Stiltgrass Bad News for Toads

Posted on September 8, 2014 by MadelineBodin

northern leopard frog Japanese stiltweed is an invasive grass species that out-competes native species in wetlands, forests and other areas. Recent research at the University of Georgia found that it isn’t doing any favors for the American toad either, a post in Entomology Today reports. The paper appeared in the journal Ecology.

The stiltgrass, the researchers found, is wonderful habitat for wolf spiders. As wolf spider numbers increase, they prey on an increasing number of juvenile American toads. The researchers had noticed low toad survival in eight areas in Georgia with invasive stiltgrass and wanted to know why. They were surprised to find an abundance of wolf spiders.

The researchers hypothesize that the stiltgrass allows the spiders, which keep their own populations in check through cannibalism, to hide from each other.

Read all the gory details in the Entomology Today post.
Read all the scientific details in the Ecology paper.

In other amphibian news, National Public Radio recently featured the North American Amphibian Program, a citizen science project that has been tracking calling frogs for 20 years. The news hook seems to be that a citizen science in Virginia recently discovered the presence there of a leopard frog species that had only been identified two years ago in the New York City area.

Photo: Leopard frog. Credit: Shaula Hedwall/USFWS

Indiana River Otters: From Recovery to Control

Posted on September 2, 2014 by MadelineBodin

otter_pair_maxwell “The [Indiana] Department of Natural Resources is considering allowing a trapping season for river otters less than two decades after being reintroduced to the Hoosier landscape,” wrote John Martino, outdoors columnist for the Kokomo Tribune last week. In the article, Martino says the river otters were official declared extirpated from Indiana in 1942.

The state’s reintroduction program began in 1995 and included 303 river otters trapped in Louisiana and released in Indiana, the article says. Ten years later river otters were taken off the state endangered species list.

In 2013 the IDNR received more than 64 formal complaints about river otters eating fish from private ponds, Martino reports. The department issued 11 nuisance animal control permits in 2012, he adds. Now, he reports, the department is considering controlling the river otter population by opening a trapping season for river otter in the counties where it is most abundant.

Read the article in the Kokomo Tribune here.
Information on river otter from the Indiana Department of Natural Resources is here. It includes links to several data sets, including a mortality study.

Photo: courtesy Indiana Department of Natural Resources

Asian Carp Head North

Posted on March 13, 2014 by MadelineBodin

asian carp map 4-13 “Asian carp have harmed the ecosystem, the economy, property, and boaters in the Mississippi River system. The diet of Asian carp overlaps with the diet of native fishes in the Mississippi and Illinois Rivers, meaning the carp compete directly with native fish for food,” says the Asian Carp Regional Coordinating Committee website.

That website, and other information on Asian carp, emphasize the danger to humans from the carp. The carp are large and jump as high as 10 feet out of the water when startled. Since passing boats startle the fish, they injure boaters.

The focus has been on keeping Asian carp, a term that includes both bighead carp and silver carp out of the Great Lakes, which already has enough invasive species, thank you, and where the carp are expected to do horrible things to the food chain.

This week, however, the bad news is that Asian carp have spread farther north in the Mississippi River. Their eggs have been found as far north as Lynxville, Wisc.

“This discovery means that Asian carp spawned much farther north in the Mississippi than previously recorded,” said Leon Carl, US Geological Survey Midwest Regional Director in a USGS press release. “The presence of eggs in the samples indicates that spawning occurred, but we do not know if eggs hatched and survived or whether future spawning events would result in live fish.”

Read the USGS press release with all the details, here.
Read an article in the Milwaukee Journal-Sentinel, based mostly on the press release here.
Another article, in the Minneapolis Star-Tribune, also leans heavily on the press release. Read it here.

Map: Asian carp distribution, as of April 2013. Map courtesy of Asian Carp Regional Coordinating Committee

NYS Creates Recovery Plan for Northern Cricket Frog

Posted on February 14, 2014 by MadelineBodin

The northern cricket frog is one of New York State’s two endangered amphibians. New York State law does not require recovery plans for endangered species, but the state Department of Environmental Conservation has proposed one for this species, a recent department press release says.

