On Dec 29th, we conducted the 44th consecutive CBC at Barr Lake. We had 35 participants among 10 survey groups and collectively we saw 34,632 birds of 81 species. We had a nice calm and warm day for the count, with ideal conditions for visibility.
Leading up to our count date we had unusually warm weather, with especially warm nights and nighttime lows that barely dipped below freezing. In fact, our starting temperature for the count day was the highest we've ever had in those 44 years. This meant Barr Lake itself and all other reservoirs in the area were entirely ice-free on the day of the count.
We average about 70 species for this count circle and our total of 81 species is our 2nd highest ever (in 2004 we had 82 species). This was due in part to a few rare species that were known to be within our count area prior to the count (Northern Cardinal and Mexican Duck) as well as a surprise or two on count day (Golden-crowned Sparrow, Cedar Waxwing). Cackling and Canada Geese nearly always top the list in abundance, and this year was no exception, with those species accounting for about 45% of our total. Waterfowl numbers across the board were about average this year, though down substantially from last years' record waterfowl numbers.
One number we always pay close attention to is our Bald Eagle count. When this count circle started in the early 1980's we would count between 1-5 Bald Eagles each year. That number began rising in the early 1990's and in recent years has been hovering around 100. This year we tallied 47 Bald Eagles, our lowest total over the last 6 years. It's hard to know what to attribute that towards, perhaps the lower water levels at Barr Lake are not as enticing, or the warm weather has more of them staying further north.
Some of our species numbers were quite low. We had an all-time low count of just 8 American Tree Sparrows (too warm perhaps...), and missed out entirely on Merlin, Townsend's Solitaire, and Brown Creeper. Surprisingly, given the warm weather, we also missed out on American White Pelican, which had become a regular if sparse CBC species in recent years. Other species such as American Robins (262), White-crowned Sparrows (302), and Dark-eyed Juncos (103) were all close to their annual averages.
Thanks to all our participants, hope to see you all again in a year!
Colin Woolley
Bird Conservancy of the Rockies
Barr Lake CBC Compiler
Wheat Ridge, CO
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