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May 2005
Vol 2 - Issue 1

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Wildlife Web site for more information and links at: http://www.purdue.edu/wildlife/

Hairless Squirrels?

By Brian J. MacGowan and Harmon P. Weeks, Jr.

squirrel

People can be taken aback by the sight of squirrels missing hair. This past winter, sightings of partially furred squirrels seemed to be more frequent than usual. Like many wildlife issues, the cause of hair loss in squirrels is not easy to answer and often results in more questions than answers. In most situations, hair loss does not impact populations of squirrels. However, individuals may be impacted during winter.

Most people assume, often incorrectly, that hair loss in squirrels is the result of mange, a disease caused by microscopic mites that burrow into the skin and are unseen by the naked eye. Hair loss attributed to the squirrel mange mite, Notoedres douglasi, has been reported in both fox and gray squirrels. Notoedric mange is different from sarcoptic mange. The latter, caused by the mite Sarcoptes scabiei, occurs primarily among red foxes and coyotes. Questions exist regarding the host specificity of mange mites. In light of new evidence, some pathologists now believe that sarcoptic mange mites are not as host-specific as previously thought. However, notoedric mange mites appear to be more host-specific, and don’t colonize non-hosts (like humans), although a few bites may occur. Transmission of notoedric manage to species other than squirrels has not been documented, including to canine and feline pets.

Symptoms of notoedric mange in squirrels includes loss of hair and dry, thickened and dark skin. Crust does not form on the skin in notoedric mange in squirrels like it does in sarcoptic mange in red fox. Mange is most commonly spread by direct animal to animal contact. Treatment of adult squirrels with mange is generally not recommended because reinfection from their nest is likely. An adult squirrel can survive mange if in otherwise good condition. While mange can be fatal to squirrels as a result of exposure during the winter, full recovery is often observed in squirrels.

While mange is commonly presumed to be the culprit, most hair loss in squirrels is caused by a variety of superficial fungal diseases generally termed dermatophytoses. Hair from squirrels infected with fungal agents is typically broken off at the skin, leaving a fine stubble of short hairs. Damp weather is thought to play a role in some fungal outbreaks. This past autumn was relatively wet for Indiana standards and may have contributed to the apparent observed increase of hair loss in squirrels this winter. Most animals will eventually gain an immune response and recover from the fungal infection without any apparent consequences.

Some hair loss in gray and flying squirrels is thought to be an inherited condition where the hair follicles are non-functional or absent, although studies confirming this have not been done. These squirrels have normal, but bare skin.

The next time you see a squirrel with hair loss, don’t become alarmed. In most cases, the hair will return with no apparent ill affects to the squirrel, other than perhaps some embarrassment and name calling among his squirrel friends.

For more information about squirrel hair loss or other wildlife diseases, check out these resources.

Turtles in Your Yard

By Brian MacGowan, Extension Wildlife Specialist, Department of Forestry and Natural Resources, Purdue University

box turtle

There are 18 species and subspecies of turtles in Indiana, and about 260 species worldwide. Turtles represent the oldest and most primitive living reptiles. Reptiles are distinct from amphibians in that they have scaly skin; eggs with a tough, calcareous (calcium-containing) shell, a yolk sac, and an embryonic membrane; clawed toes; a three-chambered heart (four in crocodilians); and a male copulatory organ (except in the tuatara).

The most obvious and distinctive feature of turtles is their shell. Relatively unchanged over the past 225 million years, turtle shells are made up of two parts. Many bones covered with skin that is modified into horny scutes (except for softshelled turtles) form each part. The domed top is called the carapace while the flattened bottom is called the plastron. The carapace and plastron are connected on each side by bone or cartilage.

Where do turtles go during the winter?turtle mouth

In colder climates, most turtles hibernate buried in the mud on the bottom of waterways, yet others will burrow underground in uplands. A combination of factors allows turtles hibernating underwater to essentially hold their breath for up to four months without drowning. Colder water holds a higher amount of dissolved oxygen than warmer water. Furthermore, turtles need far less oxygen and energy when they are near freezing. Many turtles can also supplement their oxygen supply by gas exchange through highly vascularized regions of their neck and specialized sacs around their vent.

I used to see more turtles; where did they go?

Experts agree that populations of many species of turtles have declined in Indiana and across the Midwest. Habitat loss and inadequate recruitment of new turtles into existing populations are likely factors. Eggs and juveniles are susceptible to predation by foxes, skunks, and raccoons. In specific cases, predation can approach or even reach 100%.

Turtles are not capable of rapid turnover like deer. Some turtle species do not reach sexual maturity until they are 15-20 years old. This makes populations particularly sensitive to the loss of reproductive adults, as by collection for pets and death on roadways. For many species of turtles, basic information about ecology and population biology is still unknown or poorly understood.

