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Texas 4: Lower Rio
Grande Valley, October 16 - 20, 2008
In mid-September, Dennis Paulson and Martin Reid found Blue-striped
Spreadwing Lestes tenuatus for the first time in Texas at the
Santa Ana National Wildlife Refuge. They also found Caribbean Darner
Triacanthagyna caribbea. This species was documented for the first
time the U.S. at the refuge in November 2007 by Steve Collins. Having
just returned from the Lower Rio Grande Valley, the news was a little
aggravating for me to hear. From the photographs that Martin and others
took, the darners were mature, so they were likely present during my visit
but I did not see them. Thinking back I did glimpse a darner that seemed
possibly different from all the Bar-sided Darners Gynacantha
mexicana I was finding. It flushed up and disappeared over my head
into the trees, a recollection that did little to settle my peace of mind.
I was not planning to revisit Texas. My last trip of the year was to be
Southeastern Arizona at the beginning of October. But as the photographs
of caribbea and other interesting species popped up in my e-mail,
I grew more and more agitated. It was too late to get a reasonable airfare
before October. I could go the weekend after returning from Arizona but
I would have only two days at home before leaving again. Too tough being
away from the kids. I settled on a short trip the following weekend. By
then nearly a month would have passed and who knows if Caribbean Darner
would still be around? Some of them looked a little worn in the pictures.
Thursday, October 16: The weather was bad when I arrived in McAllen,
Texas shortly after noon. The forecast was for rain and the skies were
gray. I drove straight to Santa Ana. After checking in and clearing my
permit at the visitor's center, I took to the trails. Although the weather
was not ideal for dragonflying, forest species are often crespuscular
and hang up during the day. Under the overcast they might even be flying.
I started down Chacalacha trail and immediately was greeted by a Malachite.
A spectacular, large, green butterfly, I had heard this was a particularly
good year for them. Closer to Willow Lake, a dragonfly was foraging low
following along the trail. I plopped the net on it, a male Bar-sided Darner.
It was mature, with brighter green and blue markings than the ones I saw
back in September. His wings were tinted brown and he was draped with
quite a few spider webs that he picked up in his travels through the forest.
There were lots of pondhawks Erythemis along the trails. Most were
young Pin-tailed Pondhawks Erythemis plebeja along with
some Great Pondhawks Erythemis vesiculosa. These were scarce
in September. I saw a few more Bar-sided Darners, some flying and feeding,
others hanging in the brush. Then something that looked smaller flew up
and hung up in a tree. I got my binoculars on it and saw a green thorax
with brown stripes - Caribbean Darner. In the hand, it was a young male,
without any blue markings and the eyes still brown. I was happy they were
still around and they were still emerging. Around 4 PM it started to sprinkle
again so I headed to the motel to settle in.
Friday, October 17: Spent the day at Santa Ana. It was cool in the morning
but the sky was brighter with the sun beginning to break through. I worked
the Chacalacha trail checking areas that were good in September for Bar-sided
Darners and where I found a Pale-green Darner Triacanthagyna septima.
However there was very little I could find, likely because there was less
water, the eastern end of Willow Lake having receded. I worked west along
Willow Lake trail then headed down to Cat-tail Lakes. The Cat-tail Lakes trail
was less forested and being more open I kept hoping for one of the rarer Anax
species. During the previous weekend, (the weekend I couldn't come down) a
few Amazon and Blue-spotted Comet Darners Anax amazili
and concolor had been seen in the Valley. I saw a several Common
Green Darners Anax junius and one Eastern Ringtail Erpetogomphus
designatus but dragonflies were scarce. Much more common were the butterflies.
There were so many in the forest and the open areas that their movements were
distracting. Dave Hansen reported seeing 82 species in the Valley that day,
the sun drawing them to nectar after a period of dreary weather. I ended up
taking a lot of butterfly pictures without really trying.
I did find more Caribbean Darners. I found two more young males in the
same thicket, but I wanted to find a mature one with brighter coloration.
Further afield I found and caught a mature female, her eyes blue and her
cerci broken off. I returned to the area where I found the young males
and poking through the brush flushed up an immature female. She had likely
emerged no more than a day or two before. Nearby I finally spotted my
first mature male. He was hanging in the shade on some twigs just a couple
feet off the ground. As I moved closer, he flew to another perch where
several branches were in the way of my net. I gave it a try but came up
empty.
