Archive for the ‘iMovie’ Category

Odonate exuviae collecting sites

July 29, 2019

The following video shows a “boater’s-eye view” of some sites where odonate exuviae have been collected by Joseph Johnston along Aquia Creek, located in Stafford County, Virginia USA. Joe is an avid boater and sport fisherman who kindly agreed to be my “Eyes on the Aquia,” always on the lookout for odonate exuvia to share with me.

The first photo gallery features still images of several spots shown in the preceding video. Joe estimates the water is ~5-6 feet deep outside the channel markers, and much deeper in the middle of the creek.

Joe’s boat is somewhere between the long boat docks (lower-right quadrant) and Government Island (near center), as shown in an aerial view of Aquia Creek provided by Google Maps.

The last photo gallery features still images of several exuviae, shown in situ before Joe collected the specimens. The first photo shows where it all began, when Joe collected his first dragonfly exuvia for me on 20 June 2018.

Related Resources

Credits

All media Copyright © 2019 by Joseph Johnston. Used with permission from Mr. Johnston.

Copyright © 2019 Walter Sanford. All rights reserved.

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Burst mode flash photography

October 12, 2018

This post provides a brief demonstration of burst mode flash photography using the gear shown in the following photo: Fujifilm X-T1 digital camera plus Fujifilm MCEX-11 extension tube and Fujinon XF80mm macro lensGodox XProF radio flash triggerGodox TT685F external flashGodox PROPAC PB960 Lithium-Ion Flash Power Pack; and Quantum Instruments CZ2 Power Cable (for Turbo Series Power Packs).

Godox flash photography gear.

The Fujifilm X-T1 digital camera is set for “CL” (continuous low) burst mode. The Godox TT685F external flash unit is set for Manual mode at 1/128 power, as shown on the LCD of the Godox XProF radio flash trigger mounted on the camera hot shoe. The external flash unit is connected to a Godox PROPAC PB960 power pack using a Quantum Instruments cable.

The external flash unit is powered by a set of four AA batteries, as usual. The external power pack enables a much faster recycle rate for the flash than is possible using only AA batteries.

The Quantum Instruments CZ2 Power Cable fits Canon external flash units such as the Canon MT-26EX-RT Macro Twin Lite and Canon 580EX- and Canon 580EX II Speedlites, as well as Godox external flash units made for Canon, Fujifilm, and Olympus/Panasonic digital cameras. You may want to buy two cables, since the Godox PROPAC PB860 can power two flash units at once.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Habitat for Tiger Spiketail dragonfly

August 9, 2018

In the world of odonates, there are habitat generalists and habitat specialists. Tiger Spiketail dragonfly (Cordulegaster erronea) is a habitat specialist.

Habitat: Small forest streams and seeps, often with skunk cabbage and interrupted fern. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 7028-7029). Princeton University Press. Kindle Edition.

The following video shows ideal habitat for C. erronea: A clean, seep-fed small stream in the forest.

The black rock in the middle of the creek is approximately five feet (~5′) from the place in the stream channel where I was sitting on a Coleman camp stool. The video begins with me looking at a seep that feeds the stream; then I pan left, right, and back to center stage.

Tech Tips: The preceding movie looks better viewed in full-screen mode. The video was recorded in 1080p at 60 fps using a head-mounted GoPro Hero4 Black action camera. The camera was positioned so that it recorded what I saw when looking straight ahead; the scene changed by moving my head. 60 fps was used so that I could edit the video to show smooth slow-motion video of Tiger Spiketail dragonflies in flight. I think one of the bigger take-aways is a Tiger fly-by would have been recorded clearly enough to be able to identify the species. For what it’s worth, the closest focusing distance of the GoPro Hero4 Black is approximately 12 inches (~1′).

GoPro CapCam©

A GoPro QuickClip was used to mount an action camera on the bill of a baseball cap.

GoPro Hero4 Black action camera, plus QuickClip mount.

The GoPro Head Strap + QuickClip is compatible with all GoPro cameras and sells for $19.95 retail.

GoPro Hero4 Black action camera, plus QuickClip mount.

