Rodents
As a naturalist I am sometimes confused when I hear someone uses the term “rodent” to describe an undesirable person or animal. Since when was being a rodent such a bad thing? So, let’s take a look at the rodents and find out what exactly they are and why they have such a bad reputation. And then we can decide if calling someone a rodent is a good thing or bad thing. To start with, there are over 4,500 species of mammals in the world. In order to be a mammal you need to have some basic traits, such as being warm-blooded and have fur or hair on your body. Females must have mammary glands that secrete milk to feed their young. That is all that is needed to be in the mammal club. There are 10 orders of mammals in North America, with rodents being the largest. The rodent order is called (Rodentia) under the Mammalia class. In fact there are nearly 3,000 species of rodents, which means that about three quarters of all the mammals in America, or the world, are a kind of rodent. In North America, rodents range from tiny mice and shrews which may weigh a fraction of an ounce to the Beaver which can weigh up to 90 pounds. So what makes a rodent a rodent? As varied as these animals are, they all share some common traits, such as having two pairs of incisor teeth. The incisors are the sharp front teeth on the top and bottom used for gnawing. In addition to the incisors rodents don’t have any canine teeth, which leaves a gap between the incisors and the molars. Also, the incisors are enameled on the front surface. Enamel strengthens the tooth and gives it a yellowish appearance. The incisors of a rodent grow continuously throughout the animal’s life. The action of the upper incisors working against the lowers wear away the teeth in a characteristic chisel-like beveled edge which is how these animals are able to snip right through things like wood with a single clean bite. If the teeth fail to wear down the incisors will grow too long and a malocclusion may occur, which means the teeth fail to wear down properly. These teeth will grow out of the mouth and prevent the animal from eating, resulting in death. This also explains why rodents are constantly gnawing on hard surfaces. They are wearing down their incisors. Also to be a rodent you need bulging eyes on the sides of the head, enabling them to see forward and behind at the same time. In addition rodents have four toes on the forefeet and five toes on the hind foot. Most rodents are nocturnal and are active year round. Some will hibernate during winter while others become less active during the hot days of summer (estivate). Rodents also reproduce faster than other mammals. Many rodents become sexually mature in less than 60 days of age and reproduce up to 3-4 times a year. However since just about every large predator eats these rodents they need to reproduce quickly or not survive. So there you have it. When you call someone a rodent you are basically calling him or her a small furry animal with sharp teeth, bulging eyes and that reproduces often. Come to think of it, I have a cousin like that.
Red-cockaded Woodpecker
The Endangered Species Act (ESA) turned 30 years old. President Richard Nixon signed the Endangered Species Act (ESA) into law on December 28th, 1973. Now some three decades later the ESA is at the center of controversy. Depending upon whom you talk to, the ESA is either the best legislation ever created to protect plants and animals or the worst piece of legislation in U.S. history. In 1967, the Secretary of the Interior listed 78 species as threatened with extinction under the pre-ESA Endangered Species Act. Today, the U.S. Department of Interior’s Fish and Wildlife Service (FWS) lists 517 animal species and 746 plant species as endangered or threatened, for a total of 1,263 species listed. Some biologist estimate there is about 36,500 species of animals and plants in the United States. So that means that about 3.5 percent of all species in the US are either endangered or threatened. Some of species include some very high profile animals such as the Bald Eagle, Peregrine Falcon, Manatees, Wolves and the Red-cockaded Woodpecker. Since the inception of the ESA, according to the FWS, only 15 species have been removed from the list due to increases in populations. Some of these animals include the American Alligator, and the Brown Pelican. So, lets take a look at one of the animals the ESA protects. There are twenty-one species of woodpeckers in the United States and the Red-cockaded Woodpecker (Picoides borealis) is the rarest of them all. It is listed as a federally endangered species. It ranges from the Carolina’s to Florida and west to the eastern border of Texas. Unlike other species of woodpeckers, the Red-cockaded Woodpecker excavates its nest cavities in live pine trees that are at least 60 years old. Most other species use dead trees to excavate their nest cavity. Presumably this is the reason the Red-cockaded woodpecker is on the decline. Current logging practices often start harvesting trees that are 50 years old, leaving precious few stands of old pines for the woodpeckers to find suitable nesting trees. The Red-cockaded Woodpecker lives in small social groups (clans) often composed of family members. A clan’s territory can be up to several miles square but mated pairs will nest within a couple hundred feet of each other. Pairs will remain together throughout the year, defending their food source and nest site. During winter they use their nest cavity to rest at night. This is also a very unusual behavior. Most bird species only use their nests to raise their young and never use it again. Efforts are now underway to help stabilize the decline population woodpeckers. Rectangle shaped artificial nest cavities with PVC entrance holes are installed into live pine trees of suitable size and age. So far, research shows the woodpeckers are taking well to their new homes. With continued protection and habitat preservation, the Red-cockaded Woodpecker may be one of those lucky few species that is removed from the endangered species list.
