Wednesday, September 10, 2008

Jasper's critters

During last weekend's botanical blitz of Jasper-Pulaski Wildlife Area in Indiana, we saw lots of critters: birds, bugs, spiders, etc. I bet there are a lot of interesting finds to be made yet over there. Below are two - one common, one, well, I don't know...

Very freshly emerged Black Saddlebags, Tramea lacerata. These big dragonflies were a dime a dozen in the Jasper wetlands, and I saw many freshly emerged ones like the one above. In this state, they are referred to as tenerals, which means they are not fully developed. You can see the exsuvia, or old husk of the larval stage just above the saddlebag's eyes. It amazes me that such a big, differently shaped creature emerges from that alienlike pod. It can take a while for a dragonfly to free itself from the larval case, and this one has probably only been out a few hours, at best. It is still in the process of pumping fluid to its extremities to harden them up. Teneral dragonflies are quite vulnerable to predators at this stage.

Straight down the gullet of a Black Saddlebags. Their eyes are striking. Dragonfly eyes are works of art, and among the most effective peepers of any organism. This species has very broad rear wings, and is an outstanding aerialist. Highly migratory, it is possible this one might end up in the Rio Grande Valley of Texas are some other farflung southern place.

These tiny spiders were very cool, and I am very curious as to their specific identity. I think they are one of the jumping spiders, but that covers a lot of ground I know. Perhaps a quarter inch in length, they only seemed to build webs on two species of plants within the very unusual J-P wetlands. One of these plants is a major rarity in this region: Horned Beaksedge, Rhynchospora macrostachya. The other, pictured above, is Twigrush, Cladium mariscoides, which is also pretty rare down this way. Both plants are indicators of outstanding wetland habitat. Funny the spider would be so smitten with them. Note how the spider blends extraordinarily well with the brownish spikelets of the Twigrush.

These jumping spiders are interesting little creatures, moving about as if powered by turbocharged pogosticks. They are almost eerie in how they size up us humanoids, cocking their heads and making rapid adjustments to keep us in their eight-eyed line of sight(s). If one were unfortunate enough to be suitable prey, and cross paths with one of these jumpers, your odds would not be good. All the ones that I saw had built these tiny webs, possibly for protection rather than food-catching.

If anyone knows what species this spider is, please let me know.

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