I've been interested recently in the subject of "exotic" birds and the difficulty birders have in determining their status as wild or escapees. I've spoken to several breeders of exotic birds about their practices and how frequently birds escape, but now I wanted to talk to someone on a records committee.
Records committees are the ones who have to make the "official" decision on whether or not an exotic bird seen in the field got there on its own or with some kind of human assistance. I have never sat on a records committee, and I wanted to know how such a body reviews birds like Smew or Greenfinches or Bar-headed Geese - birds that could theoretically be migrants.
It interests me because all it takes it one. Nine hundred and ninety-nine Bar-headed Geese seen in North America could be escapees, but that last one just could have been blown astray during a high-altitude migration over Asia. Would we know? Does anyone care to check?
After this brief chat with Phil Davis, a long-time members of the Maryland/DC Birds Records Committee, I feel confident that the answer is Yes. I have known a few members of records committees over the years, and I haven't met a single one who doesn't take their job very seriously. Phil continues that tradition, and his answers reveal the inherent difficulties in dealing with these types of records, as well as the common-sense approaches the MD/DCRC uses in an attempt to find an answer. Although it still may be impossible to completely determine the origin on a bird seen in the field, there are birders out there doing their best to figure it out.
PCD: When the MD/DCRC reviews a record, in addition to the question of identification, there are effectively three levels of "origin" consideration that come into play.
(2) At the other end of the spectrum are the birds whose origin is most certainly "exotic," meaning escaped or released from human captivity. An example of this category would be a Black Swan, which is a sedentary or short-distant migrant from Australia/New Zealand, that is known to be kept in captivity in ornamental waterfowl collections.
(3) In the middle are species that fall in between those two extremes. These are species considered to be of "questionable" origin, which means that the bird could be natural/wild or it could be an escaped/released "exotic;" however, there is just no way to be sure - so, it's origin is found to be "questionable." An example in this category might be a Garganey; an ornamental European/Western Asian duck, but also a species that is a long-distant migrant that clearly reaches at least the west coast of North America.
PCD: From a committee process standpoint, sighting reports are circulated among the nine voting members of the committee until a decision is reached or for a maximum of four rounds of review. If all of the members vote to "Accept" a record as natural/wild, the voting is over. If all nine members vote to accept as either "exotic" or "questionable" origin, then the voting is over. However, if the members are split between "accept," "exotic," and/or "questionable," then the report is circulated one more time so the members can review each others comments, and then the majority category prevails.
0 comments:
Post a Comment