An online resource based on the award-winning nature guide

Amphibians

Juvenile Gray Treefrogs Appearing

8-16-17 immature gray treefrog 049A2580

Being my favorite species of frog, the Gray Treefrog may get more than its fair share of exposure on the Naturally Curious blog.  This amphibian is rarely noticed outside of its June mating season, when the males’ bird-like trills can be heard throughout the night from shrubbery bordering wetlands.  Due to its emerald green coloration when young, and its mottled gray/green adult appearance, in addition to its nocturnal habits, this beguiling amphibian escapes detection by most of us throughout the rest of the summer.

However, if you keep an eye out in August,  near where you heard those trills in June, you may be successful in spotting a juvenile Gray Treefrog.  Having developed legs and lungs, absorbed their gills and tails, and reinvented their digestive system for insects, not plants, they are now permanently terrestrial, except during the breeding season. When a Gray Treefrog is young and newly metamorphosed, it usually remains near the forest floor. As it ages, it may transition to living in the forest canopy. (Photo:  juvenile Gray Treefrog; inset – adult Gray Treefrog)


Gray Treefrogs Well Camouflaged

6-14-17 gray treefrog2 206If there is an amphibian that is a master of disguise, it has to be the Gray Treefrog (Hyla versicolor).  This remarkable frog is capable of changing its color (gray, green or brown) to match its environment within half an hour, a process called metachrosis. Shades of gray are most common with black blotches on the back while green colors are more prominent during the breeding season and in yearling frogs.

Being a treefrog, it has large, round, sticky toe pads that help it cling to trees and shrubs, where it spends most of its time. Survival is more likely if predators don’t detect you, so Gray Treefrogs have evolved to look a lot like bark.

When the temperature reaches 59° F. the males’ bird-like trilling can be heard coming from foliage next to and hanging over their shallow breeding pools. If you wish to set eyes on a Gray Treefrog, now is the time, as they are calling and a silent Gray Treefrog can be extremely difficult to find!

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.

 


Amphibians Migrating

3-6-17-spotted-salamander-2-img_7608Vermonters were witness to a record-breaking (early) amphibian migration in the Champlain Valley last week on March 1st, when night temperatures were in the low 50’s.   Not only did it occur a week earlier than any other previous major migration, but records show that migration for the earliest amphibians in Vermont is now approximately two to three weeks earlier than it has been during the last decade. (as reported by Jim Andrews, www.VtHerpAtlas.org).

Spotted Salamanders, Four-toed Salamanders, Eastern Red-backed Salamanders, Blue-spotted Salamanders, Jefferson Salamanders, Spring Peepers, Wood Frogs and even an American Toad were on the move. According to Andrews, “this is a concern if the weather turns really cold and the ground and ponds refreeze. If that happens, many of the early migrants (that are not freeze tolerant) could freeze and die. If the weather stays relatively mild, with only short cold snaps, they should be fine.” Weather since these sightings has been unseasonably cold, and one can only hope they survived. (Photo: Spotted Salamander, Ambystoma maculatum)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Leopard Frogs – Too Little, Too Late

leopard-frogs-in-puddle-by-kelly-maginnis-northampton-ma-12-10-16At this time of year one would expect to find Leopard Frogs lying on the bottom of a pond, partially but not completely covered with leaves or mud as they hibernate their way through winter. Because of the depth of a pond, and the fact that in winter the water temperature is around 39°F., ice isn’t an issue at the bottom of a pond, and the frogs and turtles that overwinter there don’t usually freeze.

However, sometimes ponds freeze over before amphibians or reptiles that overwinter in them arrive at their hibernacula. Apparently this is what happened to these Leopard Frogs, and they took refuge in the only open body of water they could find – a large but shallow puddle about 10’ wide by 20’ long in a dirt road. Shortly after they arrived temperatures dropped and the frogs were trapped under (and eventually will be encased in) the ice. Unlike Wood Frogs, Spring Peepers and Gray Treefrogs, Leopard Frogs are not freeze tolerant, so their demise is inevitable. (Thanks to Kelly Maginnis for photo, and Jim Andrews for his herpetological expertise.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Fall Amphibian Migration

10-24-16-red-backed-sal-089The migration of amphibians from the woodlands where they overwinter to their breeding pools in March is a familiar spring phenomenon to most. However, some of these amphibians engage in a fall migration as well. Amphibians (and reptiles) need to find a good overwintering spot, where they won’t freeze. In some cases, that might be a few feet upstream or into a seepage area, and in others it is a few hundred yards uphill. The extent of the migration and the species participating vary in different parts of the state.

In western Vermont, Jim Andrews, Director of the Vermont Reptile and Amphibian Atlas(http://vtherpatlas.org), has observed Blue-spotted and Four-toed Salamanders moving down into wetlands in the spring, staying close to the wetland for moisture and feeding during the summer, and then moving uphill back to wintering areas in the fall. On the other hand, he has found that most Spotted and Jefferson Salamanders, as well as Wood Frogs, move down in the spring to breed, and then head back uphill in stages soon after they are done breeding.

Eastern Red-backed Salamanders (pictured) migrate as needed during the summer to maintain their body moisture, and in the fall, search for an animal burrow or crevice to hibernate in. Migration often occurs at night, while it’s raining, so as to prevent their skin from drying out. (Amphibians need to have moist skin because a large portion of the frog’s “breathing” occurs via oxygen diffusing through the skin. Oxygen will not diffuse through a dry membrane.) After the very dry summer we’ve had, a large number of amphibians were observed taking advantage of the recent rain and migrating.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Gray Treefrog: A Frog of Many Colors

7-28-16 young gray treefrog2 IMG_5078A Gray Treefrog starts life off as a ¼” yellow tadpole. Eventually it may reach 2 ½” in length, and its body will have turned olive green with a red tail. Upon metamorphosing into a frog, the Gray Treefrog turns a bright emerald green and gradually develops into a mottled greenish-gray adult which can change its color from green to gray in about half an hour to match its environment. The two color phases of the maturing frog (solid green of the young, and mottled gray or green of adult) are so different it’s hard to believe that they are the same species. (Photo:  young Gray Treefrog; insert- adult Gray Treefrog)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com   and click on the yellow “donate” button.

 


Spring Peepers Dispersing

7-21-16 peeper 089

If you live near a pond where you heard loud “peeping” in late April or May, now is the time to keep your eyes peeled for young subadult Spring Peepers in the woodlands near the pond, for they are just completing metamorphosis and moving onto land. Thanks to their enlarged toe pads, peepers are good climbers but are usually found on the ground or low in shrubbery. The best time to look for young peepers is in the early morning hours and in the late afternoon, when they tend to feed.  Even if your timing is right, it can be challenging to find one — a full grown peeper is only ¾” to 1 ¼” long, and recently metamorphosed individuals are not much longer than ¼”, about the size of your baby fingernail. You’ll know it’s young because of its diminutive size and  its snub nose!

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.