5/16/2013 9:21:00 AM
DNR scientist Meyer talks loons at 'Science on Tap'
DNR scientist Meyer talks loons at 'Science on Tap'
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DNR research scientist Mike Meyers presents “The Call of the Loon: Protecting Northwoods Loons for Future Generations” at May’s “Science on Tap.” Dean Hall photograph Craig Turk Outdoors Writer/Photographer |
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May’s “Science on Tap” at the Minocqua Brewing Company was all about our resident loons. The featured presentation: “The Call of the Loon: Protecting Northwoods Loons for Future Generations.”
Wildlife toxicologist and ecologist, Mike Meyer, from the Rhinelander DNR office, gave that presentation. About 115 were in attendance.
Meyer described Wisconsin as a “hotbed of loon research.” He said 3,500 loons have been banded and color-marked in a four-county area in the Northwoods.
“Loons – very charismatic, iconic and easy to observe,” Meyersaid, noting that loons’ habits have become well known to many.
“As folks have observed the birds over the years, they’ve learned these birds have peculiar habits that have endeared them to many couples,” Meyer noted. Chief mong those habits is attentiveness to their young.
The science of loons
Meyer said since banding and color-marking loons began, much more has been learned about loon mating behavior. Individual birds can be easily identified. He discussed research on Oneida County lakes that has been ongoing for more than 20 years.
“This is previously unexplored information because no one was able to tell one loon from another,” Meyer said.
This observational data revealed, for one researcher (Walter Piper), that loons, often thought mate for life, have “about a 7 percent divorce rate,” Meyer told the crowd, drawing laughs.
“What it turns out is, loons are not married to each other, they’re married to the lake,” he said.
Loons confronted by same-sex rivals will fight, often violently, in territorial disputes. The opposite sex does not engage the opponent. The winner is the new member of the pair, Meyer explained. Sometimes, the displaced loon will stay near and try to regain its status.
“It’s the old males that are particularly vulnerable,” Meyer said.
It has been found that a male loon will ‘yodel’ from its position at another flying over a lake. If the call is low, or “macho,” it’s far more likely that the loon flying over – a potential rival – will keep going.
A higher call means a smaller body size, or that the loon has aged. Meyer said an older male’s call becomes “much less robust.” Male loons will fight to the death in a territorial battle about 30 percent of the time.
Meyer said some loons that were banded and color-coded back when it was started in 1991 are still observed. These are older loons. Loons become especially vulnerable to loss of territory at about 30 years of age.
Meyer said information that came out of research on loons on Oneida County lakes is shared on a website called The Loon Project.
Recently, Meyer said, loon research has involved the use of telemetry. Telemetry uses radio or satellite technology to track an implanted receiver.
Loon migration routes were tracked using such technology in the wake of the oil spill in the Gulf of Mexico, which is wintering area for some of our loons.
Loons migrating from our area have two stopovers on Lake Michigan, where they stay for about a month total, before continuing south.
“It was good to learn, from the satellite telemetry, was that the loons from the Upper Midwest did not migrate down to the part of the Gulf of Mexico that was impacted by the BP oil spill,” Meyer said.
Information from the study that detailed the route and areas our loons take “is critical to maintaining their migratory requirements into the future,” Meyer said.
He said the loons will use the tailwind from early December cold fronts over Lake Michigan, and “make big hops of about 6-700 miles a day” while migrating. These tail winds are 60-70 miles per hour.
Information about their return trip has been gathered as well. Meyer said the males are first to arrive, and tend to show almost as soon as their territory is ice-free.
2012 and 2013
Regarding the early spring last year, Meyer said the loons weren’t aware their area haunts were ice-free and returned during a typical timeframe from about April 10-23.
This year has been quite different. The last time ice was on the lakes as comparably late as this year was 1996.Meyer said that the loon nesting season was affected by the late ice in 1996.
“The pairs formed once the lakes became ice-free, but only about 45-50 percent of the loons actually nested,” he said.
Meyer said returning loons will forage “for about 10-14 days before they think about starting the nesting cycle.”
This period could be affected and loons are also possibly going to arrive in poorer physical condition after being confined with many others on fewer than normal open water areas.
Nesting could decrease not only from the pressure exerted by loons normally seeking new areas, but by those that have been stalled along the way farther north, Meyer said.
Logging data
Meyer discussed the use of “data loggers” that attach to a loon but must be retrieved to get the information they record. The data logger records water temperature every hour and is equipped with a pressure sensor that reveals how deep a loon is diving.
