Dr. Charles R. Preston, Senior and Founding Curator, Draper Natural History Museum, Buffalo Bill Center of the West in Cody, Wyoming
12 July, 2010 – Vegetation in the Bighorn Basin is beginning to turn brown and crunchy, now, and most wildflowers have passed peak bloom. You can really pick out patches of cheatgrass in some areas. This alien, invasive species thrives in disturbed ground and can create real problems for wildlife and livestock grazing if it takes over too much landscape. It dries early in the season and invites the spread of wildfire. After wildfire, it often out-competes native grasses and forbs, and thus takes over even more ground. Bureau of Land Management, Park County Conservation, and several conservation groups are working to reduce cheatgrass in the Basin, but it is a tough job because of so much disturbed land around human activity.
I was able to visit many of our active and recently abandoned nests late last week and through the weekend. In several cases, eagles that have successfully fledged continue to stick around the nest area. Parents will continue to provision these youngsters for at least a few weeks longer. Richard Jones and I captured and banded one of these birds on Friday; a big, healthy fledgling from nest 31A. There are still a few nests containing eagles not quite ready to leave the nest on their own, but I’m anticipating that all successful nests will have fledged by this time next week. We’re still going through data and observations from last week’s aerial survey to tablulate final eagle nest occupancy, success, and productivity for this year. Stay tuned for our summary in the next few weeks.
Here are some of the reports I received this past week from our Golden Eagle Posse nest monitors:
Report from Anne Hay, Richard Gruber, and Don Chaffey on 08 July: Well it looks like our #1-oldest chick has fledged, at least it looked about ready last week, and it wasn’t present this week. We were unable, however, to see any signs of chick #1 in the area of the nest. The remaining nestling is healthy, dark, and looks ready to go any day now. It is certainly well fed! There was already prey in the nest when we arrived at 0600, which our remaining nestling was picking on when we arrived, then ignored for much of the day. At 0812 an adult arrived and the chick immediately pounced at the parent. As the adult moved aside I could see the chick mantling the prey.
The parent immediately left, at which time the chick closed its wings, picked up the prey, carrying it to the south side of the nest. It did not feed on the prey, but after depositing it in the corner of the nest, walked back to the north side of the nest where it stood looking around. At 1108 the chick moved to the center of the nest and fed on the prey that had been present when we arrived. After a short feeding, the nestling then moved to the prey we had seen carried in, and began feeding on that. We believe it was a young cottontail, as it had a white fluffy tail, although it was thin and quite small in size.
Report from Rosemary Hughes and John Ross on 11 July: I was out the 6th, 7th, 8th and the 10th, Days 15, 16, 17 and 18, observing these beautiful chicks. Can’t seem to get enough of them! The adults still come around and feed them. They don’t stay long though, just long enough to drop off the prey, figuring that’s all they need to do. The chicks have been moving around quite a bit, not going too far from the actual nest. When we come upon the site, the chicks are apart. By the end of most days, they are together. At times it will be the larger chick going to the smaller chick, then the other way around, but generally they end up together. And its quite fun to watch as they flap their wings, walk like penguin, kind of stiff, shoulders hunched, and then hop to perch wherever it is they want to end up.
One day was really exciting: an adult brought food to the larger chick, the smaller chick was squawking because it wasn’t getting any of the cottontail that was left. Just as the small chick started to make its move to go ‘steal’ some food, an adult, not sure it was the same one, came and brought another cottontail so that both chicks had some food. There was a bit of flapping of all wings when this occurred.
It’s been interesting to see how, when the sun is so hot, as it has been some days, they look for shade. With the sandstone outcrops they can usually find it. If only they hadn’t left the nest, they’d not have to seek out shade. One thing that we’ve found is that the smaller of the 2 chicks seems to be doing most of the ‘exercising’. It likes to walk around. Either going to the other chick or just exploring another part of its territory. It doesn’t sit still too long, unlike the large chick. It likes to stand on 1 leg. I can see the band on its right leg and when I do see the large chick perched, I can see its band on the left leg. They do stretch them out when lying down at times to where you can see them stretching their talons.
Report from Susan Ahalt and Nicole Suuck on 11 July (very typical of nests still active): Both babies were in the nest and looking more alike and very much the same size now. Both parents were there when we arrived. We’d never seen any flapping from the babies but today they each did some, more like keeping their balance than building flight muscles. I keep thinking they’ll fledge soon but at this point it may be the end of next week. It was very hot today but we passed the time in pretty good shape. The deer flies were out, so bug stuff was used as was sun screen. We both wish to be there when the babies take their first flight and only hope that will happen on our watch.
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
