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July 2009
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Florida Osprey Mortality
Filed under: General, Birding & Outdoors, Florida & SE US, Bald Eagle Nest
Posted by: Ken @ 8:38 am

Osprey in flight:

Osprey 20090330

In recent weeks, at least eight Ospreys have died along a relatively small stretch of the Florida Gulf coast in Pinellas County near Clearwater. Food for the young appeared to be adequate this spring. According to Barbara Walker, OspreyWatch Program Coordinator from Palm Harbor, these birds have generally done very well. In her estimation, fledglings have been produced in 90% of approximately 30 Osprey nests she has been observing, all in heavily populated areas. Osprey watchers have counted 140 nests in the northern part of the county, of which 90% were on man-made structures such as power poles, cell towers and nest platforms.

Barbara writes: “As far as we know they were all severely emaciated.  Some of the locations include Pasadena, Clearwater, Dunedin, and Tarpon Springs.  In one instance, on the same property, two Osprey and 1 yard cat perished. The Fish and Wildlife Commission has been contacted in hopes that they will investigate.  If anyone can share recent Osprey observations or photographs or has first hand information about a sick or dead Osprey please contact [Barbara] or call  727-431-2856.”

Osprey 20081105

“I think there is something wrong ecologically or environmentally here.One theory was that the water temperature could be too hot and the fish are too deep.  Climate change? However I would think the recent rains would have cooled the water somewhat. Anyway, we can’t help but wonder why so many deaths in such a short period of time and I am raising a red flag in this area.”

Most of the dead Ospreys were juveniles. One had been observed catching fish and visiting the nest shortly before its death, and a neighborhood cat also died mysteriously, raising suspicion that some sort of toxicity was involved. Barbara stated that one theory is that as juveniles “they were not highly skilled and were unable to catch any fish in the heavy rains.” However, she noted that the timing of the death of this particular bird “does not coincide with the other recoveries. All of these Osprey are along a specific area of the coast. We have not yet had any reports of Osprey down among other more inland groups such as the Lake Tarpon group or the North Tampa Bay Derby Lanes group to my knowledge although I am sure that more juveniles were treated at Suncoast Seabird Sanctuary that may have come from those areas or areas to the south.”

Barbara related that the Florida Fish and Wildlife Conservation Commission (FWC) is coordinating necropsies for several of the Osprey. “One was done this week. We will have to wait for the results.  Comments from rescuers have consistently been that these are the most emaciated Osprey they have seen, just feathers and bone.”

Since ospreys share the top of the fish-eating predator food chain with Bald Eagles and many other herons, gulls and terns, I find this issue, so well described by Barbara, to be a major concern. Perhaps there are particular risks along a small strip of the Pinellas County coastline. We hope the cause of the deaths is determined.

We will be following this issue on our local Pembroke Pines Bald Eagle Watchers FORUM

Here is Barbara Walker’s map, showing the locations of the Osprey deaths:

Osprey Deaths

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