More Frogs and Toads

American toad (photo taken in Arkansas)

Summer is ramping up, which makes this a great time of year to look for frogs and toads.  I will examine species in the families Ranidae (or the true frogs), Bufonidae (the true toads), Microhylidae (the narrow-mouthed toads), and Scaphiopodidae (the spadefoot toads).

Of course, habitat determines which families of frogs that you are likely to encounter in a given area.  Moist wooded areas and gardens are good places to find members of Bufonidae, the true toads.  These mostly terrestrial amphibians possess neurotoxin-producing parotoid glands, so if you ever touch a toad, just be sure to keep your hands away from your eyes and mouth!  Toads are otherwise harmless.  (Well, unless you're a bug.)

One of the most abundant toad species in Mississippi is the Fowler’s toad (Anaxyrus fowleri).  Its distinctive call is a somewhat raspy, unmusical bleat (which is similar to that of the Woodhouse's Toad, the species in the linked audio file).  The American (Anaxyrus americanus) and southern toads (Anaxyrus terrestris) are two of the other common species in the state, and both have slow, drawn-out trills that you may hear in the evening.  The oak toad (Anaxyrus quercicus) is a fairly common but hard-to-find amphibian in the southernmost third of the state.  It produces a mellow peeping sound.  Yet another possible find in southern Mississippi is the Gulf Coast toad (Incilius valliceps).  Its call is lower in pitch than that of the southern toad.

Spadefoot toads are a separate family that have a hard, sickle-shaped spade on each rear foot that they use to burrow into sandy soil.  The eastern spadefoot (Scaphiopus holbrookii) is the only species that occurs in the southeastern United States.  It is widely distributed but local in Mississippi, and the call is a very loud, throaty sound. 

If you hear a whiny, high-pitched nasal bleat while walking around a pond or weedy ditch, try not to be too alarmed.  It’s not a half-submerged goat, but an eastern narrow-mouthed toad (Gastrophryne carolinensis), the plump, small-headed Microhylid that is also sometimes called the eastern narrow-mouthed frog. 

When you think of frogs, you probably also think of water, and there are several frog species that spend their lives around lakes, ponds, streams and marshes.  These are the true frogs, or the family Ranidae.  One of the most abundant and attractive Ranids is the southern leopard frog (Lithobates sphenocephalus).  The leopard frog, which can be green or brown, is named for the many dark spots that cover its back and legs.  The call of this species is a rolling series of clucks and croaks.  A frog that appears fairly similar to this one is the pickerel frog (Lithobates palustris).  The spots on this brownish frog are square, and its call is a low-pitched snore. 

If you're near a pond and hear a sound similar to the thump of a rubber-band, you’ve probably heard the bronze frog (Lithobates clamitans clamitans), a medium-sized brownish subspecies of the green frog.  In the northeastern corner of Mississippi, the greenish version is present instead of the bronze frog.

The largest Mississippi frog is the American bullfrog (Lithobates catesbeiana).  Nearly everyone is familiar with this huge frog that produces a deep sonorous rooum-rooum similar to that of a bull.  And if there’s a frog that sounds like a bull, then it shouldn’t be terribly surprising for there to also be one that sounds like a pig!  The pig frog (Lithobates grylio) occurs in the southern portion of the state and closely resembles the bullfrog.  Its snout is more pointed, however, and the fourth toe doesn’t extend past the webbing as it does on the bullfrog.  Its call is a series of deep hoglike grunts. 

There are a few other Mississippi frogs that are very local or rare, including the gopher frog (Lithobates capito), the Mississippi gopher frog (Lithobates sevosus), and the river frog (Lithobates heckscheri).  Notably, the Mississippi gopher frog is a federally endangered species found in only a few locations on the coast.  Its rarity is a reminder of how fragile ALL amphibians and their habitats can be, so be sure to tread carefully in the frog environs that you may visit.


