Although red loons are known for their excellent fishing skills, little is known about the migratory patterns of this waterfowl in eastern North America. The University of Maine study is the first to identify her four migration routes and Arctic breeding grounds for the red loon along North America’s Atlantic coast, giving conservationists greater clarity on how to protect this bird. is showing.
Understanding a species’ migration patterns is essential to understanding its population dynamics. This is because impacts that occur during migration can extend to local populations. Therefore, to effectively protect species, we need to understand the dynamics of these migrations to determine critical areas to support animals and potential threats to the ecosystems there. .
Brian Olsen, professor of ornithology at the UMaine School of Biology and Ecology and one of the study’s authors, said: “Each bird is supported by its own strip of continent, from summer lakes to winter waters to offshore banks, and stays for weeks on each migration to rest and fish. If something goes wrong anywhere in that swath, the rune can disappear from all swaths.”
Researchers at the University of Maine tracked red loons for a year along their migration routes from the mid-Atlantic coast of the United States to their Arctic breeding grounds by tagging the birds with satellite transmitters. The white-throated loon is listed by the U.S. Fish and Wildlife Service as a species of conservation concern in both its Arctic breeding grounds and its wintering grounds on the Atlantic flyway. The aim of this study was to provide more precise information on spatial use during species annual cycles in this sensitive region.
The researchers also examined the strength of species’ so-called ‘migratory links’, the likelihood that birds that breed close to each other will overwinter close to each other and use similar migratory routes to get there. rice field. Species with high migratory connectivity may be particularly affected by changes along migration routes. This is because a disruption that affects one bird is likely to affect many.
Finally, the researchers used existing migration theories to build species migration networks to better understand the areas that birds frequent along their routes and how they use them.
UMaine researchers found four distinct migratory routes for red loons that winter on the Atlantic coast. Some reached Canada, some reached Greenland, some went straight along the Atlantic coast, and some circled the Great Lakes. There were important stopovers for birds along these routes, including James Bay and lower Hudson Bay, the southern Great Lakes, the Gulf of St. Lawrence, Nantucket Reef, and major bays in the mid-Atlantic region. Delaware Bay, Chesapeake Bay, Pamlico Sound.
Despite sampling an area representing only 5% of the non-breeding area of the Atlantic coast of North America and only 0.001% of the estimated Atlantic flyway breeding area, the birds studied spanned 65% of their breeding area. This region constitutes the center of the non-breeding range of white-throated loons in winter. Dispersed migrations also suggest low migration connectivity, although human disturbance or changing environmental conditions in relatively small wintering ranges could affect much of the North American breeding range. There is a nature.
Carrie Gray is a Boreal Research Scientist at the National Audubon Society and the lead author of the research she conducted during her PhD. at U Maine. Gray explains that the small size of wintering grounds relative to breeding ground size means that a higher proportion of the population is likely to experience the impacts associated with environmental change in that wintering ground.
“For example, if a region’s forage fish populations were above average one winter and bird productivity spiked the following summer, this could have positive consequences. On the other hand, climate change is causing ocean temperatures to rise. But as the distribution of prey fish shifts northward to track adapted colder waters, it means that the birds that depend on those fish will also need to move northward,” says Gray. “To assess how ‘hardwired’ migration to particular wintering grounds is, or whether movements during the non-breeding season are flexible and accommodating, it is necessary to keep individual loons over multiple years.” I need a follow up to track. A local condition for tracking resources.
There were also some migration stopping points that seemed very important to the species. For example, 90% of birds tracked in the spring and 61% tracked in the fall relied on a few major areas of use along the Atlantic coast of the northeastern US and Canadian waters. Factors that may affect loons in these areas include exposure to pollutants and oil spills, risk of mortality and habitat displacement from collisions from offshore wind farms, and bycatch associated with fishing nets and adverse weather conditions. may include the threat of death from
“Nantucket Reef fishing boats may be there for the same reasons birds are,” says Olsen. “Productive currents benefit both types of fishing. However, while ship operators may find handfuls of loons working in the same waters, our study suggests that they suggests that if you’re out there every day for a few weeks, you’ll be able to see the majority of all birds from the Atlantic coast of North America as they migrate across the region, with only a handful of such hotspots. Yes, and this study is the first to describe where they are.”
In the future, multi-year studies will be needed to determine whether the same birds follow the same migratory routes year after year. This is also important for understanding how easily ecological disruption can affect red lobe populations.However, this time the result study — published in the Journal of Ornithology in August 2022 — emphasizes the importance of examining large-scale migration patterns for conservation in general, as well as informing red loon conservation efforts. I’m here.
“Tracking research allows us to follow birds along their incredible migration journeys and discover the places they rely on throughout the year to protect bird populations. We need this information to identify the habitats that need to be protected, and we are thrilled to have expanded some of this knowledge on red loons, and we believe that in our field, bird conservation on a hemispheric scale We are encouraged by the increasing emphasis on .
Contact: Sam Schipani samantha.schipani@maine.edu
