A Green Frog and a Bullfrog....and the differences between frogs and toads...

After posting the photos of the Fowler's Toad (click here for that post), I had a lot of emails from readers asking how to tell a toad and frog apart, so I thought I'd put something together quickly to explain. Let's start with two frogs I recently photographed while I was up at Magee Marsh for the Biggest Week in American Birding. After you see a couple of frogs, we'll move on to telling frogs and toads apart. The first frog is a Green Frog...

Female Green Frog (Rana clamitans melanota)
The easiest way to identify a Green Frog is to study the length of the dorso-lateral fold. Notice the fold of skin that starts just behind the eye, goes over the tympanum (ear drum disc behind the eye) and runs the length of the body. This ridge is the lateral fold. On Green Frogs, it runs the length of the body.

Green Frogs (Rana clamitans melanota) and Bullfrogs (Rana catesbeiana) are both green, and a small Bullfrog can look a lot like a Green Frog, but if you look at the lateral fold, there is no mistaking the two. On a Bullfrog, the dorso-lateral fold curls around the tympanum....

Male Bullfrog (Rana catesbeiana)
Notice how the lateral fold curls around the tympanum (eardrum disc next to the eye) and does not extend down the length of the back. Young Bullfrogs can resemble Green Frogs; however, as soon as you check out the lateral fold, you'll know which frog is which!

Telling a male frog from a female frog
There is an easy trick for determining the sex of a Green Frog and a Bullfrog. Look at the tympanum behind the eye. Female tympanums are about the same size as the eye. Male's are almost twice as big!
Note: This little trick works only for Green Frogs and Bullfrogs. The tympanum on most other frogs and toads is slightly smaller than the eye.

To determine the sex of a Green Frog or a Bullfrog compare the tympanum (ear drum) to the eye. A female's tympanum is about the same size as the eye; a male's is almost twice as large! I wish this trick worked for all frogs and toads! (Pencil sketch from my sketchbook.)

What are the differences between a frog and a toad?
Scientifically, there really is no difference between a frog and a toad--both are amphibians in the order "Anura." Morphologically, however, you can see physical differences between the two, and because of that, scientists have classified them into different families. The following characteristics separate "true frogs" (family Ranidae) from "true toads" (family Bufonidae)...

• Skin   Frogs usually have wet and smooth skin because they rarely leave the water. Toads usually have dry and bumpy or warty skin because they prefer to live in damp locations away from the water. 
• Legs   Frogs have long legs and feet, and they can jump far. Toads have shorter legs and can hop, but they can't jump that far. Toads tend to walk around or make little hops. 
• Parotoid gland   Some frogs are poisonous to the touch, but only toads have the large parotoid gland behind the eyes that secretes a toxin that can burn the mouth and mucous membranes of a predator. 
• Body shape   Frogs tend to be leaner and more streamlined for swimming. Toads are often described as being "chubby" or squat.
• Eggs   Frogs usually lay eggs in clusters or mats. Toads tend to lay eggs in chains. 
• Eyes   Frogs are said to have more prominent or "buggy" eyes. Toads less so (for me, the bugginess of the eyes is harder to distinguish. They all look pretty buggy to me!).

The differences between a frog and a toad become apparent when you place them side by side. Toads definitely look chubbier, but the Parotoid gland is what really separates them for me. When I see that poison pouch, I know I'm looking at a toad, and if I see a lateral fold, I know I'm looking at a frog. (Pencil sketch from my sketchbook.) 

These characteristics are generalities and blur quickly when you look at all the Anura families. For example, a Blanchard's Cricket Frog looks a little toady at first glance. He's bumpy and muddy looking and can be found away from water, but if you look for a Parotoid gland you won't find one, because he's a frog...not a toad. (Click here for a post on Cricket Frogs. Click here to learn about the Parotoid gland on a toad.) In Ohio, you can find the following Anuran families:

Ranidae ("true frogs") - Bullfrog, Green Frog, Leopard Frog, Pickerel Frog, Wood Frog
Hylidae - Gray Treefrogs, Chrous Frogs, Spring Peeper, and Cricket Frog
Bufonidae ("true toads") - American Toad, Fowler's Toad
Scaphiopodidae - Eastern Spadefoot Toad

For a complete list of Anuran families, click here.