Sources:

The IUCN Red List of Threatened Species, http://www.iucnredlist.org/

USGS Frog Quiz, https://www.pwrc.usgs.gov/frogquiz/index.cfm?fuseaction=main.lookup

Finding Summer Treefrogs and Cricket Frogs

Mississippi is home to quite a few taxonomic families of frogs and toads, including Ranidae, or the true frogs (such as bullfrogs and leopard frogs), individuals of which are largely aquatic and can be found in ponds, lakes, and streams; Bufonidae, or the true toads; Microhylidae, or the narrow-mouthed toads; Pelobatidae, or the spadefoot toads; and Hylidae, or the treefrogs, a group that encompasses the chorus frogs (including the spring peeper and the upland and Cajun chorus frogs), as well as many other species that can be heard calling right now.  Let’s take a look at some of these hylids.

Treefrogs are distinguished by the sticky pads at the ends of their toes, which enable them to climb.  They are typically found in trees and shrubs near sources of water.  In the southeastern U.S., one of the most common species is the American green treefrog (Hyla cinerea).  As its name suggests, this frog is typically bright green.  However, like other treefrogs, it is capable of changing color to adapt to changes in temperature and environmental surroundings.  It usually, but not always, has pale stripes running along its sides, and its skin is very smooth.  The call is a nasally quank that carries for a good distance.  Large choruses of this frog can be heard in almost any wet, wooded area.

Another common species is the squirrel treefrog (Hyla squirella), a small frog with a raspy call that is reminiscent of a squirrel’s barking sound.  This extremely variable species may appear almost any color from bright green to dusky brown, depending on environmental conditions.  At first glance, a bright green specimen of the squirrel treefrog might be mistaken for a green treefrog.  However, the squirrel treefrog is smaller and always lacks the pale lateral stripes of the green treefrog.  Squirrel treefrogs were formerly restricted to the southern half of Mississippi, but have recently expanded their range northward. 

The next three species to be discussed, the common gray, Cope’s gray, and bird-voiced treefrogs, can be visually separated from the green and squirrel treefrogs by virtue of their bumpy skin.  Like all treefrogs, they are more likely to be heard than seen, so it is still a good idea to learn to recognize them by their calls.

As their name suggests, gray treefrogs are frequently mottled gray in color, although they may also be various shades of green or brown—again, depending on temperature and habitat.  The two species of gray treefrogs, common gray (Hyla versicolor) and Cope’s gray (Hyla chrysoscelis), look identical and are impossible to distinguish from each other in the hand.  This is due to the fact that one species, the common gray treefrog, is thought to have diverged from the other, the Cope’s gray treefrog.  Interestingly, common gray treefrogs are tetraploid, meaning that they have four pairs of chromosomes (i.e., genetic material)—twice the usual number.  Tetraploidy is fairly common in plants and invertebrate animals, but it is not as frequently observed in vertebrates.  While common gray and Cope’s gray treefrogs cannot be reliably distinguished from each other by sight, they can be easily identified by sound.  Both species have low-pitched trills, but the Cope’s gray treefrog’s call is faster and more snore-like than the drawn-out trilling of the common gray treefrog.  If you are a Mississippian, though, it's possible that you will not need to distinguish between the two, since the common gray treefrog may occur in only the northernmost sliver of the state: http://maps.iucnredlist.org/map.html?id=55687.  The Cope's gray occurs statewide: http://maps.iucnredlist.org/map.html?id=55448.

Bird-voiced treefrogs (Hyla avivoca) look like smaller versions of gray treefrogs.  One quick way to identify them in the field is to look at the ventral portions of their legs; unlike gray treefrogs, which have bright orange skin in this area, bird-voiced treefrogs have greenish-yellow.  You should have no trouble with identification if you hear the frogs, though; the whistling, bird-like call of the bird-voiced treefrog is drastically different from the sounds of gray treefrogs.  Also, while you could find gray treefrogs in almost any type of forest, bird-voiced treefrogs tend to be most common in swampy woods, especially those containing cypress and tupelo trees.  This is one of my favorite frog species in the state.  