Key Deer
In commemoration of the 30th anniversary of the passage of the Endangered Species Act, (Dec, 1973) lets take a look at another animal that has directly benefited from this important legislation-the Key Deer. The Key Deer (Odocoileus virginianus clavium) is a subspecies of the familiar Virginia White-tailed Deer (Odocoileus virginianus). It is one of 28 subspecies of deer and is the smallest race of deer in North America. An average adult stands 2 feet tall at the shoulders. Bucks (males) average 80 lbs and Does (females) average 65 lbs. In all other respects these deer appear like the deer that visit your backyard, only much smaller. The Key Deer occur only on a few select islands or “keys” located in southern Florida. They require Pine Rockland habitat, which is composed of several species of pine tree on what amounts to be the highest elevation (several feet above sea level) of each island. Fresh water seems to be the limiting factor in where the deer thrive. After heavy rains, depression in the ground collect the fresh rainwater which is critical to the deer’s survival. I recently meet up with Shane Whisenant, the Key Deer Biologist at the National Key Deer Refuge on Big Pine Key, Florida. Shane is a man with a passion for the Key Deer. He explained to me that the National Key Deer Refuge was established in 1957 when it was discovered that the total population of the Key Deer had fallen to about 27 total animals. Unlimited hunting and habitat destruction were presumably the factors leading to the decline of this tiny deer. Today, nearly 50 years later, the Key Deer is on the rebound, thanks to specific habitat management such as prescribed burns to open the forest and thus providing a source of native grasses for the deer to feed upon and the restoration of freshwater pools. The biology of the Key Deer is similar to that of its larger counter part in the Midwest. The life span is around 7-8 years, with most females breeding at one or two years of age. Bucks don’t start mating until they are slightly older and have developed large antlers and are able to compete against the other bucks. The rut takes place in September through November. Gestation is about 7 months with most Does giving birth to twins in April or May. Hunting of the Key Deer is prohibited, however about 100-150 deer are killed each year. Most deaths are due to being hit by cars or killed by domestic dogs. In 2003, 137 deer were lost, 91 of them to automobile collisions. Both of these causes of mortality are something the staff at the National Key Deer Refuge is activity working to reduce. And I am sure, if the rest of the staff is as caring and knowledgeable as Shane Whisenant, the Key Deer are in good hands. Do yourself a favor. Next time you are visiting southern Florida. Make a trip to Big Pine Key (part of the chain of islands known as the Florida Keys) to see these wonderful animals. They come out along the roadsides late in the day and can be observed from your car. Please don’t attempt to feed or touch the deer. This only encourages the deer to come closer to the roads. And the last thing they need is to be closer to a collision with a car..