Sources

• Minton, Sherman A (2001). Amphibians & Reptiles of Indiana, Indiana Academy of Science. ISBN 1-883362-10-5
• Platt, Carolyn V. (1998). Creatures of Change, An Album of Ohio Animals, The Kent State University Press. ISBN 0-87338-585-3
• Ohio Division of Wildlife, "Amphibians of Ohio Field Guide." Click here for a free online PDF of this guide. 

A Fowler's Toad in a clearing along the Little Miami River...

Sunday evening while I was walking along the Little Miami River trail, I decided to climb down to the river where there's a clearing with a sandy and rocky beach. It's a great place to watch the Chimney Swifts as they swoop low over the water snatching insects from the air. As the sun sets, more and more of the little birds grab their last meal of the day before returning to the huge chimney at the Peter's Cartridge Factory where they make their home. The rocky beach is large, and as I walked to one side, a Fowler's Toad moved right by my foot. I slowly crept away from him (I had my long lens) and crouched down low so I could get his photo...

A Fowler's Toad (Bufo fowleri) surprised me while I was walking along a sandy and rocky beach on the Little Miami River.

I soon found out there were three Fowler's Toads hiding out in the sand and rocks. One was large, one medium, and one small. The smallest toad was young, and the white stripe that went down his back was barely visible, but other than that, all three had distinct markings. Fowler's Toads and American Toads (Bufo americanus) look a lot alike, but if you examine the "warts" in the largest dark spots on their backs you can tell them apart. Fowler's Toads usually have three or four warts per spot, while American Toads usually have only one or two...

This toad had four "warts" in each of his larger dorsal spots, so I knew he was a Fowler's Toad (Bufo fowleri).

Another way to tell the two toads apart is to look at their bellies. Fowler's Toads have mostly white bellies with a dark spot in the center...

I laid down on the rocks so I could get a look at this fellow's belly. Sure enough, it was mostly white with a central pectoral spot. Again, confirmation that he was a Fowler's Toad. American Toads have a lot of dark spots on their bellies.

...another way to distinguish a Fowler's Toad from an American Toad is to check the warts on their hind legs. On a Fowler's Toad, the warts on the tibia are usually just a little larger than those on the thigh and foot. On an American Toad, the tibial warts are a lot larger (source: "Amphibians & Reptiles of Indiana," Sherman Minton, Jr., pg 112)...

...the tibial warts are just a little larger than those on the thigh and foot. Another clue points to a Fowler's Toad!

A Fowler's Toad blends in very well among rocks and sand along the Little Miami River. Camouflage was a great defense. When I looked away, I almost lost him. The white stripe down his back was very noticeable, and the green and gray stripes on his legs were too, but the same marks helped him blend in and disappear when I looked away. 

This Fowler's Toad is literally catching the last sun ray of the day. It lit his face for a few minutes before it slid out of sight. Fowler's Toads are mostly crepuscular (meaning they are most active at twilight), so he was just getting ready to start his day! 

About those warts...
The warts on a toad aren't warts at all. They are tiny glands that secrete a liquid toxin that burns the lining in the mouths of predators that try to eat them! The large bumps behind the toad's eyes are called parotoid glands, and they can secrete a lot of the toxin at once, causing the predator to drop the toads quickly. The toxin is strong enough to kill a dog that bites into them, but the toxin can't harm humans if it's secreted on the hands (source: "Amphibians of Ohio Field Guide" Division of Wildlife, pg 28 and Fast Facts).

The parotoid gland is located behind the eyes of the toad and contains toxins the toad uses in defense against predators. If you pick up a toad and it secretes the liquid, it won't really hurt you (and you won't get warts), but it will sting if you get it in your eyes or other mucous membranes, so be careful, and wash your hands after handling toads to avoid accidentally getting the toxin in your eyes.

