Archive for April, 2011

Creatures of the Night (in Springtime Bog)

Friday, April 15th, 2011

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American Toad (Bufo americanus)

Pitch black, heavy clouds and driving rain.  The absolute best springtime conditions to venture into swamps and bogs of Massachusetts’ South Coast to spy on the ardent rituals of awakening amphibians.  The Turtle Journal vehicle splashed through bottomless puddles.  Our lights probed the gooey darkness as we crawled along a cratered one lane road half a mile through flooded wetlands to reach the abandoned Goldwitz cranberry bog.  Our arrival was greeted by a riotous cacophony of spring peepers, American toads and wood frogs.

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American Toad from Nighttime Goldwitz Bog

We donned our field gloves, grabbed our sampling nets, snapped on our flashlights and plodded through several inches of rain as we searched the bog channels for creatures of the night.  Spring peepers were everywhere, and we decided to net one of them last because they are so difficult to restrain in the darkness.  Sue Wieber Nourse spotted an American toad and snagged it for closer examination.

Examining American Toad

The Eastern American Toad is a medium size amphibian and fairly common in the wetlands of Southeastern Massachusetts.  This specimen proved quite cooperative during documentation and was quickly released back into the bog channel to continue its mating rituals.

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Spring Peeper (Pseudoacris crucifer)

Don Lewis netted two spring peepers for closer examination.  They are brown, tan or beige, and can easily be distinguished by the dark “X” or cross on their back; hence, the name “crucifer” or cross-bearer.

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Spring Peeper from Nighttime Goldwitz Bog

These tiny frogs, ranging from less than an inch to maybe an inch and a half, are the most common voices in South Coast wetlands during the spring. 

Examining Spring Peeper

So small, they are quite difficult to control and photograph at night without harming the animal.  We snapped a couple of quick photographs and captured a short video clip as they escaped from the back of the Turtle Journal vehicle.  Within a wink, the peepers had disappeared into the night storm.  Drenched, but contented, we also disappeared into the darkness as we retraced our way back to Turtle Journal central.

Rufus Meets Male Spotted Turtle

Wednesday, April 13th, 2011

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Rufus Retriever Meets Male Spotted Turtle

Turtle Journal’s Sue Wieber Nourse and Rufus Retriever visited the Goldwitz abandoned cranberry bog on Tuesday.  On Sunday, they had found a female spotted turtle basking on the bank of a bog channel at Goldwitz.  Since then, the weather had deteriorated into a chilly overcast with spitting rain.  No self-respecting turtle would be caught dead or alive basking in such un-turtle-like conditions.

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Spotted Turtle Hides in Plain Sight

As they walked along the bog looking for turtles, salamanders, frogs and toads, Sue’s eyes caught an anomaly at the bottom of the channel.  She stopped, stared and confirmed that a spotted turtle was lying underneath.  (Take a look at the photograph above.  Can you see the turtle hiding in plain sight?  When you think you have identified the spotted turtle in the picture, click on the image and the solution will appear in a new window.)  Sue slipped down the bank, plunged into the water and grabbed the turtle in her bare hands.  Rufus skidded down the bank, jumped in the water and played. 

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Male Spotted Turtle Drab Neck

Sue had captured Male Spotted Turtle #7, whom Don Lewis had first captured on May 7th, 2007 as he basked on the banks of this same channel.  Back then, he was recorded as older than 11 years, he measured 11.39 centimeters straight-line carapace length, and he weighed 189 grams.  The next time Spotted #7 was seen occurred on March 27, 2008, when he again basked on the same bank in 40 degree sunshine.  Notice the drabness of his neck which contrasts with the colorful female Sue captured on Sunday (see below).

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Spotted Turtle Male Tail

Another indicator of #7′s maleness is his tail.  Note it is considerably thicker than Sunday’s female (see below), and also note that the anal opening falls significantly beyond the edge of his carapace.  Again, contrast with the female tail below.

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Male Spotted Turtle (Clemmys guttata) Carapace

This April Spotted Turtle #7 measured 11.45 centimeters straight-line carapace length, 8.5 centimeters maximum carapace width, and 8.1 centimeters wide along the suture between the first and second costals.  He weighed 194 grams.

