David,
The problem is predation in the artic. Right now there is an over abundance of predators there. The way it's been explained to me is that the Brant nest in a couple of smallish colonies with two other species of geese. These other two species are much more,aggressive than Brant and put up quite a ruckus defending their nests. The Brant, on the other hand, particularly the hens, are pretty passive. The foxes can be seen studying the nesting colonies and singling out the Brant. They're getting a twofer because the hen just sits and is killed, the they get the eggs,too. Last year, I'm told the nesting success rate was at an all time low. Worse, we can expect the season to remain this way for the next two years because they're not doing surveys annually anymore.
The good news is that predator populations are generally cyclic, lagging slightly behind fluctuations in the prey species populations.
Frank