Loons have been dying from the botulism toxin, and suffering especially so in a certain area. Data loggers helped draw some conclusions.
On Lake Michigan, loons “were diving, each dive, [about 100-150] feet,” Meyer said. He added that Lake Michigan has an invasive population of round gobies.
“It appears consumption of these round gobies is poisoning the loons,” Meyer said.
Invasive zebra and quagga mussels are part of the equation as well. These mussels filter lake water, clarifying it to the point that massive algae blooms take place. In the fall, the decaying algae blooms create an environment in which the botulism toxin exists.
The mussels filter the toxin and are eaten by round gobies. Finally, loons eat the gobies.
Loons in the northern highland
Meyer said biologist Gary Zimmer estimated there were about 1,700 loons statewide in 1978. Northland College’s LoonWatch began five-year counts in 1985. They found about 2,300 by 1985, and about 4,000 in 2010.
“We generated a population model for loons in the northern highlands,” Meyer said. “We calculated the adult survival rate, the reproductive rate – how many young did they produce every year? – and we quantified what proportion of the young returned to become breeding adults.”
The DNR model shows about a 1 to 1.5 percent increase in the loon population each year.
“So, we both have projections showing that the population is increasing,” Meyer said.
He added that 20-25 years of his own observations seem to confirm the increase.
Meyer said he got into studying loons checking them for mercury from ingesting fish. He pointed out that “loons eat nothing but fish” and that a loon family of four consumes about 1,500 pounds of fish per year.
There is a high concentration of mercury in samples of loon tissue, he said. It’s negatively impacting about 1 percent of our population. In New England states, up to 30 percent may be impacted he added. He noted that laws restricting mercury emissions will help loons in the long run.
Ingestion of lead sinkers and jig heads is an issue facing loons. Meyer said anglers can help by switching to non-toxic tackle. Shoreline development, thus far, hasn’t greatly impacted loons in the area.
“If a loon can find a quiet spot, where it can sit on its eggs for 30 days, undisturbed to the point where it can pull off a hatch, they’re pretty agile at getting around these lakes during recreational activities,” Meyer said.
The next “Science on Tap-Minocqua” will be held Wednesday, June 5. Ben Beardmore, post doc, Center for Limnology and Alex Latzka, graduate student, Center for Limnology, will talk about the ecology and economics of aquatic invasive species.
Minocqua Brewing Company is located at 238 Lakeshore Dr, Minocqua. MBC can be contacted at 715-356-2600.
For information on past and upcoming events, go to www.scienceontapminocqua.org/.
Craig Turk may be reached at [email protected].
Wildlife toxicologist and ecologist, Mike Meyer, from the Rhinelander DNR office, gave that presentation. About 115 were in attendance.
Meyer described Wisconsin as a “hotbed of loon research.” He said 3,500 loons have been banded and color-marked in a four-county area in the Northwoods.
“Loons – very charismatic, iconic and easy to observe,” Meyersaid, noting that loons’ habits have become well known to many.
“As folks have observed the birds over the years, they’ve learned these birds have peculiar habits that have endeared them to many couples,” Meyer noted. Chief mong those habits is attentiveness to their young.
The science of loons
Meyer said since banding and color-marking loons began, much more has been learned about loon mating behavior. Individual birds can be easily identified. He discussed research on Oneida County lakes that has been ongoing for more than 20 years.
“This is previously unexplored information because no one was able to tell one loon from another,” Meyer said.
This observational data revealed, for one researcher (Walter Piper), that loons, often thought mate for life, have “about a 7 percent divorce rate,” Meyer told the crowd, drawing laughs.
“What it turns out is, loons are not married to each other, they’re married to the lake,” he said.
Loons confronted by same-sex rivals will fight, often violently, in territorial disputes. The opposite sex does not engage the opponent. The winner is the new member of the pair, Meyer explained. Sometimes, the displaced loon will stay near and try to regain its status.
“It’s the old males that are particularly vulnerable,” Meyer said.
It has been found that a male loon will ‘yodel’ from its position at another flying over a lake. If the call is low, or “macho,” it’s far more likely that the loon flying over – a potential rival – will keep going.
A higher call means a smaller body size, or that the loon has aged. Meyer said an older male’s call becomes “much less robust.” Male loons will fight to the death in a territorial battle about 30 percent of the time.
Meyer said some loons that were banded and color-coded back when it was started in 1991 are still observed. These are older loons. Loons become especially vulnerable to loss of territory at about 30 years of age.
Meyer said information that came out of research on loons on Oneida County lakes is shared on a website called The Loon Project.
