Tuesday, June 15, 2010

The Amberwing Chronicles 2010


Evidently one pair of these little dragonflies survived predators, bad weather, getting hit by drivers not watching where they're going, and other hazards, at least long enough to produce another generation. I actually spotted two teneral females, my first of the year, between 11:00 and 11:30 am today (June 15th), but it was a windy day and one of them blew by on the breeze before I had a chance to even point the camera in the right direction.

The photos were taken just east of the boat ramp on the north shore of Stoco Lake. Given the wary nature of this species I was lucky to get this close ...




On June 25th, north of the pavillion, I saw my first male this year. Typical of its kind, it was alert to potential danger and I couldn't get close enough to take a crisp clear photo.




July 1st, about an hour before these photos were taken I observed another teneral female east of the boat ramp, at almost exactly the same place as the female above photographed two weeks ago. Also, about half an hour prior to taking the three following three pictures I saw another male, or perhaps it was this very same one. Although I managed to take some photos the dragonfly was, as usual, extremely nervous and restless; I couldn't get within three feet of it and the images were unacceptable. These photos of a male Perithemis tenera were taken north of the pavillion, late in the morning just before noon. Not perfect, but at least there's some detail visible. To date this makes four unique individuals sighted at Stoco Lake.




July 2nd, male Eastern Amberwing photographed at about 11:00 am, at the same location, and possibly the same dragonfly as, yesterday morning.




A teneral male, photographed to the north of the pavillion at about 10:30 am on July 3rd. The dragonfly obelisked as I drew near with the camera. Note the distinctive luster typical of teneral odonate wings, with only a hint of the deep amber seen in the mature males depicted above.

Later on the same day this mature male was spotted perching on the grass at the intersection of the Eastern Ontario Trail and River Street (could have done without the wind, its a blurry picture). This is a significant distance from the nearest water.

My sightings of Eastern Amberwings have gone from rare, to uncommon, to almost an everyday occurence. I'm going to keep an eye out for these dragonflies possibly breeding in the marsh bordering the trail; conditions there are similar to the areas of the lake where I'm seeing the tenerals. A picture of a mating or ovipositing pair would be desirable. Better yet, a teneral emerging from its larval exoskeleton, as I have no idea what the exuviae looks like.




July 6th ... back to the pavillion at the north shore of Stoco Lake. This obelisking male Perithemis tenera was photographed at about 11:00 am. I've observed dragonflies obelisk when taking a closeup shot and the camera encroaches on their personal space; likely this is a threat or territorial warning display. In this case I don't think I was near enough to alarm the insect (obvious from the quality of the picture). It was a very warm day and the dragonfly was regulating its body temperature.

An anterior view of the same individual. Another male, or possibly the same one photographed earlier, was observed perching in the rushes to the east side of the building around noon.




July 8th ... this mature male Eastern Amberwing was photographed at about 10:45 am at the boat ramp, flitting about on the weeds growing between the cracks in the concrete. Another male was observed foraging to the north of the pavillion about twenty minutes after these pictures were taken. No female amberwings have been observed within the past week or so.




July 10th, near the northeast corner of the pavillion, a male with an infestation of parasitic mites, photographed at about 10:45 am. This is the first time I have noticed mites on an Eastern Amberwing. This makes six sightings of distinct individuals thus far ... I'm assuming that unless there are distinguishing marks to indicate otherwise many of the dragonflies are possibly the same insect imaged on different dates.




July 11th ... this mature male Perithemis tenera was photographed at about 11:15 am, foraging on the boat ramp. How territorial are these dragonflies? How much area do they patrol? Is this the same insect imaged at this location three days ago on July 8th?

July 11th, northeast corner of the pavillion. A male was seen at this location but not photographed, about half an hour after the picture above was taken at the boat ramp. I returned here later in the day at about 5:00 pm and acquired these images of a male Eastern Amberwing. A month hasn't passed since I noticed the first tenerals flying and the dangers of life are taking their toll on the adults. This one has a distinguishing feature ... a chip on the trailing edge of the left hindwing.




July 15th: a mature male was observed and photographed foraging in the vegetation to the east of the Stoco Lake boat ramp at about 11:00 am. The images were discarded as they were too blurred to be of any value.

July 16th ... having seen only males since the first teneral females emerged about a month ago, I found this mature female hunting in the vegetation along the bank of the Moira River on the southwest side of the dam at about 2:30 pm. An unexpected locale but not all that surprising, as these little dragonflies are strong fliers and it's not that great a distance to the lake. Despite keeping an eye out for Eastern Amberwings I almost passed this one by, at first mistaking it for a wasp.