Last year when I photographed an Eastern Hognose Snake going through all his antics (click here for that post), I remember reading that hognose snakes (whose favorite food is toads) are immune to toads' toxins.

p.s. A reader wrote me about an encounter he had with a toad, and it's a good warning. While sleeping a toad landed on his chest. Startled, he knocked it off. He then rubbed his eyes and started to go back to sleep. Suddenly it felt like his eyes were on fire, and they started watering like crazy! The toxin really can burn your eyes, so always wash your hands after handling a toad... (Thanks for letting us know, Robert!)

A Cheery Veery...

I found this beautiful Veery Thrush at Magee Marsh last May during the Biggest Week in American Birding festival. I was walking the boardwalk near dusk when I saw him moving around in the undergrowth. I've never been able to get a decent shot of a Veery. They skulk around on the ground in the leaf litter, and when they do come up for air, they stay tucked deep in thickets and shrubby areas in the woods. This bird was no different. I didn't even try to photograph him because it was getting dark and he was well concealed. I was just watching him through the binocs, hoping he would sing his beautiful song, when suddenly he hopped up on a branch and stared right at me. I switched out the binocs for the camera and held my breath, hoping the lens would squeeze enough light out of the day to record that face! Such a cheery Veery...

A beautiful Veery (Catharus fuscescens) gives me the eye. It might be the stink eye, but I don't think so. 
He's too sweet for that! :-)

Veeries love the cool and damp forest floors. They also like water, which makes the Black Swamp at Magee Marsh perfect habitat! I assume this fellow is migrating through, but Veeries do nest in the northern parts of Ohio, so maybe he is staking out his territory.

I was so happy to see this bird. I don't get to see it that often in the woods around my house. During spring migration, I do get to hear his beautiful song every now and then in the evening along the Little Miami River, but it's rare. 

The Veery's song is beautiful. If you read about it, you'll often see the words "ethereal,"and "flute-like," "airy," and even "magical" or "haunting." The descriptors are intense for a reason--the song will stop you in your tracks, and once you've heard it, you'll never forget it. Click here for a link to Lang Elliott's recording of a Veery's song. I usually only hear it in the evening near dusk, and it always seems a bit haunting to me...

...such a magical-sounding little bird. If you really want to get fanciful, it's not too hard to imagine his song being a fairy call to announce the beginnings of "midnight revels, by a forest side..." (John Milton, Paradise Lost) 

For migration predictions and info on the birds being seen on the boardwalk, click here for Kenn Kaufman's "Crane Creek - Magee Birding" blog (it covers the Lake Erie Shores and islands region of northwest Ohio). Click here for a nice resource on Magee Marsh.

The Biggest Week in American Birding festival starts May 3, 2013 and runs through May 12, 2013.

Black-throated Green Warblers at Magee Marsh during the Biggest Week in American Birding

I'm back home from the Biggest Week in American Birding and am already missing the warblers! I'm definitely returning next year for the event, and I'm adding a day to my stay. This year I was there Monday-Thursday, but next year I'm adding in Friday :-) I'm going to get Matty and Rick up for a few days too. Spending a week birding and photographing warblers at Magee is heaven. I loved it...

A Black-throated Green Warbler (Dendroica virens) clings to a vine looking for something to eat along the boardwalk at Magee Marsh. He was singing up a storm, and all eyes were on him!

It's easy to see where he gets the "Black-throated" part of his name. I don't think that throat could get any blacker! 

...but where does the "Green" part of his name fit in? From below he looks black, white and yellow!

You have to look on top to catch sight of the green. If you look closely, you'll see the back of his head and shoulders are an olive green color. Now the name Black-throated Green Warbler makes sense! 

Black-throated Green Warblers were everywhere along the boardwalk, and they were very vocal. I enjoyed listening to their song. Their constant singing made it easier to find them (just like with the Yellow Warblers)!

