More frogs

Despite there being no standing water on our property, apart from a couple of trays holding bog plants, a surprising variety of amphibians call the garden home.  Here are a couple of recent sightings that add to my list of resident amphibians.

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Pickerel frog–Lithobates (Rana) palustris

Pickerel frogs are found throughout North Carolina, with the exception of the Outer Banks and some tidal regions of the coastal plain. This one was out late one evening on our concrete driveway, usually the hunting territory of more terrestrial-adapted toads.  The night was dry, so I was surprised to see any amphibian, let alone a frog.

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Green frog–Lithobates (Rana) clamitans rescued from a posthole.

I have been digging postholes for a new fence, and an inch or two of rainwater accumulated in the two-foot deep holes.  I’m glad I decided to fish around in the muddy water before dropping posts and concrete in the holes.  The extensive webbing on the feet of this species indicates that its preferred habitat is aquatic, so I’m not sure what inspired this one to leave the creek and cross an acre or two of dry oak-pine woodland to find a muddy little hole.

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Eastern spadefoot (Scaphiophus holbrookii)

In another of the postholes, I found an eastern spadefoot, a terrestrial species that I have shown before but which is uncommon enough and interesting enough to warrant showing again.

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Scaphiophus holbrookii wearing a jaunty hat of mud

Six on Saturday #52 (March 21, 2020)

For this week’s Six on Saturday, we are out of the garden and visiting the Eno River Confluence Natural Area.  The Eno River is one of the gems of this part of North Carolina.  A small river, little more than a large stream for much of its 40-mile course through Orange and Durham counties, it flows through the town of Hillsborough and city of Durham before merging with the Flat and Little Rivers to form the Neuse River.  The Eno is home to several rare species that are endemic to the Neuse River basin, and it has been aggressively protected since the late 1960s by the Eno River Association.  The Confluence Natural Area is a piece of protected land in Orange County that includes the spot where the East and West forks of the Eno flow together to form the Eno River proper.  It was opened to the public relatively recently, and this was our first visit.

When my family and I visited, we were the only people on the 200-acre preserve, so I guess that covered social distancing requirements.

1.  The Confluence

Confluence

This is the point at which east fork (left) and west fork (right) merge to form the Eno (center).

2.  Plethodon cylindraceus (white-spotted slimy salamander)

Plethodon

The kids couldn’t resist lifting a cover board that had probably been laid down for some herpetology classes.  They found a handsome pair of slimy salamanders.  To avoid crushing the salamanders, we gently moved them, laid the board back down, and then allowed the salamanders to climb underneath again.

3. Claytonia virginica (Virginia springbeauty)

Claytonia

A variety of spring ephemeral wildflowers were in bloom on the wooded slopes and rich bottomland along the riverbanks.  In North Carolina, C. virginica is a true piedmont native.  It is absent from most of the coastal plain and from the mountains, where it is replaced by Claytonia caroliniana.

4. Cardamine concatenata (cutleaf toothwort; crow’s toes)

Cardamine

I just love the name “crow’s toes.”

5. Stellaria pubera (star chickweed)

Stellaria

In addition to these three wildflowers, we also saw Hepatica americana (round-lobed Hepatica), Anemonella thalictroides (rue anemone), Sanguinaria canadensis (bloodroot), and Lindera benzoin (spicebush)  in bloom.  Mayapple (Podophyllum peltatum) leaves were up, but the buds aren’t yet open.

6. Tree “footprint”

tree footprint

The heavy piedmont clay holds together so well, that the imprint of a large tree, including tunnels left by its roots, is still clearly visible after all the wood has rotted away.  The “footprint” is slowly being covered by invasive Japanese honeysuckle (Lonicera japonica).

The propagator is the host of Six on Saturday.  Head over there to see his Six and find links to the blogs of other participants.

Salamanders

“Newts, Jeeves.  Mr. Fink-Nottle has a strong newt complex.  You must have heard of newts.  Those little sort of lizard things that charge about in ponds.”  –P.G. Wodehouse, Right Ho, Jeeves.

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an eft’s eye view of the driveway

So far,  I have written posts on garden snakes, turtles, frogs, and toads, so I still need to do lizards and salamanders for full herpetological coverage.  One Forest Fragment just wrote about salamanders, inspiring me to do the same.

The southeastern United States harbors more salamander species than anywhere else in the world, but most of that diversity is found in the southern Appalachians.  The piedmont area, where I live, is relatively depauperate, and of the roughly fifty salamander species native to North Carolina, I have found only four on our property.

Eastern newt (Notophthalmus viridescens)

Eastern newts have a fairly complex life cycle.  They begin as aquatic larvae with external gills, but after growing legs they leave the water and typically spend several years as a non-breeding terrestrial “red eft” (see photo above).  Eventually, an eft’s orange or red color fades to olive green (though still with bright red spots), and it returns to the water as a breeding adult newt.  To add to this complexity, some adults return to the land when the breeding season is finished, while others stay in the water.  Adopting the opposite strategy, newts in some southeastern localities skip the eft stage and remain in the water their entire lives [1].

I see red efts in the garden with some regularity, usually after rain, but I have not found any adult newts in the nearby creek or woodland pools.  Presumably there must be a breeding pond somewhere nearby, but red efts can wander a considerable distance (miles?) during their years as a terrestrial salamander.

Marbled salamander (Ambystoma opacum)

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Crossing the driveway on a rainy night

I suspect that marbled salamanders are the most common salamander species in the garden and surrounding woods.  In common with other mole salamander species, marbled salamanders spend most of their time underground, but I have seen more individuals of this species than all the other salamanders combined.

