Animal Species Studied for This Report Include

¶ … animal species studied for this report include the Gray Wolf (Canis lupus) and the American Black Bear (Ursus americanus). The plant species studied are the Venus Flytrap (Dionaea muscipula) and the Prickly Pear cactus (Opuntia humifusa). Each of these species has been observed at the local zoo, and further research has been conducted to learn about the environment in which each species would live in a natural setting. The behavior which have been observed within the zoo have also been combined with the noted behaviors of these species from a natural setting to give a more complete range of information. From this study, I have learned that there are many similarities between the behavior that can be observed in both plants and animals in a captive setting and their natural behavior. However, there are also many notable differences, based largely on to what degree the zoological habitat varies from that in which each species would naturally live.

Introduction

Every living creature on this planet has a unique and (usually) symbiotic relationship with the habitat that surrounds them. Through the physical characteristics and the behavior of a being, it is possible to determine a great deal about how said creature interacts with its habitat, and also to learn about the evolutionary processes that have brought this plant or animal to its current form. The purpose of my study is to gain a deeper understanding of the biological characteristics of the animals and plants I have observed in captivity and to learn about the natural habitats of the species as well. I will address both the habitat which has been created for this animal or plant in the zoological display in an attempt to mimic the natural environment in which it would be found, and also the actual natural habitat itself.

The organisms discussed within this study were chosen because, when observed, each exhibited very unique characteristics and mannerisms that were telltale of both that organism's role in the natural habitat, and also of how differently the animal may behave within the captive habitat.

The gray wolf (Canis lupus) can be found naturally in Europe, North America, Asia, and the Middle East, where the natural habitats include forests, tundras, deserts, plains, and mountains, ranging from snowy mountain tops to the heat of the desert. Wolves were once located throughout much of the world, but humans have overtaken much of their natural habitat. The American black bear (Ursus americanus) is the most common bear species in North America, and it can be found living anywhere from Alaska and Northern Canada, all the way south into Mexico, and from the Atlantic to the Pacific oceans. The black bear can also live in climates from those that are warm, in the southernmost parts of their range, to the very cold, in the Northern parts of their range. The black bear naturally lives in mountains and woodlands, and usually is found within protected parks and wildlife preserves. Like the wolf, bears have been hunted and forced from their natural habitats. The Venus flytrap plant (Dionaea muscipula) is found naturally in the wet bogs of the southeastern United States, especially around North Carolina. The soil in these bogs are lacking many nutrients, including nitrogen, which is vital to the growth of the plants, which is why the plants need to draw nutrients from flies and other insects. Finally, I observed two species of the Oputina cactus: the Eastern Prickly Pear (Opuntia humifusa) and the Plains Prickly Pear (Opuntia macrorhiza).

The Eastern Prickly Pear is found naturally east of the Great Plains in the United States, and into southern Ontario in Canada. The Plains Prickly Pear is found all throughout the Great Plains in the United States, except the northernmost areas, such as North Dakota. The Prickly Pear tends to grow in sandy or rocky soil. In a natural setting, many of the habitats of these four species would overlap, and they would in fact be found in situations where they would be interacting with each other as parts of the same ecological system.

The Gray Wolf (Canis lupus)

The Gray Wolf is considered to be among those on the top of the food chain in many of the ecological systems in which they reside, which means that the success of all species in an area can be at least partly determined by the success of the wolves. The average gray wolf ranges in size from 40 to 60 inches in length, plus a tail of between 12 and 20 inches long.

The males are larger than the females, and full-grown wolves will weigh between 26 and over 170 pounds. Wolves are known to live between eight to 16 years in the wild, but up to 20 years in captivity.

Wolves live and hunt in packs which are usually up to 12 wolves, with an alpha male and alpha female in charge, and the omega wolf at the bottom of the hierarchy. Generally the alpha pair is allowed to eat first, and is the couple to actually breed. Wolves will sometimes, though not always, leave their birth pack to claim a new territory, and wolves in search of a new pack will travel very long distances, or packs will reform if the alphas are killed. When hunting in a pack, wolves will take down prey much larger than any individual wolf, though lone wolves will catch smaller animals. Many wolves are highly skilled at fishing as well.

Wolves have many highly developed hunting methods for land prey, including surprise attacks and long chases which may last several hours.

Wolves adjust well to fluctuations in prey populations so there is little starvation among packs, and in fact most wolves will supplement the meat and fish with various forms of vegetation. Some wolves have even been known to live on a largely vegetarian diet for extended periods of time.

Vocal communication among wolves includes yips, growls, and howls, which can range from sounds barely audible to human ears, to howls that will travel for miles.

Yips are often used to communicate with the young or to call pups together. Growls are used as a warning or threat display, though they are commonly heard in wolves that are play-fighting with each other as well.

Howls will be used to summon packs together, or to establish territory.

