Emperor Geese and Carbon Flux on the Manokinak

I'm back from the Manokinak! I've spent the last 5 days out on the Manokinak River, at a USGS study site researching emperor geese on the Yukon-Kuskokwim Delta. Joel Schmutz (USGS Wildlife Biologist) has been studying emperor geese there since 1993, trying to understand why the population declined in the 1980's and hasn't really recovered.

It's beautiful country out there, the sky goes on forever.

Here's an emperor goose, they're really pretty birds! If you look them up in your bird guide their heads are white, but there's a bunch of iron floc on the sediment surface (naturally occurring in these wet environments), so their heads stain orange from poking around in the sedges to feed.

In a sense, these geese create their own feeding habitat. Take a look below. The really short veg closer to the water is Carex subspathacea, which is a different growth form of the adjacent taller Carex ramenskii. The emperor geese prefer the shorter C. subspath.; it has higher nitrogen concentrations, they don't have to pick through all the dead stuff, etc. The emperor geese maintain this habitat through intensive grazing of C. subspath. "grazing lawns."

I was helping Joel and Karen Beard (prof from Univ. of Utah) to set up a study site looking at the effects of climate change on emperor goose habitat. The idea is that, with warmer temperatures, C. subspath will grow up into the taller C. ramenskii, which is less of an ideal goose forage. To simulate warming, we set up what are basically mini-greenhouses. These were paired with exclosures to study the effect of keeping geese from grazing, and an unmanipulated control. We also did a bit of work measuring CO2 flux from grazed and ungrazed habitats.

After all of that, I got to help with nest surveys! Hatch date was quickly approaching for the baby emperor goslings, and I was able to help with assessing development of the eggs. Basically, this translated to hiking all day with Sasha (certainly a very fun assignment), visiting nest locations. You can assess how near the egg is to hatching by floating it - eggs become more and more buoyant as they near their hatch date. At one of the nests, the little goslings were starting to poke out of their eggs! Sasha helped them along just a smidge to see if she could tag their feet so they could be identified later. It was still too early to tag, so we left them with their mother (the concerned goose visible in the background - don't worry, they were reunited minutes after this photo).

We ended the day by getting caught in the mother of all storms. Dumping rain (and marble-sized hail on some other crews!) with thunder and lightning! What to do in a thunder storm with 3-second count, 2-second count, oh my god 1-second count it's right on top of us lightning when you're the tallest thing for miles? Sasha and I beat feet back to the river, put on our float coats, and hunkered down in a muddy slough for an hour or so, dreaming of dry clothes and hot gooey dinners. mmmmm, burritos... Eventually the storm passed and our prayers were answered, our trip back across the river ended with burritos for dinner and a solstice bonfire!