The Backstory

I visited the location shown in the video three times: Several Tiger Spiketail dragonflies were observed at the site on 19- and 26 July 2018; no Tiger Spiketails were spotted on 06 August 2018, the day the video was recorded. It’s worth noting that the adult flight period for C. erronea peaks in July in Northern Virginia (USA). Most of the window of opportunity was missed due to near record setting rainfall for the month of July, including a period of seven consecutive days of rain totaling nearly 10 inches!

Although I saw several Tiger Spiketail dragonflies, every individual was in flight and I was unable to shoot still photos and/or video — they were gone by the time I reached for my camera! The GoPro CapCam© is my solution to this problem.

An Apple iPad mini is used to remotely control the action camera using the GoPro app (formerly known as “Capture”) via Bluetooth. Among many features, the app provides real-time display of the camera field of view. The camera is positioned correctly on the bill of my cap by holding the iPad directly in my line of sight and adjusting the camera mount so the iPad is shown in the middle of the screen, against the background.

Copyright © 2018 Walter Sanford. All rights reserved.

Great Spreadwing damselflies (males, gymnasts)

November 9, 2015

The following photos show a Great Spreadwing damselfly (Archilestes grandis) spotted on 08 October 2015, two days after the first Great Spreadwing was observed at a small permanent pond in a remote location at Huntley Meadows Park (HMP). This individual is a male, nicknamed “Mr. Magoo” because of the prominent dark spots in his eyes.

A Great Spreadwing damselfly (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male, nicknamed "Mr. Magoo."

08 OCT 2015 | HMP | Great Spreadwing (male, nicknamed “Mr. Magoo”)

I’m not sure what “Mr. Magoo” was doing in the preceding photo. A novice odonate hunter might be fooled into thinking the damselfly is a female, ovipositing in the grass stem (endophytic oviposition). I speculate the young male was “test-driving” his terminal appendages, with the grass stem serving as a simulation of the neck of a female.

A Great Spreadwing damselfly (Archilestes grandis) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male, nicknamed "Mr. Magoo."

08 OCT 2015 | HMP | Great Spreadwing (male, nicknamed “Mr. Magoo”)

After two seasons of field observation of Great Spreadwing damselflies, I have noticed several males flexing their abdomen like gymnasts. Are they simply stretching, or is this behavior related to a pre-/post-mating ritual? It’s impossible to know for certain, but I’m sure it’s amusing to watch! In particular, notice the unusual “two-step dance” performed by the male featured in the following video.

04 NOV 2015 | HMP | Great Spreadwing (male)

I’m a fairly accomplished photographer, he said, not too modestly. In contrast, my skills as a videographer are relatively rudimentary as evidenced by the preceding video. My movies usually turn out better when I plan the shoot and use a tripod; in this case, the video clips were shot spontaneously (therefore hand-held) when an opportunity presented itself.

One of my mantras of wildlife photography/videography is “get a shot, any shot; refine the shot.” I wish the preceding video had turned out better. Although I was able to shoot a couple of video clips of this unusual gymnastic routine, there was no opportunity to refine the shots. Oh well, maybe next year!

Related Resources:

Editor’s Note: According to Ed Lam, author and illustrator of Damselflies of the Northeast, the damselfly featured in the video is grooming itself.

He appears to be grooming in the video. They can’t reach down to knock off debris, spiderwebs, etc. but they can rub their legs together or against an object. Similarly, the abdomen seems to be contacting the wings. Sometimes you see this behavior after they have been handled and released if they don’t immediately fly away. Source Credit: Ed Lam, Northeast Odonata Facebook group.

Copyright © 2015 Walter Sanford. All rights reserved.

Slaty Skimmer dragonfly (female, laying eggs)

June 28, 2015

Slaty Skimmer (Libellula incesta) is a member of the Skimmer Family of dragonflies. Females lay eggs (oviposition) by skimming the water surface repeatedly, hence the family name “Skimmer“; two flanges beneath their eighth abdominal segment (S8) scoop water that is used to flick fertilized eggs toward shore, as illustrated in the following annotated image. Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

A Slaty Skimmer dragonfly (Libellula incesta) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a mature female member of a mating pair.