Florida Manatee
Maple Trees
Although it’s still cold and wintry outside, there are signs of spring everywhere. Red-winged Blackbirds and American Robins have returned to the northland. Boxelder bugs are seen sunning themselves on the south sides of trees and buildings. Black-capped Chickadees are singing their spring time song. And another sure sign of spring is the maple sap is running within the maple trees. There are over 100 species of maples in the world. About two thirds of these are found in Asia. Here in North America we have only 13 native maple species. All of our native maples share some common traits such as opposite pairs of leaves. Each leaf has anywhere from 3-9 main veins radiating from a central base. All maples produce pairs (rarely in 3’s) of winged seeds called samara, on a single stalk. These winged seeds are often called helicopters because of the way they rotate to the ground after falling from the tree. And all maple seeds are an important source of food for wildlife. One of our most common maples is the Sugar Maple (Acer saccharum). It’s a medium sized tree averaging about 50-70 feet tall at maturity. It has a single large trunk with many ascending branches and a full round crown. Sugar Maples can live up to 200 years old. Like other maples, the Sugar Maple has oppositely attached leaves. Each leaf has five lobes (occasionally three) with pointed tips and a wavy leaf edge, which is called the margin. The leaves are yellowish green on top and paler below. This tree is the well-known source for maple syrup and maple sugar. It takes approximately 40 gallons of sap to make a single gallon of maple syrup. In spring, any broken twig or branch will leak the watery sap. These natural taps attract many species of birds and mammals to drink. Also called Hard Maple, the Sugar Maple has extremely hard wood that has been used in make furniture, flooring and cabinets for hundreds of years and continues today.Another lesser-known maple is the Silver Maple (Acer saccharinum). It grows in wet to moist soils, often growing in pure stands in the floodplain of large rivers and lakes. It is one of the first trees to send out flowers each spring which are often confused with leaf buds to the casual observer. Leaf buds and their resulting leaves don’t come out until after the tree is finished flowering later in spring. The bark of the older trees is characteristic, with long strips that often peel and curl at the ends. Silver Maples produce seeds every year but it also produced extremely heavy crops every two or three years. It’s often called Silver-leaf maple, because the underside of the leaves are silvery in appearance. The Silver Maple also produces a sap that can be collected and boiled down to make maple syrup. The yield is only slightly lower than the Sugar Maple but just as tasty. The sap flows in early spring when the nighttime temperatures drop below freezing and the day time temps go above freezing. A typical tree can produce anywhere from 5-50 gallons of sap each spring. Until next time…
Squirrels
Feeling a bit squirrelly lately? Maybe a touch of spring fever? Well, so are the squirrels in your backyard. Many people are reporting that their squirrels are exhibiting strange and unusual behaviors. The squirrels have been seen chasing each other across the ground, up trees and tumbling back down to the ground again. This outrageous behavior is all contributed to one thing–mating. Each spring our friendly backyard squirrels are establishing or reinforcing mates by an elaborate system of chasing each other. There are 60 different kinds of squirrels in North America each falling into one of two groups—ground squirrels and tree squirrels. Let’s look at a few of the “tree” squirrels. One of the most common squirrels is the Eastern Gray Squirrel (Sciurus coaolinensis). It is large, 8-10″ long, with a gray coat, hence the common name, and a white belly. They are often rusty red around the head and ears. Not all Gray Squirrels are gray, some are jet black. These are known as the black morph or black phase of the gray squirrel. The term “phase” or “morph” might make you think that their black color is temporary but it’s not. They are born black and will stay black their entire life. The largest tree squirrel is the Fox Squirrel (Sciurus niger). It is 10-15″ long, orangeish-red in color with a tan colored face and undersides. Their color is similar to the red fox, hence its common name. The most aggressive squirrel is the American Red Squirrel (Tamiasciurus hudsonicus). This powerhouse is only 7-8″ and is often seen chasing larger squirrels and even birds. Covered in a rich red coat it has a pure white belly. The smallest squirrel is the Flying Squirrel (Glaucomys sabrinus). It is only 5-6″ long. It is a one of the most abundant squirrels but since it is nocturnal (comes out at night) it’s rarely seen. The scientific name for squirrels, Sciurus combines the Greek word skia for “shadow” and oura for “tail” to indicate that they are the only animals that can sit in the shadow of their own tail. A squirrel’s tail is functional in many ways. It is used for balance when climbing or as a parachute to slow their descent in preparation for landing when leaping from tree to tree. It is also used for warmth, like a blanket, and as a communication device to signal displeasure. The more agitated the squirrel, the faster it flicks its tail back and forth. Squirrels usually live out their entire lives within 200 yards of their home. The exception to this occurs usually during the mating season (right now) when males may range widely in search of a mate. Mothers and babies stay together for up to 6 months after birth. Mothers can have two to three liters each year, consisting of three to five, babies. Until next time…
