Those OWLers anticipating the first meeting of the 2004 season were not disappointed. Our speaker, Bob Eriksen, is a biologist with the National Wild Turkey Federation, but during his 28+ years of experience with wildlife, he has been involved in field work with a variety of species including skunks, raccoons, black bears and white-tailed deer. He presented an enthusiastic and in-depth look into how he and other biologists solve the many riddles they confront in wildlife research and management in New Jersey and across North America.

One of the first things Bob wanted to point out was the difference between wildlife television personalities and trained wildlife biologists. Individuals such as Timothy Treadwell and Steve Irwin are not trained biologists, he said, but media personalities. Bob said some of the behavior he has seen these individuals engage in with wildlife is disrespectful and hazardous. They promote the idea that wildlife isn’t wild which is dangerous for both people and the wildlife. Trained biologists follow certain professional protocols when they deal with animals, especially when they conduct research that aims to solve questions about wildlife and their management.

Who ate the grapes?
This question and others like it involve figuring out which species of wildlife is responsible for eating farmers’ crops or predating on other animals. To draw conclusions, Bob relies on his extensive field experience and knowledge of animals and their behavioral habits. What might he examine to aid his conclusions? Animal tracks (their size, shape and pattern can reveal the species, sex and sometimes age of the animal); feathers (which reveal the type of bird, sex and age); scat (reveals species, diet and sometimes sex of animal; and hair (reveals species, and when DNA tested, can reveal the specific animal). Bob showed numerous slides that depicted these various clues and how to read them to assess which species are involved. Understanding these clues can often provide surprisingly accurate information about an animal. For example, he explained how two biologists came up with a formula using the weight of a wild turkey and the most recently acquired primary flight feather to determine, within 2 to 5 days, the age of the bird.

Sometimes Bob has to use more hi-tech methods of investigation. Such as when a grower of high quality grapes lost a good percentage of his crop to what he thought were wild turkeys that frequented his field. By setting up randomly placed surveillance cameras in the vineyard for a month, Bob was able to conclude that most of the grapes were eaten by white-tailed deer, not wild turkeys. Sadly, the owners do not always believe the facts and in one extreme case, a turkey had to be killed and his gullet and stomach examined for evidence of grapes (not found) to satisfy the owner.

How many are there?
Another concern for wildlife biologists is determining the population size of a particular species. Some species can be counted individually such as when counting wintering waterfowl from a plane, or when certain birds are nesting and flightless. Other methods involve getting a population estimate by marking individuals of a species and then comparing the number of marked and unmarked individuals. These numbers are then plugged into statistical formulas that are designed to get a population estimate for that species.

Depending on the species, an animal can be marked with leg bands (birds), ear tags (bears, cottontail rabbits, white-tailed deer), or tattoos (bears, coyotes). Drawbacks to some of these methods are that researchers need to sample a large number of animals to get statistically valid results, and in the case of ear tags, some identifying marks can fall off and be lost. However, bands that are recovered provide some interesting information for researchers such as how far an individual animal has moved since it was banded.

Placing radio transmitter on wild turkey.

Radio telemetry, which involves attaching a radio transmitter to an individual animal (either surgically implanted or more commonly, with a radio collar or harness) is superior to the other methods in providing information about a species because a smaller population sample is needed to draw conclusions. With radio telemetry, biologists can determine where an animal travels, which provides more accurate information about its preferred habitat, the distance an animal travels in a day, its reproductive rate, its approximate lifespan and the reason an animal died, and other information.

This method was especially successful in determining what was needed to ensure the growth of wild turkeys in the Pine Barrens. Although adult turkeys had an average survival rate and were successfully nesting, it was found that young turkeys (called poults) had poor survival rates. After studying the situation it was determined that fire suppression in the Pine Barrens – an ecosystem that developed as a result of periodic burns - created unnaturally thick stands of vegetation. These thickets were better able to conceal the presence of predators from wild turkey hens, putting their poults in danger. By restoring fire to the Pine Barrens with prescribed burns and clearing the forest understory, the birds would be better able to take advantage of their eyesight to better avoid predators. As a result, poult survival increased.

As a wild turkey biologist, Bob discussed turkeys quite a bit. After all, he works for the National Wild Turkey Federation and his Masters thesis focused on restoring these beautiful birds to New Jersey. But his depth of knowledge and expertise concerning all species was obvious. Thanks to Bob’s presentation, we gained a more in depth understanding of how wildlife biologists conduct research and how they use the data that they obtain to solve wildlife "whodunits." Thank you, Bob, for enlightening us.

submitted by Sandy Norman