Arctic deer live on islands in Canada's arctic regions. They search for food by moving over ice from island to island during the course of the year. Their habitat is limited to areas warm enough to sustain the plants on which they feed and cold enough, at

At first glance, the author’s claim that the decrease of population of arctic deer is because they cannot follow their traditional habitat by global warming seems reasonable. However, it not only suffers from logical flaws but also it bases its conclusion upon several questionable assumptions. Before the author arrives at the final conclusion, he needs to clarify the following points.

In the first place, the author referred to the report that local hunters informed that deer populations are declining. However, basing his argument on this report is not credible because methodologies of local hunters’ report are ambiguous. They might just be unable to find deer. It is also vague whether or not local hunters really counted the numbers of deer. Besides, no information about the past deer populations, research period, and other additional information about the research are all overlooked. The author has to show the evidence that the deer populations are definitely declining to prove the credibility of his argument.

In the second place, the author pointed out that global warming prevented sea water from freezing. Nevertheless, data about melting ices in their habitat is not taken into consideration in his argument. The average temperature of the earth is constantly increasing; it does not guarantee the temperature increment in the arctic deer habitat. Moreover, even if the temperature of their habitat is increasing, it does not prove that the sea water of their habitat did not freeze. The temperature is still low enough to make sea water freeze. Hence, the author must show the evidence that verify the fact that sea water did not freeze due to recent global warming.

In the third place, the author jump to the conclusion that the decrease of the deer population is because of the difficulty to follow their age-old migration. Nonetheless, not only this difficulty but also other factors would affect the reduction of deer populations. Female deer might encounter reproduction problems. The populations of predators of arctic deer were increasing. Hunters might shoot too many deer. Furthermore, it is possible that a new infection was spread among the deer. The evidence that demonstrates that the difficulty to follow their traditional migration system cause the decrement of the deer population to authenticate his argument.

As discussed above, the author’s claim is based upon several assumptions that are not sufficiently supported. Before he makes the final conclusion, the author needs to acknowledge that there are many factors that are involved in this story, and undertake additional investigation to clarify uncertainties pointed out above.