Dusky Canada Goose Nest Island Monitoring: Nestigations Sequel with a Twist

The month of June has been full of field work at the Cordova Ranger District. Many of the departments here at the US Forest Service have been busy with fish assessments, trail maintenance, bear monitoring, and so much more. Unlike the previous month of May where my main focus was shorebirds, now my main focus is to assist with the Dusky Canada Goose (Dusky) project with the Wildlife Department. The project has multiple components that are completed throughout the season. It began with nest searching for natural Dusky nests amongst the sweetgale and wetlands in the Copper River Delta. But now in June when the majority of the Duskys’ eggs have hatched into adorable goslings we focused on artificial nest island monitoring.

To provide you with a quick recap from a previous post, the Dusky Artificial Nest Island program started in 1984 by a non-profit organization, Ducks Unlimited. Biologists at the time were concerned with the rapid decline of Duskys to less than 10,000 birds in the wild due to the lack of nest habitat and increased predation. Therefore, Ducks Unlimited collaborated with the Forest Service to monitor Dusky populations and help increase their reproductive success by installing artificial nest islands. At first glance you may think, “oh that’s just another island in a pond” and not give it much thought, since the islands usually blend in with their vegetation. Upon closer inspection you notice that the structure is man made. Imagine a (approximately) 4 by 4 foot fiberglass structure in the middle of pond in the delta. An ideal nest island consists of 3 layers: the top consists of sweet gale (a 3-4 foot shrub) that provides aerial cover, the middle consists of an intact fiberglass structure that works similar to a flotation device, and the bottom layer consists of anchors to make sure the island doesn’t float away to the shore of a pond.

This is an example of a successful nest. Notice that the difference in texture between the membrane and the egg shell.

Besides assessing the condition of the island we needed to record any activities that have occurred on the island. This is when our detective skills are called into action. First we need to determine what critter has been using the island. It is not always a Dusky. That is if we find feathers, poop, and dips on the mud or trails on the grass then we can determine that the island has been used for loafing. Loafing in our assessments is when a critter, usually a species of waterfowl, has idled on the island and not used it for nesting. Species guilty of this are swans, ducks, and river otters. Given that the purpose of the artificial nest island program is to increase the nest success of Duskys we need to record if the nest islands are indeed increasing nest success. Despite multiple factors that can impact the clues left behind on the islands, how do we determine a successful nest? A consistent sign is if there are pieces of membranes and egg shell caps within the island or nest bowl. This shows that a Dusky has been using the nest and due to the membranes it can be deemed as a successful nest as well.

As a self proclaimed couch potato it was challenging work for me on the physical side of things. For one it was a constant back and forth between aerobic and anaerobic exercises. We had to pull poke boats (imagine a chubbier kayak) through alder tree lines, sphagnum moss that sucks your feet like a sponge, and all the while making sure we would get to a certain number of islands for the day. Nevertheless, overall I enjoyed the experience. I was in the beautiful Copper River Delta and in parts that are inaccessible to most people (without an airboat and grit). I had a great time because I got to learn more about the Copper River ecosystem. I was also glad to spend time with my coworkers in a different context than in town. Around dinner time we bonded with our daily tales of monitoring while eating desserts (whose creative genius reminded me of Frankenstein) and swatting away mosquitoes. That is the life of Dusky Camp and I would not have had it any other way.

Hillary Chavez
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