Category Archives: population

Early Results in Minn. Moose Calf Study

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Moose_CalfLate last month Minnesota Department of Natural Resources researchers collared 49 moose calves within hours of their birth, the Grand Forks Herald reports. Part of a larger study trying to solve Minnesota’s high moose mortality rate, the collared calves were born to collared mothers, a fact that allowed researchers to find them quickly after birth, the article says.

Results have come quickly, perhaps too quickly. Researchers knew that over half of all moose calves die within their first year. But already 22 of the calves, nearly half, have been found dead, mostly from predation by wolves and bears.

The study revealed other surprises. Of the moose that gave birth last month, 58 percent had twins, which was a higher rate than the researchers expected. They also found that the calves started eating plants earlier than had been previously thought.

The article says that the high adult death rate is the big issue in Minnesota, but a low rate of survival for calves is another concern. The 22 necropsies that will be performed on the dead moose calves should shed light on the issue.

More details in the Grand Forks Herald article, here.

Photo: A moose calf, although not from this study. By Leroy Anderson, courtesy US Fish and Wildlife Service.

 

USGS Calculates How Fast Amphibians Are Falling

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Green_Tree_Frog_in_pitcher_plant_Cressler_photoThere have been studies that have calculated the likelihood of extinction for various amphibian species, but the first study to calculate how fast amphibian populations are declining was recently published in PLoS ONE.

The study found that amphibians disappeared from their habitats at a rate of 3.7% per year from 2002 to 2011. Species that are red-listed by the International Union for Conservation of Nature (IUCN) disappeared at an average of 11.6% annually.

“Even though these declines seem small on the surface, they are not,” said US Geological Survey ecologist Michael Adams, the lead author of the study in a press release. “Small numbers build up to dramatic declines with time. We knew there was a big problem with amphibians, but these numbers are both surprising and of significant concern.”

Read the PLoS ONE article, here. (Open access.)
Read the USGS press release on the paper, here.
Read a Washington Post article that is mostly about the rate of amphibian decline, here.

Photo: A green tree frog (Hyla cinerea) sits on the lip of a pitcher plant in a bog in Alabama. Photo by Alan Cressler, used courtesy USGS.

More on Minnesota Moose

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Minn moose collaringLoss of early successional habitat, more wolves, and increased exposure to brainworm — those are the early theories on why the Minnesota moose population is plummeting. And that’s a whole lot of inference from just two dead moose.

The Duluth News Tribune has an update on the moose study begun by the Minnesota Department of Natural Resources in January. The DNR tagged 111 moose and planned to follow them for five years — deploying a team to investigate whenever one of the moose died. (We covered it here.)

So far six moose have died, the article says. Four of those deaths have been pinned on capture-related mortality. The percentage is about average for moose captures, the article says.

The two other moose were killed by wolves. The article reports on another researcher in conducting a separate study who found that one of his wolf-killed moose had pneumonia.

There are many more details about the early days of the study in the article. Read the Duluth News Tribune article here.

Photo: A moose being collared, but not necessarily for this project. Courtesy of the Minnesota Department of Natural Resources

Minnesota Cancels Moose Hunt

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MN moose_header“The state’s moose population has been in decline for years but never at the precipitous rate documented this winter,” said Tom Landwehr, Minnesota Department of Natural Resources commissioner in a press release announcing the cancellation of Minnesota’s moose hunting season.

The commissioner noted that the state’s limited moose hunt was not the cause for the population’s decline.

The 2013 moose hunt was cancelled after aerial survey revealed the sharp drop in the moose population, the press release says. The survey was part of an on-going study of the state’s moose decline. (Previously covered here.)

The hunt’s cancellation was covered on NBC News’ national news. Read the article here.
Read the Minnesota DNR press release here.
Read more about the department’s moose mortality research project, on its webiste, here.

Photo: courtesy of Minnesota Dept. of Natural Resources

Why Deer Die

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Wisconsin deer trap“Hunter harvest continues to be the greatest cause of death of both adult and yearling bucks, while predation was the leading cause of fawn mortality, with most predations occurring within the first four to six weeks following birth,” said Jared Duquette, research scientist with the Wisconsin Department of Natural Resources and lead researcher for a five-year study of causes of adult deer mortality and a three-year study of fawn mortality in an item in department’s weekly news bulletin.

According to the weekly news summary:

Capture of adults will continue through the 2012-13 and 2013-14 winters. Fawns were live-captured in May and June in 2011 and 2012 and will be captured again in 2013. A number of captured adults and fawns are fitted with radio collars. All are fitted with ear tags. Additional metrics are collected including body weight and size, blood samples, sex, presence of external parasites and age. Does are also examined for pregnancy. Deer are followed by radio signal until death, at which time researchers study the mortality to determine cause.

More details on the two studies are available in the department’s news report. Wisconsin is also conducting some other interesting deer studies. You can see the list here. I’d be interested to know the results of “An evaluation of the usefulness of deer-vehicle collision data as indices to deer population abundance.”

Read the weekly news item detailing the two deer studies here.

Photo: Closed box trap with deer feeding around it, courtesy of the Wisconsin Department of Natural Resources.

Bad Year for Bear-Human Conflicts in Colorado

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Black bearIt started off with a late spring frost that killed off the bears’ seasonal food. It continued with a regional drought. It all added up to the worst year for bear and human conflicts in Colorado since the state started keeping records a few years ago, says an article in the Glenwood Springs Post Independent.

