Archive for the ‘amphibians’ Category

Confused by mild fall weather

November 12, 2017

A frog-let/toad-let — my term for small frogs and toads — was spotted during a photowalk along Easy Road at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. Turns out it’s a Spring Peeper (Pseudacris crucifer), as indicated by the dark “X” on the frog’s dorsal side.

Every spring, the sound of male Spring Peepers calling for mates is deafening. You hear them, but you see them rarely. You don’t expect to see them during the second week in November!

Some amphibians have been confused by the mild weather in Northern Virginia, thinking it’s spring. The first hard freeze this fall occurred overnight on Friday-Saturday, November 10-11, when the record-setting low temperature at Reagan National Airport (DCA) was 26°F. I hope this little one hunkered down like frogs are supposed to when it’s cold.

Related Resource: Spring Peepers, a blog post by Alonso Abugattas, Natural Resources Manager for Arlington County Parks, Virginia USA.

Copyright © 2017 Walter Sanford. All rights reserved.

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Life-list additions in 2016

December 28, 2016

2016 was the “Year of the Clubtail dragonfly.” Unofficially, that is. Or maybe it only seems like I saw a lot more clubtail dragonflies than in past years, including four new species for my life-list of odonates. Not that I actually maintain a list — it’s more like a memory file in my brain.

There were three other non-odonate “firsts” this year, one of which was a long time coming! My life-list additions in 2016 are presented in reverse-chronological order.

Shadow Darner dragonfly

Shadow Darner dragonfly (female), posted on 18 October 2016.

Although I’ve seen many male Shadow Darners, this is the first female I photographed.

A Shadow Darner dragonfly (Aeshna umbrosa) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a female heteromorph.

14 OCT 2016 | JMAWR | Shadow Darner (female heteromorph)

Russet-tipped Clubtail dragonfly

Russet-tipped Clubtail dragonfly (male), posted on 26 September 2016.

I spent a lot of time unsuccessfully looking for Russet-tipped Clubtail dragonflies at Accotink Bay Wildlife Refuge. Soon after I surrendered in defeat, a Russet-tipped Clubtail found me. Imagine my surprise and delight when I spotted one at Jackson Miles Abbott Wetland Refuge (JMAWR). Whoa, didn’t see that one coming!

Clearwing Moths

Clearwing Moths (Genus Hemaris), published on 04 October 2016.

Dusky Dancer damselfly

Dusky Dancer damselflies (mating pair), published on 12 September 2016.

A mating pair of Dusky Dancer damselflies (Argia translata) spotted along Pope's Head Creek at Chapel Road Park, Fairfax County, Virginia USA. This pair is "in tandem."

29 AUG 2016 | Chapel Road Park | Dusky Dancer (mating pair)

Black-shouldered Spinyleg dragonfly

Black-shouldered Spinyleg (male), published on 11 August 2016.

Eastern Ringtail dragonfly

Eastern Ringtail dragonflies (males), published on 13 August 2016.

Powdered Dancer damselfly

Powdered Dancer (males, female), published on 23 August 2016.

A Powdered Dancer damselfly (Argia moesta) spotted along the Potomac River at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

04 AUG 2016 | Riverbend Park | Powdered Dancer (male)

Swift Setwing dragonfly

Making new friends, published on 10 July 2016.

A Swift Setwing dragonfly (Dythemis velox) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male.

26 JUN 2016 | JMAWR | Swift Setwing (male)

Dragonhunter dragonfly

Dragonhunter dragonfly (female), published on 24 June 2016.

This is the first female Dragonhunter I photographed.

A Dragonhunter dragonfly (Hagenius brevistylus) spotted at Hidden Pond, Meadowood Recreation Area, Fairfax County, Virginia USA. This individual is a female.

21 June 2016 | Dragonhunter dragonfly (female)

Calico Pennant dragonfly

Calico Pennant dragonflies (males), published on 20 June 2016.

A Calico Pennant dragonfly (Celithemis elisa) spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a male.

18 JUN 2016 | OBNWR | Calico Pennant (male)

Prince Baskettail dragonfly

Changing of the guard, published on 16 June 2016.

Although I’ve seen many Prince Baskettail dragonflies, this one is the first I photographed. Prince Baskettails are fliers, not perchers.

A Prince Baskettail dragonfly (Epitheca princeps) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This individual is a male, shown in flight.

14 JUN 2016 | JMAWR | Prince Baskettail (male, in flight)

Slender Bluet damselfly

Slender Bluet damselflies (mating pair), published on 24 October 2016.

A mating pair of Slender Bluet damselflies (Enallagma traviatum) spotted at Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA. This pair is "in heart."

14 JUN 2016 | JMAWR | Slender Bluet (mating pair, “in heart”)

Common Sanddragon dragonfly

Common Sanddragon dragonfly (emergent male), published on 08 June 2016.