Spring Ephemerals
There are many aspects of nature that might remind a person of the changing season from winter to spring. The thick sheets of ice melting from winter chilled lakes, the return of migratory birds, the fanciful flight of the Mourning Cloak butterfly, or even the whine and sting of the years first mosquito. But for me, spring is trumpeted by spring ephemeral wildflowers. Ephemeral wildflowers are a special group of woodland flowers. Often the average nature watcher might mistakenly believe that the first wildflowers of spring don’t emerge from the frozen ground until May or June. Not so with the group of wildflowers classified as spring ephemeral. Ephemeral flowers are so named because they appear above ground in early spring—they flower and fruit and then die back into the ground all in a short two-month period. Long before the trees had a chance to unfurl their leaves. Ephemeral wildflowers such as Bloodroot, Cut-leaved Toothwort, Trout Lily and Trilliums emerge in April and are all gone by May or June. As a group they constitute one of the largest groups of wildflowers. By the time the warm winds of summer begin to blow, these flowers are long gone. Often unnoticed by the casual nature explorer. This remarkable group of wildflowers has adapted to the rhythm of the trees that they dwell underneath. A rhythm tied to the soil moisture, soil nutrients and available sunlight. Not to mention a very important relationship to ants. Essentially a spring ephemeral wildflower appears early each spring, before the leafing out of the deciduous trees in which it dwells underneath and when full sunlight streams uninhibited to the forest floor. Sunlight is one of the keys to the ephemeral wildflower. If the flowers where to wait until the weather warms up, the leaves of the trees would enclose the canopy of the forest and cut off any sunlight. In addition to the sunlight factor, this is the time of year when soil moisture is at the highest because the trees are not actively soaking up all the available moisture. Soil nutrients are also at the highest levels at this time of year. A considerable amount of decay from the previous year’s leaves took place last autumn leaving a bumper crop of nutrients in the soil. The spring ephemeral wildflowers have first crack at this abundant food supply. There are many questions brought up when considering spring ephemeral wildflowers. The first is, how does this class of wildflower unfurl their leaves without any damage from unpredictable temperature extremes. The answer lies in the moist earth that buffers the extremes of the day and night temperatures. Plants can leaf out nearer the ground sooner than they can thirty or fifty feet above the ground. Supporting this idea is the fact that the earliest flowering ephemerals are shorter than the flowers that come later in the season. In some cases, the earliest of spring wildflowers are not only close to the ground, but they have leaves that envelop the main flower stem to trap warm air, such as Bloodroot. Another successful strategy to trap warm air is to be covered with dense hairs such as the early prairie bloomer, the Pasque Flower. This flower is so heavily covered with tiny hairs it looks like it is wearing a fur coat. Many of the spring ephemeral wildflowers have seeds that contain a special oil that is especially attractive to ants thus ensuring the ants will carry off the seeds. The ants store these seeds underground and the seeds often sprout before they are consumed by the ants. This is a great way for the plants to disperse their seeds into the surrounding environment. Until next time…
May and Morel Mushrooms
