Thursday, September 23, 2010

Tiny migrant

This tiny creature delighted me last weekend, when it caught my notice in the yard by landing with its scarlet body and wing marks on an echinacea seed head. I searched the internet for information on dragonflies.

Apparently it might be a skimmer - Ondonata family - and possibly a migrant. The photograph doesn't do it justice - it's body was brilliant crimson in the sun - and the flashers - what I call the markings on its wings similarly red and shiny. It did not appear to be afraid of me for when I got within about a foot of it - it just twitched its eyes looking back at me - when I would move its eyes would follow the movement. Needless to say I was fascinated.

National Geographic has done a story on dragonfly migration and there is tons of information. There are some 400 members of this species, but not all of them migrate.

From National Geographic: Only about a dozen of the approximately 400 known dragonfly species are believed to migrate, journeying from the northern U.S. and southern Canada to the southern U.S., the Caribbean, and Mexico each fall. Scientists believe these migrants' offspring then return north. 

To get the details, a field team has been fitting green darner dragonflies (Anax junius) with radio transmitters. The National Geographic Society funds the work, which is being led by Martin Wikelski, a professor of ecology and evolutionary biology at Princeton University in New Jersey.

Wikelski and colleagues attached the first tags in September. The field team is currently tracking the insects as they make their flight south along the Atlantic seaboard.
The transmitters—which weigh 0.01 ounce (0.3 gram) and are about 0.4 inch (1 centimeter) long—are glued to the insects' undersides. A single wire antenna runs the length of the abdomen, and a tiny battery powers the device for up to a week.
Wikelski has a receiver that picks up the transmissions within a range of about one mile (one and a half kilometers) on the ground and five miles (eight kilometers) in the air.
As a pilot, Wikelski is able to put the receiver in his plane and follow the insects.
"It's important to do it from the plane, because they move so much," he said. "From the ground it's almost impossible to follow them."
Now I don't know about you - but I find all this quite fascinating. Then yesterday when walking the pups in a field to the north east of my place, I saw about a dozen of these little red insects flying around, protected from the wind and settling on top of centaurea seed heads or alfalfa blossoms in the hay. These ones however didn't wait and watch as my friend in the garden did... they quickly flew away. So I guess mine was either tired, or friendly. Whichever, I wished at the time I'd thought to take video of its eyes moving around - obviously watching me. Amazing what this blog is teaching me about nature.
(Please forgive the delay in getting this posted - my computer or my "high speed" have been playing tricks and I've not been able to post anything for quite a few days... most frustrating. Then when it was finally ready yesterday somehow I hit the wrong key and the entire site disappeared. I gave up at that point.)

No comments:

Post a Comment