The pine woods treefrog (Hyla femoralis) and the barking treefrog (Hyla gratiosa) are two species found in the deep southeastern portions of the U.S.  Unfortunately, I have had few encounters with either, and have heard pine woods treefrogs only in forests on the coast.  However, a friend and mentor of mine has heard that species as far north as Newton County, Mississippi, so it is certainly possible to find them fairly far inland.  They have strange calls—perhaps best described as sounding like hyperactive Morse code messaging.  The call of the barking treefrog, on the other hand, is throatier in sound than the green treefrog’s call.  Choruses of this species bring to mind—well, for me, anyway—hundreds of bouncing rubber balls.  The barking treefrog frequently has dark spots and is also noticeably bumpy-skinned, making it easy to distinguish from green treefrogs.  In the hand, pine woods treefrogs could be mistaken for squirrel treefrogs, but their inner thighs have rows of pale spots, unlike those of squirrel treefrogs.

The tiny, aptly-named cricket frogs are not technically treefrogs, as they belong to the genus Acris.  Nevertheless, they are hylids, and, like their relatives, they can commonly be found in vegetation near water.  Unlike treefrogs, cricket frogs tend to stay very low to the ground.  The southern cricket frog (Acris gryllus) and the northern cricket frog (Acris crepitans) are the two most common species in the state.  They are similar in appearance, and their insect-like calls are also a bit difficult to distinguish from each other.  However, the southern cricket frog has a raspier sound than the northern.  Both of these tiny frogs can be found in grasses and herbaceous vegetation near water. 

So much for the adult hylids—but what about the earlier life stages: eggs and larvae?  Well, if you peer into small ponds, woodland pools, roadside ditches, or potholes on old dirt roads, you might be lucky enough to see these.  Frog eggs are in clusters, while toad eggs are in strings.  Tadpoles may take a month or more to fully metamorphose.  May the summer months be hopping!

Sources

The IUCN Red List of Threatened Species, http://www.iucnredlist.org/

USGS Frog Quiz, https://www.pwrc.usgs.gov/frogquiz/index.cfm?fuseaction=main.lookup

Species Profile: Cope’s Gray Treefrog (Hyla chrysoscelis), Savannah River Ecology Laboratory, http://srelherp.uga.edu/anurans/hylchr.htm

Species Profile: Pine Woods Treefrog (Hyla femoralis), Savannah River Ecology Laboratory, http://srelherp.uga.edu/anurans/hylfem.htm

Participate in the North American Migration Count!

For many birders, the hobby of birding is at its best in the springtime.  While you head out into the field, the observer of the changing landscape with all its fresh, different sights, there will be transient birds migrating through, new residents staking out territory, early breeders busy at their nests, and winter visitors moving on north.  This is clearly one of the best times to survey the vast numbers of bird life on this continent and make a useful contribution to science.  This is the idea behind the North American Migration Count—which is held on the second Saturday of May.  Although this date falls later than the peak of spring migration for the Southeast, there should still be plenty of migrating birds moving through.  Migration counts may be conducted by teams of birders or individuals, but each count area must be confined to a single county.  All wild birds within the count area may be included in the tally, and the counting procedure is very simple and straightforward—like that of the Christmas Bird Count.

I was a teenager when I first participated in the North American Migration Count.  The Oktibbeha Audubon Society asked me to survey a route in the southeastern part of the county.  My dad and I headed out on our route at about 9:30 a.m., hitting the Bluff Lake levee first to tally any herons, egrets or songbirds that crossed over into Oktibbeha County.  The morning was warm and muggy but full of birds.  Very quickly we picked up Acadian Flycatcher, Common Yellowthroat, Yellow-throated Warbler, Great Crested Flycatcher, Eastern Kingbird, Prothonotary Warbler, White-eyed Vireo, Indigo Bunting and many other species in the woods, including a Ruby-throated Hummingbird feeding from Trumpet Creeper blossoms.  We heard a Fish Crow and also counted many egrets flying overhead, a couple of Wood Ducks, and one Great Blue Heron, which surprisingly, would turn out to be our only one all day.  Just as we were leaving the area, I glimpsed a group of three large birds flying high overhead—White Ibises.

