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How to count a bird without really trying

March 25, 2008

In my daily blog perusal I was interested to note that the ABA checklist committee (CLC) is taking into consideration the status of the Common Myna in Florida. For those not aware, the CLC is the group responsible for determining whether or not you can put a bird on your official ABA lifelist. For us listers out here in bird limbo, their decisions are often eagerly awaited, especially as they regard splits (potential additions), lumps (potential deletions) and status of exotic populations.

Common Myna is an interesting case, first noted in the ABA area in 1983 from a Christmas Bird Count in the Miami area. Since then its numbers have rapidly increased from the original 6 birds, though the population still remains relatively small and widely scattered. The Florida Bird Record Committee has accepted it as an established species and as far as I know this is the first time the ABA has considered it for inclusion in their list of established North American avifauna.

The ABA CLC operates separately outside the realm of the other preeminent committee, that which is organized by the American Ornithologist’s Union or AOU. While the vast majority of species are shared by both checklists and the evidence debated for rarities is the same, each committee meets and decides independently. These decisions are often exactly the same, but there are some birds one group has accepted that are not accepted by the other. For example, a mystery Elaenia, a neotropic flycatcher, found in Florida in 1984 was accepted by the ABA as Caribbean Elaenia, but not by the AOU. While undoubtedly an Elaenia, the AOU wouldn’t accept to species of what is traditionally a very difficult genus, and the record sits as only 99% positive and thus, not definitive.

The most important difference between the lists, however, pertains to the count area. While the ABA includes only Canada and the US, without including Hawaii (because the Hawaiian birdlife is so very distinct), the AOU includes Hawaii, the West Indies, and all of Central America to the Panama-Colombia border. It should be noted that the Common Myna is well-established in Hawaii, and thus, already on the AOU list.

So the case of the Common Myna as it pertains to the ABA remains an interesting one as it is not a native species. To be come countable, a species must meet several criteria, including having a peer-reviewed journal article on its status written and published to be considered by the CLC. I had not heard of a population study this being done for the Common Myna though it was expected, so it must be fairly recent for the committee to begin considering it.

The article must suggest that the population is self-sustaining and can be considered somewhat arbitrarily “established”. I say this because some established species that at one point had self-sufficient populations, and were countable, might not always be considered as such. The Red-whiskered Bulbul in Miami, for instance, is such a case. In the 70s the bulbul had a thriving population in the Kendell suburb of Miami. However, the bird’s current population is declining, it’s now less than 100. It may soon be considered unsustainable and the bird would therefore be delisted and moved to an extirpated exotics list, like the Yellow-chevroned Parrot and Crested Myna before it.

Many of us consider exotic bird species to be a nuisance at best and a threat to native birds at worst. Though, in many cases they are here to stay so we might as well add them to our lists.


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