This little fellow was just passing through the Black Swamp at Magee Marsh, which provides critical habitat for migrating neotropical songbirds. He was fueling up for his long trip over Lake Erie to reach his nesting grounds further north, but even though this bird prefers cooler northern temps, you can find Black-throated Green Warblers nesting in Ohio. You just have to head to the deep gorges found within the Hocking Hills region in southeastern Ohio. In 2009 we were hiking the Old Man's Cave trail in Hocking Hills in the heat of summer when we heard this bird's call. It took a while to focus in on the bird, but eventually we found him. That's when I really started appreciating the microclimates of the deep dolomite gorges carved out by meltwater from the retreating Wisconsinan glacier 10,000-15,000 years ago. The cooler temperatures of the shaded gorges allow hemlock trees (boreal relics from seeds swept down and deposited by the glacier) to thrive and creates habitat for species that prefer the cooler northern coniferous woodlands. Within a short time of seeing the Black-throated Green Warbler, we heard and saw a Hermit Thrush--another bird that normally nests much farther north. According to the breeding bird atlas map in Peterjohn's "The Birds of Ohio," small breeding populations of Black-throated Green Warblers also nest in northeastern Ohio east of Cleveland.

For migration predictions and info on the birds being seen on the boardwalk, click here for Kenn Kaufman's Crane Creek - Magee Birding blog (covers the Lake Erie Shores and Islands Region of northwest Ohio). Click here for a nice resource on Magee Marsh.

The last bird of the evening...a spunky Yellow Warbler!

Photographing my last bird of the evening on the last evening of my trip made me feel a little sad. The phenomenon of spring migration along Lake Erie is addictive, and I knew tomorrow it would be very hard to walk away from the Magee Marsh boardwalk and the "easy pickin's" of its colorful neotropical songbirds. The only consolation was my farewell bird was a specific male Yellow Warbler that had been tugging at my heart all week. You may be wondering how it was possible to separate one male Yellow Warbler from the hundreds that sing and flit along on the boardwalk! Simple...he was the mate of a sweet little female who had been working nonstop to build her nest. This little male had to be the most dedicated Valentino on the boardwalk, serenading the industrious female with endless rounds of robust and lively song! I enjoyed watching the couple and learned a lot. Every now and then the female would abandon her work and the two would take off together, flying like mad through the branches of a huge old tree just across the boardwalk from her nest, but she'd never play around too long. Soon she was back to work, scouring the deep crevices in the craggy bark of that old tree looking for food, but mostly looking for spider silk that she would take back to her nest...

...my parting shot of the male Yellow Warbler (Dendroica petechia) I had grown fond of this week.  

The large black eyes on the plain yellow faces of the Yellow Warblers get me every time. I never grow tired of seeing one of our most common nesting warblers. Their song is loud and cheery too, and the chestnut streaking on their flanks and chest is striking...

...the hard-working female Yellow Warbler looks like she's resting here, but she's not. She had just deposited a small clump of spider web and was busy tamping it down with her body. Every time she would add something to the nest, she would sit in the nest and move around, molding the small cup to her body.

...again, she's working, not resting, as she molds the nest to fit her body. She was especially keen on gathering bits of spider's silk she found in the deep crevices of the bark on the nearby old gnarly tree.  

The shrubby tree she had chosen for her nest hung out over the water, and I had to shoot through about eight feet of leaves plus the distance on the boardwalk--in other words, these photos are cropped down to the hilt.

...till next year Mr. Yellow!

Learn more about migration at Magee Marsh...
If you want to learn more about Magee Marsh and spring migration along Lake Erie, click here for an article titled "Magee; Anatomy of a Migrant Hotspot," by Kenn Kaufman. I stumbled across the article earlier on the American Birding Association blog, and it explains everything that is going on at this birding hotspot!

...I will probably be blogging about The Biggest Week in American Birding and this trip for the next three weeks, but don't worry, it won't get boring. I have a lot of cool bird photos (and other critters) and learned a lot too...

p.s. Did you see the Kirtland's Warbler today?
If you want to see a fantastic photo of the beautiful and rare Kirtland's Warbler seen on the boardwalk today, click here to go to Bobby Harrison's blog. Bobby was in the right place at the right time, and the ever-drooled-after K-bird practically flew in front of his lens and posed!