July 17th: between 9:00 am and 10:00 am, at least five, possibly more sightings of Eastern Amberwings along north shore of Stoco Lake, from the east side of the boat ramp to the pavilion. This blurry long-distance image of a male perching on the beach at about 9:20 am is of little value other than the time stamp ... but there's enough detail to see that the wings are not damaged.

Five images of a male perching on the boat ramp, taken at about 9:30 am. No damaged wings, parasitic mites or other distinguishing features; is it the same one photographed at this locale on other occasions? This can't possibly be the same male I saw a few minutes earlier.

This female was foraging in the vegetation at the northeast corner of the pavillion at about 9:45 am. Judging by the luster of the wings it's just making the transition from teneral to breeding adult. Within a radius of two or three feet of this female were two mature males (not likely either one was the male just seen on the boat ramp). A mating in the offing? Too much was happening too fast and I didn't acquire photos of the males, and failed to note and any individuating features.

The last photo of this July 17th group (unless I see more amberwings on a later safari in another locale) ... a male observed about fifty feet to the north of the female, shortly before 10:00 am. Note that the left front wing is badly damaged.




July 18th, a total of four Eastern Amberwings spotted today, three along the north shore of Stoco Lake. A female was seen foraging on the boat ramp at about 9:30 am (not photographed). Two males were later observed at the northeast corner of the pavillion. The following first two images are of one of the males, taken around 10:00 am.

At about 10:30 am, roughly ten feet south of the male photographed above, another male was observed consuming its prey. Fortunately both dragonflies were in my sight at the same time because there are no distinguishing marks to tell them apart. In the first image below, note the position of the two front legs while the dragonfly perches on the remaining four. I've noticed other skimmer species assume this pose ... are the legs being used to hold the dragonfly's food?

Still July 18th, different locale. This my fourth amberwing sighting of the day, a female perching in the tall grasses in the marsh to the north side of the trail at about 1:45 pm. The marsh is a potential breeding site with a habiat similar to that frequented by amberwings at the lake, but no mating pairs or tenerals have been encountered here yet.




July 19th ... a teneral female emerging from exuviae at about 11:30 am near the northeast corner of the pavillion. The emergence must have taken place the small hours of the morning when it had been raining very hard. This is likely why grains of sand are visible adhering to the dragonfly's wings and exoskeleton. It seems that the storm washed the exuviae away as well and despite searching in the water around the rushes I was unable to recover it. So I still don't have a sample exuviae to study. (Note: I returned shortly after 3:00 pm and this teneral was gone. Was it the victim of a frog or larger odonate? Or did it recuperate from the effects of the storm and mature enough to take flight?)

At the same locale, about ten feet south of the teneral female, this mature male was imaged at about 11:45 am. No differentiating marks are visible, so this may be one of the males encountered here yesterday and on earlier occasions.

July 19th: a male Eastern Amberwing with a very badly twisted right hind wing, the deformity easily seen from a distance, was observed foraging in the grass at about 12:45 pm to southwest side of the dam on the Moira River. The wing appeared crumpled rather than broken, as if the damage had occurred while the dragonfly was emerging from its nymphal exoskeleton and the wings were still soft. This certainly didn't impede the insect's ability to fly and I was unable to obtain a photo, but I made a return trip at about 4:45 pm and not only acquired images of this male ...

... but another one as well. In this individual the amber wash does not appear to be as deep as seen in most males of this species, and it fades out toward the ends of the wings. Will the color fade or darken with age? That's three dragonflies at this location ... are they breeding in the quiet pools along the banks of the Moira River?




July 21st, about 12:15 pm at the marsh bordering the Eastern Ontario Trail about one kilometer west of town, this female Perithemis tenera was foraging just a few feet west of where I photographed a female on the afternoon of July 18th. In the field I assumed both dragonflies were probably the same individual, but having compared the images at home on the computer ... are they? The markings on this dragonfly's wings are stronger and more extensive; especially note the patches toward the bases of the wings. Do the spots on the wings darken as the insect ages?




July 22nd, two males sighted at about 11:00 am near the northeast corner of the pavillion, only one was photographed. There was no point in taking pictures of both as there were no distinguishing marks. Both dragonflies were in almost exactly the same places as the two males seen on July 18th (probably the same individuals).

July 22nd, shortly after noon on the Eastern Ontario Trail, a male was sighted about one hundred feet west of the culvert (note the wild bergamot the dragonfly is perching on, an abundant species in bloom along the trail at this time of year). This is the first male amberwing I have encountered this far west on the trail, foraging in the marsh rather than in fields a significant distance from any water. This makes three Eastern Amberwings observed at this locale.