This autumn, the state of Indiana passed new regulations for Eastern Box Turtles. It is now prohibited to collect Eastern Box Turtles from the wild. You are required to obtain a special purpose turtle possession permit to keep an Eastern Box Turtle as a pet.

While new environmental regulations may not be welcomed by all, recent research has determined that many populations of Eastern Box Turtles are in trouble. Contributing factors include:

  • High adult population density is critical for successful reproduction since the males must literally see and recognize potential mates.
  • Locally abundant predators including raccoon, red fox, and skunk.
  • Eastern Box Turtles can live beyond 60 years. Many people who collect them turn the turtles loose when they are no longer wanted. Displaced box turtles have difficulty surviving and may pose disease risks to free-ranging turtles.

For more information, visit http://www.in.gov/dnr/fishwild/endangered/turtle.htm.

box turtleEastern Box Turtle
Identification

The Eastern Box Turtle is a small terrestrial species that possesses a horny beak, stout legs, a high domelike carapace that is slightly keeled, and a hinged plastron that allows total shell closure. The coloration of the carapace varies, but is usually brownish or black with varying amounts of yellow or orange radiating patterns of lines, spots, or blotches. The edges of the carapace flare outwards. Body coloration is also variable, but is usually brown with some yellow, orange, or white spots or streaks. In very young Eastern Box Turtles, the carapace is predominately dark with a yellow rim and spots on the vertebral keel and center of each scute. In many individuals, the color expands as the turtle ages. The plastron of young turtles is yellow with a central dark blotch. The sexes are similar in size. The carapace of an average-sized adult is about 5 to 6 inches (12 to 16 cm). The iris of most adult males is red, the rear lobe of their plastron is concave, and the hindclaws are longer and more curved. Females have a brown iris (Fig. 17), a flat or slightly convex plastron (Fig. 18), short and straighter hindclaws, and a relatively more domed carapace.


distribution mapDistribution and Status

The range of the Eastern Box Turtle extends from southern Maine to Michigan, and south to Florida and eastern Texas. It is declining in the Great Lakes region, but populations can be locally common in areas not bisected by heavily traveled roads. They are a species of Special Interest in Ohio, and of Special Concern in Michigan. The Eastern Box Turtle is found throughout Indiana, but is much more common in the southern half of the state. Casual collection, collection for the foreign pet trade, and roadway kills (Fig. 19) are all significant threats to this species. In some areas, nest predation by raccoon, foxes, skunks, crows, and snakes can be significant natural mortality factors. Eastern Box Turtles cannot be sold or purchased in Indiana. Moreover, as of October 23, 2004, no Eastern Box Turtles may be taken from the wild in Indiana.

woodlandsEcology and Behavior

The Eastern Box Turtle is found almost exclusively on land, predominately in moderate to well-drained woodlands. They can also be found in thickets, fields, pastures, vegetated dunes, marshes, and on the edges of bogs. Access to water is still important for the Eastern Box Turtle. Individuals will sometimes soak around the edges of small streams or ponds on the hottest days. They are primarily active during daylight hours although nesting females are active at night. Fruits, berries, fungi, snails, worms, slugs, and insects are all readily consumed by this species. They will also eat carrion on occasion. Eastern Box Turtles reach sexual maturity at seven to ten years of age and reach full size around 20 years. Some evidence suggests that individuals may live up to at least 120 years of age.

turtle guide coverTo learn more about all 18 species of turtles native to Indiana, visit www.agriculture.purdue.edu/fnr/wildlife/turtles/index.htm for information how to order Turtles of Indiana.

 

Other Information

Wildlife Research Working for YOU!, http://news.uns.purdue.edu/UNS/html4ever/031125.Swihart.squirrels.html

Calendar, http://www.agriculture.purdue.edu//fnr/html/Calendar.htm

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Wildlife Research Working for YOU!

wild turkey

Wild turkeys don't gobble up crops, say Purdue experts

A common perception among farmers throughout much of the United States is that turkeys, which are becoming more common in the agricultural landscape, knock down and eat crops ranging from corn and soybeans in the Midwest to grapes in California's vineyards. Research by Gene Rhodes, professor of wildlife ecology, and Brian MacGowan, Extension wildlife specialist, has found that deer and raccoons, and not turkeys, are the crop-munching culprits.

Rhodes and MacGowan outfitted a small army of wild turkey, raccoons and white-tailed deer with various tracking devices to monitor their movements throughout the fields of northcentral Indiana. Members of the research team also walked the fields, identified which species caused the damage based on what they saw, and spent time observing and photographing wildlife in the fields throughout the growing season.

Two years of fieldwork gave the researchers a solid set of data vindicating turkeys. Over the past two years, deer and raccoons caused 95 percent of the damage in the fields surveyed, Rhodes said.