Lens envy...

...do I even need to say anything?

Monster camera lenses can be found all over the boardwalk...

Chestnut-sided Warbler on the boardwalk at Magee Marsh
...lucky for me the warblers at Magee don't care what size of lens you have. They come in so close a 200mm lens with a 2x extender picks them up just fine! 

The Biggest Week in American Birding at Magee Marsh
Whoa......today was another stellar day of birding. I was on the boardwalk by 7:30 a.m. (for those of my friends that know my night-owl ways, be impressed...) and quickly started adding warblers. My birding friend, Rob  Ripma (The Nutty Birder) put me on an Olive-sided Flycatcher, a life bird for me. I also picked up a Golden-winged Warbler and a Canada Warbler. From there the birds just kept coming, but on top of that, so did the birding friends I know. Some of the birders I saw on the boardwalk today...

Rob - The Nutty Birder
Dawn - Dawn's Bloggy Blog
Kathi - KatDoc's World
Susan - Susan Gets Native
Sharon - Birdchick
Gunnar - Kolibri Expeditions
Kim - Birding with Kenn and Kimberly
Bobby - Bobby's Photo Blog
Ann - editor of the Cerulean (Ohio Ornithological Society)
Linda - Photo Feathers
Debbie - Naturally Beautiful Photography Moments
Mardi - Kymry Group

To learn more about Magee Marsh, click here. 
To learn more about the Black Swamp Bird Observatory and The Biggest Week, click here. 

Wow! It really is Warblermania here...

I made it to the boardwalk at Magee Marsh by 3:45 and birded until 8:00 p.m. I have never seen so many warblers in one place at one time! Everything you've heard about the boardwalk during spring migration is true! Pretty much...wherever I looked, I saw something, and I wasn't even there at prime time...

A Palm Warbler looks at me as I snap his photo on the boardwalk at Magee Marsh. 

I'm exhausted! I took some really cool photos today, but I ran out of light quickly. I'm getting up early tomorrow and hope to get a few more shots tomorrow. Here's a quick list of what I saw today...Nashville Warblers, Blackburnian Warbers (intensely orange!), Cape May Warblers, Magnolias, Yellow, Palm, Yellow-throated, Black-throated Green, Yellow-rumped, Chestnust-sided, Hermit Thrushes, Swainson Thrushes, a Northern Waterthrush, Scarlet Tanagers, Hooded Orioles, Warbling Vireos, Black-throated Blues, Wilsons, Redstarts--this list is not complete and doesn't include any of the regular birds, swallows, terns, herons, egrets, etc.--I'm just too tired to think of the rest! Until tomorrow...

p.s. I also saw a life-turtle...a Blandings! He was high on my wish list. I couldn't believe it. I looked over at a log and there he was...

Click here to read more about The Biggest Week in American Birding!

Yellow-thoated Warblers...and the BIGGEST WEEK in American Birding!

I can't wait, I can't wait! I'm just a few days away from packing up the Jeep and heading north to Warblermania, Lake Erie, Magee Marsh, and the Black Swamp Bird Observatory for the BIGGEST WEEK in American Birding! This will be my first time to spend spring migration on the famous boardwalk at Magee Marsh. From what I hear the trees drip with exhausted warblers as they rest up before crossing Lake Erie on the final leg of their journey northward to their summer breeding grounds. I've had so many birding friends tell me the boardwalk at Magee Marsh is the place to be when the warblers start moving through. I'm hoping to be eye level with a few of my favorite warblers while I'm there...so my sketches and photos won't always be of their little warbler bellies...

Painting 222. Yellow-throated Warbler Above Me
(...a quick watercolor and pencil sketch from a walk along the Little Miami River this spring.)

