Crane Genetics
The following is a discussion of the recent findings regarding
the subspecies of Sandhill Cranes.
George Archibald:
Ken’s work showed two highly distinct groups of Sandhills – the
Lessers and the Others. Within the
Others there are distinct subpopulations
that merge
(cline)
from one to the next over space, that is, birds at the extremities
of the range are quite different while those where the populations
meet which are quite similar.
That’s the way nature works. If a population becomes geographically
isolated, and that apparently is what happened with Sandhills during
the Ice Age, they sometimes rapidly diverge to that point that if
they subsequently meet, interbreeding is impossible. The later is
the general definition of a species. Gary Krapu, who has done so
much work on Sandhill genetics, suggests that the Lessers were
isolated in the Berring Sea area during the last glaciations, and
subsequently reconnected with the Others
after the ice disappeared. Lessers might have been nonmigratory
during the Ice Age. That area was quite mild.
Gary Ivey:
Here
is the latest from Ken Jones on our Ridgefield/Sauvie Island cranes.
He is saying they are classified as greaters
genetically. There are still some striking morphological differences
in these birds and they should be managed as a separate population
in the Pacific Flyway.
5621 Female with Tabida mtDNA
6343 Female with Tabida mtDNA
8725 Male with Tabida mtDNA
8726 Male with Tabida mtDNA
8737 Female with Tabida mtDNA
8746 Male with Tabida mtDNA
8824 Male with Tabida mtDNA
8827 Female with Tabida mtDNA
Gary Ivey
Ken is saying that the other subspecies are subpopulations of
greaters. I don’t believe he has published his work yet. Regardless
of the genetic results, Mississippi, Florida, and Cuban sandhill
cranes will retain their status as T&E species, and different
populations will have different levels of conservation concern. The
Flyways already recognize separate populations of greaters; however,
the Canadian subspecies has never been formally acknowledged in the
Pacific Flyway and I am recommending that they be identified as a
Pacific Coast Population and receive some additional conservation
attention.
I
spoke with Myke
Chutter of BC Wildlife and he is going to use our data on
nesting locations to set a buffer for protection of known nesting
sites. Cranes are on BC’s Blue List of species of conservation
concern.
