Bug catchers of two different kinds

photos by Garry Brandenburg — If you do not like some bugs in the air, namely mosquitoes, then you will definitely like cliff swallows. And the little common tree frog likes to eat bugs of all kinds if they are small enough to swallow. Summer season will soon be upon us with its warm air temperatures, occasional thunderstorms and rain, and yes....bugs, the kinds we like and the kinds we find not so nice. In nature’s plan, they all have a purpose even if we humans do not understand all the nuances of natural life cycles. Cliff swallows make a unique call to others of their large flocks when food is found. If a swarm of flying bugs is located, the call goes out and the “you-all-come” message is relayed. Cliff swallows eat by catching bugs while flying. Common tree frogs catch their bugs while sitting upon tree branches or on the ground near low growing vegetation.

To start off this weekend’s Outdoors Today adventure into natural history, I have picked two small but mighty creatures, one that flys and one that keeps its sticky suction cup toes on the ground, or on tree bark or tree branches. I hope you enjoy this brief exploration into and among some of the smaller critters that live close by.

CLIFF SWALLOWS are one of several types of swallow birds we may see locally. However it the unique nest type and group behavior that sets Cliff swallows apart from its cousins. However, Barn swallows also make similar style nests. Rough-winged swallows may also nest under bridges, riverbanks, cliffs or culverts but only as single pairs. So what are us humans to do to separate and distinguish the differences between swallows? The answer is found by paying close attention to detail in the feather markings, tail shapes, and other subtle behaviors.

Today’s image of a group of Cliff swallows was made while standing on the Stanley Mill bridge over the Iowa River. Sunshine was filling the valley after morning fog had dissipated. All of a sudden, a few at first and then in large quantities, the swallows began an aerial show of intricate and fast flight. How they missed hitting each other in the air seems a mystery to me. For these birds, I’m sure they do not consider their flock mates aerial maneuvers a problem at all.

Nests of Cliff swallows may be typically found in large colonies attached to the underside of bridges and bridge beams. Using little balls of mud picked up near water edges of rivers or ponds, the sticky goo is plastered onto the concrete. Eventually a small ledge is formed and when finished, the nest will have an entrance hole just big enough for the birds to enter. it is estimated that a nest may be built from 900 to 1,200 mud pellets. The nest will be lined with dried grass to finish out the gourd shaped structure.

Where do Cliff swallows spend time during our North American winter? The answer is in southern South American grasslands, marshes,and farmlands during the southern hemisphere’s summer. It is a long flight for these mighty aerial masters who catch their food while flying.

My other small featured creature for the day is our Common Tree Frog. It goes by the Latin name of Hyla versicolor for good reasons. This frog can change its markings to help match and camouflage itself to its tree bark, tree branch or leaf litter hiding places. The skin color may vary between greenish gray tones. Its toes have large rounded adhesive discs that enable the frog to climb, clinging to rough or smooth surfaces. A large white patch of skin is found below its eye. Female common tree frogs may lay up to 2,000 eggs, attached singly or small groups, to vegetation at the surface or beneath water. Eggs hatch in two to five days. Tadpoles are olive-green with a bright orange-red tail. Tadpole stage of life lasts from one to two months. When emerged from water sources, the frogs are about 1.5 inches long and bright green. Young will seek out trees to climb. Adults can grow to about two or two and one-half inches long. Hibernation can be beneath leaf litter, under rocks or in underground crevices. They can withstand temperature of minus 20 because they have the ability to manufacture glycerol in the blood. How about that for a neat trick from Mother Nature?

Last week’s story featured a very small bird, the Ruby-throated Hummingbird, a female on her nest. It has been determined that her eggs hatched during one of the last few days of May. So I will try going back this weekend to hopefully make a few new photographic images of her in the process of feeding her young. Wish me luck. By mid June those young may be out of the nest, flying about the backyards of neighbors, and learning how to become self sufficient hummingbirds. The life cycle of hummingbirds continues in its ages old quest of survival for the species.

A FOGGY IOWA RIVER VALLEY greeted me last Wednesday morning at about 6 am. A quick look about from a hill top told me that the subtle beauty of low lying fog was not going to last long. It was time to capture some images with my camera. A short drive to Timmons Grove park was in order whereupon my view upstream and downstream offered milky white fog mixed with just the shaded outlines of river bank trees. The entire scene reminded me of thin wispy veils blocking out details, yet offering just enough landscape elements to compose a few photographs. Fog formed over the river because the water surface was warmer than the layer of cool air above it. As soon as the sun became higher above the horizon, all the fog disappeared. It was good to watch this tiny spectacle offered by Mother Nature.

You still have time this weekend to go fishing. It is Iowa’s temporary ‘holiday’ from fishing license requirements. No fishing license is needed by adults who wish to try out the sport of casting a line with a baited hook, or colorful lure into a river, stream, lake or pond. Starting again on Monday morning June 7th, a fishing license is required.

Iowa fishermen and women, boys and girls, may consider entering your name into the DNR’s First Fish Award. To help you celebrate the event, just fill our a handy dandy form that can be found inside the DNR Fishing Regulations booklet for 2021. Your name, address, species of fish caught, where it was caught, its length and weight and photograph can be submitted. Send it to First Fish Program, Iowa Dept of Natural Resources, 57744 Lewis Rd, Lewis, IA 51544. Electronic images should be sent to fish.awards@dnr.iowa.gov. There is also the option of using an online application at www.iowadnr.gov/firstfish.

DUCKS UNLIMITED reminder: The DU Iowa River chapter will host their banquet on June 12th at the Regency Inn at Marshalltown, IA. Doors open at 5 pm. Dinner is at 7 pm. Silent and live auction will follow. Wetland conservation holds tremendous value for all kinds of wildlife, not just for seasonal migration of ducks and geese. There are literally hundreds of species, microscopic invertebrates to bald eagles and every size in between that need wetland conservation areas for their life cycle. Help the cause by donating to DU and or attending the event in person.


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