Posts Tagged ‘arboreal’

Data mining for Autumn Meadowhawk

October 28, 2019

This is a follow-on to my last blog post, Are adult Autumn Meadowhawks arboreal?

Data mining can be used to recognize patterns in official records of field observations by many amateur and professional odonate hunters, confirmed by experienced vetters.

Let’s begin by looking at the adult flight period for Autumn Meadowhawk (Sympetrum vicinum), the target species for a proposed field study during 2020 at the Vermont Institute of Natural Science.

Adult Flight Period

According to records for the Commonwealth of Virginia maintained by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage, the adult flight period for Autumn Meadowhawk (S. vicinum) is from May 28 to January 03. The species is classified as “common.” Its habitat is “ponds.”

Bear in mind, Dr. Roble’s records are for the entire state, therefore the adult flight period for S. vicinum seems to be longer than it is in reality. The adult flight period for a single site is probably shorter. For example, according to records for Northern Virginia maintained by Kevin Munroe, former manager of Huntley Meadows Park, the adult flight period for Autumn Meadowhawk is June 13 to December 10 (seen most September to October).

DSA Odonata Central Records

What is shown by a deep-dive into the Dragonfly Society of the Americas Odonata Central records database for Autumn Meadowhawk in the Commonwealth of Virginia?

There are currently 38 confirmed records for S. vicinum in Virginia, as shown by the following distribution map.

Source Credit: Abbott, J.C. 2006-2019. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at http://www.odonatacentral.org. (Accessed: October 27, 2019).

Key: blue dots = Dot Map Project; green dots = Accepted records; yellow dots = Pending records.

Analysis

There are 14 records for teneral/immature adult Autumn Meadowhawk, ranging from 30 May to 19 August: May (1); June (5); July (5); August (3). Notice that the greatest cluster of records for teneral/immature adults occurs in June and July. There are a few records for mature adults toward the end of this time period and no records for mating pairs.

There are 24 records for mature adult Autumn Meadowhawk, ranging from 07 August to 03 January: August (2); September (5); October (13); November (1); December (2); January (1). Only a few records for teneral/immature adults occur at the beginning of this time period. The greatest cluster of records for mature adults occurs in October. Seven (7) of the records throughout the time period are for mating pairs, beginning in September; the greatest cluster of records for mating pairs also occurs in October.

What are the take-aways?

38 records is an admittedly small sample size. In the opinion of the author, patterns in the data are muddied by analyzing data for the entire state rather than a single location. There is almost certainly a south-to-north pattern in dates of emergence, mating, and disappearance for any given species, as well as atypical patterns resulting from micro-climates that exist throughout the state.

All of that being said, the data in the DSA Odonata Central records database for Virginia is consistent with my first-hand observations in Northern Virginia showing that Autumn Meadowhawk emerges in mid- to late-June, disappears for two- to three months, and returns to the ground/water when it’s time to mate during fall.

One big question remains to be answered: Where do adult Autumn Meadowhawks go when they disappear soon after emergence — do they live in the forest canopy? One thing we know is certain: There are few if any official records for mature adult Autumn Meadowhawk on the ground during mid- to late-summer. Food for thought.

Related Resource: Are adult Autumn Meadowhawks arboreal?

Copyright © 2019 Walter Sanford. All rights reserved.

Are adult Autumn Meadowhawks arboreal?

October 25, 2019

Autumn Meadowhawk (Sympetrum vicinum) is classified as a fall species of odonate. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early to mid-summer and reappear during fall. Where do they go? No one knows for sure. I speculate Autumn Meadowhawk is an arboreal species of dragonfly that returns to the ground/water when it’s time to mate.

Emergence

The first individual — photographed soon after emergence — is a/an teneral/immature male, as indicated by the tenuous appearance of his wings, coloration, and terminal appendages.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral/immature male)

The next individual is a/an teneral/immature female, as indicated by the tenuous appearance of her wings, coloration, and terminal appendages.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral/immature female)

Time to mate

Fall is the time to mate for mature adult Autumn Meadowhawk dragonflies (S. vicinum), as you can see in the following photo.

