Bruce Glick was kind enough to send a good photo of the Ross's goose
over in Holmes Co., and it reminded me of a discussion at the meeting of
the Ohio Bird Records Committee last week. A perennial topic at these
meetings is "when are we going to take Ross's goose off the Review
List?" In other words, when is the Committee going to stop insisting on
acceptable documentation to add a sighting of this species to the
official record? After all, there were a minimum of eight of these
little geese here just over the winter; I saw six of them, all in the
same spot. They just aren't that rare any more.
        Well, after discussion, Ross's goose remains on the Review List, and
here's why. First, some not-so-ancient history. If you look at the first
edition of Bruce Peterjohn's "The Birds of Ohio" (1989) you'll see there
was at the time only *one* Ross's goose record for Ohio, a bird found at
Ottawa NWR on 18 March 1982. Peterjohn acknowledged growing populations
of these little geese, but stated "they will probably remain accidental
visitors." Well, the Holmes Co bird is at least the ninth so far just
this year.
        Peterjohn attributed Ohio's first record to burgeoning geese
populations in the Arctic. These numbers have continued to grow, to the
point that some wildlife managers have foreseen the destruction of vast
tracts of the tundra by foraging geese, and called for action. Well,
managers will always want to manage, but no doubt goose populations,
especially 'light' geese, are up, and this is behind the new status of
Ross's goose in Ohio.
        With larger populations have come increasing interactions between
(lesser) snow geese and Ross's geese, including hybridization. These
hybrids were first described in a 1971 article in the Auk (Trauger et
al.), and Birding magazine ran a piece on them in Feb 1993 (Roberson),
the latter including a photo of an Ohio bird thought to be a hybrid. It
was presented as an esoteric problem that a few birders might
occasionally encounter, but it's now bigger than we thought.
        I've seen one hybrid Ross's X snow goose, and photos of several more,
in the past couple of years here in Ohio. There are some fairly
predictable field marks, but many good birders are not yet familiar with
them. Kevin McGowan offers a useful tutorial on the topic at
http://www.birds.cornell.edu/crows/rossgoos.htm ; be aware he discusses
only two likely hybrid individuals, and that other intermediate
characteristics are possible.
        So, while Ross's geese were once extremely rare here, the committee
quite reasonably felt they should still be documented, since not
everyone is familiar with hybrid forms, and understandable wishful
thinking might influence undocumented reports. Today a lot more birders
are comfortable telling Ross's from lesser snow goose, but now there are
subtler distinctions that must be made. These hybrids are apparently
fertile, and that means back-crosses will be increasingly likely. So if
you learn how to ID hybrids that are half Ross's, do you have to see two
before you can count Ross's goose on your Ohio list?  Well, it's your
list...
Bill Whan
Columbus





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