Category Archives: amphibians

Stiltgrass Bad News for Toads

Posted on by
Reply

northern leopard frogJapanese 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

Updated Prohibited Species List in Oregon

Posted on by
Reply

Some reptiles and amphibians are off, and two otter species are on. The Associated Press reported this week that the Oregon Wildlife Integrity Program has updated its list of prohibited species in a three-year long process. The Wildlife Integrity Program is part of the Oregon Department of Fish and Wildlife. In some states prohibited species are handled by the department of agriculture or the department of commerce.

The reptiles and amphibians taken off the list are not considered a risk of competing or surviving in Oregon if they escape. Three other amphibian species were kept on the list because they do pose a risk.

The two otters prohibited are the eastern subspecies of North American river otter, and the Asian small-clawed otter.

Read the Associated Press article in the Seattle Post-Intelligencer for the specific species.

NYS Creates Recovery Plan for Northern Cricket Frog

Posted on by
Reply

Northern_cricket_frog_at_Neal_Smith_National_Wildlife_RefugeThe 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.

Environmental DNA Survey Reveals Hellbenders

Posted on by
Reply

floydwithhellbender_original_cropFrom 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

Pond Study Points to Chytrid Reservoir

Posted on by
Reply

pond research chytridAbout a third of the ponds in a Missouri study harbored chytrid fungus. A Washington University in St. Louis scientist decided to take advantage of the fact that the fungus does not seem to cause amphibian deaths in the region, and tried to tease out the factors that lead to the fungus flourishing in one pond and not another.

The 29 ponds studied were all roughly the same size and depth. They were clustered in the east-central section of Missouri (no surprise, around St. Louis).

No single factor determined which ponds had the fungus and which did not. But some fancy statistical analysis showed that the affected ponds shared amphibian community structure, macroinvertebrate community structure, and pond physicochemistry.

Since the research was done, crayfish and nematodes have been found to be infected with the chytrid fungus, making them possible reservoirs for the disease. This study suggested that variations in invertebrate communities was a factor in which ponds harbored the fungus.

In the paper, which was published in PLoS ONE, the researchers recommend that more research be done on the non-amphibian life in infected ponds to figure out how they are contributing to sustaining the fungus.

Read the Washington University in St. Louis article here.
Read the PLoS ONE paper here.

Photo: A pond survey crew samples the creatures that live in a Missouri pond in order to better understand the differences between ecosystems that favor chytrid and those that do not. Alex Strauss, the first author on this paper, is wearing a blue shirt.  Photo credit: Elizabeth Biro/Washington University – Tyson Research Center

Newly Discovered Chytrid Fungus

Posted on by
2

fire salamanderA new species of chytrid fungus has a different ecological niche than the one that has been wiping out amphibians all over the globe, says John Platt it Scientific American’s Extinction Countdown blog.

The familiar strain of chytrid fungus thrived in warmer temperatures. The newly discovered species thrives at lower temperatures, the blog post says. The fungus was identified in salamanders in the Netherlands. Midwife toads exposed to the fungus in the lab did not die.

Is this good news or bad news? It could be good news if the fungus is only lethal to a small number of species and is only viable in a certain temperature range. Limits are good when it comes to chytrid fungi.

However, if this species of chytrid fungus is totally different from the other species that has already done a good job of wiping out amphibians worldwide in everything but how lethal it is — in could just hit amphibian species and environments that the other species hasn’t gotten to yet, which would be very bad news indeed.

Read the Extinction Countdown blog post here.
Read the Proceedings of the National Academy of Sciences paper here. (Fee or subscription required for full article.)

Photo: Fire salamander in France, by Didier Descouens. Used under Creative Commons agreement.

Chytrid Fungus Found in Kansas

Posted on by
2

Witchita chytrid frogA press release from Wichita State University says that students there have detected chytrid fungus in the frogs they tested. A previous test of five Kansas frogs did not detect chytrid fungus.

Read the Wichita State press release, here.

Pro-MED has lots of helpful technical details about chytrid fungus in its commentary about the press release, including its complex life cycle and its role in the worldwide decline of amphibians.

Read the Pro-MED comment, here.

In reading that chytrid fungus was newly found in Kansas, I found myself wishing for a map of its presence, as is available for white nose syndrome in bats and chronic wasting disease in deer. You can find that map right here.

Photo: One of the frogs tested. By: Lainie Rusco, used courtesy of Wichita State University

Troublesome Creatures

Posted on by
Reply

spotted owlEfforts around the country to remove troublesome creatures — whether invasive or otherwise — have been met with a variety of reactions. In all cases the creatures are being removed because they are harming an ecosystem.

No one seems to mind that California Fish and Wildlife Department is removing South African clawed frogs from Golden Gate Park. The frogs are not native to the area, they completely destroy the habitats they invade, and they carry a fungus that is deadly to native amphibians. Read about the recovery effort in Bay Nature.

In Michigan, the Department of Natural Resources would like there to be fewer invasive mute swans. Mute swans are aggressive and don’t allow the native trumpeter swans or loons to nest. (They also have it in for ducks and geese.) Plus, they eat so many wetland plants that they can destroy wetlands. Oiling eggs has been too costly and too slow, so the department will begin to kill mute swans. Michigan Live has published several articles on the subject.
Here’s Michigan Live on why.
Here’s the plan in one county.
And here the reaction to the plan in that county.

And then there are barred owls. They’ve long been identified as a threat to northern spotted owl recovery in the Pacific Northwest. Spotted owls rely on old-growth forests. Barred owls are not so picky, and have moved into the spotted owls’ turf as the habitat has become more variable, because the old-growth forests were cut. The U.S. Fish and Wildlife Service has decided to start killing barred owls to try to improve matters for the spotted owl. The Oregonian did two stories on the situation. This one several years ago. And this one now that the program has begun.
There’s been no shortage of news coverage. See a lot of it here.

Photo: Spotted owl, courtesy US Fish and Wildlife Service

Frogs and Pesticides

Posted on by
Reply

pacific tree frogTwo fungicides are showing up in the tissues of Pacific treefrogs, even those that live in pristine national parks, a recent paper in the journal Environmental Toxicology and Chemistry shows. The pesticides aren’t just coming from agricultural operations, but also from illegal marijuana farming.
Read the LiveScience article here.
Find the abstract for the paper here.

A study published in the journal Evolutionary Adaptations found that frogs collected from ponds where their ancestors were likely exposed to the pesticide chlorpyrifos showed greater tolerance to that pesticide themselves, perhaps showing an evolutionary adaptation to surviving exposure to that pesticide.
Read the KQED story here.
See the abstract for the paper here.

Photo: Pacific treefrog, courtesy Washington Dept. of Natural Resources

Bullfrogs Die From Fungus Too

Posted on by
Reply

bullfrog OSUA recent study by researchers at Oregon State University and the University of Pittsburgh shows that bullfrogs are not just carriers of Batrachochytrium dendrobatidis, also called Bd or a chytrid fungus, but can die from it as well. The paper was published in the journal EcoHealth.

These researchers found that bullfrogs are not even a particularly good host for the fungus — although they say that this may depend on site-specific conditions.

The take-away? Scientists should keep searching for chytrid carriers, and wildlife managers in places where bullfrogs are native, should keep an eye on their populations. It wouldn’t be the first time a species was in trouble at home while being an invasive species elsewhere.

Read the Oregon State University press release here. (All other media coverage was just a reprint of the release.)

Photo: by Megan Cook, courtesy of Oregon State University