Thursday, February 25, 2016

Shelling at Lake Erie...

I love trips to Lake Erie because birding is always involved, but this time, unexpectedly, a little shelling was thrown in too...

These small, beautiful conically shaped shells are gastropods, or snails. They are probably Pleurocera acuta.
Conical-shaped shells we found on the beach along Lake Erie at Maumee Bay State Park.

Thousands of these spiral-shaped conical shells were clumped along the beach at the water's edge at Maumee Bay State Park (near Toledo, OH). They were all in perfect shape and incredibly beautiful. I know nothing about shells, so I took a handful home to learn about them. After a few Google searches, I found a NOAA site from the Great Lakes Environmental Research Laboratory (GLERL), and learned these beautiful little shells had once been homes to aquatic algal grazers in the gastropod family, commonly know as...snails!

Thousands of the shells were clumped together near the water's edge.

From the photos and the descriptions on the GLERL page, I'm guessing these shells are Pleurocera acuta (common name, Sharp Hornsnail). According to the information on the webpage, these snails are native to the Great Lakes and Ohio River. They like to burrow in sand and mud, and they like the slower flowing areas of rivers near the bank. I'm going to start looking for them along the Little Miami River. Since it drains into the Ohio, they might be there too.

This is a photo of several Sharp Hornsnail shells. One is black and white stripes, two are amber, two are maroon and white striped, one is blueish, and another is black and white striped.
The color variations among the Sharp Hornsnail (Pleurocera acuta) shells are beautiful...greens, ambers, blues, browns, pinks, maroons, and whites. It will be interesting to see if the colors fade over time. 

The whorls can be multi-colored like the shell on the left of dark blue, orange, and white, ...or made of similar colors, like the roses and pinks of the shell on the right.
"Whorls" are the rings spiraling the conical shell. Pleurocera acuta can have up to 14 whorls.
After checking the shells I brought home, I found most had between 9 and 11 whorls.

Although they look like black and white stripes, closer inspection shows the dark stripe is really a dark chestnut brown.

Sharp Hornsnail shells from Lake Erie (Pleurocera acuta)

Further reading
If you want to learn a little about snail shell morphology, click here for the paper, "North American Freshwater Snails," by J. B. Burch, and go to page 25 (in Walkerana, 1986, 2(6) on the Freshwater Mollusk Conservation Society (FMCS) website. You can learn about the whorls, aperture, shell size, and shell shapes, e.g., the shape of our little Sharp Hornsnail is "elongate conic." This booklet is packed with a lot of information.

Freshwater Gastropods of North America is a blog with higher-level scientific info. Click here for a link to "Pleurocera acuta is Pleurocera canaliculata," by Dr. Rob Dillon. Just like in birding, it seems the species names of gastropods can change!

Where did the colors come from?
In the comments section, Mary Ann asked if I new why the same mollusk would make shells in various colors. I didn't, so I did a quick check to find out. Click here for a blog post by Richard Goldberg titled, "The Significance of Snail Shell Color and Pattern" (6-19-2009) on the Art and Science of Nature blog. Goldberg explains that these varied colors ("inter-population variability") can be explained through evolutionary science, mentioning "extreme color polymorphism" in a population is good, because "looking different from your neighbor" prevents predators from developing a "search image" for its prey. Read the article for more details.

As for the colors themselves, they are produced in many ways, including pigments the mollusk acquires from what it eats, pigments the mollusk produces to strengthen shells, hereditary colors to offer camouflage, and much more. Click here for an article by Gary Rosenberg titled, "Why do Shells Have Their Colors?" on the Conchologists of America, Inc. website for details.

I emailed Dr. Rob Dillon, a professor in the Department of Biology at the College of Charleston, to make sure I had identified Pleurocera acuta correctly. He replied that I did (yeah!). But there's 2013 Pleurocera acuta received the trinomen "Pleurocera canaliculata acuta" as a subspecies and "junior synonym" of canaliculata. (Pleurocera acuta was first described by Thomas Say in 1821 as canaliculata and the new name reflects that history.) Thanks, Professor Dillon!  See the paragraph above under "Further reading" for a link to Dr. Dillon's blog. Click here if you want to learn what a subspecies is. 

This post is part of our "Big Water" trip to Maumee Bay. Click here for more posts in the series.

Wednesday, February 24, 2016

Red-shouldered beauty in winter...

When winter has drained the color from the trees, and gray settles in like it owns the place, our Red-shouldered Hawk is conspicuously beautiful. His red shoulders and the strong contrast between the black and white stripes in his tail feathers pop in the landscape...

A Red-shouldered Hawk takes flight from a young oak tree in our backyard.

This is the first time I've seen our Red-shouldered Hawk perch in the young oak tree. It started as a sapling about 10 years ago and has been growing quietly ever since. It finally caught Big Red's eye. Our little oakling is growing up.

Even from behind, and at a distance, a Red-shouldered Hawk is gorgeous and stops you in your tracks.

Thursday, February 11, 2016

Red loves his new platform feeder!

Earlier this winter, the platform feeder my dad made me back in 1990 when Rick and I moved from our apartment into our first house died. I went out to stock it with seed, and it was shattered on the ground...raccoon, squirrel...Sasquatch? Who knows who dealt the final blow. All I knew was it broke my heart. That feeder was part of our backyard landscape for over 26 years, and because my dad made it, I loved it all the more. It was Red's favorite feeder as well, and I was surprised how hollow it made me feel to look out and not see Red and his buddies crowded around eating sunflower seeds from it. The thought of putting a new store-bought feeder in its place made me feel even worse, so I just threw seed on the ground and ignored the gaping hole until Rick stepped in to save the day by making a beautiful "Cedar Palace" for Red and me...

Northern Cardinals visit a cedar platform feeder covered in snow.
Red and his buddies took to Rick's cedar platform feeder right away. When the snow melts away,
I will take a few closeups of of it. The Cedar Palace is a work of nails, btw...all mortise and tenon.

Rick took the dimensions from my dad's feeder and got to work. He came up with his own design, and even made cedar shakes for the roof by hand. This thing is sturdy and will no doubt last as long as my dad's, which when added to my current age will make me 80...wait...80???? That can't be right, but after a quick re-add, it is. (I think I'm going to ignore that bit of info for now and just keep watching, painting, and photographing the birds.)

If you want to see my dad's old feeder, click here for the post from 2009, "This bird feeder has seen a lot of action..." It was only 20 years old back then!

(Thank you, Dad, for making the best bird feeder ever, and thank you, Rick, for carrying on the tradition. Lots of hearts, lots of smiley faces, lots of love.)