Sex- Based Migration in Black Bears (Ursus americanus)
Introduction:
Ursus americanus, the American black bear is the most common of the world’s bear species, about up to twelve times more abundant than grizzly or brown bears. They usually occupy forested areas but their habitats are highly variable— from the Louisiana Bayou to the Labrador Tundra, and the Northwestern rain forests in between. (Wilson & Ruff, 1999) American black bears are hunted legally seasonally due to their widespread population and distribution. However, with the increase in deforestation for industrialization in the Tri-State (New Jersey, New York, Pennsylvania) area, the habitat loss could have adverse effects on the black bear populations. An interference with their
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Urus americanus are not known to monogamous and mate promiscuously. (Rogers, 1987) Males mate with more than one female and disperse more, sometimes looking for other females to mate with. Female mothers, on the other hand have a predilection to stay close to their den and care for their cubs. (Garneau, Boudreau, Keech, & Post, 2008) Female bears, or sows, usually breed between June and July around the average age of 4 and produce litter of one to six cubs in late January to early February. (North American Bear Center) However, no molecular data studies have been performed to substantiate previous studies. Since a strong male based dispersal system has been observed in black bear populations, I propose to study this sex biased dispersal using microsatellite markers on the X and Y …show more content…
Fruits or meat will placed about 6 ft high as bait to ensure that the bears reach up between the snares and hair is snagged in the wires. (Engle, 2013) RAPD analysis would be used initially for basic species specific identification from hair-root and scat samples in the field. ‘Minisatellite loci’ can then be used in DNA fingerprinting to identify individuals in the species for the study. If the DNA from a hunted bear matches a previously known individual from either a hair snare or scat sample, that bear will be categorized as a “recapture”. Mitochondrial DNA (mtDNA) would further be used to assign females. A combination of Y-based SNP (single nucleotide polymorphism)—SRY, AML, and ZF, three sex-specific genes, would further be used in distinguishing males from “non-male” bears. (Pagès, Maudet, Bellemain, Taberlet, Hughes, & Hänni, 2008) The genetic data collected and amplified by PCR will be used in assignment tests to determine dispersal and migration in black bears.
The study will take about 5 years (A year being calculated as a period of twelve consecutive months). Each year will be divided into 3 seasons to accommodate for hibernation, migration and mating, and finding new dens. For large mammals like black bears, natural barriers such as rivers do little to hamper migration. Therefore expected dispersal ranges can be over 50
Grizzly bears live in a variety of environments .All of which includes dense forests, subalpine meadows, open plains and arctic tundra . In the past though, they could be found from Alaska to Mexico, and from California to Ohio. Though Nowadays there are efforts trying to make it so grizzly bears can make a comeback and the wild, and all of their efforts are proving to be working, there are 4 times as many grizzlies in the wild as there were in 1975, at
Good literary text can communicate messages more powerfully than good informative text. 2 different texts, Moon Bear Rescue by Kim Dale, and the brochure Southern Asian Moon Bears, are chosen to represent in the argument between literary and informative. Both books are similarly capable of delivering a message, but which is more powerful? Informative clearly states the facts and provide consecutive information; raises awareness for the objective, i.e. Moon Bears, whereas the literary tends to tell more of a story, perhaps information, adapted to entertain the reader, and sometimes, to educate. Because of this, I feel that the literary is much more capable of providing a powerful message, mostly informative text lacks the friendly and heart-warming story that the literary text provides.
Since the beginning of the year we have been reading a book by Ben Mikaelsen named Touching Spirit Bear. Cole starts out as a devious miscreant who never forgave or forgot. Cole soon gets banished to an island for a year. Throughout his experience he learns to start caring and forgiving after being mauled by a bear. To add to that he makes totem faces for everything he encounters such as sparrows, wolves, mice and bears. Each teaching him how he was and what they represented. This project is about how I can be like Cole and make a totem about my life and each animal face symbolizes every part of my life.
The grizzly bear trophy hunt is an issue regarding the citizens of Canada who immorally hunt and kill grizzly bears for pride, thrill, and trophy. Many people question whether this is morally acceptable as hunters kill without a conscience. Grizzly bears are vital to Canada’s environment, as they are essential to maintaining a healthy ecosystem. As keystone species, they regulate prey, disperse seeds of plants,and aerate soil to maintain forest health. Due to the vulnerability and over-hunting of grizzly bears, Pacific Wild and many other non-profit organizations, are working to protect wildlife in British Columbia, especially the grizzly bear habitat.
In this research paper, I will address the changes that occurred within the ecosystem of Yellowstone National Park since the reintroduction of the grey wolves. The paper will consist of four sections; the first section will include the history behind the extirpation and subsequent reintroduction of the gray wolf in Northern America. The second section will explore the political controversy that surrounds the reintroduction of the gray wolf in Yellowstone. The third section will contain discuss the gray wolf and its impact on the ecosystem of Yellowstone. I will conclude my essay by explaining how the gray wolves act as climate change buffers in Yellowstone amidst global warming.