Prothonotary Warbler

We drove a little down the road, looking and listening for some of the forest species such as Red-eyed and Yellow-throated Vireo, Pileated Woodpecker, Eastern Wood-Pewee and Yellow-billed Cuckoo.  By now our list was around 40 species.  There were good numbers of singing Yellow Warblers, and I could make out two Northern Parulas trilling close by.  As we got out to walk a trail that cut through the woods, there was a harsh chittering overhead, which alerted us to about two dozen Chimney Swifts circling.  These were probably natural-nesting swifts, choosing a hollow tree over a manmade chimney.

The woods were mostly deciduous, with tall pines mixed in here and there.  There were also many deep puddles of muddy water from a recent rainfall.  Pine Warblers, chickadees, titmice, towhees, and vireos noisily proclaimed their territories in the dense woods, seeming almost indignant at us traipsing through their home.  I accidentally flushed a Cooper’s Hawk from its roost.  It flew away, disturbing the singing birds for a few minutes.  I heard White-breasted Nuthatches in the distance and saw a pair of Summer Tanagers in the trees.  Bird songs were not all that we heard:  Gray Treefrogs were also making their presence known in the forest with low-pitched croaks.

Cooper's Hawk

I had just commented to my dad on the odd absence of Kentucky Warblers, when one in a thicket burst emphatically into song.  A Hooded Warbler added its short, eight-syllable whistle to the other sounds of the forest, while wrens and skinks scuttled through the thickets and leaf litter, the wrens putting in a word now and then, unlike the lizards!  There was a creek by this trail where we were likely to find Louisiana Waterthrushes, and in the trees near it, American Redstarts.  Unfortunately, neither species showed up for us, and eventually we moved on, making a mental note to come back to the trail later. 

We went up Oktoc Road for more counting.  The habitat here was mostly thickets, fields and pastures, with scattered trees, which meant a whole new group of species for us.  Bluebirds and kingbirds perched on the wires; grackles and blackbirds foraged in the pastures.  We were able to add Red-headed Woodpeckers and many more Cattle Egrets to the tally.  Eastern Meadowlarks, Orchard Orioles, Barn Swallows and Purple Martins also put in appearances.  Overhead, there were vultures, Red-tailed Hawks and a Green Heron that flew from a small pond.  A little farther down the road, I heard a loud ringing song coming from a thicket—a Swainson’s Warbler.  I listened to the recording on my audio field guide back in the car; no doubt about it:  the song was a Swainson’s Warbler’s.  Since this is a fairly scarce bird, I wrote down the location, including the mailbox number, and we headed on.

We came to a place down the road where mixed forest grew on one side and young trees and shrubs were just coming up on the other.  Almost immediately our ears picked up Northern Bobwhite, Yellow-breasted Chat and one Prairie Warbler.  A few more Kentucky Warblers and Indigo Buntings sang loudly, and I spotted another Summer Tanager pair.  Then I noticed something lower down in an oak tree.  I investigated with binoculars and found myself looking at a beautiful male Scarlet Tanager, just sitting on a limb in a little shaft of sunlight, his jet-black wings and tail contrasting with the bright-red of his body.  What a treat!