15 NOV 2013 | HMP | Autumn Meadowhawk (mating pair, “in wheel”)

This mating pair is “in wheel”: the male is on the upper-left; the female is on the lower-right. All dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back: male dragonfly secondary genitalia, called hamules, are located in segments two and three (S2 and S3); female genitalia in segment eight (S8). Dragonflies form the mating wheel in order for their genitalia to connect during copulation.

Forest Canopy Walk at Vermont Institute of Natural Science

Observing dragonflies at the Earth’s surface is fairly easy; observing dragonflies at the treetops, not so much. The new Forest Canopy Walk at the Vermont Institute of Natural Science (VINS) should facilitate the latter.

During 2020, I hope to collaborate with Kelly Stettner, Black River Action Team (BRAT), and Anna Morris, Lead Environmental Educator, VINS, to gather evidence that supports my speculation that adult meadowhawk dragonflies are arboreal. Field observations will be collected on the ground and along the Forest Canopy Walk.

Hosted by Anna Morris, Kelly Stettner and her family scouted the VINS site on 05 October 2019, including the new Forest Canopy Walk and nearby water bodies that provide suitable habitat for Autumn Meadowhawk. Special thanks to Anna for providing a behind the scenes tour a week before the official opening of the Forest Canopy Walk.

Gallery photos used with permission from Kelly Stettner, BRAT.

A week later, Autumn Meadowhawk was observed along the Forest Canopy Walk for the first time. The following photos provide circumstantial evidence that we might be on the right track. I love it when a plan comes together!

Gallery photos used with permission from Anna Morris, VINS.

I’m happy to share that during our public Forest Canopy Walk opening today [12 October 2019], I was stationed at the Eagle platform and got to see two (2) meadowhawks zooming around, then perched on the railing (pictures attached)! This is about 60 feet up, near a Sugar Maple and a Red Oak. [More meadowhawks were seen] the next day at nearly 90 feet up! At this height and as it was so sunny there were at least four individuals zooming around, landing on visitors, etc. Source Credit: Anna Morris, Lead Environmental Educator, VINS.

Related Resources

Copyright © 2019 Walter Sanford. All rights reserved.

Blue-faced Meadowhawk (immature female)

July 28, 2018

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) was spotted at Occoquan Regional Park (ORP), Fairfax County, Virginia USA. This individual is an immature female, as indicated by her coloration and terminal appendages.

24 JUN 2018 | ORP | Blue-faced Meadowhawk (immature female)

Now you see her; now you don’t.

Blue-faced Meadowhawk dragonflies are classified as a fall species of odonate. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Blue-faced Meadowhawks are an arboreal species of dragonfly that returns to the ground/water when it’s time to mate.

Editor’s Note

Sincere thanks to my good friend Mike Boatwright, administrator of the Virginia Odonata Facebook group, for verifying my tentative identification.

Copyright © 2018 Walter Sanford. All rights reserved.

Time to mate (Fall 2017)

October 11, 2017

I speculate Blue-faced Meadowhawk is an arboreal species of dragonfly that returns to the ground/water when it’s time to mate.

A mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) was spotted near a drainage ditch alongside a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA. This pair is “in wheel“: the male is on top; the female on the bottom. The female is a heteromorph, as indicated by her tan coloration.

All dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back: male dragonfly secondary genitalia, called hamules, are located in segments two and three (S2 and S3); female genitalia in segment eight (S8). Dragonflies form the mating wheel in order for their genitalia to connect during copulation.

Copyright © 2017 Walter Sanford. All rights reserved.

Blue-faced Meadowhawk dragonflies

October 9, 2017

“Target(s) acquired. Shots fired!” That’s my generic field report after a successful odonate hunting excursion. Usually I have an idea of the target species I hope to see every time I go photowalking. Shadow Darner dragonfly, Great Spreadwing damselfly, and Blue-faced Meadowhawk dragonfly were the target species for a recent trip to a favorite hotspot where all three types of odonates can be found.

Several Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) were spotted near a vernal pool at a remote location in Huntley Meadows Park, Fairfax County, Virginia USA.

Both individuals featured in this blog post are male, as indicated by their terminal appendages and turquoise-colored faces.

