In the argument, the author concludes that the reason for the decline of the arctic deer population is global warming, since it melts ice and makes migration impossible. To support this point, the author cites the information on local hunters’ reports and the global warming trend. Nevertheless, the evidence lends little credibility to the conclusion for some other indispensable evidence is needed to evaluate the argument.

In the first place, the author mentions reports from local hunters but fails to prove the representativeness and the authority of those reports. Only when made by scientific analysis and based on numerous examples can reports be convincing. However, the fact is that the author does not mention how many hunters have reported the phenomenon and whether those reports can cover the majority of Canadian islands. If reporters are from several hunters and a minority of islands, they will not present us with the whole picture. For example, current disturbance may also be able to change the climate of an area. Moreover, hunters’ reports are barely based on their rough observation and estimate. Considering that they are not experts, hardly can they accurately report the population change. Maybe, it is just a normal fluctuation. In this case, the author should invoke some scientific analysis and statistics to draw a conclusion.

In the second place, the author contributes the decline to global warming. Although two facts happen simultaneously, the author does not provide any direct proof of the existence of the causality. Assuming that it may be a coincidence, global warming is present but is not strong enough to induce the significant ice melt in the north pole. When trying to build a connection between those two facts, the author should provide evidence about how much global warming affects the ice melt in the particular area.

In the third place, the author does not testify that when being unable to migrate, deer cannot survive. Actually, it seems to be not the case. Generally speaking, animals migrate to forage for food. When global warming raises the temperature there, the climate will get hospitable enough for more plants to survive. Under this scenario, deer are able to get enough nutrients without migration. In order to buttress the point, the author should prove that deer still have to migrate to forage for food.

To sum up, the conclusion lacks credibility for evidence is still too scarce to roll out alternative possibilities. To strengthen the argument, the author would have to furnish more information concerning the quality of reports, the connection between global warming and the decrease in deer population, and the necessity of migration after the temperature rising.