If you are at all like me, you can’t wait for the month of May. By far, it’s a month that has so much to offer a nature nut like myself. It’s a time of birth and bloom. Woodlands are filled with spring flowers such as hepatica, bloodroot, trout lily, spring beauty and one of my personal favorites–trilliums. While many of the migrating birds have already returned to the northland by the beginning of May, there are many more to come. Migrating shorebirds and warblers migrate during the month of May. And no backyard bird watcher can deny the splendor and excitement when the baltimore orioles and ruby-throated hummingbirds return to our gardens during this wonderful month of May. However, the month of May can have its dark side. A deep lurking illness that remains hidden throughout the rest of the year. A disease that can cause the most normal person to act out in strange and bizarre behaviors. There is no cure for this malady of May. What is this plague upon our woodlands—MOREL MADNESS!! That’s right, run for cover, lock the doors and bar the windows, its morel mushroom time again. If you feel a fever and an over-whelming desire to crash through the woods in search of this elusive fungus, then you can be certain that the morel madness bug has bitten you. The only cure for morel madness is a couple days searching your local woodland for this spongy devil. Depending upon which expert you talk to, there are up to 10 species of morels (Morchella sp.) and fortunately all are edible. However there are several species of mushroom that appear similar to the morel which are not edible. So, for safety sake, lets go over some general rules to keep you safe if you succumb to the morel mushroom sickness. Morels grow in a short window of time, usually for a couple weeks during the month of May. Many mushroom hunters use the blooming of wildflowers to signal when the conditions are right for the morels. It is said that when the Trilliums are blooming or when the Lilac bushes are blooming is when the morels are up and ready to be plucked. That means right now. Morels have hollow stems and caps. One of the safety checks is to cut your morel mushrooms in half, lengthwise to inspect the interior. A morel will be completely hollow like a straw inside. If there is any cottony material within it’s not a morel. The cap of the morel is connected directly to the stem. This means the cap shouldn’t hang over the cap like a typical mushroom. Morels always grow on the ground. It’s a fungus that breaks down dead plant material, called saprophytic. If you think you found a morel and it’s growing on a log or stump, it’s not a morel. The cap or top of the morel is sponge-like (some would say brain-like) and is covered with pits and ridges. Also, morels don’t have any gills like the typical button mushroom. I have some advice for anyone who hasn’t been out morel hunting. Don’t do it!! It will quickly take over your life. Once you start hunting for these elusive fungi there is no turning back. Before you know it you’re life will be in shambles. First you will start to neglect your family, than you will start to call in sick to work just to hunt for the morels. And before you know it your life is ruined. There is no cure for morel fever, so do yourself a favor. Stay home and paint your house. You’ll thank me in the end. For me, its too late, I will probably be unemployed by the end of the month. Until next time…I hope.
Butternut Canker
Not ten feet out my office window stands a dying American Elm tree. Ten feet to the left of this dying tree is another elm that is already dead. Not 6 weeks ago these trees were alive and doing well. That’s how fast Dutch Elm disease claims the lives of these wonderful trees. But the occurrence of Dutch Elm is old news. Are you aware of the Butternut Canker disease? Its worse than Dutch Elm. The Butternut tree (Juglans cinerea) is a highly valued deciduous tree native to the eastern US. It is sometimes called White Walnut because it is closely related to Black Walnut and has nearly white wood. Its wood is very strong and is sought by woodcarvers and cabinet makers worldwide. In addition, the abundant nut crop is a very important food source for all sorts of wildlife including White-tailed Deer and Turkeys. Its common name comes from its butter-like oil, which some Native Americans once extracted from the nuts. The nuts (fruit) are egg-shaped or sometimes oval, and are 2-3″ in length and grow in tight clusters. Each nut is covered with a sticky green husk that turns brown upon maturing. The husks surrounding the nuts were often used to dye fabrics. During the Civil War, the color of the Confederate uniforms was created using butternut husks. Currently, all the butternut trees in the entire eastern US are being devastated by an exotic fungal disease that causes branch and stem cankers and ultimately death. The name of this fungus is Sirococcus clavigignenti- juglandacearum, a mitosporic fungus that belongs to a large group of fungi called Fungi Imperfecti. It was first described in Iowa in 1967 but is believed to have spread to Iowa from southeastern U.S. some forty of fifty years prior. In 1995, the Forest Service estimated that 75 percent of all butternuts in the southeastern U.S. were dead with the remaining trees heavily infected and no longer reproducing. There isn’t a region that isn’t already affected by the disease. This rapid decline of the butternut population is so severe that the U.S. Fish and Wildlife Service have listed the species as a species of Federal concern. In our area the Butternut tree is dying in record numbers. Rarely do I find a live and healthy Butternut in all of my travels. Unlike the Dutch Elm which quickly takes the life of the tree, the Butternut Canker slowly kills the tree over several months to years. Spores of the fungus can be dispersed by rain