Thesis: The population of white-tail deer in Alabama has drastically increased over the past century causing significant damage to property and homeowners, caused by hunters being less active.
The characteristics of the grizzly bear as a top predator also make it highly vulnerable to threats. Although it is an omnivore, because it relies heavily on salmon to make it through the winter, it is vulnerable to anything that impacts on salmon runs. It needs wide-ranging habitat and is slow to reproduce. As such, grizzly bears are considered not just a key species but also an ‘umbrella species’ because the protection of their habitats will result in an ‘umbrella of protection’ for a wide range of other species. The protected areas that have been set aside in the Great Bear Rainforest are not enough to sustain healthy populations of grizzly bear so it requires additional habitat set aside from logging. Trophy hunting of grizzly bears also continues to place their population at
(1) Most Field and Stream enthusiasts know that cougars are a fast and agile animal that can live for many years with no real predator other than humans. Another name for the cougar is the well used mountain lion which many Eastern states have named stores, schools, and even sports teams after. The distinction that the Mississippi river stops cougars from traveling into Eastern states can’t be proven because there are many animals in the West that are in the East. In Craig Springer’s "A Rumor of Cougar" article posted in the Field and Stream magazine depicts falsehood due to three interesting fallacies, a fallacy of distraction and two causal fallacies. [SS-1]
Populations of the white-tailed deer have increased in great numbers. These will increase if the death rate is low and the food supply is high. A single doe can reproduce every year until they die (7). Because of this, the average herd can double in size every two to three years (3). Deer are also adaptable to the changing ecosystem around them. The growing suburbs provide open lawns, the summer gardens, varieties of shrubs, and patches of forest cover. The population cannot be controlled naturally because natural predato...
...ions in those locations. With less regulation of introductions and more regulation of human termination of wolves, it may be possible to restore the gray wolf to its previous sustainable numbers in the United States.
The winter will last 8 to 10 months followed by the short and much less cold summer. During the summer some lower areas of the Tundra will defrost at which point most of the flora and fauna will start to creep out of hiding. The few summer months are used by many animals such as the polar bear, to mate and to prepare for the once again oncoming winter. During the winter months, most everything remains frozen. Many of the animals migrate south for the winter whereas some stay behind or even group together for ritual group suicide (lemmings).
In the last decade, from the Rockies to New England and the Deep South, rural and suburban areas have been beset by white-tailed deer gnawing shrubbery and crops, spreading disease and causing hundreds of thousands of auto wrecks. But the deer problem has proved even more profound, biologists say. Fast-multiplying herds are altering the ecology of forests, stripping them of native vegetation and eliminating niches for other wildlife. ' 'I don 't want to paint deer as Eastern devils, ' ' said Dr. McShea, a wildlife biologist associated with the National Zoo in Washington, ' 'but this is indicative of what happens when an ecosystem is out of whack. ' ' The damage is worse than anyone expected, he and other scientists say. Higher deer densities have affected growth, survival, and reproduction of many plant species which have aesthetic, economic or ecological value. In some cases, many species of trees have also been shown to have reduced growth as a result of high deer density (Environmental Benefits of Hunting, 1). Deer prefer certain plant species over others and frequently feed on economically valuable tree species. For example, they prefer oak and sugar maple seedlings, as well as acorns, over less palatable species like American Beech and striped maple. Thus, less marketable species are more likely to survive to maturity,
The one way to keep bears and humans safe and living in the same environment is learning to understand them and being able to tolerate them. If people don’t do these things theses beautiful animals will begin to decrease in numbers. While there are a lot of black bears in Alaska, an estimated 100,000, hunters believe that you can just hunt and hunt and the population will decrease to average, but the plans of some hunters seems just over the top of making these bears go on to the endangered species list. But with the help of people and cooperation the Black Bears will continue to live in Alaska.
The Arctic region is home to a variety of valuable animals and plants, including polar bear, seal, and so on. The ecosystem of the Arctic region is fragile because these animals are evolved to live in extreme conditions. With the climate change, many animals are endangered. Ice is the habitat of polar animals because they have to rely on sea ices for resting, food, and reproduction. With the climate change and the decrease of sea ice, the number of polar animals is decreasing and their health is threatened. For example, the average weight of female polar bears in 1980 was about 650 pounds, but the number reduced to about 500 pounds in 2004 (Djoghlaf 15). The earlier breakup and later condensation of sea ice shortens the hunting season of polar bears. Polar bears mainly feed on seals that indwell icy land. The melting ice reduces the number of seals and food intake of polar bears. In addition, polar bears are used to living in ice caves. The rising temperature causes the collapse of ice caves, which can kill baby bears. The climate change is negatively affecting the biodiversity in the region and will definitely harm the ecosystem
Sikes, Roberts. and William L. Gannon. "Guidelines of the American Society of Mammalogists for the Use of Wild Mammals in Research." Journal of Mammalogy 92.1 (Feb. 2011): 235-253. Academic Search Premier. EBSCO. Web. 5 Oct. 2011.