Blue-faced Meadowhawk is classified as a fall species of odonate. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Blue-faced Meadowhawk is an arboreal species of dragonfly that returns to the ground/water when it’s time to mate.

Consistent with my speculation, Blue-faced Meadowhawk seems to prefer habitats where standing water is found near the forest, such as the small vernal pool located at a clearing in the forest at Huntley Meadows Park. Be on the lookout for Blue-faced Meadowhawk everywhere you find similar habitat.

Copyright © 2017 Walter Sanford. All rights reserved.

You know it’s fall when…

October 5, 2017

mature adult Autumn Meadowhawk dragonflies (Sympetrum vicinum) are seemingly everywhere there is water. Several Autumn Meadowhawks were spotted recently near a vernal pool at a remote location in Huntley Meadows Park (HMP), Fairfax County, Virginia USA.

The first individual is a male, as indicated by his terminal appendages.

03 OCT 2017 | HMP | Autumn Meadowhawk (male)

The last individual is a female, as indicated by her terminal appendages, noticeably thicker abdomen, and coloration.

03 OCT 2017 | HMP | Autumn Meadowhawk (female)

Autumn Meadowhawk is classified as a fall species of odonate. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Autumn Meadowhawk is an arboreal species of dragonfly that returns to the ground/water when it’s time to mate.

Related Resource: More previews of coming attractions, a blog post by Walter Sanford.

Copyright © 2017 Walter Sanford. All rights reserved.

Time to mate

November 13, 2016

In a recent blog post, I wrote…

Both Blue-faced Meadowhawks and Autumn Meadowhawks are classified as fall species of odonates. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Blue-faced Meadowhawks and Autumn Meadowhawks are arboreal species of dragonflies that return to the ground/water when it’s time to mateSource Credit: More previews of coming attractions.

Fall is the time to mate for Autumn Meadowhawk dragonflies (Sympetrum vicinum), as you can see in the following photo.

A mating pair of Autumn Meadowhawk dragonflies (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This pair is "in wheel."

06 NOV 2016 | HMP | Autumn Meadowhawk (mating pair, “in wheel“)

This mating pair is “in wheel.” All dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back: male dragonfly secondary genitalia, called hamules, are located in segments two and three (S2 and S3); female genitalia in segment eight (S8). Dragonflies form the mating wheel in order for their genitalia to connect during copulation.

Odonates (dragonflies and damselflies) are aquatic insects. Most of their life is spent underwater as a nymph. The life span of a nymph depends upon the species: it’s a few months for some species; a few years for other species. Individual adult odonates — like the ones we see flying around Huntley Meadows Park (HMP) — usually live one- to two months, although many different individuals from the same species may be seen for longer periods of time. Adult odonates have one goal: mate in order to reproduce. When fertilized eggs are laid in water, the circle of life comes full circle: eggs; prolarvae; larvae; emergence/adult males and females; mating pairs; males guide females to egg-laying sites (some species, such as Autumn Meadowhawk) or solo females lay eggs (all other species).

Copyright © 2016 Walter Sanford. All rights reserved.

More previews of coming attractions

November 5, 2016

Several Autumn Meadowhawk dragonflies (Sympetrum vicinum) were spotted during photowalks at two wildlife watching parks located in Northern Virginia (suburban Washington, D.C.). All specimens are teneral, as indicated by their coloration and the tenuous appearance of their wings.

Occoquan Bay National Wildlife Refuge

During mid-June 2016, a single Autumn Meadowhawk was spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a teneral female, as indicated by its terminal appendages.

Female abdomens are slightly thicker than those of males and noticeably flared toward both the thorax and tip of the abdomen. The “subgenital plate,” located under the ninth abdominal segment (S9), is a large scoop-like structure used for laying eggs (exophytic oviposition).

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a teneral female.

18 JUN 2016 | OBNWR | Autumn Meadowhawk (teneral female)

The dragonfly is perching on “soft rush” (Juncus effusus), the common name for the shoreline/emergent plant with a light green round stem and brownish flowers shown in the preceding photo. Soft rush is common in wetland areas. Thanks to Christopher Wicker and Bonne Clark, naturalists at OBNWR, for identifying the plant.