Scarlet Tanager

We still had to head through Starkville, so after tallying, we drove on.  While in town, we saw plenty of House Sparrows and European Starlings and two Eurasian Collared Doves.  Our next stop was a sewage lagoon where we supposed to locate a few ducks and shorebirds.  As we began walking around the pond, we flushed bunches of Red-winged Blackbirds and saw Northern Rough-winged Swallows overhead, but the edge of the pond, choked with weeds, just didn’t look promising for sandpipers.  Farther up, however, we noticed the drastic difference in the habitat.  There were obvious mud flats with shorebirds feeding.  Three Solitary and one Spotted Sandpiper dotted the bank with several Killdeer, too.  We saw two Blue-winged Teal, a pair of Canada Geese with four large fuzzy young, and thirteen Wood Ducks—two adults and eleven ducklings. 

The count list was pretty big so far, but I did notice that we were missing a few birds.  We managed to find some Blue Grosbeaks by retracing our route and only counting species that were new to us, not ones we’d counted already.  We managed to hear a flock of Cedar Waxwings this way, and then went to search again for the redstarts and waterthrushes.

The woods were a lot quieter now; it was about 4:00 p.m. and I doubted that we’d see the elusive species we were looking for.  Although we didn’t pick up any new birds while we were there, we did see other wildlife.  Butterflies fed on the flowers, Ichneumon wasps flew up from the grass, and a Southern Leopard Frog was in one of the puddles.  My dad was pleased to observe a Toad Bug that I located near another pool of water.  We watched it as it hopped about, its coloration blending in amazingly well with the gritty mud of its habitat.

Back in the car, we counted up the species we had found during the day:  seventy-six, and hundreds of individuals all over.  It had been a great count.  We were both exhausted but filled with a sense of accomplishment and exciting memories of that spring day. 

Even if your schedule doesn't permit you to count every bird that you see for an entire day, it’s still worthwhile to spend some time marveling at the diversity of species during this fascinating season!

Birdsong

This was published on the blog in 2019.  It seems relevant again!

Singing Indigo Bunting

As any serious birder knows, the more commonly used term that denotes our hobby—birdwatching—is terribly misleading.  A newcomer or an outsider usually assumes that because the pursuit is called “bird-watching”, then they should always be able to see birds, and see them well.  Binoculars, naturally, are often thought of as instruments serving to endow bird-watchers with a nearly super-human ability to see the birds that fly their merry ways, unseen to the casual observer.

Nothing could be further from the truth.  The fact is, “bird-watching” could just as easily be called “bird-listening.”  According to bird-watching experts, most birders (a term I prefer to bird-watchers—but due more to its brevity than its accuracy) identify at least 80 percent of the birds they find by sound, not sight.  Admittedly, we birders could probably actually see a fair chunk of this 80 percent if we made the effort to look, but in a lot of cases, these birds call and sing from the middle of dense woods, marshes, briar thickets—places we’d rather not go.  Of course, if the bird making sounds in this uninviting terrain is one that is new or especially exciting to us, we’re more than happy to make the effort to actually see it, even if it means braving poison ivy, saw-edged marsh grasses, skin-ripping greenbriar, ticks, mosquitoes, and venomous snakes; or maneuvering more mundane obstacles such as fallen trees, creeks, holes, gnats, etc.  And, succeeding in the face of all these impediments—finally seeing the rare bird—wins the hardworking birder a valuable excuse to brag at the next bird club meeting.

But I digress.  Another great truth of birding: binoculars are excellent tools, and without them birding as we know it would be next to impossible.  However, they will not give you any extraordinary abilities in locating birds; the most they can do is magnify what you’re seeing, so that the amazing beauty and variety of birds are more apparent.  As to locating birds, the only way to improve this skill is with practice.  Even with years of field experience, though, there are some birds that will manage to elude you, or at least elude your eyes.

