Introduction
This presentation focuses on a single bird species, the American Crow. It is a common name of this bird, while its scientific name is Corvus brachyrhynchos (Townsend, Taff, et al., 2019). Its picture is present on the slide to demonstrate its appearance. American Crows typically live in the northern United States and eastern Canada. They can also appear in the southern US, but smaller numbers reside in this region. The current presentation will offer the bird’s physical description, life cycle and reproduction peculiarities, and essential conclusions that will summarize the information about the American crow.
Why Choosing American Crow
There is specific reasoning behind choosing this species for review. Firstly, the birds’ current locations in the northern United States result in the fact that American Crows are interesting for the presentation. Secondly, this species has exciting breeding and reproduction tendencies that deserve attention. Thirdly, the birds’ ability to communicate and warn others of approaching predators represents another focus of interest and demonstrates how the birds’ brains function. Consequently, all these and a few other factors contribute to the fact that there is a strong research interest behind studying the American Crow and identifying behavioral features of this species in the given presentation.
Physical Description
Even though the picture on the slide may not reflect it, an American Crow is a large bird. In particular, an adult male or female American Crow is 40-53 centimeters in length, weighs 316-620 grams, and its wingspan ranges between 85-100 centimeters (Cornell Lab of Ornithology, 2017). Simultaneously, the American Crow is entirely black, including feathers, legs, and beak. This description demonstrates that this species includes middle-sized birds that have a distinctive appearance. Consequently, it is not problematic to locate and notice the American Crow in the wild.
Life Cycle
The American Crows live in huge nests that they build from sticks (Freeman & Miller, 2018). These birds build their dwellings on conifers and oak trees to ensure that nests are sufficiently hidden under the foliage and benches. Like all the birds, American Crows are oviparous, and they use their nests to lay legs and reproduce (Freeman & Miller, 2018). These birds typically live seven to eight years in the wild. This information demonstrates that the American Crows do not have many unique characteristics regarding their life cycle, while a 7-8-year lifespan can be considered a specific feature compared to other species.
Reproduction
As has already been mentioned, the American Crows are oviparous, and their reproduction behaviors are interesting. It is worth admitting that these birds are monogamous and draw sufficient attention to choosing a mating partner. However, it is reasonable to state that American Crows have inbreeding preferences that refer to mating between relatives (Townsend, Taff, et al., 2019). This feature results in the fact that American Crows suffer from inbreeding depression that, in turn, leads to low heterozygosity contributing to weaker immune response, lower survival probability, and many others (Townsend, Taff, et al., 2019). Consequently, American Crows are subject to deviant reproductive behaviors that adversely affect the offspring’s quality.
Functioning
Now, it is reasonable to comment on how the American Crows function in the wild. These birds use their wings for multiple goals since they help the birds fly, search for food, and find mates. Since American Crows are omnivorous birds, they have specific beaks that allow them to eat almost everything (Bradford, 2017). Cawing is the primary means of communication between these birds. They rely on this strategy to signal that they have found food and to warn others when they see a dangerous predator. In particular, communication patterns of the American Crow deserve more attention, and this area is covered in the following slide.
Communication
According to the previous information, cawing allows American Crows to disseminate and obtain information, but it is necessary to mention what specific data these birds can use. On the one hand, American Crows make alarm calls when they witness a predator that can harm them or conspecific creatures. Simultaneously, the same calls are responses to finding dead crows, and an experiment by Swift et al. (2020) with artificial objects in the picture has proven this thought. On the other hand, the American Crows can make food begging calls in particular situations to ask for help (Swift et al., 2020). This information demonstrates that American Crows have an extended communication system.
Intelligence
In many cultures, crows are a symbol of intelligence, and there is some reasoning behind this suggestion. Sufficient evidence demonstrates that American Crows are capable of solving difficult tasks to gain food. For example, a laboratory experiment by Pendergraft et al. (2020) identified that these birds could easily get a piece of fried chicken that was hanging on the string. In fact, the picture by Pendergraft et al. (2020) reveals three methods of how the birds solved the task. Furthermore, the researchers identified that American Crows were likely to copy conspecific models in getting the food. That is why it is not a surprise that many people admit high intelligence of this species.