Although this was the second emergent dragonfly I saw during 2016, this was the first time I was able to observe the entire metamorphosis from beginning to end.

A Common Sanddragon nymph/dragonfly (Progomphus obscurus) spotted along Dogue Creek at Wickford Park, Fairfax County, Virginia USA. This individual is an emergent male.

01 JUN 2016 | WP/DC | Common Sanddragon nymph/dragonfly

Cobra Clubtail dragonfly

Cobra Clubtail claspers, published on 19 May 2016.

A Cobra Clubtail dragonfly (Gomphus vastus) spotted at Riverbend Park, Fairfax County, Virginia USA. This individual is a male.

16 MAY 2016 | Riverbend Park | Cobra Clubtail (male)

Polyphemus Silkmoth

Polyphemus Silkmoth, published on 21 April 2016.

A Polyphemus Silkmoth (Antheraea polyphemus) was spotted along the Hike-Bike Trail at Huntley Meadows Park.

Spring Peeper frog

Spring Peeper, published on 01 May 2016.

Although I’ve heard Spring Peepers (Pseudacris crucifer) every spring for many years, this is the first one I saw.

Editor’s Note: The following location codes are used in some photo captions, shown above.

Copyright © 2016 Walter Sanford. All rights reserved.

Spring Peeper

May 1, 2016

Michael Powell and I were searching for the elusive Springtime Darner dragonfly (Basiaeschna janata) during a photowalk at Huntley Meadows Park on 15 April 2016. (By the way, we found one later the same day!)

As we were walking along a thorny thicket of greenbrier (Smilax sp.), I noticed a frog-let/toad-let — my term for small frogs and toads that are seen commonly in the wetlands at the park, especially during spring. The individual shown in the following photos is an inch or less in length!

My first thought is usually, “Oh, it’s just a frog-/toad-let. Nothing to see here. Move along.” Good thing I decided to take a closer look. Turns out the frog-/toad-let is a Spring Peeper (Pseudacris crucifer), as indicated by the dark “X” on the frog’s dorsal side.

A Spring Peeper (Pseudacris crucifer) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

These photos were years in the making. Huh? I have been a frequent visitor at Huntley Meadows Park for over 30 years. Every spring, the sound of male Spring Peepers calling for mates is deafening. You hear them, but you never see them, that is, until this year when I spotted my first ever Spring Peeper!

A Spring Peeper (Pseudacris crucifer) spotted at Huntley Meadows Park, Fairfax County, Virginia USA.

I spotted the first peeper; Mike spotted a second peeper while we were photographing the first one. The peeper shown in this photo set is actually the second one we saw; photos of the first peeper will be published in a follow-up post.

Related Resource: Spring Peeper, by Mike Powell.

Copyright © 2016 Walter Sanford. All rights reserved.

Common Ribbonsnake eating a frog

March 26, 2016

The following time-series of photos, shot on 16 March 2016 during a photowalk along the Hike-Bike Trail at Huntley Meadows Park, shows a Common Ribbonsnake (Thamnophis sauritus sauritus) eating a Southern Leopard Frog (Lithobates sphenocephalus).

Although the amphibian looks similar to Pickerel Frog (Lithobates palustris), I tentatively identified the species as Southern Leopard Frog based upon one of two field markers that were visible: distinct dorsolateral folds that extend the full length of the body (shown); a distinct white spot in the center of the tympanum (not shown). Sincere thanks to Alonso Abugattas — Natural Resources Manager, Arlington County Parks, Virginia — for verifying my identification.

A Common Ribbonsnake (Thamnophis sauritus sauritus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is eating a Southern Leopard Frog (Lithobates sphenocephalus).

As shown in the first photo, the snake had a fatal grip on the frog by the time I spotted the pair.

A Common Ribbonsnake (Thamnophis sauritus sauritus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is eating a Southern Leopard Frog (Lithobates sphenocephalus).

Notice the small green bubble, located on the frog’s dorsal posterior, that is visible in the second and third photos. I consulted the experts of the Virginia Herpetological Society for help in identifying the bubble.

The general consensus is the cloaca (a bag through which reproductive- and waste products leave the body) is inverted and protruded through the anus due to the internal pressure the snake is putting on the body cavity. If the frog were a female in reproductive condition, it could also be either eggs (unlikely due to color) or jelly being forced out, again due to pressure. Source Credit: John, Virginia Herpetological Society.

Just as I thought — the snake was actually squeezing the guts out of the frog!

A Common Ribbonsnake (Thamnophis sauritus sauritus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is eating a Southern Leopard Frog (Lithobates sphenocephalus).

A Common Ribbonsnake (Thamnophis sauritus sauritus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is eating a Southern Leopard Frog (Lithobates sphenocephalus).

