Red fox and red-tailed hawk

IMAGES BY GARRY BRANDENBURG — Predators come in all sizes. For today’s column, the Red Fox and the Red-tailed hawk are just a tiny sampling of animals whose lives depend on finding prey animals to eat. In Mother Nature’s scheme of things, to survive, each needs to hunt for food. Locating food is different from catching food. Once catching has occurred, then eating can take place. Eating is ultimately the process by which energy in one form is transformed into energy to sustain life in another form. Predation is the biological interaction where one organism, the predator, kills and eats another organism, its prey. Each predator is highly specialized for its hunting role using acute eyesight, hearing or smell, and then the fangs or talons take care of the process of eating.

Predation: it is an essential part of life, whether in the wildlife give and take of life and death, or in a more constrained and husbandry role of livestock raising and feeding. Ultimately, one form of life is utilized to sustain the lives of others.

This process of predation has been going on for hundreds of millions of years, even perhaps billions, as organisms adapted to the environments of their time to live another day, and those days turned into eons and millennia all over the face of the earth.

Some of the earliest predators were microbial organisms. They ‘grazed’ upon each other and others in primordial settings. The fossil record demonstrates a long history of very tiny critters, with or without shells, leaving tracks on old ocean floor muds.

When those old ocean muds solidified into rock layers over geological time, and eventually were to become exposed to mankind’s investigative efforts, stories began to emerge of the hide and seek efforts of predators trying to find prey to eat. Early predators adapted bone-like plates to crush the shells of bivalves and Gastropods mollusca. Some developed appendages to grasp prey, hold it, and allow the prey to be eaten.

The early oceans of the world had many small, medium to large fishes all concentrating their efforts of survival on hunting down smaller critters. Now, museums hold specimens from the fossil record of some gigantic fish such as Dunkleosteus, a bony plated head of a large fish, its jaws without teeth but with incredible power to crush hard shelled animals or whatever it could catch. This fish grew to be 20 feet long and lived during Silurian and Devonian geologic time frames. It was a top of the food chain predator of its time.

Insects of giant sizes were flying during the Early Carboniferous to Late Devonian periods. Flight helped these insects avoid becoming prey from fish or other aerial predators. Yet at the same time, dragonflies with two foot wide wingspans were a top predator on other smaller insects, and we have all seen replicas of the skeletons of other top predators from the Cretaceous period, those theropod dinosaurs such as Tyrannosaurus rex, a meat eater who hunted for and killed herbivorous dinosaurs like hadrosaurs, ceratopsians, and ankylosaurs.

The study of the incredible diverse interactions between animals at all levels of the food chain reveal a cycle by which life’s continuum presses on. A predator must assess a possible food source after a successful search for it and then decide to pursue it or not.

If the answer is yes, then the process may be to wait in ambush or stalk within range to make a kill. Once captured, the prey must be handled first to hold it, then kill it, then to break it down into manageable chunks and consume its nutrients.

Insects may be small, but they have to eat. Examples could be fleas or mosquitoes that consume blood from other living animals, or aphids that consume sap from plants. These do not kill the host so we humans call them parasites. Animals that eat seeds, they are eating a form of life in its entirety.

Some seeds pass through and if they drop into the correct soil conditions, may take root. Another predation form is called scavenging, eating something that is already dead. Turkey vultures come to mind in this instance. A jackal or hyena of the African plains are opportunists, scavenging if that works, or making the initial kill if that works.

A bird like the red-tailed hawk is a hunter. Its sharp vision is critical to locating food sources big enough to be worth its efforts and not too big as to cause possible injury to itself. The talons on its toes are the tools to make the kill or grasping actions. The bill will be used to make the final call by breaking the neck of a vole, mouse, rabbit or snake.

A red fox uses its tremendous smelling ability and hearing ability to locate mice, voles, rabbits or snakes. Even through 30 inches of deep snow, a fox can listen and pinpoint the movements of a mouse moving within its ground level grass lined tunnels and take a close look at the pupils of the eyes of the fox in today’s photo.

The fox pupil is vertical, or more cat-like, and those eyes allow a fox to be a good nighttime predator and hunter. Foxes can sense the earth’s magnetic field. They can run 45 mph. An adult may weigh 20 to 24 pounds, and its thick fur can help it survive temperatures of – 40 F. An omnivorous diet helps them find many types of foods, and the red fox has about 40 different barks, screams, yelps, or calls it can make when communicating with other foxes.

Predators and prey are natural enemies. One must keep in mind that maybe one in 10 attempts by a predator to kill a prey species is successful. Keep in mind that the prey is not helpless or devoid of its own tactics and tricks to evade that predator.

In this give-and-take scenario of trying to live, predators are successful just enough times to make a living, and prey species are in the long run successful at avoiding becoming a meal for the predator just enough times to remain living. Together, this system is a demonstration that predation is an essential part of life.


River recreation via canoe or kayak is a popular summertime activity. As of now, the Iowa River is flowing slow and low, but not too low, to float the watercraft of choice, canoe or kayak. Emerging sandbars are beginning to show above the waterline.

While paddling, one has to look at and read the ‘dark’ water to know that this is where the deeper water is located for effective paddle strokes. The current will meander back and forth across the river channel.

Do always be careful about getting too close to log jams on sharp river bends. Here, the current can and will attempt to pull the watercraft and you under the water’s surface. There have already been too many water recreation related incidents and a few deaths in Iowa this summer. Safety is a full time need while on the water.

About 29 miles of the Iowa River flows through Marshall County from the Hardin County line to the Tama County line. Boat ramp access points can be utilized at the Forest Reserve, Timmons Grove, Riverview park, Furrow Access, and Three Bridges County Park.


Hunter safety class, the last in person hands-on classroom instruction for 2022, will be held Aug. 18, a Thursday evening from 6 to 9 p.m. and the following Sat., Aug. 20, 8 a.m. until 4 p.m., at the Marshall County Izaak Walton League grounds near Marshalltown.

The course has been posted on the Iowa DNR website where persons are urged to seek out, register, and then set aside those dates and times. Those wishing to attend must register. The web site is www.iowadnr.gov/huntered.

Hunter safety classes are mandatory for students under the age of 18. The course is designed to help teach safe skills with firearms and handling techniques. This course was mandated by the 1997 Iowa Legislative session. Students learn the concepts of conservation history, conservation practices to assist wildlife populations, firearm types and safety considerations of each. Video and films, hands on live fire at the range with one-on-one instructors, an archery demonstration, plus discussion with wildlife game warden Tyson Brown will be presented.


Quote: “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” — John Muir


Garry Brandenburg is the retired director of the Marshall County Conservation Board. Contact him at P.O. Box 96, Albion, IA 50005.


Today's breaking news and more in your inbox

I'm interested in (please check all that apply)
Are you a paying subscriber to the newspaper? *

Starting at $4.38/week.

Subscribe Today