July 26th, the north shore of Stoco Lake, from the east side of the boat ramp to the pavilion ... a total of seven Perithemis tenera encountered here today. At 11:00 am one female and one male were seen foraging about fifty feet north of the pavillion (only the male was imaged for the sake of the time stamp). Then I noted four more males at the northeast corner of the pavillion with an area of about fifteen feet by fifteen feet. The amberwings seem to favour this location, a combination of lakeshore emergent plants, low shrubs and grass. Finally, at about 11:15 am a male was sighted foraging to the east side of the boat ramp.

Still July 26th, about 11:45 am ... two males and three females were sighted at the intersection of the Eastern Ontario Trail and River Street. Since this is about equidistant from Stoco Lake and the marsh bordering the trail the large number of dragonflies in this seemingly dry area struck me as rather odd. Further investigation revealed that there is a good sized pool of stagnant water hidden in the vegetation on the south side of the trail and small pools created by local road construction.

Only one of the females was imaged; I wanted at least one photo of the unusual color of the wings. As a rule the dark areas of a female's wings are pretty well defined with just a bit of smudging at their boundaries, but this one had a considerable amount of amber wash. The color visible in the picture isn't caused by blurring due to the image being out of focus; the wings were actually tinted amber to the point that at first I mistook this female for a male.

Later at noon I saw a female at the marsh (further west along the trail), at exactly the same location, and more than likely the same individual, as the female photographed on the July 18th and July 21st. Lastly, at about 3:15 pm, south of the dam on the west bank of the Moira River I saw two females and one male (the male had a large chunk missing from its left hind wing).

This makes a total of sixteen Eastern Amberwings encountered in a relatively short span of time today (July 26th). Henceforth, unless there's an interesting aspect to the photo such as a mating pair, an emerging teneral or an exuviae, I won't be posting any more images, just text notes. It's becoming impossible to overlook these small dragonflies ... our local waters are infested with them ...




Observations for July 27th ... (9 total)
11:00 am: Stoco Lake, two males at the northeast corner of the pavillion
11:15 am: Stoco Lake, two males to the east corner of the boat ramp
11:30 am: Stoco Lake, one male perching on the sand at the beach
12:00 noon: two males and two females at the intersection of River Street and the Eastern Ontario Trail




July 29th ... a total of eleven Perithemis tenera were spotted along the north shore of Stoco Lake today. No doubt I'm often encountering the same individuals on different days, but today three of the dragonflies were definitely "new" ... they were tenerals. At 10:30 am, about fifty feet north of the pavillion were two males, and at the northeast corner of the pavillion were another two males, two mature females and one teneral female. The teneral female was photographed; the spots on its wings are little more than smudges.

A mystery on the beach ... at about 10:40 am I found a freshly killed male in the sand. There were no signs to indicate what happened. It wasn't crushed and it's hard to imagine someone getting close enough to an adult Eastern Amberwing to step on it by accident. Nor is there vehicular traffic in this area.

11:00 am ... a mature male was sighted sitting on the lilypads a few feet offshore, west of the boat ramp. East of the boat ramp a teneral male and a teneral female were perching in the shrubbery. The teneral male was photographed; note how the amber wash on the male's wings can hardly be seen. In contrast, the teneral female was the second one I have observed with a considerable amount of wash on its wings; they were tinted significantly darker than the male below. I tried taking a picture of this female but it took flight before I could bring the camera to bear. Oh well, them's the breaks, and one takes what one can get.

July 29, at 11:30 am, two males and three females were active near the standing water in the ditches at the intersection of River Street and the Eastern Ontario Trail. This brings the total count for today to sixteen Eastern Amberwing sightings.




July 30th, 11:00 am, north shore of Stoco Lake ... four males and one female were active north of the pavillion; one mature male and one teneral male were observed east of the boat ramp at about 11:15 am. The teneral male is not the same one encountered yesterday. It's impossible to judge scale from the image, but this dragonfly was really tiny. Both the body length and wingspan were about three to five millimeters less than average.


Eastern Ontario Trail , 11:45 am ... one male was foraging in the low grasses at the northeast corner of the intersection of Metcalf Street and the Eastern Ontario Trail. One male and one female were seen at the intersection of the trail and River Street. Most of the water at this intersection has dried up and the vegetation has been cut. The total count for today is ten; I'm still seeing a lot more males than females.




July 31st ... north shore of Stoco Lake, at 10:00am, one male and one female were sighted on the north side of the pavillion. About fifty feet to the north two teneral males were encountered (one photographed). One male was seen foraging in the grasses to the west side of the boat ramp at about 10:15 am.