The article quotes Perry Will, a 38-year veteran of Colorado Parks and Wildlife (CPW), a division of the Department of Natural Resources, who manages an area of western Colorado, as saying that he’s never seen a year as bad as this one for conflicts between humans and bears.

Development has set the stage. Colorado’s 5.2 million residents are more likely to hunt or hike or live in bear country, says another article on the topic in The Durango Herald. The state’s surging bear population is another factor the Post Independent article says. Add the frost and the drought, and it’s a recipe for disaster. The number of bears killed this year because of conflicts with humans was nearly triple last year’s total and almost twice as much as the last drought year.

In the article Will says that a year with normal rain could set things right. The state has seen the conflict level drop sharply in the past.

Glenwood Springs Post Independent article, here.
Durango Herald article, here.

Photo: bear, courtesy US Fish and Wildlife Service

The Bears Are Back

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web_Bear-Hair-in-TrapBlack bears are back in northeastern Alabama and southern New Jersey, recent reports say.

In Alabama, the return of black bears to northeastern Alabama has inspired studies of the species’ population dynamics in the state. According to a press release from the Alabama Department of Conservation and Natural Resources:

Research is currently underway in the Little River Canyon National Preserve, Talladega National Forest and the Mobile River Basin. Sampling for black bears in northeastern Alabama involves the deployment of hair snares and trail cameras. In the southern part of the state, EcoDogs are also a vital tool. The canines from Auburn’s EcoDogs program are capable of sniffing out and locating bear droppings. Once the hair and droppings are collected, they can be used to determine dietary habits, habitat use and population size.

According to the press release, the established population of black bears in northern Alabama is about 50, but black bears are moving into the northeastern part of the state from Georgia and Tennessee.

There appear to be more black bears in southern New Jersey as well, but the situation there is different. According to an article in the Philadelphia Inquirer:

“The population is too sparse to effectively survey them,” said Larry Herrighty, the Division of Fish and Wildlife’s assistant director of operations. Plus, he said, the cost to do so would be prohibitive because of the area involved.

This year is the third year that there has been a black bear hunting season in New Jersey, although that is only in the northwest corner of the state, the article says.

Read the Philadelphia Inquirer’s article here.
Read the Alabama Department of Conservation and Natural Resources press release here.

Photo: bear hair in a snare. (Could you even make something like that up?) Courtesy of the Alabama Department of Conservation and Natural Resources.

Michigan Confirms U.P. Mountain Lion Photos

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cougar_mqt_county_nov_2012_404621_7Not sure how we missed this in our recent wild cat news round-up, but a Michigan Department of Natural Resources press release says:

Three recent trail camera photos of cougars in the Upper Peninsula have been verified by the Michigan Department of Natural Resources.

Two of the photos, both of a cougar with a radio collar, were taken in October in Menominee County – one near Cedar River and one near Menominee just north of the Wisconsin border. The third photo was taken in northern Marquette County in November. The cougar in the Marquette County photo is not wearing a radio collar.

The DNR does not place radio collars on cougars; North Dakota and South Dakota are the nearest states where wildlife researchers have placed radio collars on cougars to track their movement. The DNR has not yet been able to determine the origin of the radio-collared cougar that is in Michigan.

Cougars are otherwise known as mountain lions, Puma concolor to scientists.

Read the Michigan DNR press release here.
Read the UpNorthLive.com report here.
And read The Mining Journal article here.

Photo: trail cam photo of a mountain lion courtesy of the Michigan Department of Natural Resources

Montana Surveys Bats

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gray batThe Montana Natural Heritage Program is collecting baseline information on the state’s bats that will be vital if the state is ever struck with white nose syndrome (WNS), an article in the Flathead Beacon reports.

The survey has lead to the discovery of three additional bat species in Glacier National Park, the article says. The project has been assisted by the North Rocky Mountain Grotto caving club and the Bigfork High School cave club.

According to information from the Montana Natural Heritage Program, Montana Fish, Wildlife and Parks is a partner in the project.

Read the Flathead Beacon article here.
Read more information about the project, plus additional bat research being conducted by the Montana Natural Heritage Program here.

Photo: bat, courtesy of the US Fish and Wildlife Service

Stickers Help Fund 2015 Heron Survey

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According to the Heron Observation Network of Maine (HERON) blog:

The great blue heron was designated as a Species of Special Concern in Maine in 2007 due to a decline in breeding pairs along the coast. Little was known about the inland breeding population before 2009 when the Maine Department of Inland Fisheries and Wildlife ramped up its monitoring efforts by creating the Heron Observation Network.

Through HERON, volunteers across the state monitor known great blue heron colonies during the breeding season, collecting information that helps state biologists understand the species’ population trend and prioritize future conservation efforts.

In addition to the data collected by volunteers, it is important to periodically do a statewide aerial survey to find new heron colonies that may have recently popped up.

To help fund the next aerial survey, scheduled for 2015, HERON is partnering with Burly Bird (a Maine-based conservation sticker company) to create a UV-coated vinyl sticker that shows a black and white silhouette of a great blue heron.

The stickers can be purchased from the Burly Bird website or through the Maine Department of Inland Fisheries and Wildlife’s online store.

The Maine Sun-Journal covered the story, here.