During the Arctic summer at Polar Bear Pass National Wildlife Area, located on Bathurst Island in Nunavut, Canada, fierce sub-zero winter conditions gradually give way to the warmth of 24/7 daylight, melting snow, and filling ephemeral pools and ponds that provide breeding grounds for countless insects. Herds of Musk Oxen and Peary Caribou shake off their winter coats and begin congregating in the marshy tundra to eat the newly abundant grasses and sedges. Lemmings and their predators, including Snowy Owl, Arctic Fox, and Jaegers, begin their annual survival race. This is the time period when shorebirds migrate to the Arctic latitudes to begin their breeding season. The shorebirds are drawn to the high latitudes to sync their egg hatching with the abundant insect life of the Arctic summer.
The shorebird team, consisting of Canadian Wildlife Service (CWS) biologists, technicians, and myself, arrive in late June just after the snow melts. We are in luck, because in years past the CWS staff has been greeted by deep snow and blizzards in early July. We enjoy mild Arctic weather throughout the season, with temperatures above freezing during the entire expedition and countless sunny days. The only drawback to such great weather is the temporally advanced state of shorebird nesting, with many species already incubating complete clutches of eggs when we arrive. Ideally the field season would commence during the early stages of nesting and incubation, but predicting the snow melt date is incredibly difficult to do year to year at these high latitudes.
Daily activities include monitoring study plots for breeding shorebirds using both Arctic Shorebird Demographic Network (ASDN) and the Program for Regional and International Shorebird Monitoring (PRISM) protocols. Data collected across the Arctic is compiled and important parameters such as breeding success, adult survivorship, and breeding densities are used to model the populations of shorebirds across a vast geographic region. Nests are found using a variety of behavioral clues and by walking nearby to flush birds off of nests in likely breeding habitat. Nest success is tracked using a form of the Mayfield method. Mayfield himself spent several summers at Polar Bear Pass studying the breeding ecology of Red Phalaropes. We apply a unique color combination and/or alpha-numeric flag on virtually all captured shorebirds. On select shorebirds, we apply VHF radio “nanotags” in an effort to track southbound migration through an array of VHF receivers positioned along the Atlantic Coast of Canada and the United States.
The main objective on this expedition is to deploy six 5-gram satellite transmitters on Black-bellied Plovers nesting within the study site. Very little is known about the annual life cycle of shorebirds, and as tracking devices become smaller more species find themselves as candidates for satellite tracking, allowing researchers a remote glimpse into their migration routes and life cycles from afar. Black-bellies fit the profile well for tracking – they are fairly large compared to the small transmitters, they have the proper body structure to hold a harness, and they are abundant and easy to catch at the study site. Plovers are trapped on nests and the transmitters are attached during the incubation cycle.
The tracking of Black-bellied Plovers is a collaborative effort between Canadian Wildlife Service and The Center for Conservation Biology and was initiated by CWS in 2014. Logistical support for the Bathurst Island field expedition was provided by the Polar Continental Shelf Program in Resolute, Nunavut. The tracking of the Plovers is an ongoing project and the birds can be followed at Seaturtle.org.
Written by Fletcher Smith | firstname.lastname@example.org | (757) 221-1617
September 30, 2015