Since the population appeared to be centered around this end of West Willow
Lake I kept working the brush. It was getting later in the afternoon so
I was curious if the darners would become more active. Then, flying along
the edge of the lake was a small darner. The Common Green Darners that
patrolled the lakes earlier were gone and a male Caribbean Darner was
flying low over the water occasionally hovering to investigate the shoreline
vegetation. Another small darner flew in and was chased. I made my way
to the edge of the lake. The dragonfly flew by a couple of times, once
down by my feet where I could see the blue between its wings but it was
too close for the length of my net. It was getting dark and I felt like
I was hunting shadowdragons Neurocordulia again. The darner didn't
fly quite as erratically as some shadowdragons but the stop and start
nature of its flight was difficult to anticipate and I had a hard time
tracking it in the dying light. Finally I swung, missed, and it did not
return.
Saturday, October 18: I met with Dave Hansen at Bentsen LRGV State
Park in the morning. The previous weekend he and Jan and David Dauphin
saw Amazon and Blue-spotted Comet Darners along the Resaca Vieja trail.
We walked the trail and he showed me exactly where they found the dragonflies.
I could imagine them perching in this tree or that tree. But imagining
was all I could do since we did not see much more than a couple of Common
Green Darners. A week is a long time.
We hitched a ride back to the visitors' center, and then took a quick
look through the gardens for butterflies. While Dave headed to NABA butterfly
park to look for an Evan's Skipper, I went back to Santa Ana determined
to get a mature male Caribbean Darner.
Back at my "spot,"
on Willow Lakes trail, I found a couple more immatures before flushing
out an adult male Caribbean Darner. I would find another nearby and even
managed to take a few field pictures.
Sunday, October 19: I tried the Resaca Vieja trail at Bentsen again
in the morning. Again I saw nothing of interest. What luck it was for
these rare dragonflies to be found together here. I could not see why
the habitat along this trail would be any more attractive than anywhere
else in Bentsen or Santa Ana. Dry open forest, mesquite and grass. I found
a small wet area but only a Band-winged Dragonlet Erythrodiplax
umbrata was present.
Again I headed back to Santa Ana. Having collected what I needed for Caribbean
Darner I was hoping for other possibilities like Pale-green Darner, Evening
Skimmer Tholymis citrina (also seen at Santa Ana the previous
weekend) and perhaps a rare pondhawk Erythemis species like
Claret mithroides or Black attala. But first
I stopped at Martin's spot along the Rio Grande 4 miles east of Santa
Ana. It was my best place for dragonflies in April but I did not try to
return after hearing that the construction of the misguided border wall
had cut off access to it. But Martin reported visiting the site the week
before so I wanted to try it. Being Sunday there was no one working on
the levee. It wasn't clear to me that access was prohibited so I continued
down the dirt road to the river. Still I didn't feel comfortable spending
much time here but I did find one species that I was looking for, Straw-colored
Sylph Macrothemis inacuta. I saw 3 or 4 males flying up and
down the road and then the female that I needed.
I walked the trails of Santa Ana for the last time this year. I tried
Pin-tail Lake and saw 3 male Twelve-spotted Skimmers Libellula
pulchella a rare species in the Valley but they're having a good year.
I walked the trail along the Rio Grande and had a Russet-tipped Clubtail
Stylurus plagiatus. I saw this species emerging here in April.
Except for a Variegated Meadowhawk Sympetrum corruptum,
I didn't find anything else that was different. It will be interesting
to see if the population of Caribbean Darner is able to persist. Santa
Ana is not managed for dragonflies and areas are alternately flooded and
then left to dry. I don't know if I'll be doing much work in Texas next
year but someone will surely be looking and chances are, they will find
something new. Seven species were added to the Texas State list in 2008.
Of the seven, five were new to the United States, adding to my work load.
Monday, October 20: I took a quick look at Anzalduas County Park
in the morning because Josh Rose had an Evening Skimmer near the dam on
Saturday. There wasn't much good looking habitat there for this forest
dweller but I tried. With time running out before my flight I ran over
to Bentsen and walked Resaca Vieja one more time, out of a sense of obligation
rather than having any real expectations. I was not rewarded. With a few
minutes left I photographed a couple of butterflies nectaring at the flowers
but their numbers were down. It had been sunny over the weekend and the
butterflies had scattered.
Thanks to Dave Hanson, Josh Rose, and the staffs of Bentsen LRGV State
Park and Santa Ana NWR. Thanks to David Riskind for granting permission
to collect at Texas State Parks and Mitch Sternberg for permission to
collect at Santa Ana/LRGV NWR.
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