A Common Ribbonsnake (Thamnophis sauritus sauritus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is eating a Southern Leopard Frog (Lithobates sphenocephalus).

A Common Ribbonsnake (Thamnophis sauritus sauritus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is eating a Southern Leopard Frog (Lithobates sphenocephalus).

Copyright © 2016 Walter Sanford. All rights reserved.

Amplexus gone wild!

March 24, 2016

A mass of mating Eastern American Toads (Anaxyrus americanus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. It's difficult to tell whether there are pairs of males and females in amplexus within the group of toads.

A mass of mating Eastern American Toads (Anaxyrus americanus) was spotted in a vernal pool during a photowalk along the Hike-Bike Trail at Huntley Meadows Park on 11 March 2016. It’s difficult to tell whether there are pairs of males and females in amplexus within the group of toads.

A mass of mating Eastern American Toads (Anaxyrus americanus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. It's difficult to tell whether there are pairs of males and females in amplexus within the group of toads.

It’s like the toads were playing either rugby (the pile of toads reminds me of a scrum) or “Twister.”

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

Amplexus

March 22, 2016

Amplexus is the nexus between male and female frogs and toads that results in fertilization of eggs. Many mating pairs of Eastern American Toads (Anaxyrus americanus) were observed in amplexus in a vernal pool located along the Hike-Bike Trail at Huntley Meadows Park on 11 March 2016.

The first photo shows a mating pair in amplexus plus another male interloper.

A mating pair of Eastern American Toads (Anaxyrus americanus) plus another male interloper spotted at Huntley Meadows Park, Fairfax County, Virginia USA. The mating pair is in amplexus.

And action! The following photo — my favorite in the set — shows another mating pair in amplexus plus an aggressive male interloper. Notice the strings of toad eggs in the water.

A mating pair of Eastern American Toads (Anaxyrus americanus) plus another male interloper spotted at Huntley Meadows Park, Fairfax County, Virginia USA. The mating pair is in amplexus. Notice the long strings of toad eggs in the water.

Look closely at the full-size version of the preceding photo. Notice the nictitating membrane covering the eyes of all three toads — a translucent third eyelid that protects the eyes of toads when they are underwater. Looking at the other three photos, can you tell which toads’ eyes are (or were) below water?

The next photo shows a mating pair in amplexus. Notice the long strings of toad eggs in the water.

A mating pair of Eastern American Toads (Anaxyrus americanus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in amplexus. Notice the long strings of toad eggs in the water.

The last photo shows another mating pair in amplexus.

A mating pair of Eastern American Toads (Anaxyrus americanus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in amplexus.

Answer Key: Photo 1) The male interloper is under water. Photo 2) All three toads are under water. Photo 3) Both toads are under water. Photo 4) Both toads are above water.

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

Eastern American Toads (mating pair)

March 20, 2016

A mating pair of Eastern American Toads (Anaxyrus americanus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is in amplexus. Notice the long strings of toad eggs in the water.

Many mating pairs of Eastern American Toads (Anaxyrus americanus) were spotted in a vernal pool during a photowalk along the Hike-Bike Trail at Huntley Meadows Park on 11 March 2016. This pair is shown in amplexus, in which the male (top) holds onto the female (bottom): the female lays eggs in the water; the male fertilizes the eggs, externally from the female.

Notice the black-and-white strings of toad eggs in the water.

The eggs are laid in long spiral gelatinous strings and each egg is 1/25 to 1/16 inch in diameter. The eggs, 4000 to 8000 in number, are laid in two strings, and hatch in 3 to 12 days. Source Credit: eastern American toad (Anaxyrus americanus americanus), Virginia Department of Game and Inland Fisheries.

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

“Air bag” deployed

March 18, 2016

An Eastern American Toad (Anaxyrus americanus) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male, calling (trilling) for females.

Many Eastern American Toads (Anaxyrus americanus) were spotted in a vernal pool during a photowalk along the Hike-Bike Trail at Huntley Meadows Park on 11 March 2016.

It’s mating season for toads in the mid-Atlantic region of the United States of America. The mating process begins when male toads, such as the one shown above, go to a body of water and begin calling females.

Look closely at the full-size version of the photo. Notice the waves radiating outward from the toad’s air bag, technically called a “dewlap.” Sound is a wave phenomenon caused by vibrations in a medium such as air and water. Light is a wave phenomenon too (as well as a particle phenomenon). Who knew still photos could capture both light and sound waves?

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

Señor Frog

March 6, 2016

During the “off-season,” I use the downtime exploring new sites for wildlife photography and for experimenting with new photography gear and techniques. For example, I spent a few days in the “BoG Photo Studio” recently experimenting with extension tubes.

Macro extension tubes are inserted between the lens and the camera body and increase the distance between the lens elements and the sensor enabling users to focus on subjects much closer to the camera. Source Credit: Fujifilm Macro Extension Tubes MCEX-11 and MCEX-16.

