Dr. Charles R. Preston, Senior and Founding Curator at the Draper Natural History Museum, Buffalo Bill Center of the West in Cody, Wyoming
19 July, 2010 – There are still several eagle youngsters in the nest or hanging around the nest for shelter and continued feeding. Richard Jones and I visited several nests last week and found that some young eagles that had fledged several days ago were back on the nest ledge, under rocky outcrops for shade. Temperatures soared to 100 degrees F in the Bighorn Basin, so shade was popular and critical especially to youngsters who may have trouble with thermoregulation!
We continued collecting prey remains from some of the nests that have been abandoned. Most nests are filled with cottontails, cottontails, and more cottontails, but other nests held some surprises. One nest near Meeteetse held the remains, including skull, of a pronghorn fawn, along with a jackrabbit pelvis, a red fox skull, at least two snakes, and a cast pellet full of raven feathers. Another nest held the remains of at least two young coyotes! We found a massive infestation of lice and other ectoparasites in one nest.
This particular nest was abandoned by its two youngsters about 2 weeks before they could fly—these pests may explain the early departure, and may provide clues to some of the nest failures. They found shaded shelter beneath the nest site and were fed by parents for at least 13 days before they disappeared from the site. At last observation, both birds appeared ready to fly. These birds were banded, so we may be able to determine the fate of them one day.
Nearly all wildflowers are past blooming in the Bighorn Basin just as peak blooming hits the Yellowstone Plateau and the high country. I’ll be hitting subalpine and alpine sites this week with Center photographer Chris Gimmeson to capture new photographs for an upcoming book on the Draper Museum and for our exhibits. Richard Jones and I will also be out in the Basin to continue documenting nest sites and collecting prey remains—we’re hoping for some cooler weather, and will keep you posted.
Here are some of the reports I received this past week from our two teams of our Golden Eagle Posse nest monitors from the same nest:
Report from Barb and Jeff Russell on 16 July: We went to the nest about 6 p.m. this evening—where it was 100 degrees—the first hour we thought we were watching both nestlings laying in the sun in the “spare room” (the small area to the left of the nest). After about an hour, we saw three eagles flying. One was the juvenile we’ve been seeing at the other end of the dirt road. At the same time that one of the adults briefly grappled with the juvenile, the other adult flew into the nest, touched down and flew out again—the chick jumped over and made contact with the adult. That’s when we realized… ONLY ONE NESTLING.
We’re pretty certain it’s the smaller of the two, the head and neck are still pretty scrawny. Not long after this contact one of the adults brought a rabbit to the nest. Then at 20:30 when we were getting ready to leave, one of the adults perched just a few feet directly above the nest for a minute or two. The nestling chirped and chirped. Then the adult repeated the first behavior—dropped briefly into the nest, the nestlings made contact and then the adult flew out and perched on the highest peak. We’ve not seen this behavior in previous visits; looks like adult may be encouraging nestling to fly? All in all an exciting evening!
Report on the same nest from Susan Ahalt and Nicole Suuck on 18 July: Have been visiting our nest more frequently now, hoping to witness our chicks’ first flights. One bird (we call Slug) is< still in the nest. The other baby that left the nest a few days ago apparently decided leaving home so early wasn’t a good idea so has been making his way back to the nest (we call this one Rock). He spent most of the three hours we watched them calling for his parents and didn’t move from his rock. The adults were gone a lot but ended up below the ridge point just chilling. As it went from 66 to 85 in that same three hours it was a good idea.
Many thanks again to all of our Posse members. I can’t include all of your reports each week, but I do read them all and look forward to following your progress. Just a reminder, your data sheets and field journals are due when your adopted eaglets fledge. That will be soon for some of you! Stay tuned for further updates next week.
Best wishes, C.R. Preston