The plan includes conserving appropriate, but unoccupied habitat. The plan also included reintroducing frogs to unoccupied habitat, but only “if suitable habitat still remains, northern cricket frog habitat requirements are understood, and a funded and scientifically sound protocol is in place to monitor northern cricket frog abundance and assess potential causes of decline at any re-introduction site.”

In other words, more research is needed. There is a very brief paragraph about data gaps, and an even briefer one about recovery partnerships. A long list of potential tasks, includes sections on research and recovery tasks.

The comment period on the plan closes a week from today, Feb. 21, 2014.

Download the recovery plan here.
Read the NYS DEC press release about the plan here.
Read a Reptile Magazine article about the plan here.

Photo: Northern cricket frog at Neal Smith National Wildlife Refuge in Iowa. Photo by Sara Hollerich, used courtesy US Fish and Wildlife Service.

Wyoming Studies Mule Deer and Burbot

Posted on January 3, 2014 by MadelineBodin

Wyoming Game and Fish Department personnel, researchers with the Wyoming Cooperative Fish and Wildlife Research Unit at the University of Wyoming, personnel from the Bureau of Land Management and US Forest Service, and many volunteers are trapping mule deer for two research projects in southwest Wyoming, a Wyoming Game and Fish Department (WGFD) press release says.

In one region, the department would like to know how many deer travel between Wyoming and Colorado, an important point of information for managing mule deer in both states. In that study, mule deer are netted when they feed at a bait of apple pulp and are fitted with bright yellow numbered ear tags and white vinyl visual collars. Some bucks are fitted with VHF ear tags.

In another region, the deer are netting by helicopter and fitted with GPS collars.

Read all the details, including the time frame of these multi-year studies, in the WGFD press release, here.

WGFD has also teamed up with researchers from the University of Idaho and Trout Unlimited to learn more about an illegally introduced population of burbot (a fish) in the Green River, according to another WGFD press release.

The tricky part is that burbot are native to some watersheds in Wyoming. The research, says the press release, “aims to study the effectiveness of various sampling gears for capturing burbot in flowing water, learn more about how they are potentially affecting this world-class sport fishery and what actions can be taken to prevent such negative impacts.” It notes that in some parts of its native range, burbot are in decline.

Photo: a Wyoming mule deer captured in the second study. Courtesy of Wyoming Game and Fish.

Environmental DNA Survey Reveals Hellbenders

Posted on December 3, 2013 by MadelineBodin

floydwithhellbender_original_crop From the Georgia DNR Georgia Wild newsletter:

Eastern hellbenders have become a bit less elusive in north Georgia.

DNA analysis of water samples from 98 sites across the top of the state have provided Department of Natural Resources wildlife biologist Thomas Floyd a clearer picture of where the massive salamanders are still found in Georgia.

Floyd said the collaborative research with The Orianne Society (“Hellbenders in a bottle,” Sept. 30), part of a larger State Wildlife Grants project aimed at conserving Georgia amphibians and reptiles, “has given us a better idea of hellbender distribution and will allow us to concentrate our conservation efforts.”

That’s good for hellbenders and the scientists who study them (video)….

Hits and misses

The eDNA analysis confirmed the presence of hellbenders at six of 10 historical sites where they had not been seen in at least five years, 13 of 25 streams that had not been physically surveyed before and one site where hellbenders had been reported but researchers had been unable to find them in recent surveys. Also, although what looks like suitable habitat is found in streams that drain into the Chattahoochee, Conasauga, Etowah, Oostanaula and Savannah rivers, samples confirmed the presence of hellbenders only in the Tennessee drainage.

Some results were sobering.

Floyd, who works for DNR’s Nongame Conservation Section, said lab analysis showed that DNA amounts at historical sites that tested positive were minimal compared to levels found in streams with healthy populations. Also, eDNA tests did not detect hellbenders in any northwest Georgia stream, including those in the Tennessee basin where the species had been seen before.

