Gray-crowned Rosy-finches and eBird

[colorad...@aol.com]

Hi all:

Gray-crowned Rosy-Finch is represented in Colorado by two subspecies groups.  eBird's nomenclature for the two groups is:

Gray-crowned Rosy-Finch (Gray-crowned)

and

Gray-crowned Rosy-Finch (Hepburn's).

The second of these two subspecies groups is of birds with nearly entirely gray heads, while the first is of birds with brown "cheeks."  I am currently trying to analyze the ratios of these two subspecies groups in the state, but I am hampered by the inconsistency of eBird reporting of the two groups.  So, I write this note to request that if you report any birds using the subspecies-level entry for Hepburn's, please don't report any other Gray-crowned Rosy-Finches using the species-level entry, unless you understand what you're reporting.

As example, if you see 48 Gray-crowned Rosy-Finches and determine that 12 of them are Hepburn's subspecies group and 36 are referable to the "Gray-crowned" subspecies group, please report these birds as follows:

12 Gray-crowned Rosy-Finch (Hepburn's)

36 Gray-crowned Rosy-Finch (Gray-crowned)

Do not report as follows:

36 Gray-crowned Rosy-Finch

12 Gray-crowned Rosy-Finch (Hepburn's).

That is because in the second option, you are saying that you are positive that the 36 birds belong to the SPECIES Gray-crowned Rosy-Finch, but that you are unsure as to which SUBSPECIES GROUP they belong.  I cannot determine subspecies-group ratios from data reported as such, because I have to assume that the subspecies group was undetermined in the second example, even though the observer (in this hypothetical case) knew that they belong to the "Gray-crowned" subspecies group.  I am having to throw away an awful lot of data due to this inconsistency.

Thanks,

Tony

Tony Leukering

Wiley, CO