Archive for January, 2015

Green Frog (male, calling)

January 11, 2015

I spotted a Green Frog (Lithobates clamitans) along the boardwalk in the hemi-marsh at Huntley Meadows Park on 25 May 2014. This individual is a male, as indicated by the size of its tympanum (eardrum).

Females and males can be differentiated by the size of the tympanum (the eardrum, located behind the eye and below the dorsolateral ridge). In females, it is about the same size as the eye and in males it is much larger than the eye. Source Credit: Northern green frog, a Project Noah spotting by Kara Curtain/Jones, graduate student and teaching assistant at George Mason University, Department of Environmental Science and Policy.

Tech Tip: The preceding video looks better viewed in full-screen mode.

Related Resources: Some species of amphibians, such as Spring Peeper (Pseudacris crucifer), are heard more often than seen. In 2014, I resolved to learn the calls of many of the amphibians that are common at Huntley Meadows Park. The following alphabetical list provides quick links to audio recordings of several species of frogs and toads of Virginia, courtesy Virginia Herpetological Society.

Test your skill in identifying frog calls by visiting the USGS Frog Quizzes Web page. Be forewarned: The quizzes are challenging! Refer to Virginia is for Frogs for more frog-related resources including Teacher’s Corner, featuring ideas for lesson plans and activities.

Copyright © 2015 Walter Sanford. All rights reserved.

Green Frog (female)

January 9, 2015

I photographed a Green Frog (Lithobates clamitans) alongside the boardwalk in the hemi-marsh at Huntley Meadows Park on 02 April 2014. This individual is probably a female, as indicated by the size of its tympanum (eardrum).

Green frogs are variable in color and pattern, but can be differentiated from similar species — such as bullfrogs and leopard frogs — by the dorsolateral ridges that run from behind each eye to about three-quarters of the way down the back. In leopard frogs, the ridge continues all the way down the back and bullfrogs lack these ridges altogether. Females and males can be differentiated by the size of the tympanum (the eardrum, located behind the eye and below the dorsolateral ridge). In females, it is about the same size as the eye and in males it is much larger than the eye. Source Credit: Northern green frog, a Project Noah spotting by Kara Curtain/Jones, graduate student and teaching assistant at George Mason University, Department of Environmental Science and Policy.

Green Frog (Lithobates clamitans)

Green Frog (Lithobates clamitans)

Green Frog (Lithobates clamitans)

Copyright © 2015 Walter Sanford. All rights reserved.

Male gymnast

January 7, 2015

Great Spreadwing damselfly (male)

This post features photos of a Great Spreadwing damselfly (Archilestes grandis) spotted on 17 October 2014 near a vernal pool in the forest at Huntley Meadows Park. This individual is a male, as indicated by its coloration, hamules, and terminal appendages.

Looking at the next three photos you may be wondering, “What’s up with this guy’s gymnastic poses?” I think the Great Spreadwing is simply stretching rather than preparing for mating.

Great Spreadwing damselfly (male)

Great Spreadwing damselfly (male)

Great Spreadwing damselfly (male)

I discovered my first Great Spreadwing damselfly on 09 October 2014, an aggressive individual that came to be known as “Crinkle-cut.” This guy was the next one I spotted.

Great Spreadwing damselfly (male)

With handsome azurite-colored eyes complemented by green and yellow racing stripes on their thorax, male Great Spreadwings have become one of my favorite damselflies!

Great Spreadwing damselfly (male)

Copyright © 2015 Walter Sanford. All rights reserved.

Red-footed Cannibalflies (mating pairs)

January 5, 2015

The following photographs show mating pairs of Red-footed Cannibalflies (Promachus rufipes) spotted on 06 October 2014 near a vernal pool in the forest at Huntley Meadows Park. Red-footed Cannibalfly is a species of robber fly seen commonly at the park.

It never occurred to me that male and female robber flies might look different — I just assumed they look the same. Well, you know what they say about that kind of thinking. As it turns out, there is an obvious difference in appearance that I didn’t notice until I examined the photos of these mating pairs. By coincidence, the male is shown on the left and the female on the right in every photo. Do you see what I saw?

Red-footed Cannibalflies (mating pair)

The male’s abdomen is “tiger-striped” for its entire length; the female’s abdomen is two-thirds tiger-striped, one-third black.

Red-footed Cannibalflies (mating pair)

I never noticed the difference in appearance between males and females until I edited these photos. When I took a second-look at other photos of Red-footed Cannibalflies posted on my blog, it was easy to identify the gender of the specimens. Who knew?

Red-footed Cannibalflies (mating pair)

Copyright © 2015 Walter Sanford. All rights reserved.

Top 10 Photos of 2014

January 1, 2015

The following gallery shows 25 finalists for my “Top 10 Photos of 2014.” The photos are presented in reverse-chronological order beginning in October 2014 and ending in April 2014.

This year I decided to select the Top 10 photos using reader feedback. Please enter a comment at the end of this post listing the number for each of your 10 favorite photos. If listing 10 photos is asking too much, then please list at least five photos, e.g., No. 2, 5, 11, 20, 21, etc. Thanks for sharing your selections, and thanks for following my photoblog!

Editor’s Note: The “Discussion Settings” for this blog were edited to remove most of the “filters” that are intended to prevent SPAM comments. This should make it much easier for regular readers to share their list of favorite photos.

No. 1

No. 2

No. 3

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No. 5

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No. 10

No. 11

No. 12

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No. 23

No. 24

No. 25

Common Ribbonsnakes (mating pair)

02 APR 2014 | HMP | Common Ribbonsnakes (mating pair)

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

Copyright © 2015 Walter Sanford. All rights reserved.


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