Wolves will not howl very often when they are attempting to avoid conflicts with nearby packs. Like many other wild dogs which hunt in packs, it is the norm for only the alpha male and the alpha female to reproduce. Mating season is usually between February to May, and wolves normally only reproduce once a year. Gestation for puppies is usually around two months, and litters vary in size depending on many factors. Wolf pups are born helpless to fend for themselves at all, and they will reach sexual maturity at two years of age, like most breeds of dog. Few wolf pups survive their first winter in the wild due to the harsh conditions, however the most significant risks for grown wolves are humans, in the form of hunting, poaching, and car accidents. Wolves are also at risk from injuries sustained from fighting and hunting, and from the diseases such as rabies, mange, and worms which also affect domesticated dogs. (In fact, the domestic dog is often classified as a subspecies of the wolf, Canis lupus familiaris, so wolves and dogs share many similar traits.) Wolves, domesticated dogs, jackals, and several other similar species appear to have evolved from the same origins.

In observing the wolves, there were many striking physical features and behavioral characteristics of which I took note. The first was an observation of their build. Obviously, wolves have evolved to have superior running ability, through long legs and a slender body, which could be accurately described as aerodynamic. The coats on the wolves have a heavy, thick undercoat and also a more slick outer coat of longer fur. This provides excellent protection from the cold climates in which many wolves live, and also is waterproof for wolves that spend much time hunting or playing in the water. The jaws on the wolves were at the same time powerful and also well controlled. Unlike many domesticated dogs who seem to have little control over their snapping jaws, the wolves were able to use their mouths very delicately when playing and wrestling with each other; in fact, mouthing at each other seemed to be a form of both play and communication among the wolves observed. The wolves also have highly responsive ears that turn to pick up even the faintest sounds, and this developed sense of hearing would be a great asset when hunting, or when avoiding hunters. The pack hierarchy was highly observable in the wolves, and the alpha male spent a great deal of time getting on top of rocks and other high places to help establish his place of dominance. The omega wolf was also easy to spot, as the others were ceaselessly pinning him to the ground and otherwise asserting their dominance. The omega wolf would keep his head hung low, while the Alpha kept his head held very high. Although the wolves in captivity obviously did not hunt prey, they did play with large beach balls provided to them in a manner similar to what I would expect from a pack hunting, with the different wolves running around to keep the "prey" herded in while others lunged in for the attack.

The American Black Bear (Ursus americanus)

The black bear, also known as the cinnamon bear, is the most common bear in North America. In fact, 39 of the 50 United States have black bear terrain within them. Today the number of black bears sits below 200,000, though once there were as many as two million in North America. The black bear is about five feet long. Males, which weigh in around 290 pounds, are much larger than females, which are usually only around 90 pounds. Incredibly, some black bears have been recorded as weighing close to 700 pounds. Cubs are born weighing about one pound. Black bears have small eyes compared to their long snout and large body. Their ears are round, and they have a short tail. Black bears are usually but not always black, and can in fact range in colors from white and blonde to dark brown, and the fur is shaggy.

Black bears normally walk in a shuffle on all fours, though they might stand on their hind legs to walk for a brief time. The paws have five claws each that are very strong and used for digging in the ground, climbing trees, and tearing flesh.

They enjoy forested and shrubby land, but also roam meadows, tidelands, ridgetops, and a wide variety of terrain.

They utilize heavy forest cover for hiding and warmth, and will climb trees to escape danger. These bears do hibernate over the winter in warn dens.

These bears are sexually mature at four years old, and they only breed every two to three years. They breed in May or June, but the majority of fetus development takes place over the winter while the mother hibernates, and they will be born during the winter. Black bears do not generally hunt, although they could easily take down large prey animals. They eat mostly vegetation, but also some carrion and insects.

The Black Bears I observed were not nearly as active as the wolves previously studied. However, it was easy to tell that their heavy fur was protective against the cold and also against the water in which they seemed to enjoy swimming. I did at one point see a black bear stand on his hind legs and grab for a tree branch with his front paws, so it was possible to tell how the bear has evolved to be able to both shuffle on all four legs, but also to stand on the hind legs alone to use the heavy front paws and additional height to reach for things. When the bears hid under the brush in their habitat, they were very difficult to see, and again this camouflage is a great evolutionary advantage. The bears seemed very gentle and lazy, not quite the roaring vicious image portrayed in movies.

The Eastern Prickly Pear Cactus (Opuntia humifusa)

The Prickly Pear is one of the most common of the cactus family that natively grow in the Eastern parts of the United States, and they are remarkably resistant to both the cold and to the heat. The Prickly Pear Cactus consists of several levels of flattened pads, up to 10 inches long each, that build from the ground up. The oldest pads are usually blue-green, while the newest pads are more of a yellow-green color. The pads are have several spines, each growing from a raised aureole. The spines appear gray or brown, and are up to four inches long. The plant will also produce yellow flowers with an orange or red center, which will bloom for one day during the summer. It also may briefly have leaves each year. It also produces a delicious, but dangerously prickly, fruit. Usually, this plant stands up to 2.5 feet tall.