Season
Because of precautions necessary due to the SARS-CoV-2 pandemic, the Hog Island Audubon Camp will be closed during the summer of 2020. This reality saddens us for many reasons, one being that we will not be able to directly observe and enjoy the Hog Island Osprey. There will not be the regular presence and activity of campers and staff on the island, and we will not be able to maintain the mannequin, light, and sound deterrence. This circumstance will produce an unplanned, or “natural” experiment: How will the osprey and their predators behave in the absence of all of us?
We have implemented one additional experiment this year, adding a new osprey nest platform atop nearby Porthole Lodge, the tallest building on Hog Island. This location is near Steve’s existing nest, but further away from trees and water—an advantage that may make this nest site safer from predators. A nest platform in this site also has a good chance of attracting another pair of ospreys, which could assist in defending the general area from predators. Or it might become a future nest site for Steve and his mate. Some will recall that Steve was building a new nest on the Crown Royal, a fishing ship that was anchored nearby, until the owner moved it in 2018.
The recent addition of a nest platform atop the Audubon boathouse was planned for this same reason. To attract additional Osprey pairs to the immediate vicinity with the thought they would help to defend the Hog Island nest. With less activity this summer, we are hopeful that a pair will settle here. The early signs are encouraging.
We hope readers find this rationale helpful both upfront and as the season proceeds--especially if predation attempts occur at these osprey nests. Meanwhile, we look forward to another season of osprey watching with you!
—Don Lyon, Director of Conservation Science, National Audubon Society