VIII,Local Ecosystem: Lke Bachman sparrow, some animals prefer frequently burned areas like gopher tortoises that feed on grasses and herbs in frequently burned areas, and their burrows are often used by Bachman’s Sparrows for escape cover. Bachman sparrow disperses seeds and destroys some insects and other bugs to balance the ecosystem. Their commensal/parasitic species (symbiotic relationship in which one species is benefited while the other is unaffected ) are brown-headed cowbirds…
Oliver begins this essay by contrasting the horned owls commanding presence compared to that of other species. The saw-whet and Screech owl are described as “delicate.” The saw- whet is even compared to a big soft month. These descriptions set up a stark contrast of the horned owl which is described having, “razor tipped toes” and “a heavy hooked beak.”…
* For example, hawks feeding on field mice kill certain individuals (over ecological time), reducing population size (an ecological effect), altering the gene…
A recovery plan was established in 2008 along with the first critical habitat. The Late-Successional Reserves (LSR) was created across the owl range for suitable nesting areas. This recovery plan includes efforts to recommend non occupied forest lands of the owl to be harvested rather than their current habitat. They also started an experiment to manage the competition such as the Barred Owl and removed many of them from a shared area with the Spotted Owl to see how their numbers were affected and if it made a difference. The studies showed that it did increase the Spotted Owls population growth due to greater space and less of a threat. “Estimates suggest that the amount of suitable habitat available to spotted owls has been reduced by over 60 percent in the last 190 years. Owl numbers appear to have declined annually since 1985 when many studies began. Spotted owls are currently declining at an average rate of 2.9 percent rangewide each year.” (OFWO). Unless in the next few years we can conserve their habitats in these forests, they are at great risk of…
Along with being found in the same habitat the Bobwhite Quail and Texas Horned lizard are both found at the bottom of the food chain. These two animals are prey items for a very wide array of animals. Bobwhite nests are commonly predated upon and this is why the nesting cover aspect of the habitat management is so important. Habitat managers are now even able to determine what animals are predating Bobwhite nests by how the eggs are broken and/or arranged after being eaten (Hernandez et al 1997). A well known avian predator, the Roadrunner (Geococcyx) is known to eat just about anything including Texas Horned Lizards and Bobwhite Quail eggs making it an arch enemy of many ranchers (Sherbrooke 1990). One of the most brutal predators these animals face is the Shrike (Laniidae) commonly called the “Butcher Bird”. This is because it impales its prey onto barbwire, cactus,…
One of the animals that live in the tundra, the snowy owl, is very interesting! It is very different from other owls. The snowy owl's niche is to reduce the competition for food. It hunts for prey when other owls are asleep so they will not have to watch out for others. It is a secondary consumer that eats mice.…
Have you ever heard of the Black-Footed Ferret? You probably haven’t because they are becoming extinct! To begin, elements that are killing these animals include death by car, trapping, predatory animals and malnutrition. Next, in 1973 the government put the Black-Footed Ferret on the endangered list, and is currently still considered endangered today. Nevertheless, Defenders of Wildlife is an organization that's trying to assist with restoring the ferret to its original numbers and reintroducing them brand-new areas. However, Defenders of Wildlife also must try to save the prairie dogs as well since they are ninety percent of the Black-Footed Ferrets diet. So to recap, we need to breed the ferret, be more mindful on the roads, and stop killing…
The Farallon Islands aviary wildlife is under attack and something needs to be done about it. The Farallon Islands are a chain of islands about 28 miles west off the coast of San Francisco. They are used by by hundreds of seabirds for feeding, nesting, and breeding. In fact these islands have a greater variety of bird species than almost any other place in the world. The problem is that mice have overrun the island eating the bird eggs and killing the young birds. Some areas are so densely populated with mice that the biologists on the island say that sometimes the ground seems to move (Frimrite, Peter 1). There are three suggested solutions to the problem so far. One solution would be to do nothing. Another would be to use a less potent poison such as Diphacinone but distribute it often and for a long period of time. The final option would be to use an extremely potent poison such as Brodifacoum and distribute it for a shorter period of time and less often. In this paper we will look at the second option of using a less potent poison and try and determine whether this would be the best approach.…
