Colorado Grouse Apr 14—23, 2006
Posted by Marshall Iliff
This was a historic Colorado Grouse trip, enjoying better weather and a higher total species list than any of our previous trips. Despite the slightly earlier date, our group managed to record some 203 species, which was three better than the previous record and 13 better than the next best. It is worth remembering that we have conducted this trip for almost 20 years!
First and foremost, we had excellent experiences with all six of our target grouse species. We began with Gunnison Sage-Grouse, which is the most distant lek, and often the most difficult species to observe well. This year’s show went on for about 45 minutes after sunup, and was the best show that either of the leaders had seen. Some females lurking around the edges of the lek kept activity high, and everyone had good views of the birds through scopes.
Two days later we greeted dawn at the Lesser Prairie-Chicken lek. Despite our fears about the declining population and low counts recently recorded, we had at least 12 birds on the lek, including eight animated males facing off, quarreling, and trying to impress several females that were strolling around looking generally disinterested. When the birds finally departed, we were all grateful to be able to take a restroom break at last!
A couple of days later we were comparing the displays of Greater Prairie-Chickens with those of the Lessers. The low hooting sounds produced by the Greaters gives an eerie and less frenetic feel to the lek, in comparison with the bubbling and cackling of the Lessers. The highlight at the Greater Prairie-Chicken lek was watching a Northern Harrier come lazing over the lek and suddenly shift into attack mode as it stooped and swooped on prairie-chickens. Since the chickens probably weigh more than the harrier, this was a surprise to us all. The harrier was persistent, as were the chickens; immediately after escaping the talons of the harrier, the male chickens would return to continue their displays. This in turn gave the harrier multiple chances to bag a chicken, but despite at least 15 passes and two very near misses, the harrier went away hungry.
Two mornings later the rising sun illuminated perhaps the most impressive grouse lek of our trip: on the road in front of us and on both sides stood some 75 Greater Sage-Grouse, some as close as 10 feet from the van! Over the course of our morning’s observation, we saw males contest the valuable central spots on the lek with running charges that looked like a perfect hit in football or ice hockey. Other males sidled up to one another and delivered slaps to the face with their opposing wings. Still others engaged in staring matches until the weaker bird backed down. Some of us also got to see a rare copulation?remember that it may be just 5% of the males at a given lek that perform 95% of the copulations. In grouse this is a quick affair, with the entire process taking less than 15 seconds from her wings down presentation pose to the parting of the ways. That evening we worked hard for our fifth species of grouse, the Blue Grouse. Blues do not lek the way the prairie grouse do; instead, they congregate loosely along ridges and attract females with their low hooting noises. After a couple of hours of beating the bushes, we finally came up with several males that put on great shows for us. In fact, once they started displaying, they barely let us leave for our dinner reservations!
The next morning we watched the choreographed dance of the Sharp-tailed Grouse, with males wheeling in circles with their wings held out jet-plane-style, tails cocked straight up, and their purplish air sacs producing their own odd, gargling sound. For icing on the cake, we managed to find (for only the second time ever on this tour) a male White-tailed Ptarmigan in its snowy white plumage atop Loveland Pass. Unfortunately the bird was high up on a trail and required a strenuous hike to reach it, but most of the group got to see this crème-de-la-crème of the Colorado grouse.
Our list will reveal a host of other avian highlights, but I’ll stress just a few here: all three rosy-finches at point-blank range; an aggressive Grasshopper Sparrow right outside the window; three rare flycatchers, plus Carolina Wren and Northern Parula in the southeast; both longspurs doing their aerial displays on the Pawnee; a surprise Three-toed Woodpecker at Cameron Pass; a Glossy Ibis; and, most amazing of all, a very lost Mexican (Mallard) Duck at Walden. Thanks to you all for being such a fun and genial group. This will be my last Colorado Grouse trip for a while, and it was great to end it on such a high note.