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a pair of marbled salamanders that I found together under a rotten log

Across the lane from our property, the local creek forms a muddy oxbow that holds water even when the creek stops flowing in late summer.  This pond is full of dead leaves and live Ambystoma larvae.  Most are probably larval marbled salamanders, but some may be offspring of the next species.

Spotted salamander (Ambystoma maculatum)

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I have only found one spotted salamander since we moved to this location eleven years ago.  It was under a rotten log in the woods adjacent to the garden proper–the same log, in fact, that previously harbored the two marbled salamanders shown above.  Since spotted salamanders, like their marbled cousins, spend most of their lives underground, they may be more common than it would appear.

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Spotted salamanders can reach an impressive size.  This one was 7.5 inches (19 cm) long, nose to tail tip.

Southern two-lined salamander (Eurycea cirrigera)

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Two-lined salamanders and the related three-lined salamanders (Eurycea guttolineata) are common under rocks in the creek bed, but for some reason, this one relocated to my compost bin. I suppose that the bin provides a moist, dark habitat full of small invertebrate prey, but to reach it the salamander had to navigate several hundred feet of dry pine woods–an impressive journey for a lungless salamander that relies on keeping its skin moist to breathe.

Reference

1.  Mitchell, J., and Gibbons, W. (2010).  Salamanders of the Southeast.  University of Georgia Press, Athens, GA.

Toads and “toads” in the garden

I saw the first toad of the year last week, so this seems like a good time for a post about these garden residents who are some of my favorite amphibians.  In addition to the true toads, we also have a couple of “toads”–species that are not in the toad family, Bufonidae, but share the common name because of their terrestrial habits.

1. American toads and/or Fowler’s toads

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Judging by the multiple warts in some of its dark spots, I think this is a Fowler’s toad (Anaxyrus fowleri)

In the NC piedmont, the true toads are represented by the American toad (Anaxyrus americanus, formerly Bufo americanus) and Fowler’s toad (Anaxyrus fowleri, formerly Bufo fowleri). I’m not entirely sure which species we have in the garden.  Fowler’s toads are here, but I wouldn’t be surprised if American toads are too.  I haven’t paid enough attention to be certain.  Although they are the most common amphibians in my garden, I find that I don’t have many photographs of them.  Familiarity doesn’t breed contempt, exactly; I love having them around and think they have much more character than their froggy cousins, but I don’t go rushing off for a camera whenever I find one hopping across the garden path.

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Staying cool in the bog garden on a hot summer day.

True toads exude bufotoxins, a witches’ brew of chemicals, including cardiac glycosides and neurotransmitter analogs, from their skin and especially from the bean-shaped parotid glands behind their eyes.  When I was a teenager, we had a dog who loved to lick toads.  They always made her wrinkle her lips and foam at the mouth, but she never learned to avoid them.  I’m not sure if she was getting a buzz off the bufotoxin, or if she lived in eternal hope that the next toad would be the one that tasted good.  In any case, it’s probably a good idea to wash your hands after you pick up a toad.

Around the same time that we had the toad-licking dog, I kept a recently metamorphosed toadlet as a pet for a summer.  It soon became quite tame and would get very excited whenever I opened the top of the terrarium.  The way to a toad’s heart is definitely through its stomach.  If you have never fed a toad, do yourself a favor and give the next one you find a large earthworm.  The way a toad uses its hands to shovel the wriggly spaghetti into its mouth is both fascinating and hilarious.

2. Eastern spadefoot

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Eastern spadefoot (Scaphiopus holbrookii).  You’d look grumpy too, if you had been unceremoniously unearthed and then rinsed clean of dirt to make a better photograph.

The eastern spadefoot (Scaphiopus holbrookii) is a beautiful little amphibian, and I was thrilled to discover that they live in my garden.  It’s rather surprising that they are here.  S. holbrookii is primarily a species of the sandy coastal plain, and we’re at the very edge of its recorded range.  Their presence in the garden might even be a minor range extension, as the NC Museum of Natural Sciences doesn’t seem to have any specimens collected in Orange County.  But despite our dense piedmont clay not being their preferred habitat, I stumble across a spadefoot every year or two, suggesting that there is a small breeding population in the vicinity.  About half of them have been accidentally unearthed while I was gardening, and the other half were hopping around on the surface, usually at night or early in the morning during warm, wet weather.

spadefoot2
Posing with some British soldiers lichen (Cladonia cristatella).  It matches the spots on the spadefoot’s sides.

Spadefoots can be distinguished at a glance from true toads by their vertical pupils; other toads have horizontal pupils.  If you gently pick one up and turn it over, you will see the hard,  brownish spades on its hind feet which allow it to burrow out of sight.

3.   Eastern narrowmouth toad

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Eastern narrowmouth toads (Gastrophryne carolinensis) eat mostly ants.

Like the eastern spadefoot, the eastern narrowmouth toad (Gastrophryne carolinensis) is another species that you are much more likely to hear than see.  If you have ever heard the desperate bleating of a tormented lamb emanating from the leaf litter after rain, you have heard an eastern narrowmouth toad.  They seem to be even less likely than the spadefoots to wander around on the surface, and in twenty years I have only found three.  Two of them I accidentally uncovered, but the one photographed here came to my attention because it was out during the day and had been found by a chipmunk.  I noticed the chipmunk repeatedly run up to a small object and then dance backwards when it hopped.  I’m not sure if the chipmunk was attacking (they sometimes prey on insects and other small animals) or playing, but when I rescued the narrowmouth toad, it didn’t seem to have suffered any damage.  Perhaps it was protected by its noxious skin secretions, just like a true toad.

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Ignore the pathetic state of the grass, and appreciate the beautiful reddish brown stripes on the narrowmouth toad’s sides and forelegs