Hi all:
A late report, but when I was visiting with the Colorado Springs Acorn Woodpecker on Thursday, 1 Feb, I found an immature White-throated Sparrow across Willow from the yard in which the woodpecker is often seen -- just a heads-up.
As for the discussion about remotely-sensed records, I would be quite happy to vote to accept as a valid Colorado record should there be:
1) unequivocal evidence that the geolocatored or telemetered bird was identified correctly (as noted by Doug, a photo of the individual would suffice) and
2) the remote methodology's error rate in location (see below) was sufficiently small to have the entire polygon of possible locations be inside the state's boundaries.
I believe that the combination of photo of subject bird and the remotely-sensed location should be sufficient as "physical evidence" for even a first state record.
More about remotely-sensed location error rates
Geolocators: As noted in Beason et al. (2013), the latitudinal error rate using geolocators is some 200 kilometers (or ~124.25 miles). Considering that the maxium north-south distance in Colorado is ~451 km (280 mi.), we can readily see that there is really very little margin for error for a remotely-sensed Colorado bird record. Though some might think that this should allow some 250 km of potential error, that would be a mistaken belief. This is because not only does the location have to be 200 km from the northern border, it also has to be 200 miles from the southern border. That leaves a band of just 50 km (31.1 mi.) or so crossing the state from about latitude 39°10'50.09"N south to about latitude 38°48'15.07"N. This band of latitude includes, from E to W, Hugo (but not Burlington), Colorado Springs (but not Larkspur), Hartsel (but not Fairplay), Buena Vista (but not Salida), Crested Butte (but not Gunnison or Aspen), and Grand Junction (but not Delta). Thus, I think it highly unlikely that the CBRC will ever accept a geolocatored-bird record.
Satellite transmitters: The location error rates are much, much smaller using this technology (as compared to geolocators), allowing for much better precision and a much higher likelihood of the CBRC accepting a record of a bird recorded in the state using the technology. However, satellite transmitters are very expensive ($5000/unit or more) and there is an absolute size limit in birds that, currently, can wear such a heavy package. Most of the weight in a satellite-transmitter package is taken by the battery, so reducing battery size can enable deployment on smaller species, but at the cost of unit longevity. Thus, the last time that I looked, female Peregrine Falcons could bear these units, but not males of the same species. Undoubtedly, with the rapid advance in battery and electronic miniaturization, the line has been lowered to smaller birds since last I looked, but probably not all much. The costs are also prohibitive for dealing with species without large sources of funding behind them. So, while I can easily imagine Colorado getting remote-sensed records of California Condor and Whooping Crane (both species with a relatively large percentage of the individual species' populations currently wearing active satellite transmitters (in fact, the CBRC ought to seek out such records), but we can probably forget about getting the state's first Bicknell's Thrush record via this techonology; at least, anytime in the near future.
That is my two cents' worth.
Tony Leukering
Villas, NJ
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