The subject in this set of test shots is a toy frog. His name is “Señor Frog,” as in, “I seen your frog, Señor.” Just look at him. He’s SO CUTE, don’t you want to kiss him? I found Señor Frog in a geocache located in Fairfax County, Virginia USA; the item I traded for Señor Frog is cool but he is cooler!

Canon EOS 5D Mark II

The first photo was shot on 19 February 2016 using a Canon EOS 5D Mark II plus Canon EF 70-200mm f/2.8L zoom lens, the 20mm Kenko macro automatic extension tube (from a set of three), 580EX II Speedlite & Vello diffuser, and Vanguard Alta Pro 263AB tripod and Manfrotto 054 Magnesium Ball Head with Q2 Quick Release.

The original image is a RAW file (CR2), taken using manual exposure and manual focus; the flash was on and fired. The minimum focusing distance for the 70-200mm lens is 1.2 m (3.9 ft.). Adding the 20mm extension tube reduced the minimum focusing distance: at a focal length of 135mm, the working distance was ~1.5 feet; at 200mm the working distance was estimated to be 2-3 feet.

IMG_0187-CR2-Ver2_Aperture

ISO 400 | 148mm | 0 ev | f/32 | 1/160s

Fujifilm X-T1

The next photo was taken on 18 February 2016 using a Fujifilm X-T1 digital camera plus Fujinon XF18-55mm (27-82.5mm, 35mm equivalent) “kit” lens, Nissin i40 external flash (TTL), and Vanguard Alta Pro 263AB tripod and Manfrotto 054 Magnesium Ball Head with Q2 Quick Release.

The original image is a RAW file (RAF), shot using manual exposure and automatic focus; the flash was on and fired. The working distance was ~30cm, the same as the minimum focusing distance for this lens. That’s fairly close to the subject considering no extension tubes were used! The 10mm “Fotasy” brand extension tube (set of two) works well with this lens, reducing the minimum focusing distance to ~7 inches (~18 cm). At that distance, it was impossible to see the entire subject.

"Señor Frog," a toy frog found in a geocache located in Fairfax County, Virginia USA.

ISO 800 | 55mm (83mm, 35mm equivalent) | -2 ev | f/16 | 1/250s

The last photo was shot on 15 February 2016 using a Fujifilm X-T1 plus Fujinon XF55-200mm zoom lens, both “Fotasy” brand extension tubes (set of two, stacked together), Fujifilm Shoe Mount Flash EF-42 (TTL), and Vanguard Alta Pro 263AB tripod and Manfrotto 054 Magnesium Ball Head with Q2 Quick Release.

The original image is a RAW file (RAF), taken using manual exposure and automatic focus; the flash was on and fired. The minimum focusing distance of 1.1 m (3 ft. 7 in.) is estimated to be half as far using both extension tubes (10 + 16 = 26mm).

"Señor Frog," a toy frog found in a geocache located in Fairfax County, Virginia USA.

ISO 800 | 134.5mm (202mm, 35mm equivalent) | 0 ev | f/11 | 1/180s

Lessons Learned

So what are the take-aways from my experimentation? The time to figure out how your gear works is not when the photo opportunity of a lifetime presents itself! My skill set now includes several photographic techniques for getting closer to the subject, thereby enabling smaller subjects such as frogs and odonates to fill the frame, that is, assuming these subjects are less skittish than usual.

Copyright © 2016 Walter Sanford. All rights reserved.

Green Frogs

November 3, 2015

Several Green Frogs (Lithobates clamitans) were spotted at the “Amphibian Pool,” located behind the Visitor Center at Huntley Meadows Park. These individuals may be Bronze Frogs, a subspecies of Green Frog.

The first photo shows two frogs: the one on the upper-right might be a male; the one on the lower-left is probably a female.

Males also possess a larger tympanum and stouter forelegs and thumbs than females. Source Credit: Green Frog, Virginia Herpetological Society.

Two Green Frogs (Lithobates clamitans) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. These individuals may be Bronze Frogs, a subspecies of Green Frog.

21 OCT 2015 | Huntley Meadows Park | Green Frogs

The next individual is probably another male. The green aquatic plant is duckweed. Duckweed oxygenates the water and provides shelter for animals like frogs.

A Green Frog (Lithobates clamitans) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual may be a Bronze Frog, a subspecies of Green Frog. The green aquatic plant is duckweed.

21 OCT 2015 | Huntley Meadows Park | Green Frog

The last individual may be another female.

A Green Frog (Lithobates clamitans) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual may be a Bronze Frog, a subspecies of Green Frog. The green aquatic plant is duckweed.

21 OCT 2015 | Huntley Meadows Park | Green Frog

Copyright © 2015 Walter Sanford. All rights reserved.


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