Thursday, 11 January 2018

Waterfowl Deaths Warming Lakes Linked

Photo of dead waterfowl on the beach.

Photo by Michigan Sea Grant – University of Michigan

Researchers at the UW Madison found that tissue in a majority of dead waterfowl found at three locations around Lake Michigan contained botulism toxin. They just published their findings in the Journal of Applied Ecology. These deaths followed warm water algae blooms where counts of botulism producing bacteria (Clostridium botulinum) spiked.

According to the USGS Field Manual of Wildlife Diseases, “Most botulism outbreaks take place during the summer and fall when ambient temperatures are high.”

Lake Michigan waterfowl botulism deaths linked to warm waters, algae

Wildlife Study

Professor Ben Zuckerberg led the research into botulism deaths in Great Lakes waterfowl.

Microscopy image of waterfowl with Clostridium botulinum.

Photo from Wikipedia

Invasive zebra mussels have increased water clarity which along with warmer waters temperatures created the low-oxygen environment where the botulism toxin-producing bacteria thrive.

Birds do not use bacteria as a food source, however, they eat the insects and other invertebrates that do. According to the USGS “Invertebrates are unaffected by the toxin and, because they feed on decaying matter, they can effectively act to concentrate toxin.” That is how birds get lethal doses of the botulism bacteria.

To keep track of these deaths, the USGS National Wildlife Health Center created a citizen-science program called AMBLE (Avian Monitoring for Botulism Lakeshore Events) in 2010. Volunteers from AMBLE walked beaches in three areas around Lake Michigan.

 The Zuckerberg team also found that die-offs were located within a roughly 25-mile radius of one another.

These findings are no surprise to anglers and duck hunters on the Upper Mississippi. Rafts of cutes have been washing up on Mississippi dams along the State’s western border for several years now. There too toxicology reports show botulism as the cause.

Looking Forward

The hope is that scientists may be able to predict when botulism outbreaks could occur by watching environmental conditions.

2017

October 2017

Sunday, 01 October 2017

The Long Flight Home

Caterpillars are finishing their feast on milkweed plants across Wisconsin and preparing to shed their skin to change into monarch butterflies. Monarch butterflies are important pollinators collecting reading plant pollen as they collect nectar. While they feed on a wide variety of plants, monarch butterflies only lay their eggs on milkweed plants.

This super generation of monarchs will spend their entire lives flying to their wintering home in Mexican state of Michoacan. Once there, they will lay their eggs and die.

The offspring of this super generation overwinters in and begins their journey back the following spring. This first generation of the new year only migrates as far as Texas and the Gulf coast where they lay eggs that spend the next month developing into larvae, caterpillars and then butterflies. The second generation continues the migration to the summer home grounds where the third and fourth generations spend the warm months feeding and breeding.

In late summer the fourth generation lays the eggs that will become the next southward bound super generation. Warm weather in September allowed monarchs to continue feeding in southern Wisconsin. This super generation is now making its way south. 

There are two distinct populations of monarch butterflies, those east of the rocky mountains that winter in the mountains of central Mexico and the western monarchs that winter coastal tree groves in California and spread out across to forage and lay their eggs throughout California, Arizona, Oregon, Washington. Urbanization and extensive use of pesticides by farmers have dramatically reduced the amount of milkweed plants that western monarchs need to lay their eggs.

Our eastern monarchs, currently numbering some ten million, have been extensively studied for nearly forty years. Only recently have the western monarch butterflies received careful study. The results of that study, funded by the USFWS, are stunning. According to the study’s author, Washington State University researcher Cheryl Schultz, western monarch populations have plummeted from 10,000,000 forty years ago to approximately 300,000 today. This decline is so steep that the authors predict that western monarch butterflies have a 63% chance of extinction in the next twenty years and an 84% likelihood of extinction within the next 50 years.

Want to be involved in helping monarch butterflies? Journey North is a citizen science project that tracks the movement of monarch butterflies and other species.

Their projects provide scientist with valuable information about their movements.

March 2017

Wednesday, 15 March 2017

Make Frog and Toad History

picture of gray green frog on a purple cone flower.

Volunteers will get to know Gray tree frogs (and many other frog and toad species) well through the Wisconsin Frog and Toad Survey. Photo Credit: J. Rowe

Be part of the longest running citizen science amphibian calling survey in North America. The Wisconsin Department of Natural Resources is looking for volunteers to lend their ears for the Wisconsin Frog and Toad Survey.

The survey was initiated in 1981 as a response to known and suspected declines in the 1960s and 1970s in numerous Wisconsin frog species. The project’s goals are to determine the status, distribution, and long-term trends of Wisconsin’s twelve frog and toad species.

Since 1984, volunteers have contributed over 8,300 survey nights and 83,000 site visits. During this time, citizen scientists have helped DNR conservation biologists define the distribution and population trends of all 12 frog and toad species in the state.

Volunteers sign up to take one of the available Wisconsin Frog and Toad Survey routes. Just look for one of the green marked routes at the Wisconsin Frog and Toad Survey’s website. If the route you want is not available you may ask to be placed on a waiting list for future years as requested routes or counties become available.

If you are interested in volunteering contact the department’s Wisconsin Frog and Toad Survey Coordinator for further information.