American Beaver: A Keystone Species of the US Animal Kingdom - Essay Sample

Introduction

In the natural sciences, a keystone species refers to a class of living organisms that possess a disproportionately magnanimous impact on their habitats relative to its abundance. Across the many ecosystems around the world, several organisms qualify as members of this class, either plant or animal. In America, the American Beaver, scientifically referred to as Castor canadensis, is among the keystone species in the continent's animal kingdom. In this context, this discussion will explore the life history of the American Beaver, highlighting its evolution, ecology, reproduction, and physiology.

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Evolutionary Biology and Phylogenetics of The American Beaver

Beavers are the largest rodents in continental USA and Canada. Typically adult beavers weigh between 16 and 31.5 kilograms, with most attaining a total length of 120 centimeters. Beaver has a generally muscular body characterized with short forelegs, thus a greater heigh at the hips of the animal. The unique feature of the beaver is its dorsoventrally flattened tail, which is shaped like a paddle. Apart from this unique feature, the beaver generally resembles most large rodents whos body proportions result in a short, thick appearance with the broadest part of the animal just anterior of the hips.

Historically the beaver family Castoridae dates back to approximately 40 million years ago with only two extant species today, Castor Canadensis in North America and the Castor fiber in Eurasia. According to Horn et al., earlier attempts by biologists to identify the phylogenetic of the beaver relative to other rodents were considerably tricky due to the lack of morphological differerences, poor sampling texhnique, limited sequence data and contemporaneous radiations across several rodent lineages (3).

In recent years, however, technology has made it easier to localize and clearly distinguish the phylogenetics of the beaver. Horn et al. 's study, for example, recovered six mitochondrial genomes in one monophyletic group within the mouse-related clade of rodents, as had been earlier indicated in nuclear gene sequencing and transposon insertions. The study now placed beavers in the clade of the daily scaled squirrel. Nonetheless, mitochondrial genomics fails to put the beaver in the Geomyoidea, which were earlier thought to be related to beavers, according to multigene studies. Summarily, many studies have proven that substitutions, phylogenetic analyses, and divergence estimates still fail to localize the phylogenetics of beavers to a single clade (Care, Animal, and Use Committee).

Ecology of The American Beaver

Beavers' habitats include freshwater streams and lakes. Beavers are considered keystone species due to their ability to alter their habitats since they cut down trees and construct dams, excavate canals, and form lodges. Beaver building adjusts the circulation and abundance of such a significant number of living beings. Along these lines, we have delivered separate surveys for various gatherings of creatures and plants influenced by beaver designing (Touhiri et al., 23). Snap the accompanying connects to become familiar with the impacts of beaver designing on specific types of flora and fauna. Many predators usually prey on beavers. However, the most impactful have been wolves. While wolves have the potential of significantly reducing the number of beavers, they also enable the beaver to thrive since they scare away other potential predators in their ecosystem (Anderson & Ozlin).

Reproduction in American Beaver

Similar to most mammals, reproduction in beavers is through mating. Beavers are generally monogamous, with the breeding season being between January and February. On average, each pair of beavers produce 2-4 kilts annually after a gestation period of 105 days, meaning that most births occur from April to June. According to studies, beavers achieve breeding capability at 1.5-3 years of age. Nonetheless, these figures may vary dependent on habitat and the availability of food (Feldhamer et al.).

Physiology

Generally, it has been observed that the growth of American beavers is dependent on their environment with climate, the extent of exploitation, latitude, and availability of food being the major determining factors. According to Feldhamer et al., growth in beavers usually peaks between the ages of 4-5 years at approximately 19kgs before declining as the beaver reaches the age of 9 (290). In adults, growth is only limited to the summer, while the kilts continue growing even during the winter. During the winter, beavers thermoregulate through seasonal torpor and their increased body fat as well as through huddling together in the lodge.

Digestion in beavers is enhanced by a prominent and unique cardia gastric gland on the animal's lesser curvature of the stomach, a glandular digestive area as well as through a dominant trilobed cecum containing commensable microbiota that aid it digest the high cellulose diet they consume. Concerning their circulation, beavers lack a unique oxygen storage capacity with the only distinguishing feature about the mammal being the varying heart rhythm, and the countercurrent heat exchanging system is existing at the base of the animal's tail.

Conclusion

Conclusively, the American beaver Castor canadensis is an important member of the ecosystems they inhabit, contributing to biodiversity. Their engineering activities as well as help to the thriving of other species, including birds and reptiles. From the discussion, it is clear that regardless of it being a common animal in the North American content, the science behind its evolution and phylogenetics is still unsolved.

Works Cited

Andersone A, Ozolins J (2004) Food habits of wolves Canis lupus in Latvia. Acta Theriologica 49: 357-367

Feldhamer, George A., Bruce Carlyle Thompson, and Joseph A. Chapman. Wild mammals of North America: biology, management, and conservation. JHU Press, 2003.

Care, Animal, and Use Committee. "Guidelines for the capture, handling, and care of mammals as approved by the American Society of Mammalogists." Journal of Mammalogy (1998): 1416-1431.

Horn, Susanne, et al. "Mitochondrial genomes reveal slow rates of molecular evolution and the timing of speciation in beavers (Castor), one of the largest rodent species." PloS one 6.1 (2011).

Touihri, Moez, et al. "North American beaver (Castor canadensis Kuhl) key habitat characteristics: review of the relative effects of geomorphology, food availability and anthropogenic infrastructure." Ecoscience 25.1 (2018): 9-23.