Regarding exotic species

[Cliff Otto]

If an exotic species escapes from its owner/breeder/farm/whatever, it strikes me that the chances of it being recaptured are quite slim; thus, it becomes feral. Of course if it is the only one that escapes, it probably won't find a mate and it might also have trouble surviving the winter here.

If it becomes feral, under what conditions would it be counted as a state species? I'm simply curious. Is there a population size that determines this? Is there a time period of observation?

Cliff Otto

Manchester

[mresc...@aol.com]

Cliff raises some excellent questions regarding countability of exotics.  I'll try to shed some light on this issue, writing in my capacity as the Secretary of the NH Rare Bird Committee -

 

First of all, since the Shelduck has not yet been added to the official list of the ABA, I believe acceptance of this individual (or any future population) in NH would be a 2-step process - first it has to be accepted by the NH Rare Bird Committee, then it has to be accepted by the ABA Checklist Committee as a countable species and added to the ABA list.  Note that there was a recent record of a Hooded Crane in TN, IN, NE, and ID that was accepted at least by the IN, NE and TN state-level rare bird committees, but was not accepted by the ABA committee.  Therefore it was not added to the ABA list, and could not be counted even in IN/NE/TN where it was accepted at the state level. 

 

As for exotics, the ABA has 8 criteria that have to be met for a species to be added to the ABA list.  (see - http://listing.aba.org/criteria-determining-establishment-exotics/ )  In a nutshell, these criteria are -

1) The species is recorded in the form of a published photograph or a specimen archived in an ornithological collection

2)  There is a more-or-less-contiguous population of interacting or potentially interacting individuals, rather than a scattering of isolated individuals or pairs.

3)  The population is not currently, and is not likely to be, the subject of a control program where eradication may be a management goal that is likely to succeed.

4)  The population is large enough to survive a routine amount of mortality or nesting failure

5)  Sufficient offspring are being produced to maintain or increase the population

6)  The population has been present for at least 15 years

7)  The population is not directly dependent on human support

8)  A publication, ideally in a peer-reviewed journal or book, describes, how, when, and where the above seven criteria have been met

 

For the NH Rare Bird Committee to accept the Shelduck, since it would be a first for the state, a unanimous vote of the committee is required.  By comparison, for all other records, no more than one dissenting vote is allowed to accept the record.  The NH Rare Bird Committee by-laws do not specifically address criteria for accepting records of introduced or exotic species.  If the record was presented to the Committee as a wild bird, given that the Shelduck record would also be scrutinized by the ABA Committee as a potential first record for the ABA, I would imagine that I and the other members of the Committee would evaluate any such record using a very high level of scrutiny.

 

And two key caveats -

 

The above discussion discusses official ABA and NH rules for counting species.  Anyone can keep their own lists however you want to.  But if you are reporting your list totals to the ABA, you have to follow their rules.

 

Records can be re-submitted in the future if additional information on the record becomes available.  I bring this up to address this hypothetical scenario - what if Shelduck vagrancy patterns change in the future and they become regular migrants to the northeast (as has been the case for Barnacle Geese and Pink-footed Geese).  Although many would be skeptical of the first Shelduck record(s), once a pattern of vagrancy is established, those first records can be re-reviewed.  Imagine the skepticism of review committees when the first Barnacle or Pink-footed showed up in the northeast, even if they appeared during likely migration/wintering periods.  Now that they are regular migrant/wintering birds in the northeast, committees are more likely to accept rather than reject these Geese within their accepted periods of vagrancy at least on the basis of provenance.

 

 

I'd be happy to discuss this further on the list (or off-line) if anyone is interested.

 

 

Mike Resch

Secretary

NH Rare Bird Committee 

 

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