Biological Weapons

About a year ago I started writing occasional articles for the Entomological Society of America’s website “Entomology Today.” These assignments prompted me to delve into some biology I might not have otherwise and it has been so much fun. I’d like to share my entomology articles with my blog readers by posting links to them here. If you are interested, check out what I am doing over there. I hope you enjoy it.

Here’s a look at the diabolical biological weaponry predators and parasites use against one another. Click on the killer photo by entomologist and photographer extraordinaire, Alex Wild, to read the article.

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Biological Weapons

Tiny Terror

A Sharp-shinned Hawk devours a starling it has captured. Photo by Laura M. Eppig. Check out her excellent nature photography at http://laurameppigphotography.smugmug.com
A Sharp-shinned Hawk devours a starling it has captured. Photo by Laura M. Eppig. Check out her excellent nature photography at http://laurameppigphotography.smugmug.com

Feeding the birds is typically associated with peaceful domesticity and little old ladies singing “tuppence a bag.” But when you feed the birds, you invite nature into your backyard and as Tennyson put it, nature can be “red in tooth and claw.”

In the wintertime, one of the regulars at my backyard feeder is not there for the birdseed, but rather for the seed-eaters. A Sharp-shinned Hawk, North America’s smallest hawk, visits almost everyday and occasionally makes a meal out of one of the sparrows, finches or doves that come to dine. A visit from a bird-eating hawk is not unusual during the winter. Nic Korte recently wrote about hawks visiting his backyard feeders in the “Birds and More” blog. Typically, you only see Sharp-shinned Hawks in town during the winter, because they spend the breeding season in dense forests, such as those on the Grand Mesa. They move to forest edges or suburban areas in the non-breeding season.

The idea of a hawk in your suburban backyard may seem odd because we usually think of hawks as large, soaring birds like the Red-tailed Hawk. These birds are usually seen perched on a telephone pole or soaring high above grassland. But the Sharp-shinned Hawk is a different kind of hawk all together.

Hawks are divided by biologists into two groups: the large, soaring hawks with long wings and relatively short tails are buteos; while the smaller, shorter-winged hawks with longer tails are accipiters. Accipiters are build for speed and maneuverability in order to catch their main prey- other birds. While a buteo will typically dive down on an unsuspecting rodent from high in the sky, an accipiter engages in high-speed ambush and pursuit to catch a bird.

Slide1There are only three species of accipiter in North America and the Sharp-shinned hawk is the smallest- less than a foot high. It is easily confused with its cousin, the Cooper’s Hawk, which has virtually identical markings, but is larger and in flight, you can see that the end of its tail is curved rather than straight. (Here’s a trick to remember “Straight = Sharp-shinned, Curved = Cooper’s.”) Sharp-shinned Hawks are also sometimes confused with Merlins, another very small bird of prey with similar markings. However the Merlin is a falcon, built for high speed with very pointy wing tips. If the Sharp-shinned Hawk is fast and agile like a Porsche, then the merlin is a fighter jet.

Maybe you will think me ghoulish if I admit that I enjoy having the Sharp-shinned hunt in my yard. It’s always easy to tell when the hawk is around: in a flash, the birds disappear into the nearest dense cover and start giving a high-pitched, soft “chip” call- a warning to their fellows. My kids and I immediately start looking for the “Sharpie” as we call him. Usually he misses and perches in the tree right across from our kitchen window to plot his next move. Occasionally, he will succeed and fly off with a hearty breakfast clutched in his talons. And if we are lucky, he will enjoy his meal in our yard while we watch and talk about how we feel bad for the little bird, but the hawk has to eat too. After all, nature is not gentle, and bird feeding is not always for the timid.

This post originally appeared in the February 15, 2015 issue of the Grand Junction Daily Sentinel http://www.gjsentinel.com

 

 

 

 

 

Tiny Terror