Painting 223. My Neck Hurts Looking up at You!
...could you come down out of the treetops for just five minutes so I could see you head-on?
(...another quick watercolor and pencil sketch from a walk along the Little Miami River)

Our Little Miami River Yellow-throated Warblers...
Every year a Yellow-throated Warbler couple takes up residence along the same stretch of river-front property along the Little Miami River. The male starts singing early, and often, and I look forward to his effusive and amorous strains that fill the treetops. The only problem is, Mr. and Mrs. Yellow-throat like their high-rise digs and never come down to visit us earth-bound bipeds, so my photos of them are always fuzzy and grainy and over-cropped...

...he's mocking me. I know it.

He's sitting pretty, but way beyond 400mm shooting... 

...sing out little fella! Everyone loves to hear your song.

Join me at the Biggest Week!

...if you're heading to Cleveland for spring migration, let me know. I'll be at Magee Marsh Monday - Thursday. If you're not going to be there, stay tuned. I'm going to report in every night with photos of all the sweet birds that came my way. I can't wait!!

See you on the boardwalk!!! :-)

A tisket, a tasket, two little pollen baskets!

A week or so ago I was walking along the Little Miami River when I looked up and saw a honey bee buzzing around the blossoms on a Buckeye tree. She was high over my head, but I could still see two little red balls on her hind legs. "What are those?" went through my mind. I've seen yellow "clumps" on a honey bee's hind legs before, which I assumed were grains of pollen the bee had picked up while pollinating flowers, but I had never seen red clumps, much less red balls. A quick Internet search when I got home solved the mystery--"pollen baskets." Not all bees have pollen baskets, and not all pollen baskets function the same, but it seems the color of the pollen in the baskets is determined by the pollen source. Our little bee was pollinating Buckeye trees when I saw her, but maybe the red pollen came from a flower she had just visited. Either way, the thought of the busy bee inspired a quick painting...

Painting 220. Busy Bee with Red Pollen Baskets (oil pastel)
This is just a generic representation of a bee...it came out of my head, so it doesn't match any species in a field guide!

Pencil sketches from my sketchbook of honey bees with full pollen baskets...
When I got home that evening, I created an entry in my sketchbook. Again, these are just generic drawings of bees as I see them in my imagination. I don't know the species. I just thought the pollen baskets were cool, and wanted to record what I saw.

More about pollen baskets...
A pollen basket (or "corbicula") is a slightly concave, smooth surface on the hind legs of bumble bees, honey bees, orchid bees, and stingless bees. The "basket" is surrounded by guard hairs that hold in pollen the bee has dampened with nectar or honey and compressed into a "pollen pellet." When the bee mixes the pollen with nectar, the color of the pollen changes, but it is the source of the pollen that really determines the color of the pollen pellets in the pollen basket. Bee keepers can identify the pollen source just by looking at the pellets deposited at the hive. Bees that don't have pollen baskets have other structures for transporting pollen. Some use "scopa," a brush of hairs often on the hind legs and some carry the pollen in their crop. (Soure: Encyclopedia of Entomology 2008, pgs 419-434, here; Wikipedia, here, and for examples of pollen sources and their color, click here.)

...the red balls on this honey bee's hind legs (tibia) are called pollen baskets (corbicula). Pollen is a bee's main source of protein, fat, minerals, and some starches, so it's important the bee has a way to transport the food back to the hive. (Click here for a detailed article on bees that explains more about their dietary needs.)

...this little bee has been very busy! Her pollen baskets look almost full. It takes a worker bee from three to eighteen minutes to fill up the pollen baskets and return to the hive. That's quite a difference. I guess it depends on the abundance of pollen at the source...or whether the busy little bee is simply a slacker! (Source: Wikipedia. To learn more about bee research, check out Karl von Frisch, here.)

A buckeye tree with newly emerged leaves and blossoms just beginning to open was a favorite of this honey bee. Through the camera lens I could just make out the red balls on her legs. I almost didn't photograph the bee because she was so far away, but I wanted to find out what those red balls were! I'm glad I did...

...a sketchbook scribble I almost didn't include, but it's fun...and I need the paintings for the challenge! :-)
Painting 221. Busy Little Bee, Take That Pollen on Home! 
(watercolor and pencil--scribble idea for a future painting)