I’d like to start off by retracting a statement I made in a previous blog post. That statement was in regards to dusky nest searches, and I proclaimed that I had “exerted myself more than I probably ever have before.” That is no longer true, after the dusky nest island monitoring. I have spent the past week at dusky camp bushwhacking and kayaking across the Copper River Delta visiting nest islands. Over 300 nest islands were installed into ponds across the delta in an effort to ameliorate declines in this species that occurred as a result of the 1964 earthquake. The earthquake caused the level of the delta to rise, changing the nesting habitat of duskys and making them more susceptible to depredation. Nest islands are placed in ponds anywhere from 10 to 40 meters away from shore. The island floats on the water and is anchored in place. The goal of the nest island monitoring project is to determine what sort of maintenance these islands do or do not need. Each island has a layer of dirt and is fortified with shrubs and other vegetation. When we visit an island, we document the shrub height and percent shrub cover. We also look for any beaver or muskrat damage and use by any other species. We use clues like feathers, egg shell color and size, and scat to determine what species have been utilizing the island. The majority of the nest islands I encountered were utilized by duskys, but next in line were various ducks and swans, and Mew Gulls. When a nest is found on the islands, we use our best judgement to determine if it was successful, not successful or depredated. Successful nests will have egg membranes that are, for the most part, intact. When a chick is hatching, it generally pecks an almost complete ring near the top of the narrower part of the egg, leaving a membrane cup and cap with shell fragments still attached to the membrane and scattered in the nest. A depredated nest will generally have mostly intact egg shells with a pecked hole, and sometimes remnants of the yolk present on the egg shells or nest. At first it was difficult to tell if a nest is successful or depredated, but after seeing a few examples in the field we got pretty good at it. All of this data is then used to determine which islands need maintenance and which islands, if any, should be taken out of the program. An island is taken out of the program when damage from wind, snow, ice. etc. causes it to fall into extreme disrepair year after year, making it unavailable for nesting.
This was my first experience living and working in the field, and it was so fulfilling. I was completely engrossed in the cause. It’s surprising to me how much a person can be pushed beyond what they believe are their limits. I definitely felt exhausted at times, but I was still able to power through it. It’s funny how different I felt the second I got back into town, like suddenly I realized how tired my body was. I loved being out there, though, sweating it out for duskys with the whole crew. I can’t wait to do it again.
Melissa Gabrielson, air-boat master deluxe.
Checking out a nest island in a sea of Equisetum.
A dusky taking flight.
A hen protecting her brood with a distraction display. We saw so many ducklings/goslings/signets/chicks! The delta is poppin’ with life right now.
This photo is a shout out to Jimena Cuenca who took a photo of the same cotton grass field by our camp last year.