Huntley Meadows Park

About one week later, many teneral Autumn Meadowhawks were spotted at a vernal pool in Huntley Meadows Park, Fairfax County, Virginia USA.

The first individual is a teneral female, perching on soft rush.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral female)

The next specimen is also a teneral female.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral female)

The following individual is a teneral male, as indicated by his terminal appendages.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral male.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral male)

The last specimen is another teneral male.

An Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral male.

24 JUN 2016 | HMP | Autumn Meadowhawk (teneral male)

Editor’s Notes: This post is a belated companion piece for Previews of coming attractions, published on 04 June 2016, that documented teneral Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) observed during late-May 2016. About two weeks later, the first teneral Autumn Meadowhawks were observed.

Both Blue-faced Meadowhawks and Autumn Meadowhawks are classified as fall species of odonates. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Blue-faced Meadowhawks and Autumn Meadowhawks are arboreal species of dragonflies that return to the ground/water when it’s time to mate.

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

Return to terra firma

September 16, 2016

Several Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) were spotted near two vernal pools at a remote location in Huntley Meadows Park. All of these individuals are males, as indicated by their coloration and terminal appendages.

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

12 SEP 2016 | HMP | Blue-faced Meadowhawk (male)

The next photo shows one of the males perching in the obelisk position.

Many dragonflies [perch in the] obelisk position to limit the amount of sunlight hitting their body and use their wings to shade their overheated thoracic flight muscles. Why not just find a shady spot? If he did he would relinquish his territory and that would reduce his chances for mating. Source Credit: Richard Orr, renowned expert on odonates of the mid-Atlantic region of the United States.

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

12 SEP 2016 | HMP | Blue-faced Meadowhawk (male)

Regular readers of my photoblog know I’m fond of head-tilts in which the dragonfly seems to display some of its personality, especially when the individual is looking at me. I nicknamed this guy “Paleface” because his face is a lighter shade of turquoise than most male Blue-faced Meadowhawks.

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

12 SEP 2016 | HMP | Blue-faced Meadowhawk (male)

The last three photographs were taken in a dry drainage ditch located near one of the vernal pools. According to the most recent U.S. Drought Monitor update, parts of the Washington, D.C. metropolitan region are “abnormally dry” — one classification category from “drought.”

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

12 SEP 2016 | HMP | Blue-faced Meadowhawk (male)

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

12 SEP 2016 | HMP | Blue-faced Meadowhawk (male)

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a male.

12 SEP 2016 | HMP | Blue-faced Meadowhawk (male)

The Backstory: Teneral Blue-faced Meadowhawk dragonflies were observed at Huntley Meadows Park during late-May and early-June 2016, documented in Previews of coming attractions by Walter Sanford. (Hey, that’s me!) A pull quote from that blog post explains the title of this one.

Blue-faced Meadowhawk dragonflies are classified as a fall species of odonate. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Blue-faced Meadowhawks are an arboreal species of dragonfly that returns to the ground/water when it’s time to mate.

It must be time for Blue-faced Meadowhawks to mate, because they’ve returned to terra firma!

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.

Previews of coming attractions

June 4, 2016

Two Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) were spotted at Huntley Meadows Park (HMP). Both individuals are teneral females, as indicated by their coloration and terminal appendages.

No. 1

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female.

31 MAY 2016 | HMP | Blue-faced Meadowhawk (teneral female)

No. 2

Although Female No. 2 has a malformed hind wing she was able to fly, albeit weakly.

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female with a malformed wing.

31 MAY 2016 | HMP | Blue-faced Meadowhawk (teneral female)

A Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park, Fairfax County, Virginia USA. This individual is a teneral female with a malformed wing.

31 MAY 2016 | HMP | Blue-faced Meadowhawk (teneral female)

Now you see ’em; now you don’t.

Blue-faced Meadowhawk dragonflies are classified as a fall species of odonate. In the mid-Atlantic United States, meadowhawks seem to disappear for several months after they emerge during early summer and reappear during fall. Where do they go? No one knows for sure. I speculate Blue-faced Meadowhawks are an arboreal species of dragonfly that returns to the ground/water when it’s time to mate.

Related Resources:

Copyright © 2016 Walter Sanford. All rights reserved.


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