The Peregrine Falcon (Falco peregrinus), or Duck Hawk, is a medium-sized raptor weighing 2 to 2 ½ pounds. These remarkable birds of prey measure 15-21 inches and have a wingspan of about 3 ½ feet. Their name, Peregrine, comes from the Latin word peregrinus, which means “to wander”. The name fits, given that they have one of the longest migrations in North America and are found on every continent besides Antarctica. Peregrine Falcons hunt pigeons, crows, waterfowl, starlings, jays, and other small to medium sized birds. They are also known to hunt for bats and other small mammals (Defenders of Wildlife). They are best known for their spectacular hunting methods in which they catch their prey mid-air. If that is not impressive enough, they do it while plunging at speeds of up to 200 miles per hour, killing or stunning its prey instantly (National Geographic). What is even more impressive than any of this is the fact that the Peregrine Falcon was on the verge of extinction and has made a remarkable comeback. The cause of their brush with extinction was the result of the use of organochlorine pesticides, mainly dichloro-diphenyl-trichloroethane (DDT) (The Santa Cruz Predatory Bird Research Group).…
2.) Carey, Andrew. January 2004. “Squirrels Cannot Live By Truffles Alone: A Closer Look At A Northwest Keystone Complex”. Science Findings. Issue Sixty.…
Why are field studies, such as the monitoring of owls, important in the study of ecology?…
Road construction and operation often cause the topography, vegetation, runoff and micro-climate characteristics to significantly change, resulting in interference to wildlife, forcing original living habits and activity patterns to change. For example, traffic noise affects the communicating, living and breeding activity of birds. In 2011, an estimated 300 dead birds have been found on the side of the I-65 highway in Alabama; some large habitats which are low in reproductive rate and require specific biotopes are more sensitive to the highway construction and operation, such as Alabama red-bellied turtles, which are endangered species in Mobile Bay, Alabama. During the construction of highways, construction also can result chaos to the soil animals and amphibians. During during the operation, it easily causes the roadkill of the small animal who tries to cross the highway, like the dead raccoons always found on the Interstates in Alabama.…
Evidence provided to support these claims of human and wildlife harm is largely from laboratory studies in which large doses are fed to test animals, usually rats or mice, and field studies of wildlife species that have been exposed to the chemicals mentioned above. In laboratory studies, high doses are required to give weak hormone activity. These doses are not likely to be encountered in the environment. However the process of bioaccumulation can result in top-level predators such as humans to have contaminants at levels many million times greater than the environmental background levels (Guilette 1994). In field studies, toxicity caused by endocrine disruption has been associated with the presence of certain pollutants. Findings from such studies include: reproductive disruption in starfish due to PCBs, bird eggshell thinning due to DDT, reproductive failure in mink, small penises in alligators due to DDT and dicofol (Guillette 1994, Colburn et al 1996). In addition, a variety of reproductive problems in many other species are claimed to be associated with environmental contamination although the specific causative agents have not been determined. One recent discovery that…
species or its' habitat. It is the latter part of the bill that causes the…
Casida , a professor of Environmental Science at the University of California in Berkeley, when observing pesticide-environment interactions reported; “A large number and great variety of pesticides… have reproductive and endocrine disrupting effects in mammals and wildlife” (Casida, 492). Many pesticides cause hormone levels within animals to become unbalanced, affecting sexual organs and reproductive systems, causing them to have unnatural issues. Such effects range from small, unnoticeable changes in the physiology and behavior of a species to destroying bird embryos to permanently altered sexual differentiation. In a recent case, bald eagles were at the top of the endangered species list. As a result of exposure to the pesticide DDT, the eggshells of the eagles became thin, causing them to break during the incubation period. DDT was banned in the late 1970’s and the bald eagle populations have been rising since (Bald Eagles, Sea to Shining Sea). As one could imagine, if DDT had not been regulated and banned in the United States, then the country would have lost its majestic national bird to pesticide poisoning. This shows that pesticides are extremely harmful to wildlife and can cause detrimental damage not only to the animal itself, but to its…