Mayslake Marsh Update: Amphibian Traps

by Carl Strang

I set out some amphibian traps in Mayslake Forest Preserve’s stream corridor marsh to assess how the marsh has recovered from the drought of 2012 and another drying out in 2013.

This leopard frog still is dark from its recent emergence.

This leopard frog still is dark from its recent emergence.

I have caught and released several of the large predaceous diving beetles, Dytiscus hybridus.

I have caught and released several of the large predaceous diving beetles, Dytiscus hybridus.

Similar in size, this water scavenger beetle, Hydrophilus triangularis, was an addition to the preserve species list.

Similar in size, this water scavenger beetle, Hydrophilus triangularis, was an addition to the preserve species list.

The club-like end of the antenna separates the water scavenger beetles from the predaceous diving beetles, whose antennae are thread-like.

The club-like end of the antenna separates the water scavenger beetles from the predaceous diving beetles, whose antennae are thread-like.

The identification of this juvenile crayfish is uncertain, but the slender pincers have me thinking White River crayfish, in the past the most common species in that marsh.

The identification of this juvenile crayfish is uncertain, but the slender pincers have me thinking White River crayfish, in the past the most common species in that marsh.

I caught only one magnificent adult White River crayfish against 10 or so juveniles, sign of a recovering population.

I caught only one magnificent adult White River crayfish against 10 or so juveniles, sign of a recovering population.

Meanwhile, the grassland crayfish have been opening up their tunnels around the peripheries of the wet areas.

Meanwhile, the grassland crayfish have been opening up their tunnels around the peripheries of the wet areas.

Grassland crayfish mainly come out at night to forage on land. Sometimes these foragers become foragees.

Grassland crayfish mainly come out at night to forage on land. Sometimes these foragers become foragees.

The marsh’s muskrats regard the amphibian traps as suitable platforms for their territorial markings.

The marsh’s muskrats regard the amphibian traps as suitable platforms for their territorial markings.

Through all of this, the marsh’s sounds have been dominated by the songs of western chorus frogs. They are so small that they can squeeze their way out of the traps.

Through all of this, the marsh’s sounds have been dominated by the songs of western chorus frogs. They are so small that they can squeeze their way out of the traps.

 

Eagle Marsh Bioblitz

by Carl Strang

Each year the Indiana Academy of Sciences selects a site within that state for a bioblitz. This past weekend’s was my third, and it always is a great way to kick off the field season. The location this year was Eagle Marsh, on the western fringe of Fort Wayne.

A large open barn in the center of the site made for a good headquarters.

A large open barn in the center of the site made for a good headquarters.

Support for the visiting scientists and other volunteers was excellent. Here, the morning’s adventures are shared over box lunches on Saturday.

Support for the visiting scientists and other volunteers was excellent. Here, the morning’s adventures are shared over box lunches on Saturday.

The objective of a bioblitz is to find as many species of organisms as possible in a brief period, usually 24 hours. Scientists who specialize in different taxa lead teams that explore the site. Eagle Marsh is dominated by wetlands, as the name implies. In fact it sits on the boundary between two watersheds, the Great Lakes to the north, and the Mississippi River drainage to the south.

This fence is intended to block Asian carp from reaching the Great Lakes when the rivers flood. It soon will be replaced by a more reliable berm.

This fence is intended to block Asian carp from reaching the Great Lakes when the rivers flood. It soon will be replaced by a more reliable berm.

The site largely is a restoration project begun in 2005, though some teams found surprising diversity in parts of the preserve. My singing insects team was limited by the early date. We found a grand total of 3 species.

This Roesel’s katydid nymph was one of a small cluster we found on an elevated bank.

This Roesel’s katydid nymph was one of a small cluster we found on an elevated bank.

This bioblitz invited members of the public to assist those scientists open to such participation. I was delighted to have a team, for a change, and we enjoyed all the organisms we were finding.

Northern leopard frogs were abundant, a sign of how rapidly the wetland is improving in quality.

Northern leopard frogs were abundant, a sign of how rapidly the wetland is improving in quality.

Peck’s skipper was one of a number of butterfly species we observed.

Peck’s skipper was one of a number of butterfly species we observed.

Jeff Holland’s Purdue University entomology team always provides a highlight with their beetle-drawing lights.

1000 watts of power.

1000 watts of power.

Helpers collect some of the insects that fall to the sheets below.

Helpers collect some of the insects that fall to the sheets below.

Here is what they were seeing.

Here is what they were seeing.

Congratulations to Betsy Yankowiak and the Little River Wetlands Project team for a job well done.

Betsy presented an overview of the area’s geology for interested participants.

Betsy presented an overview of the area’s geology for interested participants.

New Trap Critters

by Carl Strang

One way of assessing the biodiversity of an area is by the rate at which new species are added to the area’s list with sampling effort. There are ways of doing this quantitatively, but in my amphibian trap sampling of the stream corridor marsh at Mayslake Forest Preserve I am (so far) just getting a qualitative sense of what is there. My sampling has been limited to just a few tens of trap-days last season and this. Still, the traps continue to produce new finds, including three species last week.

It must have taken some effort for this 3-inch bullfrog to squeeze into the trap.

Two leopard frogs were in another trap. I didn’t take a photo. I also caught a few water bugs.

They all have been this size (less than an inch long), and they have the shape of giant water bugs.

One of them proved to be an adult male, with eggs attached to his back.

The males carry the eggs, keeping them clean and oxygenated.

There are 3 genera of giant water bugs in the eastern U.S. The ones I had heard of, the ones famous for attacking tadpoles, fishes and other vertebrates, have a significantly larger body size at maturity. The second genus, with only one species in the eastern U.S., was easily ruled out. That left genus Belostoma. I was not able to determine the species from the photos.

I keep records of all individuals caught in the traps. At some point I will be able to chart number of species added against number of individuals caught, and number of species added against trap-days, to get a more quantitative sense of the marsh’s biodiversity. As long as I am catching new species this frequently, though, it makes sense to wait.

First Frog

by Carl Strang

Last week I put out the amphibian traps in the stream corridor marsh at Mayslake Forest Preserve. On the first two days the traps caught nothing, but while wading out to one of them I did see the first amphibian of the year. It was not, however, what I would have expected.

Northern leopard frog

As a general rule, and in my experience true in every year before this one, the first frogs we notice in DuPage County are the western chorus frogs. Though I have heard reports of others hearing them, the chorus frogs at Mayslake haven’t started singing yet. While others have reported seeing or hearing leopard frogs at Mayslake in recent years, this was my first.

The frog, very cold and newly out of hibernation, didn’t twitch as I maneuvered around it taking pictures.

The empty traps were themselves of some interest. Last year I put them out later in March, and right away began catching some of the large Dytiscus water beetles. So, I expect to learn something about them this year, either that there is a later time when they become active, or that there is significant variation in their numbers from year to year.

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