A Rare Encounter from Columbia

Truth be told, ospreys are not protected in their wintering areas. In many areas they are seen as direct competitors with people for food (from the fish that they eat) or as pests at commercial fish farms in South America where they winter in large concentrations. I've herd that some fishermen shoot at them while they're on migration south over the Caribbean and Central and South America. Most band encounters from South America are not accompanied with a lot of photos and a report from a veterinarian. Really, we are lucky to get a report at all... This is one exception where an individual and a community became engaged in trying to save an osprey that originated in New Jersey.

Alberto Aguilar holds out the wings of the rescued osprey in Columbia.

This banded osprey (hatched in 2011) was encountered in Colombia recently near Cienaga del Cristo, Tamalameque, Cesar. Alberto, an environmentalist there, tried to help save this individual. He was found entangled in old fishing nets and was emaciated and dehydrated when found. He was examined by a local veterinarian and was found to be loaded with parasites, had an enlarged gall bladder, and had an ulcer on its left nictitating membrane (3rd eyelid). Unfortunately, the veterinarian was unable to save him. He was banded on July 7th on a nesting platform that is located to the north of Stone Harbor Blvd. by one of our volunteer banders, Hans Toft. Hans recalls visiting this nest:

"I remember this nest well because it is a long walk with the ladder to get to it. The nest is on the north side of Stone Harbor Blvd (175A024) and is easy to check on by car with binoculars. I am always going over to my boat in Stone Harbor anyhow . After we banded the two chicks I kept an eye on them and remember watching the two birds during the summer, and seeing them fledge. Also, the birds were eating a bluefish when we banded them.  Of course, we have our problems also with fishing lines, nets, etc.  good to hear that the bird will be put to good educational use."  Hans

We were sent a bunch of photos of the bird and the report from the local veterinarian. From the photos you can see that this bird has already molted most of its juvenile flight and body feathers (as a juvenile they have a buff tip and as an adult they are all dark). The eye is also yellow instead of orange. It weighed a total of 1200 grams which indicates that its a male (females weight from 1600 - 2000 grams). He also is lacking the dark necklace of feathers that female ospreys develop on their breast.

Alberto and many of the locals were very excited about this rare encounter. They have decided to mount the bird and use it as a way to educate people there about old fishing nets and the need to be careful with them.

To view more photos, click here.

A photo of the osprey after it was rescued in Columbia.

This bird was banded at a nest on a
platform off of Stone Harbor Blvd
by one of our volunteers, Hans Toft.

       

Migration Revealed!!!

Since this past summer when myself and our volunteers banded almost 80% of the young (357 out of 454) that were produced we have gotten several recoveries of those bands. When a band is recovered, it is found on either a live or dead bird. So far we have had 5 bands recovered from this year's fledglings. Most of the time the bird is found found dead. In this case the bird was found dead and the USGS Bird Banding Lab was notified by the finder calling the phone # that was on the band (1-800-327-BAND).

This bird originated from a nest on a channel marker in West Wildwood and was banded by one of our volunteer banders, Hans Toft. Amazingly enough, this juvenile actually lost it's mom due to being entangled by monofilament. The adult was found dangling from the nest and had its legs bound by the line. Luckily a bulkheading crew that was passing by cut the bird free and got it to us so we could transport to our rehabilitator, Don Bonica of Toms River Avian Care. Tragically the adult did not survive, but we do know that the adult male was successful with raising its two young to fledge, and one of those young survived enough to make it to it's wintering area in South America.

The bird and band was recovered on 10/28 and was found near Tolima, Colombia in the town of Ibague. This recovery shows that this juvenile osprey traveled around 2,300 miles to its wintering area. Ospreys normally spend the next breeding season in that area then return to NJ the following year. So young that were produced this year will most likely return to NJ in late March, 2010.
However, not many young survive during the first year of life. A young osprey faces many difficult challenges and the mortality rate for most birds of prey including ospreys is around 80%. So of the 454 fledglings from NJ, only 91 may survive to return to breed in NJ in 2010. Not a very optimistic statistic.

While in their wintering areas ospreys face many perils that they do not see here in the U.S. In South America, many countries still have not banded DDT (however it isn't used as heavily as it was here in the 1960's) and other harmful chemicals which eventually runoff and make their way into the water table (where ospreys find food). Also, in many areas in the Southern Hemisphere there are large fish farms. These fish farms are bound to attract the attention of young ospreys and when they do, the farmers probably do not hesitate to shoot them! Other major causes of death are impacts with many man-made structures including buildings, power poles, and radio guide wires. Electrocution is another cause of death when an unsuspecting bird perches on a power pole.

I'll post more maps of where we have had other recoveries from this years young soon. If you'd like to see more detailed accounts of other fledglings from Delaware and Massachusetts, click here for a link to a satellite tracking project with UNCC.