Abundant wildlife | News, Sports, Business

PHOTOS BY GARRY BRANDENBURG – In late summer, wildlife populations can peak for a time because finding food, escape and freedom from predators are least of concern during this time of abundance. Green forage plants for deer or rabbits are everywhere. Life is easy. It’s also easy to find a place to slip into the shadows and avoid detection by predators. Warm summer temperatures mean the battle against bitter winter cold is still a long way off. Summer food and cover allows these creatures and many other species to build up fat reserves and overall good body condition before the constraints of the coming fall and winter seasons. Upland wildlife survey count data should be released by Iowa DNR biologists this time next month.

How many wild animals are there in Iowa? Well, it is impossible to count every species of bird, insect, reptile, amphibian, mammal or invertebrate. Biologists pay attention to the habitats where these animals live and to which they are specially adapted.

If the habitat is adequately sized and well managed and receives cooperation from Mother Nature in the form of timely rains and strong storms, survival becomes easier.

Biologists use specialized software, indices, and knowledge of habitats to estimate populations.

Survey data adds specific observations. These “counting” methods are used to determine trends for each species or upland birds or mammals, the most easily observed species. Year-by-year data can be compiled to make very reasonable quantities.

In fisheries, biologists can also implant small electronic transmitters into fish and track these tiny animals in rivers or lakes. Other small electronics can be placed on the insects to follow them.

Birds can carry lightweight signaling devices to communicate their position anywhere on Earth. Deer can wear neck collars to send signals to waiting ground or air-based receivers. Collecting data is what biologists are after.

After the data is collected, interpretation and analysis are next. It’s not just confusing numbers. Data must have meaning and purpose that can be critically reviewed over time. Behind-the-scenes work in offices and laboratories can make sense of raw data and raw numbers collected from the field.

The result would be, for example, trend lines showing fairly accurate estimates of waterfowl numbers by species prior to fall migration. Hunting season start dates, end dates and bag limits may be adjusted accordingly. Another example, in this example, is whitetail deer, nighttime spot light surveys, post-winter post-hunt weather estimates, fall hunter confirmation reports, and knowledge of Iowa home ranges all add information.

The issue of soil bearing capacity is often raised. Carrying capacity is a term used by scientists to determine how many wild animals of all shapes and sizes can live in a given habitat. Because soil types, residential zones, and land uses vary greatly across Iowa, there are no simple and easy answers.

However, when the big picture emerges, it becomes clear how many animals there are. Beyond that, numbers can be determined and reduction methods implemented.

Example: If unlimited growth were the official policy, how many deer could Iowa manage? Answer: at least 5 times more than what we have now!

This potential is well understood and known to biologists before anyone gets too knee-jerk about allowing deer numbers to increase to five times what they are now. Because biologists also know what the soil can produce in spring, summer and fall may not be close to what winter allows.

Thus, for game animals, hunters play an important conservation management role to harvest or take a certain percentage that varies by habitat so that at the end of a winter the total reproduction and remaining population is still adequate. season takes place and the new spring season begins next year.

There is also the political equilibrium or “social carrying capacity” that boils down to what people will tolerate. I can assure you that allowing too many deer to flourish is the end game no one wants to see. Thus, a more even and gentle series of ups and downs is preferred in a wildlife population rather than having large ups and downs.

Land owners engaged in animal husbandry know the limits of their land. For example, too many cattle may graze pastures in unhealthy conditions for grass. The recent dry conditions mean controlling animal numbers anywhere at any time to avoid damaging the soil itself. I’ve seen this many times with farmer/farmer friends where a year with plenty of rain meant good pasture production.

Total animal units can theoretically be increased. Then when a normal year series enters the cycle, there will be more cattle mouths to feed than in past abundant years. Soil bearing capacity is always a moving target, even for pets. The wildlife carry ability works the same way.


My other critter today is the Cottontail Rabbit (Sylvilagus floridanus). The first part of this scientific name is of Latin and Greek origin, meaning wooden rabbit.

Silva refers to a tree. Lagos refers to animals called rabbits. The second part of the name Floridanus refers to the area where the animal was first described and collected.

There are common names attached to rabbits. The Eastern Cottontail Rabbit is the main rabbit we see locally. The name comes in part from the white fluffy ball of fur on its short tail.

White-tailed Jackrabbits can be found in western Iowa. A few of these species may still exist in large prairie grassland complexes in northwestern Iowa. Black-tailed Jackrabbits live in the desert environment of the southwest.

Pikas are rabbit-like mammals with a smaller body and very small ears. They live on the slopes of high mountain rocky talus. Rabbits have two pairs of upper incisors. The long ears are our first clue

and a medium body shape with large hind legs is another. The fact that rabbits can run and run quickly adds to our personality.

The ability to run fast is important because rabbit populations can grow very quickly, and predators from the sky (hawks, eagles, and owls) and predators on the ground (foxes, coyotes, snakes) need it to survive. Notice the big bulging eyes of the rabbit in today’s picture. These eyes allow you to detect movements forward, backward, up and down in an almost 360-degree view. This adaptation is important to avoid predators.

Cottontails feed on vegetation that changes depending on the season. Leaves, stems and flowers will work. Fruits and berries come into play later in fall and winter. The bark of woody plants can be used in difficult times of deep winter.

Gardeners know that a rabbit fence can be essential to keep these mammals away from growing vegetables. After a fresh winter show covers the earth, people see rabbit tracks that the animals explore all kinds of places while looking for food the night before. Snow leaves evidence like rabbit trail depressions.


Duck hunters who like to chase the fast-flying little ducks called teal will soon get their chance. The start date is September 1. The US Fish and Wildlife Service monitors teal populations in all breeding areas. If populations are high, and then the service may allow hunting of early-migrating teal for 16 days in early September.

In 2022, it is. State waterfowl biologist Orrin Jones notes that breeding conditions were favorable last year in the Dakotas, Minnesota and Canadian prairie. Therefore, there will be a good supply of teal moving into Iowa in mid to late August.

A change in weather conditions in the north may encourage the river to advance from the cold front. An open water swamp once overnight can have a lot of teal the next morning. Nocturnal migrations are characteristic.

Hunting season is open only to teal, blue-winged or green-winged. Correct identification is essential. Another difference in hunting is the time frame – only from sunrise to sunset. In addition to regular game, a state migratory game bird fee and federal duck stamp are also required

hunting license.

Another fall season begins on September 1, and this one is for pigeons. These fertile birds are numerous. Fields of sunflowers or mowed grass fields can attract either mourning doves or Eurasian collared doves.

Dove hunting time is one and a half hours from sunrise to sunset. Chocks on shotguns should be used to limit projectiles to three. Non-toxic shots may be required north of I-80. Hunters must also register in advance with the HIP (Hunter Information Program) through the website link at www.iowadnr.gov/waterfowl or www.gooutdoorsiowa.com. The pigeon limit is 15 per day and the ownership limit is 30.


On August 25th, Hunter Safety classes with a private classroom will be held at the Izaak Walton League on Thursday evening from 6:00 pm to 9:00 pm and the following Saturday from 8:00 am to 4:00 pm. attend, study and pass the exam.

This certificate is required before obtaining a hunting license and is a one-time thing, good for life and honored by all other states. Register for hunter safety at www.iowadnr.gov/huntered.


Garry Brandenburg is the retired director of the Marshall County Conservation Board. He is a graduate of Iowa State University with a BA in Fish and Wildlife Biology.

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