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Male Spotted Turtle Plastron Concavity

This plastron photograph illustrates all of his male attributes: the drably colored neck, the thick tail and significant concavity posterior of the bridge.  Spotted #7 measured 8.5 centimeters straight-line plastron length along the central suture and 5.7 centimeters wide behind the bridge.

Rufus Say Farewell to Male Spotted Turtle

After recording morphometric data and examining the health of Spotted Turtle #7, Sue released him back into the bog channel … with a lot of health from Rufus the Turtle Dog who escorted Lucky Seven back into the water.

Female Spotted Turtle Basks in Goldwitz Bog

Monday, April 11th, 2011

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Rufus, Sue Wieber Nourse and Female Spotted Turtle

Rufus Retriever, the new Turtle Journal research dog, and Sue Wieber Nourse discovered a mature female spotted turtle basking on the channel bank of the abandoned Goldwitz cranberry bog in Marion, Massachusetts on Sunday.  Turtle Journal has been checking this bog since mid-March and this turtle marked the first spotted we have seen at this location in 2011.

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Female Spotted Turtle (Clemmys guttata)

Spotted turtles are a small, elusive wetlands species.  This mature female weighed only 189 grams and showed annual growth lines that indicated she was approximately 11 years old.

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Female Spotted Turtles Have Bright Colorful Necks

Spotted turtles exhibit sexual dichromatism.  Beyond morphological differences, females can be identified by a brightly colored yellow/orange neck.  Males in contrast have a drably colored brown or gray neck.

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Female Spotted Turtle Tail

Female spotted turtles also have a thinner tail than males, and the anal opening generally falls inside the carapace (top shell).

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Female Spotted Turtle Carapace

As usual, we took three straight line measurements of the carapace.  The length of the carapace measured 10.4 centimeters and its maximum width was 8.2 centimeters.  The width at the suture between the first and second costal scutes measured 7.9 centimeters.

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Female Spotted Turtle Plastron

The plastron (bottom shell) measured 9.7 centimeters from front to back along the central suture line.  The width of the plaston behind the bridge was 6.05 centimeters.  Female spotted turtles have a largely flat plastron while males have a concavity in the center of the plastron posterior to the bridge.

Spotted Turtle Somersault

Spotted turtles offer a special show when they return to the bog channel after basking on its banks.  A good number of them slip and slide down the steep bank and hit the bottom at such an unusual angle that they do an unintentional somersault into the water.  The one captured in the video above obligingly showed her stuff for the Turtle Journal cameras.

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Wild Turkeys Lead Turtle Journal Out of Bog

As Sue and Rufus drove out of the bog along its one-lane wooded road, they were led by a couple of wild turkeys who moved with a slow sureness that showed they considered this roadway their own.

Tiny Juvenile Horseshoe Crab Emerges

Sunday, April 10th, 2011

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Juvenile Horseshoe Crab in Wellfleet Marsh

Saturday proved a glorious early April day with bright sunshine and temperature rising into the lower 50s.  Turtle Journal decided to make its annual spring pilgrimage to the Indian Neck salt marsh system in Wellfleet on the Outer Cape in search of emerging juvenile horseshoe crabs 

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Juvenile Horseshoe Crab Tracks in Marsh Channel

The Fox Island Wildlife Management Area on Indian Neck lies on the north bank of Blackfish Creek.  Protected by barrier dunes, these salt marshes are extremely productive, and each year we look to this area for our first sighting of tiny juvenile horseshoe crabs rising from their winter slumber along the oozy bottom.  As we examined the main salt marsh near King Phillip Road, Don spotted telltale signs of miniature horseshoe crab tracks on the channel bottom.

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Don Lewis Searches Marsh Bottom for Horseshoe Crab

He photo-documented the marks and then began to solve the maze to determine where the actual critter might be.  Once you make your first pass along the bottom, turbidity will obscure the search.  So, you better be right the first time.  You can play the game yourself.  Click on the crawl mark photograph to enlarge it, and see if you can determine the most likely spot to make your first probe for the critter.