Energy Ecology
The American Crows are from the kingdom Animalia, meaning that they are warm-blooded creatures. Consequently, they consume food that is turned into energy necessary for the birds to fly, grow, and reproduce. With this, Townsend, Staab, et al. (2019) conducted a study and found that urbanization behaviors among American Crows resulted in the fact that the birds have high cholesterol levels. This fact occurs because they consume high-calorie and high-fat anthropogenic foods (Townsend, Staab, et al., 2019). However, it is worth admitting that this phenomenon does not result in deteriorated body condition, according to Townsend, Staab, et al. (2019).
Migration
As has been mentioned above, the American Crows typically live in the northern United States and eastern Canada. However, they tend to change their habitat in winters and during breeding seasons. In particular, the birds tend to overwinter in large communal roosts, and when winter is over, some of them migrate north to breed (Townsend et al., 2018). The picture by Townsend et al. (2018) reflects the migration roots of an American Crow in Utica, New York. Another characteristic feature of the birds’ migration behaviors is that they typically return to the same locations after the breeding period or when winter is over.
Aggression
Furthermore, it is necessary to explain that the American Crows are subject to interspecific aggression that is typical among different birds. In particular, American Crows can attack Common Ravens irrespective of the fact that ravens are larger than crows (Freeman & Miller, 2018). According to a scientific study is observed during March-May when American Crows have a nesting period (Freeman & Miller, 2018). Consequently, these birds consider Common Ravens a threat and attack them to protect offspring. Another essential feature is that a smaller size makes American Crows gather in small groups to attack Common Ravens and avoid one-to-one contests (Freeman & Miller, 2018).
Conclusion
In conclusion, the presentation has offered a comprehensive overview of the American Crow. These all-black birds live in the northern USA and eastern Canada and have a few features that deserve attention. Thus, the American Crows are monogamous and also have inbreeding preferences leading to low heterozygosity and connected consequences. With that, the species shows high intelligent levels since these birds use cawing to communicate and can learn from conspecific models to solve tasks. They are omnivorous, which results in high cholesterol levels that, in turn, do not imply adverse impacts. Finally, the American Crows are partially migrant and aggressive to other birds during nesting periods.
References
Bradford, A. (2017). Facts about crows. Live Science. Web.
Cornell Lab of Ornithology. (2017). American crow identification. Web.
Freeman, B. G., & Miller, E. T. (2018). Why do crows attack ravens? The roles of predation threat, resource competition, and social behaviour. The Auk, 135(4), 857-867. Web.
Pendergraft, L. T., Lehnert, A. L., & Marzluff, J. M. (2020). Individual and social factors affecting the ability of American crows to solve and master a string-pulling task. Ethology, 126(2), 229-245. Web.
Swift, K. N., Marzluff, J. M., Templeton, C. N., Shimizu, T., & Cross, D. J. (2020). Brain activity underlying American crow processing of encounters with dead conspecifics. Behavioural Brain Research, 385, 112546. Web.
Townsend, A. K., Frett, B., McGarvey, A., & Taff, C. C. (2018). Where do winter crows go? Characterizing partial migration of American Crows with satellite telemetry, stable isotopes, and molecular markers. The Auk, 135(4), 964-974. Web.
Townsend, A. K., Staab, H. A., Barker, C. M. (2019). Urbanization and elevated cholesterol in American Crows. The Condor, 121(3), 1-10. Web.
Townsend, A. K., Taff, C. C., Jones, M. L., Getman, K. H., Wheeler, S. S., Hinton, M. G., & Logsdon, R. M. (2019). Apparent inbreeding preference despite inbreeding depression in the American crow. Molecular Ecology, 28(5), 1116-1126. Web.