“Hellbenders weren’t even detected from a stream stretch where a specimen was found in 2011, which indicates that – like several of the historical sites – the populations there are likely really small and it is uncertain as to whether they can persist into the future,” Floyd said.

He is disappointed by the lack of hits outside the Tennessee drainage, but says the research will lead to more efficient conservation. “We don’t have to expend time, effort and resources surveying, even in really good habitat, where we now know that hellbenders don’t occur.”

Read the rest of the article in Georgia Wild, here.
See a previous Georgia Wild article on hellbenders, here. It details the sampling technique. (And keep following the links back to trace the project to its beginnings.)

Photo: Biologist Thomas Floyd with a hellbender. Ga. DNR

Infection and Capture Fatalities

Posted on November 25, 2013 by MadelineBodin

It happens. An animal is captured for study, is released, but dies soon after. A certain percentage of fatalities is expected in any study where animals are handled. In Chile recently, five fur seal pups died after being captured, AAAS’s ScienceShot reports. There had been no previous fatalities in the four years of the study.

Veterinarians studying the dead pups found they all had a hookworm infection. The infection sent the seals’ adrenal glands into over-drive, stressing their hearts. The researchers say that fieldworkers should not try to capture seals that show signs of chronic infection, which is probably good advice when working with other animals as well.

Read the ScienceShot article here. It includes links to the paper and other information.

Oregon Fish Biologists in Helicopter Crash

Posted on November 1, 2013 by MadelineBodin

Three people were injured when a helicopter carrying two Oregon Department of Fish and Wildlife biologists on a salmon spawning ground survey hit a power line and crashed into the river they were surveying on Monday, Oct. 28. None of the injuries were life-threatening, reports said.

News reports say that the pilot was airlifted the hospital and is now in fair condition. The assistant district fisheries biologist, Holly Huchko, suffered a broken back and is in intensive care. Eric Himmelreich, a fisheries habitat biologist, broke two vertebrae in the crash and is now in good condition.

Read the Oregon Department of Fish and Wildlife press release here.
The KPIC reports contains a video of the helicopter in the river.
The Mail Tribune article focuses on the helicopter.
The Douglas County News-Review has the most detailed report.

Southwestern Naturalist Round-up

Posted on August 15, 2013 by MadelineBodin

southwesternnaturalistcover Here are some papers from the most recent issue of the Southwestern Naturalist that may be of interest to others outside the region, or of particular interest locally:

Fine-Scale Selection of Habitat by the Lesser Prairie-Chicken. Temperature turns out to be very important.

Consumption of Seeds of Southwestern White Pine by Black Bear. Black bears steal from squirrel caches. Go figure.

Is False Spike (a freshwater mussel) Extinct? First Account of a Very Recently Deceased Individual in Over Thirty Years. This species may still be in Texas.

Horsehair worm: New to the Fauna of Oklahoma. A second species of horsehair worm is discovered in the state.

New Distributional Records for Four Rare Species of Freshwater Mussels in Southwestern Louisiana. It’s not easy being a mussel. These are hanging on.

River Otters Have Cat Disease

Posted on July 22, 2013 by MadelineBodin

euro_otter_by_Catherine_Trigg You may remember toxoplasmosis being the key factor in the deaths of sea otters a few years ago. (If not, find a refresher here.) But what about river otters?

A recent paper in the journal Parasites and Vectors found that 40 percent of the river otter carcases tested in England and Wales were positive for toxoplasmosis. None of the river otters in the study had died of the infection. (The concern, of course, is any sub-lethal effects.)

You can find the full text of the paper in Parasites and Vectors, here.
You can read the press release from the American Bird Conservancy, here.

A similar study on US river otters, specifically North Carolina river otters, was published in 1997. There, 46 percent of the tests were positive. Read the abstract, here.

Ten years later, another study, this one in the Journal of Wildlife Diseases, found that river otters who feed in the ocean are more likely to be infected with various human pathogens, including the one that causes toxoplasmosis, if they lived closer to urban areas. You can read the abstract, here.

Photo: Eurasian otter by Catherine Trigg, used courtesy of the American Bird Conservancy

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Category Archives: aquatic ecosystems