I’m certainly not immune to the caprices of bird behavior.  The times that I’ve been outmaneuvered by birds are too numerous to name.  Sometimes it is an individual bird on one particular day; other times an entire species seemingly conspires against my earnest efforts to see it.  For example, I have yet to observe The Chuck-will’s-widow and Whip-poor-will—both secretive night birds with calls proclaiming their names—up close and through binoculars.  I have seen a live Chuck-wills-widow in the wild—it flew up from the road in front of the family car one night.  I saw just enough of its brown wings and white-bordered tail to positively identify it.  These birds’ secrecy is part of their mystique, though, so I’m perfectly happy to just listen to their rhythmic, intriguing nighttime songs, and if I happen to see one in full view someday, so much the better.

Other nocturnal birds like owls also prove elusive.  However, since owls are generally large and hunt from relatively prominent places—not impenetrable thickets like the haunts of the Chuck-wills-widow and Whip-poor-will—they are usually a little easier to observe.  Where I live in Macon, there are Great Horned Owls that live and hunt around the pastures and backyard pecan orchards.  I have seen them on a number of occasions, but more often I hear their resonant hoots, especially on moonlit nights in late winter when the trees are bare.  It’s a very comforting sound, and it foretells the owls’ courtship and eventual nesting, since these charismatic hunters breed and raise young very early in the year.

Sometimes vocal but difficult-to-see birds can be very frustrating.  The arrival of spring brings lots of migrating songbirds, many of which choose to proclaim their territories through song from the tops of the very tallest trees.  Then, it is literally a pain in the neck to try to see these birds, craning your head back as you look through your binoculars, trying to focus on the five-inch long warbler flitting forty feet above you as it sings its squeaky melody.  Of course, it could be worse; a lot of warbler songs are too high-pitched for some people to hear—the songs of Blackpoll, Bay-breasted, Black-throated Green, and Blackburnian Warblers, for example.  Even John James Audubon, one of the founders of American ornithology, is said to have had difficulty hearing the songs of a number of birds, especially wood-warblers.  On the other hand, several warbler species have very loud songs and are relatively easy to see; go into a swampy woodland, and you may see and hear a vivid yellow Prothonotary Warbler making its shrill tweet tweet tweet tweet song in the deep, gloomy shade of the cypress trees.  I promise you, it’s an amazing experience.

One of my favorite warblers, interestingly, is one that I haven’t actually seen more than a few times.  Not that that’s anything unusual: Swainson’s Warblers are notoriously tricky to see.  One of these sightings was of a bird flying away after I attempted to creep on it while it sang in a thicket.  More recently, this year I heard a Swainson’s Warbler in an overgrown wood during a spring migration survey.  After tallying it, I decided to walk through the dense undergrowth in hopes of spotting it.  Sure enough, as soon as I deduced what direction it was in, the bird moved to another spot and began its loud, ringing song again.  Despite the frustration it sometimes provokes in me, this incredibly secretive behavior coupled with the interesting song is one of the reasons I find the Swainson’s Warbler so fascinating, and I always enjoy encounters with them, visual or otherwise.

Probably you can think of at least a few birds whose sounds are particularly meaningful to you in some way.  Maybe they evoke fond memories; or are associated with certain seasons or times of day; or perhaps are simply beautiful, amusing, awe-inspiring…the list goes on.  The robin’s hurried morning warblings, the mockingbird’s nighttime virtuoso recital, the softly lilting tur-a-lee of the bluebird, the energetic drummings of woodpeckers, the shrill scream of a Red-tailed Hawk, the echoing honks of migrating geese—these and countless other calls not only hold special significance to birders, but are familiar sounds in our day-to-day relationship with the natural world.  Even something as seemingly mundane as a crow’s guttural caw caw can bring a lot of interesting feelings to an observer.

Seeing birds is always a pleasure, but sometimes it helps to just stop and listen to them as they go about their lives.  This can be difficult; it’s hard to resist the impulse to search for a bird that you can hear but not see (after all, this is bird-watching), but even hearing birds fills you in on interesting aspects of their ecology, enables you to identify them, and just makes birding more fun and meaningful.  Another thing to keep in mind: although you can see the birds that are right in front of your eyes during birding jaunts, their songs are all around you.