|
The latest breakdown is 236 adults and an unknown number of chicks in the Wood Buffalo/Aransas population (chicks can't be counted accurately until the population finishes the migration to Texas); 40 adults and 1 chick in the reintroduced non-migratory Florida population, with the possibility that some remain uncounted; 55 adults and 28 chicks (captive bred) in the Necedah/Chassahowitzka population; 0 adults and 0 chicks in the Rocky Mountain population; and 143 adults and 6 chicks in all captive populations. Total number in existence, 509, plus whatever the production was at Wood Buffalo National Park this year. I think the expectation is 50 or chicks from the 70 or so adult pairs will show up, for a final annual tally of ~559.
Things are up and down for the species. The Aransas population keeps growing slowly, and is always under threat from potential spills in the Texas Intracoastal Waterway, development around Aransas National Wildlife Refuge, development around Cheyenne Bottoms in KS (migration stopover), development and water withdrawals from the Platte River (migration stopover), loss of prairie potholes in ND, SD, and southern Canada, and hydrology changes due to climate change at the nesting site in the Northwest Territories. Somewhat amazing to me that so many threats to this population are allowed to go forward, given the way the Endangered Species Act is written. The Necedah population is very new and individuals are pairing off, but the one pair that produced an egg this year is a full sibling pair, and when staff tried to replace their egg with a fertile egg, they abandoned the nest. The habitat in both central WI and western FL seems to be adequate for them, so I suppose this population will take off eventually, but it will still take time. The Florida resident population has decent habitat but seems to get whacked pretty good by bobcats. That population does have a bunch of pairs and did produce a chick this year, maybe it will start to take off.
I really don't think true recovery is possible. There has been just too much loss of historic breeding and wintering habitat-the historic core of the breeding range used to be wetlands and prairie in Illinois, Iowa, Minnesota, the Dakotas, Manitoba, and Saskatchewan, the wintering range seems to have been all along the coast of Texas and Louisiana into Mississippi. Pretty much none of that is left. There were two other known historic populations, one that summered in Wyoming and Montana and wintered in north central Mexico, and one that summered somewhere between the Great Lakes and Hudson Bay, and wintered between the New Jersey and Georgia coasts. Sandhill cranes still follow that Rocky Mountain migration corridor, and a whooping crane reintroduction was tried there, but wasn't successful-were it not for the ridiculous energy development and settlement in the area, I'd think that they would try to reintroduce that population again. The Hudson Bay/mid-Atlantic migration route is so densely populated now that recovery there would be pretty much impossible. Toss in diseases, hurricanes, tornadoes, development, genetic drift, inbreeding, petrochemical spills, transmission lines, wind turbines, and I just don't see where there is room for recovery to the point it can be delisted. Just building a population large enough that mutations can begin to rebuild genetic diversity seems out of reach.
But that's just my opinion, I work with ferrets...I'm predisposed to pessimism.
|