We have been waiting for an opportune moment to remove the transmitter from Coley since mid-April when we discovered his broken strap. Ospreys follow the same migration route each year, so we’ve already learned about 90% of what we can learn by tracking him, and removing the transmitter will keep him safer.
On Tuesday April 23 we attempted to catch Coley. The process usually involves placing a lightweight metal snare trap (like the one below) over the nest so that when the Osprey comes to incubate the eggs, the talons get caught in the snares. Catching the male usually requires catching and holding the female thus allowing the male to take his turn at incubating the clutch of three eggs.
That day we successfully caught the female while Coley was in the area. He flew over the nest a few times but never actually landed. We held the female for as long as possible but then decided we could keep her no longer. We set her free and she flew off to one of the couple’s favorite perches. As we were walking back to the Jamaica Bay Wildlife Refuge Visitor Center, we saw Coley fly in with a fish, heading to the female. When we reached the Visitor Center, we checked the nest through a telescope and lo and behold, there was Coley, incubating. A series of expletives followed as we vented out frustration, but we already had pushed the disturbance limit so we decided not to go back out and to try again another day.
Tuesday, May 7 was our second attempt. This time we did not disturb the female until Coley arrived with a fish. Most of the time, when the male catches a fish, he will eat his fill, usually the head and upper body, then fly to the nest to transfer the remainder to the female. Then she will go off to eat while the male incubates the eggs until she returns. Around 11 am Coley flew in with a Menhaden or Bunker and headed to his favorite perch to eat. We waited and waited but Coley did not bring the fish to his mate. We proceeded to catch the female, thinking that Coley would fly in, but alas he kept away from the nest. Frustrated again, we let the female go, packed up everything and headed back to the Visitor Center.
And guess what? No sooner had we reached the Center than Coley was incubating the eggs. Half our team had already departed, but Park Ranger Colleen Sorbera, Harbor Conservancy Staff member Blanca Begert and I decided that we would give it one more shot – all or nothing! We headed out, set up the trap, and waited in the distance. Coley flew over and so did his mate. The female landed briefly on the nest and then flew to a nearby perch. Coley would not come in.
We gave him 10 minutes, until 2:55 pm, and then threw in the towel and headed down the trail from our distant post to remove the trapping device. When we got close enough to see the nest again from behind the shrubs on the trail, we saw what we thought was the female caught on the nest. The last thing we wanted to do was to catch her twice in the same day! As we ran out to set her free, an Osprey flew over, the female. We realized then with amazement that Coley was the one trapped on the nest! We raced over, put up the ladder, and got Coley under control in record time. Within minutes we removed his transmitter, gave him a quick check over to make sure the transmitter or harness hadn’t hurt him in any way, and set him free.
The strap from the transmitter that ran over the right wing to the front of the breast where all four straps were sewn together had been chewed in half. Apparently the other three straps provided enough stability for the transmitter to remain in place and functioning. Coley was neither left in danger nor hurt by the broken strap.
So what is next? We will try to put Coley’s transmitter on one of his neighbors, following him to his wintering home and back and gaining new information on the movements of Ospreys in Jamaica Bay. Let’s hope the trapping attempt goes more smoothly with a new Osprey than it did this time with Coley! Stay tuned.
Coley and Dr. Bob, Signing Off