10 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (mature female)

The preceding still photo shows a mature female Slaty Skimmer dragonfly resting immediately after copulation.

The following movie shows the same female laying eggs in a large pool of water downstream from the central wetland area at Huntley Meadows Park on 10 June 2015.

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

Copyright © 2015 Walter Sanford. All rights reserved.

Painted Skimmer dragonfly (female, laying eggs)

June 6, 2015

Painted Skimmer (Libellula semifasciata) is a member of the Skimmer Family of dragonflies. Females lay eggs (oviposition) by skimming the water surface repeatedly, hence the family name “Skimmer“; two flanges beneath their eighth abdominal segment (S8) scoop water that is used to flick fertilized eggs toward the shore, as illustrated in the following annotated image. Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.

The following movie shows a female Painted Skimmer dragonfly laying eggs in a vernal pool at Huntley Meadows Park on 20 May 2015. (Same day, different time. Same park, different location. Same species, different female.)

Editor’s Note: Copulation between male and female Painted Skimmers occurs in-flight and is very brief, lasting just a few seconds. In my experience, oviposition is brief too. My camera was set up for shooting still photographs when I spotted the mating pair; by the time I moved into position, the pair had separated and the female was laying eggs. Fortunately I had the presence of mind to shoot video rather than stills. The video quality isn’t great, buy hey, at least I captured the moment, albeit brief!

Copyright © 2015 Walter Sanford. All rights reserved.

Painted Skimmer dragonfly (female, breathing and grooming)

June 2, 2015

The following movie features a Painted Skimmer dragonfly (Libellula semifasciata) spotted on 20 May 2015 during a photowalk alongside the wetlands at Huntley Meadows Park. This individual is a female, as indicated by its terminal appendages.

Dragonflies breathe through small holes in the underside of their thorax and abdomen called “spiracles.” Notice the dragonfly’s thorax and abdomen expanding and contracting as she inhales and exhales.

The female appears to be grooming while perching on vegetation, using her front legs to wipe her eyes and face. The author has observed many species of dragonflies engaged in similar behavior.

Tech Tips: The preceding movie looks better viewed in full-screen mode.

The video clips used to create this movie were shot on a very windy day. I used a tripod for my camera and centered the subject in each clip, but the wind caused the dragonfly to drift off-center at times. Not that I’m a perfectionist or anything.

Related Rescources:

Copyright © 2015 Walter Sanford. All rights reserved.

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.

Autumn Meadowhawk dragonfly (female, breathing and grooming)

December 28, 2014

The following video features an Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted on 15 November 2013 during a photowalk along the boardwalk in the hemi-marsh at Huntley Meadows Park. This individual is a female, as indicated by its coloration and terminal appendages.

Dragonflies breathe through small holes in the underside of their thorax and abdomen called “spiracles.” Notice the dragonfly’s thorax and abdomen expanding and contracting as she inhales and exhales.

The female appears to be grooming while perching on the warm surface of the boardwalk, using her front legs to wipe her eyes and face. The author has observed many species of dragonflies engaged in similar behavior.

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

Related Rescources:

Copyright © 2015 Walter Sanford. All rights reserved.

Insex | Part 2: Pas de deux

December 26, 2014

What happens after odonates copulateAutumn Meadowhawk dragonflies (Sympetrum vicinum) engage in a form of guarding behavior known as “contact guarding,” in which the male and female fly “in tandem” to egg-laying sites. Contact guarding is used by some species of odonates to prevent aggressive males from hijacking the female.

The following video shows several mating pairs of Autumn Meadowhawks spotted on 27 October 2014 at a vernal pool in the forest at Huntley Meadows Park. Each pair is in tandem: the male is in front; the female in back. Autumn Meadowhawk is a member of the Skimmer Family of dragonflies: the female dragonfly is laying eggs by the process of oviposition; guided by the male, she skims the water repeatedly, picking up drops of water that are used to flick fertilized eggs toward the shore.

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

In ballet, a pas de deux (French, literally “step of two”) is a dance duet in which two dancers, typically a male and a female, perform ballet steps together. Source Credit: Pas de deux, Wikipedia.

Copyright © 2014 Walter Sanford. All rights reserved.


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