At 10:40 am one male and one female were observed at the intersection of the Eastern Ontario Trail and River Street. Fewer dragonflies were out and about today (total count of seven) but the day was overcast and relatively cool with the temperature hovering around 20°C. Like other odonates Eastern Amberwings definitely seem to prefer hot sunny weather.




Observations for August 1st (9 total) ... more females than males were encountered today
11:00 am: one female at the intersection of River Street and the Eastern Ontario Trail
12:15 pm: Stoco Lake, one female east of the boat ramp, one female west of the boat ramp
12:30 pm: Stoco Lake, four males, two females at the north side of the pavillion




Observations for August 2nd ...
11:20 am: Stoco Lake, one female foraging at the north side of the pavillion




Observations for August 3rd ...
10:45 am: Stoco Lake, two males were observed on the floating vegetation to the west of the boat ramp, one about five feet out over the water, the other about fifteen feet. The dragonflies were in flight almost continuously, seldom stopping to rest.
11:00 am: Stoco Lake, one female foraging at the north side of the pavillion
11:15 am: one female at the intersection of River Street and the Eastern Ontario Trail

The two females are likely the same ones encountered on previous field trips. But what's happened to all the males? The weather has been ideal the last two days ... hot, hazy and humid. Did they become the victims of predators? Leave for greener pastures?




Observations for August 2nd ...
11:20 am: Stoco Lake, one female foraging at the north side of the pavillion




Observations for August 4th ...
11:00 am, Stoco Lake, along the sandy stretch of beach, three males were observed about ten feet out over the water. There is no vegetation in this area and the insects were flying continuously. This is radically different than their usual wasp-like short flights over low grasses with frequent rest stops.

Another three males were engaging in the same behaviour to the west of the boat ramp. On the way back, between these two locales, I noticed another four ... six ... there were too many male Eastern Amberwings to count.
The question now is, where are the females? I thought that perhaps the males were guarding oviposting females but there wasn't a single one in sight. (Or, does this species oviposit in tandem?)




Observations for August 5th (9 total) ... another humid day with the temperature hovering around 30°C.
10:45 am: Stoco Lake, along the sandy stretch of beach two males were flying about ten feet out over the water. One female was perching on the emergent vegetation along the shoreline. Two males were observed over the water to the west side of the boat ramp; another two males were competing for territory in the shrubbery on the east side.
11:00 am: Stoco Lake, one male and one female were foraging at the north side of the pavillion.




Observations for August 6th (4 total) ... very few odonate species are active today; relatively cool and overcast, temperature about 20°C.
10:40 am: Stoco Lake, one male was active near the boat ramp
10:50 am: Stoco Lake, two males and one female observed at the northeast corner of the pavillion




Observations for August 7th (3 total) ... sunny and warm today but the number of Eastern Amberwing sightings remains low since the maximum of August 4th.
10:15 am: Stoco Lake, one male and one female active at the northeast corner of the pavillion
10:20 am: Stoco Lake, one male foraging in the emergent vegetation, west of the boat ramp




Observations for August 11th ...
10:50 am: Stoco Lake, four males observed over the water about fifteen feet out, to the west of the boat ramp. The dragonflies are constantly making brief contacts with the surface. I can't see what they are doing, are they hunting insects such as water striders?




Observations for August 12th ...
3:30 pm: Near the marsh bordering the Eastern Ontario Trail, about ½ km west of town, three males were perching in the tall vegetation near the locale where the female was encountered on July 18th and July 25th.




Observations for August 13th ...
3:30 pm: 12:40 pm: Stoco Lake, three males observed at the northeast corner of the pavillion.




Observations for August 12th ...
3:30 pm: Near the marsh bordering the Eastern Ontario Trail, about ½ km west of town, three males were perching in the tall vegetation near the locale where the female was encountered on July 18th and July 25th.




Observations for August 16th ...
11:30 am: Stoco Lake, one male and one female were seen foraging at the boat ramp; fewer Eastern Amberwings have been encountered in the past two weeks.




Observations for August 19th (at least 15 total) ...
11:50 am: Stoco Lake ... sunny with cloudy periods this morning, about 27°C, and the Eastern Amberwings are out in full force today. At least six males and four females (there were more, too many to keep track of, and I lost count) were active along the shoreline north of the pavillion. One male and one female were perching on the sand along the beach, one male was seen to the west of the boat ramp and two more males were sighted on the east side.




Observations for August 27th ...
12:00 noon ... two females and one male were foraging northeast of the pavillion. The dragonflies will be observed more closely in the near future in order to establish how late they fly.




Observations for September 7th ...
11:40 am ... three females were active north of the pavillion. The female in the image below is in good shape but wings of the other two insects exhibited serious signs of wear and tear.