Monday, August 16, 2010

Now You See It…


Enjoying the late summer butterflies? Soon butterflies like the Black Swallowtail, pictured in the photo by Laurie Sheppard, will not be around. According to How to Spot Butterflies, by Patricia Taylor Sutton and Clay Sutton (Houghton and Mifflin Company, 1999), these butterflies will have mated, produced eggs and died by mid September. Their caterpillars will pupate and winter over until next spring. Over much of the country, Black Swallowtails, as well as other swallowtails, are “double brooders” - in spring the new butterflies will mate, lay eggs and die, with their egg-caterpillar-pupa cycle resulting in a second wave of butterflies from mid to late summer. This second “wave” is what we are seeing now.

Other butterflies go through only one brood cycle - some are long lived, like the Mourning Cloak, but others live only a short time as butterflies, mating and laying eggs. After the larva feed, they go into the pupa stage and remain there until the next spring, in some cases, for almost a year. Some butterfly species have life cycles which last for several years.

Some additional resources about butterflies include http://www.dallasbutterflies.com, the website for the Dallas Lepidopterists’ Society, maintained by Dale Clark, who was the speaker for Second Saturday at Hagerman NWR in June, and two books recommended by Clark: Field Guide to Butterflies of North America by Jim Brock and Kenn Kaufman, and Butterflies of Oklahoma, Kansas and North Texas by John M. Dole, Walter B. Gerard and John M. Nelson.

Butterflies abound at Hagerman NWR, and a free two page Butterfly Guide is available at Refuge Headquarters. For more information about programs and activities at Hagerman NWR, see http://www.friendsofhagerman.com, and for the official Refuge website, see http://www.fws.gov/southwest/refuges/texas/hagerman/index.html.

Sunday, August 8, 2010

Dog Days


By Laurie Sheppard

The dog days of summer arrived weeks ago and according to the Farmer’s Almanac, are due to depart on August 11th when Sirius, the so-called Dog Star, is no longer visible at dawn. That’s the astrological end of the dog days, but true Texans know that the sultry summer heat will continue into early September.

Let’s face it. It’s hot! Not that I’m complaining – I was the one who couldn’t wait for spring – but it has affected the way I enjoy the refuge. I find that birds and animals are most active in the relative cool of early morning. As the sun climbs, the birds become scarce as they hide in the shade of the trees, returning to feed near sundown. That doesn’t mean there’s nothing to see, though.

Egrets and Herons manage to stay cool standing in the water along the shore of the lake. You can find them hunting for fish and forage at any time during the day. If you see egrets perching on a tree, take a closer look – you’ll see their throats vibrate as they rapidly pant to keep their body temperature down. Smaller birds also use this technique, sitting open-beaked through the hottest part of the day.

Some birds migrate through the refuge on their way north and will be returning in a few months, but others spend the summer on Lake Texoma. Those can be reclusive, so it’s a challenge and a thrill to see or photograph a Prothonotary Warbler or a Little Green Heron. Still other birds are rare or occasional visitors – some uncommon guests seen recently were a Long-billed Curlew and an Anhinga.

Spring fawns who stayed hidden in early summer are now seen more frequently, as does and their offspring feed on the lush grass available in so many areas on the refuge. Twins seem quite common this summer and all ages of deer have not been frightened away easily, which has led to wonderful photographic opportunities. Raccoons (photo by Laurie Sheppard), squirrels, armadillo and occasional bobcats have been sighted and photographed this summer as well.

The most common wildlife to find this time of year is a wide variety of dragonflies and damselflies. (Pick up a wildlife guide at the Visitors Center to see pictures of some of the more prevalent ones.) It’s impossible to drive on Egret Road without seeing dozens of dragonflies swarming about in the shade of a cottonwood tree or out in the open sun. Look closely and you will see they are hunting and dining on bugs. Dragonflies will also show you how hot it is – when the sun is very strong and high in the sky, instead of perching in a normal straight position, some dragonflies will raise their abdomens to the sun to minimize the surface area exposed to the rays. They do this to maintain a lower body temperature.

Butterflies are also frequent daytime feeders, even on the hottest days. Most species have two or even three broods per year. On any given day you should see several varieties, ranging in size from tiny Dainty Sulphurs to Eastern Tiger Swallowtails the size of a man’s hand, in varying shades of yellow, orange, brown and black. Enjoy their fragile beauty and frenetic flight as they search for nectar and the exact right plant host for their offspring.

Signs of autumn are already showing up as the Buttonbush turns red and leaves begin to yellow. Sunflowers will bloom through fall and Snow On The Prairie is beginning to bloom. Change is inevitable, and isn’t it delightful?

Find out about activities and programs at Hagerman NWR by visiting http://www.friendsofhagerman.com or visit the official Hagerman NWR website, http://www.fws.gov/southwest/refuges/texas/hagerman/index.html.

Monday, August 2, 2010

Garden spider - Argiope


By Pat Rowland

ED: You may have seen this spider around your house. Today’s blog post is a timely reprint of an essay by Pat Rowland, originally published in the Featherless Flyer in December, 2007, and the photo is by Kay Karns, taken at the Refuge..

One of my favorite spiders is the Garden Spider (Argiope). This past summer one made her home around my house from August until early November. During this time she ate numerous flying insects plus bonus crickets that I provided when mowing the yard. She moved and laid egg sacs at three different locations until early November.

The following information came from an article by Valerie in Garden Bits (http://home.att.net~larvalbugrexc/argiope.html). The largest orb weaver in our gardens is the black and yellow Argiope. The female is the large spider seen on the web. The males are much smaller and may be seen hanging out close by. Spiders are capable of creating as many as seven different kinds of silk using several different glands that supply the spinnerets. The silk coming out of the spinnerets can vary from an extremely fine single line sued in creating the web to wide ribbons used for subduing prey or making the central design on the web.

In order to grow, spiders must periodically shed their exoskeletons. This is when they are most vulnerable to predators. Just before laying eggs, the female spider is often quite large and her abdomen distended. Argiopes produce large numbers of young in their egg sacs. A female may lay one or several egg sacs in a season. The young spiders hatch in the fall but overwinter in the egg case. The Argiopes live only one year, expending all their energy producing eggs. Once winter arrives, they die.

ED: Don’t miss Dr. Steve Goldsmith’s presentation on Insects, 10 a.m., Saturday Sept. 11, for Second Saturday at Hagerman NWR. For more information on the programs and activities of Friends of Hagerman, see http:www.friendsofhagerman.com. To visit the official Refuge website, see http://www.fws.gov/southwest/refuges/texas/hagerman/index.html.