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Tiny Juvenile Horseshoe Crab Netted

With a small sampling net, Don probed the bottom about two inches deep at the most likely location.  Of course the net became filled with loose sand and ooze.  It took several dips of the net back into the water to clear away the muck, as though panning for gold, to reveal a tiny, exquisite juvenile horseshoe crab.

Juvenile Horseshoe Crab (Limulus polyphemus)

Juvenile horseshoe crabs are delightful to watch.  Appearing as ancient as the earliest trilobites, horsehoe crabs create awe in the Turtle Journal team as we study them each year.  Sadly, humans have harvested these marvelous creatures to the edge of extinction, impoverishing our entire tidal and inter-tidal eco-systems, as well as driving certain shorebirds that survive long migrations on horseshoe crab eggs to the brink, too.  It gives us joy, though, to find juveniles each spring as we hope for sanity to prevail in state and federal management of this important species.  As you may know, horseshoe crabs are true blue bloods (with copper rather than iron) that yield a powerful bacterial detector that saves human lives.  They’re also extremely valuable in the research of vision (with both compound and simple eyes) as well as many other scientific and medical breakthroughs.

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Underside of Tiny Juvenile Horseshoe Crab

Upside down, this little horseshoe crab presents a nice view of its five pairs of walking, swimming and foraging legs, as well as its book gills behind the legs.  You may know that to grow, a horseshoe crab must molt.  It leaves its shell when it gets too confining, and soon a new, larger shell hardens around its soft tissue.  It takes sixteen and seventeen molts respectively over a period of nine to eleven years for a male and a female to reach maturity.

Release of Juvenile Horseshoe Crab Back into Marsh

As soon as we finished our analysis of this youngster, we released it back into the same marsh channel.  It took a couple of attempts to make sure that the critter was safe and sound, as it burrowed itself back under the oozy bottom to enjoy the rest of this beautiful April day.  Bon chance, young horseshoe crab!

Return of the Crabby Hermit

Friday, April 8th, 2011

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Flat-Clawed Hermit Crab (Pagurus pollicaris)

The tidal flats in Sippican Harbor off Buzzards Bay warmed enough today for flat-clawed hermit crabs to become active.  This morning a crabby hermit scurried along the shallows at Silvershell Beach in Marion in a small moonsnail shell. 

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Flat-Clawed Hermit Crab (in Moonsnail Shell)

These vagabond crustaceans adopt abandoned shells of snails and whelks.  But of course, they move quite differently than the snails and whelks who formerly occupied these shells.  As a consequence, a portion of its new home constantly drags along the tidal flats and creates a telltale “bald” or shiny spot, which can be easily spotted in the photograph above.  With the shell flipped upside down, you can see where its new home rubs against the bottom. 

Besides the common name “Flat-Clawed Hermit Crab,” these animals are also called “Broad-Clawed Hermit Crabs.” 

Meet the Crabby Hermit

Okay.  Perhaps the flat-clawed hermit crab lacks a little something in the cuteness category.  But Turtle Journal loves these seemingly comical critters; and when you get the chance to see one outside its shell, we believe they display an adorably playful presence.  We rescued this particular hermit crab in October.  It had been residing in a whelk shell that was swooped up by a gull that dropped it from considerable height just as we happened on the scene.  The force of the crash on the concrete boat ramp smashed the whelk shell and trapped the hermit crab inside.

Crabby Hermit Finds a New Home

We decided to give Nature (and this crabby hermit) a helping hand by first freeing it from the crushed whelk shell, and then offering a selection of empty whelk shells for it to choose a new home.  The video clip above shows our crabby friend adopting its new abode.

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Flat-Clawed Hermit Crab

Today’s specimen in its moonsnail shell was much smaller.  This photograph with the barnacle in the upper left gives a good sense of the hermit crab’s size.

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Flat-Clawed Hermit Crab with Snail Fur

Hermit crab shells provide habitat for snail fur (Hydractinia echinata).  This hydroid grows in colonies on snail shells that have been taken over by hermit crabs.  According to Marine Life of the North Atlantic by Andrew J. Martinez, “It is believed that the stinging cells of the hydroids protect the hermit crab against some predators.”  The image above show the polyps in full glory.