House wrens invest in natural pest control with spider egg sacs

Published 9:00 am Sunday, July 13, 2014

Nature’s World by Al Batt

My neighbor Crandall stops by.

“How are you doing?” I ask.

Sandhill cranes wander off in the distance. – Al Batt/Albert Lea tribune

Sandhill cranes wander off in the distance. – Al Batt/Albert Lea tribune

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“Everything is nearly copacetic. I looked at a full moon recently and realized that I’d never get over it. I’ve never fully recovered from the fate my handsome visage suffered in our high school yearbook. There I was, snarling back at all who wanted a look and who didn’t? I was as handsome as two movie stars. Yet, instead of placing my name under my most photogenic of photos, someone had printed, “Picture unavailable.”

“Those scamps from the yearbook staff,” I say. “They were just jealous, I’ll bet. At least you were spry and hadn’t lost a step until your junior year.”

“Pop has the imagined symptoms of a man twice his age. That said, he does snag the occasional real one. He just had his appendix removed and while the doctor was in there, he took out Pop’s table of contents, too. Pop says that getting old is a walk in the park. In one of those parks where nobody picks up after their dogs. The hospital has had to increase its food budget to keep Pop’s stomach from growling so loudly that it was frightening new mothers in the maternity ward. Pop is slow on words, but fast on food.”



Every June, I do a Breeding Bird Survey, BBS, for the U.S. Department of the Interior. I’ve been doing this for many years. My route has changed through the years. Roadwork, flooded roads, tornadoes, new houses, pastures gone and wetlands drained. Building sites eliminated, hayfields replaced with row crops and lofty wind turbines erected. Fewer pastures and hayfields mean fewer meadowlarks.

This year’s BBS, like every BBS, was a thrill to do. It gave me a chance to feed the mosquitoes. I could easily do a mosquito census, too. Wild roses, sweet clover, goat’s beard looking like an oversized dandelion and campion bloomed, as did red clover. I used to bale grasses that grew wild. It was commonly called “wild hay,” but if there was enough red clover in it, I referred to it as “red top hay.”

I started at 5:02 a.m., attempting to bloom along with those plants. I watched a great horned owl fly up from the road and perch on a utility pole where it was immediately harassed by four crows.

I spotted a young crow with blue eyes. Crows have blue eyes when they hatch, but their eyes turn black with age.

I saw deer galore and a fox walking down the road to her kits. Nothing much cuter than baby foxes. There were many cottontail rabbits and meadow voles. The voles are the potato chips of prairies. They are food to many predators. A young groundhog scurried under my car. I didn’t want to run over the youngster, so I yelled at it. It remained beneath my vehicle. I whistled loudly and it found safety in the road ditch.

I saw a wild turkey with seven poults. I watched two gray catbirds chase a blue jay from a cottonwood tree. Catbirds typically build nests on horizontal branches hidden at the center of dense shrubs, small trees or vines. Blue jays are known to eat the eggs of other birds. In a study of blue jays, only one percent had evidence of eggs in their stomachs. Most of their diet was composed of insects and nuts.

I made a stop near what used to be an elk farm. It was always a favorite stop for me when the ungulates resided there, but they are gone.

Each of my 50 stops in Freeborn, Mower and Steele counties consists of three minutes of looking and listening. I count any bird that I could see or hear.

I looked out into a field that once fed elk. There was a pair of sandhill cranes and their colt. The colt looked golden in the sun.

What a fine day that was.


Jumping ducks

I watched baby wood ducks jump from their nest cavity as their mother encouraged their leaps. I reckoned the jump was about 35 feet.

I remembered a time in my boyhood when our gravel roads were closed to school buses because of winter weather. I needed to walk 3 1/2 miles to the nearest paved road to board a bus to school.

I didn’t complain. The ducklings had a tougher journey.



“Why don’t I find many mosquitoes in the sun?” Mosquitoes don’t like the hot, dry sun, preferring the higher humidity of night. They also don’t like wind. It takes a lot of energy for a mosquito, with a small body and small wings, to fly against the wind. During the day, most mosquitoes seek shade in wooded areas that tend to hold in moisture. There are a small number of mosquito species in Minnesota that feed during the day.

“I watched house wrens putting tiny white balls into their nest. What were they?” Wrens often add spider egg sacs to their nest materials. In lab studies, once the spiders hatched, they devoured the nest parasites. Many interior decorators use spider egg sacs for ornamental reasons, but the wrens may employ the spiders for parasite control.

“Why do goldfinches wait until July to nest?” Goldfinches wait for the thistles to bloom. Their nests are made primarily of the fibers and down of thistle blooms. By the time the eggs hatch, the thistle has gone to seed, which is perfect timing for feeding young goldfinches. The parents consume the thistle seeds and regurgitate the partially digested seeds into the mouths of their nestlings.

Elaine Seath of Hartland asked why she had no house wrens in her yard. They are pretty much in everyone’s yard. Try moving the current houses or putting up more houses. I’m sorry I don’t have a better answer. Predators could be an issue.


Thanks for stopping by

“Always carry a flagon of whiskey in case of snakebite and furthermore always carry a small snake.” — W.C. Fields

“Until you make peace with who you are, you’ll never be content with what you have.” — Doris Mortman


Do good.


Al Batt of Hartland is a member of the Albert Lea Audubon Society. Email him at