Sharp-shinned Hawk (Case History #1)

Nestlings raised in nest basket at nest site by “nest-site hacking”

Two nestling Sharp-shinned Hawks were found on the ground near a hiking trail at Oak Mt. State Park, only a fifteen-minute walk from the Alabama Wildlife Center.  Age when received is estimated at about 14 days.   The nest site was scouted, but the nest was high up in a very slender pine tree, too dangerous for climbing.  Five days after separation, a nest basket was placed about 50 feet away in a more accessible tree, and alarm calls were played to attract the parents.  No sign of the parents was ever detected, however.  The most likely explanation is the delay of five days in attempting to reunite the birds, although this interval has not been significant in reuniting  many other species.

Because Sharp-shinned Hawks are bird-eaters, it is extremely difficult to offer any useful practice at hunting live prey to fledglings raised in a flight cage.  To give young Sharp-shins the best chance of making it through the difficult fledging period, they should be raised by hacking if they cannot be reunited or fostered.  In this case, because the nest site was so close to the Wildlife Center, we decided to leave the nestlings in the nest basket, and hack the birds in their parents’ nest territory.  The birds were about 19 days old, and were capable of feeding themselves.  However, we could not leave a ladder at the hack site, since it was close to a hiking trail.  The ladder would have drawn attention to the basket, and might have resulted in the birds being disturbed or even stolen.  Instead we rigged a rope to pass through a pulley suspended directly above the basket.  Small plastic baggies about half-full of ice were used to transport mice to the birds in the morning and the evening.  A mouse-sized hole was cut in the bottom of the baggie just before clipping it to the rope and hauling it up to hang immediately above the basket.  When the ice melted about 20-30 minutes later, the mice would fall directly into the nest. The birds were fed by this method twice a day.  Although Raptor Intern Jessica Leonard also wore a ghost outfit when approaching the hack site, the ice bag also helped to keep the birds from associating feedings with humans. (See page 31 for a complete description of this device)

The nestlings were placed in the nest basket on June 17, when they were about two and a half weeks old.   They were first seen to leave the nest basket on June 22nd.  A game camera was later positioned near  the nest basket, but only a few useful pictures were obtained.  The first photo shows one of the fledglings perched on the rim of the basket on July 14 at 4:28 p.m., apparently waiting for the ice to melt for the afternoon feeding.

Another photo snapped at 8:26 a.m. on July 15 shows a wing and a tail as a fledgling checks to see if the morning feeding had been delivered (it had not.)

 

 

 

 

A third picture taken at 11:48 on July 15 shows one of the fledglings waiting for the ice to melt on  the morning’s feeding.  This was three weeks after the birds had fledged, and morning feedings were by then being deliberately delayed to encourage the birds to hunt.  Feeding was discontinued in mid-August, as the birds had left the nest area and were no longer coming to the hack site.

 

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