splashing and air currents. No doubt insects are also transmitters of this deadly fungi. The fungi can survive and reproduce on a dead tree for up to 20 months. The disease causes dead branches, top dieback, and discolored bark which has an inky black fluid coming from the cracks. Cankers are elongated and sunken and almost always cause death of the branch by cutting off the circulation. Cutting and removing the infected wood will slow the spread of the infection but there are no known cures or control. Work is now underway to locate healthy stands of Butternuts and graft resistant trees into clone banks to preserve the genetic makeup of this tree. In addition once the physiology of the canker causing fungi is understood there might be a chance to save this tree. But for now we continue to loose another sentinel of our forests just like the American Chestnut and the American Elm. Until next time…
Ticks
Just bring up the words “Wood Tick” and even the most ardent nature lover cringes and starts to get the heebie geebies. Even as I write this my skin is crawling. As a naturalist I try to look for the “good” in all aspects of nature. I have spent my career explaining the virtues of plants such as the Poison Ivy and birds such as the American Crow to people that find them unfavorable. I try to convey something interesting that might spark a new way of looking at the “bad” plant or animal, something that might make you say “gee-whiz, that is interesting”. But I seem to be at a loss for words when it comes to the Wood Tick. But here it goes anyway. Ticks are members of the Mite and Tick order, which are closely related to spiders. There are over 1,000 named species of ticks worldwide. Some estimate there are up to a half million more species tick yet to be discovered. Now there’s a comforting thought. There are 2 types of ticks—hard bodied and soft bodied. Wood Ticks are a hard bodied tick and are so named because of the hard plate on top of their bodies. This is also why it’s difficult to kill them simply by squeezing or crushing. Soft bodies ticks lack the hard plate and have mouth parts located under their heads as compared to the hard ticks that have mouth parts in front of their head. Newly hatched young, called larvae, have only 6 legs. They are extremely tiny and obtain 2 more legs after the first molt for a total of 8 legs, just like spiders. Just like the adults, the larvae also feed on blood, but they concentrate on small animals such as mice and voles. With each blood meal (total of 3-5) the larvae molt (shed their old skin) and grow larger. Once they are adult size they feed on larger mammals such as deer and people. Ticks find their hosts by clinging to the tips of plants while extending their fore legs to grab any passing mammal (see image of female Wood Tick). They may remain perched on the end of a twig or blade of grass for weeks before a large mammal passes by within reach. Once they have landed upon a potential host, they often climb to the highest point and search for a warm and protected spot such as behind the ears, nape of the neck or the collar. (Are you starting to itch now?) Once in position they use their forward facing mouth parts to pierce the skin and begin to feed on the blood. Once fully engorged, they drop off and molt and lay eggs. Mature females will mate just before their last blood meal. Using the nutrients from the blood meal, she will develop and deposit many eggs which hatch into tiny 6 legged larvae and the cycle starts over again. Most full grown Wood Ticks are 1/8 of an inch long. Males and females are the same size but you can tell them apart. Males are reddish brown with two white strips running length wise down their body. Females are the same color but have a single U-shaped mark. An easy way to differentiate the sexes is to remember, males have markings that look like he is wearing suspenders while females look like they are wearing a necklace. Wood Ticks are sometimes called American dog tick. Because they are feeding directly on blood, they can transfer disease from one host to the next, including Rocky Mountain spotted fever, tularemia and tick paralysis. If you find a tick attached to yourself, you can carefully remove it with tweezers. Grasp it around the head, as close to your skin as possible and gently yet firmly pull it out. Home remedies such as covering the tick with Vaseline or burning it off with a hot match do not work. Save any ticks that were attached for prolonged periods of time for identification by an expert. Of course the best way to not get a tick bite is avoid the ticks in the first place. Avoid walking in tall grass. Wear long sleeves and long pants. Tuck your pants into your socks so you can see the tick crawling up the outside of your pants, not inside. Apply insect repellent, such as products containing DEET (N,N-diethyl-meta-toluamide) to clothing also helps. Of course consult your doctor before applying DEET to children. And always check yourself as soon as possible. As for me, ticks don’t bother me, it’s those darn mosquito that drive me crazy. Until next time…