Recently, Meyer said, loon research has involved the use of telemetry. Telemetry uses radio or satellite technology to track an implanted receiver.
Loon migration routes were tracked using such technology in the wake of the oil spill in the Gulf of Mexico, which is wintering area for some of our loons.
Loons migrating from our area have two stopovers on Lake Michigan, where they stay for about a month total, before continuing south.
“It was good to learn, from the satellite telemetry, was that the loons from the Upper Midwest did not migrate down to the part of the Gulf of Mexico that was impacted by the BP oil spill,” Meyer said.
Information from the study that detailed the route and areas our loons take “is critical to maintaining their migratory requirements into the future,” Meyer said.
He said the loons will use the tailwind from early December cold fronts over Lake Michigan, and “make big hops of about 6-700 miles a day” while migrating. These tail winds are 60-70 miles per hour.
Information about their return trip has been gathered as well. Meyer said the males are first to arrive, and tend to show almost as soon as their territory is ice-free.
2012 and 2013
Regarding the early spring last year, Meyer said the loons weren’t aware their area haunts were ice-free and returned during a typical timeframe from about April 10-23.
This year has been quite different. The last time ice was on the lakes as comparably late as this year was 1996.Meyer said that the loon nesting season was affected by the late ice in 1996.
“The pairs formed once the lakes became ice-free, but only about 45-50 percent of the loons actually nested,” he said.
Meyer said returning loons will forage “for about 10-14 days before they think about starting the nesting cycle.”
This period could be affected and loons are also possibly going to arrive in poorer physical condition after being confined with many others on fewer than normal open water areas.
Nesting could decrease not only from the pressure exerted by loons normally seeking new areas, but by those that have been stalled along the way farther north, Meyer said.
Logging data
Meyer discussed the use of “data loggers” that attach to a loon but must be retrieved to get the information they record. The data logger records water temperature every hour and is equipped with a pressure sensor that reveals how deep a loon is diving.
Loons have been dying from the botulism toxin, and suffering especially so in a certain area. Data loggers helped draw some conclusions.
On Lake Michigan, loons “were diving, each dive, [about 100-150] feet,” Meyer said. He added that Lake Michigan has an invasive population of round gobies.
“It appears consumption of these round gobies is poisoning the loons,” Meyer said.
Invasive zebra and quagga mussels are part of the equation as well. These mussels filter lake water, clarifying it to the point that massive algae blooms take place. In the fall, the decaying algae blooms create an environment in which the botulism toxin exists.
The mussels filter the toxin and are eaten by round gobies. Finally, loons eat the gobies.
Loons in the northern highland
Meyer said biologist Gary Zimmer estimated there were about 1,700 loons statewide in 1978. Northland College’s LoonWatch began five-year counts in 1985. They found about 2,300 by 1985, and about 4,000 in 2010.
“We generated a population model for loons in the northern highlands,” Meyer said. “We calculated the adult survival rate, the reproductive rate – how many young did they produce every year? – and we quantified what proportion of the young returned to become breeding adults.”
The DNR model shows about a 1 to 1.5 percent increase in the loon population each year.
“So, we both have projections showing that the population is increasing,” Meyer said.
He added that 20-25 years of his own observations seem to confirm the increase.
Meyer said he got into studying loons checking them for mercury from ingesting fish. He pointed out that “loons eat nothing but fish” and that a loon family of four consumes about 1,500 pounds of fish per year.
There is a high concentration of mercury in samples of loon tissue, he said. It’s negatively impacting about 1 percent of our population. In New England states, up to 30 percent may be impacted he added. He noted that laws restricting mercury emissions will help loons in the long run.
Ingestion of lead sinkers and jig heads is an issue facing loons. Meyer said anglers can help by switching to non-toxic tackle. Shoreline development, thus far, hasn’t greatly impacted loons in the area.
“If a loon can find a quiet spot, where it can sit on its eggs for 30 days, undisturbed to the point where it can pull off a hatch, they’re pretty agile at getting around these lakes during recreational activities,” Meyer said.
The next “Science on Tap-Minocqua” will be held Wednesday, June 5. Ben Beardmore, post doc, Center for Limnology and Alex Latzka, graduate student, Center for Limnology, will talk about the ecology and economics of aquatic invasive species.
Minocqua Brewing Company is located at 238 Lakeshore Dr, Minocqua. MBC can be contacted at 715-356-2600.
For information on past and upcoming events, go to www.scienceontapminocqua.org/.
Craig Turk may be reached at [email protected].
