32. Are Michigan loon populations viable? 1 4 3 2 0.70 0.34 0.27 0.14 Maximum productivity – 2 chicks/pair
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35. Peg Comfort, Linda Gallager, Tiffany Gilligan, Jeff Lange, Linda & Kevin O ’Meara, Fred Sittel, Bill Truscott, Cody Truscott, and Chris Williams Elk River Chain of Lakes Watershed Loon Network (Michigan Audubon) Intermediate Lake Association (Scott Zimmerman) Three Lakes Association (Dean Branson) Bellaire Lake Association (Linda & Kevin O ’Meara) The Blue Pelican Inn (Chris Corbett) Dole Family Foundation Lakeside Condominiums (Round Lake) National Park Service Elyssa Kellerman
Range contractions in the past century Loons once breed as far south as N. Indiana, Illinois, Ohio and Pennsylvania. James Audubon wrote of loons breeding in Ohio and as South as Maryland. The current range of the common loon in North America extends from northern Canada and Alaska to the Northern United States, with Canada (approx. 500,000 loons) and Minnesota (approximately 11,000 loons) composing the bulk of the species abundance.. Today, loons are considered endangered in Vermont, threatened in New Hampshire and Michigan and have been extirpated from the previous states mentioned.
In Michigan, where there are 11,000 lakes, early writers (late 1800s to early 1900s) spoke of loons on all lakes in the state containing suitable habitat. The species statewide status was unknown until A.J. Cook published his seminal treaty on Michigan Birds in 1883 and summarized the efforts of early chroniclers of Michigan natural history that characterized the species variously as “very abundant in spring, summer, and autumn; throughout the state. Frederick Hubel, 1903, wrote “There are records of sets [of loons] from almost every lake of considerable size in this country. I know of lakes where the same pairs of birds nest year after year”. In 1912, Barrows wrote, “there is hardly a pond on which Loons are not seen each season.” Between approx. 1920 and 1960, there is little discussion of loons in writing, until 1953 when the last breeding in Oakland County was documented. By 1992 the Common Loon was virtually absent from the lower third of the state. The first systematic surveys of loons in Michigan did not occur until the 1980 ’s when Bill Robinson of NMU indexed lakes into suitability “stratums” for loons based mainly on recent occupancy, size (over 40 acres were considered most suitable) and the presence of islands. The results of these surveys conducted between 1983-87 indicated that loons had virtually disappeared from the lower third of the state, and the total population was estimated at 300 pairs. These shocking findings prompted the State Legislature to designate the Common Loon a Threatened Species in 1987. The timing of these surveys overlapped with two initiatives that proved important for Michigan loons; 1) the Michigan Breeding Birding Atlas (1983-1988) which provided the first comprehensive range map for the species in Michigan and will serve as an important baseline for future comparisons (including the MI Breeding Bird Atlas currently in progress), and 2) the initiation of a loon research program in 1987 at Seney National Wildlife Refuge.
Common loons are essentially seabirds that migrate inland to breed on northern freshwater lakes. Their bodies are designed for a life on the water: with solid bones and legs to the rear of their bodies, they are stealthy divers who maneuver quickly underwater, propelled by foot to catch their prey (fish). Mention wing-loading Describe a little bit about seney: managed pools, 15 pairs
The spring arrival of loons corresponds (to the day) with spring ice-off. This spring (2008), with later than usual ice-off on breeding lakes, returning loons had to take up temporary residence on open water found on the Great Lakes and rivers until their breeding lakes thawed. This caused problems for some loons who mistook wet pavement for water or landed on in waterbodies too small to take-off from (e.g., Donken ditch). We had reports of three such loons this spring. As of May 2, inland lakes on isle royale, where over 30 loon pairs breed, are still frozen, forcing loons to group up on open water on Lake Superior, a situation which surely makes for some interesting social dynamics.
When loons arrive in the spring, they immediately establish a territory. Male and female loons do not migrate together, so it takes some time for the pair to form a bond, which they do through some ritualistic, if non-showy, behaviour, which involves circling around each other, bill dipping, and rapid diving. The two most important factors of a good territory are availability of nesting habitat and prey. Territory size ranges from the size of a football field (1ac) to the largest freshwater lake, Lake Superior
Quite frequently, loons will have to defend their territory against conspecifics. This is done by chasing intruding loons and when the male gives a yodel call he is advertising his territory. Yodels carry quite a distance, and can be heard (and recongnized) by neighboring pairs.
Clutch size, nest requirements; incubation period
Loon chicks are semi-precocial at hatching. Family groups leave the nest within hours of hatching. Chicks may back-ride for up to two weeks and parental care is shared.
Loon chicks are semi-precocial at hatching. Family groups leave the nest within hours of hatching
Loons are obligate piscivores, and feed their young fish from day 1 until they can fledge at 9-10 weeks of age. Both male and female share responsibilities of chick-rearing.
Mercury is deposited atmospherically as a consequence of industrial activity, especially coal burning. In aquatic ecosystems it is transformed into the potent neurotoxin methylmercury, which magnifies in concentration as it rises within the food chain. As top predators, loons are vulnerable to methylmercury exposure at high levels, particularly when breeding upon lakes with low pH. Prior studies have demonstrated various sublethal effects associated with elevated methylmercury levels in Common Loons:
This example is for juvenile loons.
Juveniles not eligible to return as breeders until 3 years of age.
If all is well, a juvenile, after spending up to three years on wintering turf, gains its first breeding plumage and rejoins a northern population as a breeder. 25 % recruitment in well-covered sites. Most dispersal within 12 miles (sex-biased). Age at first breeding 5 - 11 years. This is ABJ – adult banded (as a) juvenile. ABJ was born to Papa on G pool in 1987 (Papa died in 1988 by an eagle). ABJ was one of the first three loons ever banded at Seney NWR. He was the first color-marked juvenile to return to the refuge as a breeding adult (at age 3), and the first to ultimately acquire his own nesting territory and nesting partner (at age 11). As of 2007, he was the oldest common loon of known age [2] in the world.
Annual adult survivorship is 96%, of which 80% return to the territory they had the previous year, 12% switch territories, and 4% are unpaired. At this high rate of survivorship, we predict that 50% of the breeders will still be breeding after 15 years and 20% will still be breeding after 30 years
At least 18 years old, and having hatched at least 17 chicks in his tenure at Seney, C3 met his end on this Lake Michigan beach near Naubinway Michigan in the fall of 2007
Bar graph of numbers and species of killed birds
Bar graph of numbers and species of killed birds
Among all these other things we have learned from the banded loons at Seney, Seney has also provided a benchmark to which we can compare population parameters of other loon populations. For example, productivity among other study sites is low; suspected causes; trends in the ONF; notable productivity: Moon lake, 2 nd territory on Beatons Lake, nesting on Fishhawk, and productivity on Florence Lake
Add map for each?
Replace map with a gray tone map of just up Seney National Wildlife Refuge, located in the east-central UP, serves as a baseline for loon research across North America and continues to provide important life history details not previously known for loons such as territory fidelity, adult survivorship, juvenile dispersal, and contaminants exposure. Long-term monitoring at Seney continues (and celebrates it ’s 20 th year this year) and has since been expanded to three additional populations in the upper peninsula. Reobservation of banded loons has been one method we have used to learn about life histories of loons. As I go through this talk, I will throw in some snippets of what we have learned from these efforts. Give some background about why seney is a good baseline: no water recreation, lead is banned, low mercury, no development Talk about bands and banding In this talk, I ’ll discuss some of the specifics of loon life history traits, pointing out aspects that may have contributed to their decline, as well as conservation and protection efforts.
