Imagine yourself seated comfortably on the couch reading a book, when
someone turns up the thermostat. As the room gets warmer, you start to get uncomfortable.
You take off your sweatshirt and kick off your shoes, but you continue to read
for a while. Pretty soon the heat gets to be too much. You try changing
positions and moving to different parts of the room, but eventually you succumb
to the heat and are forced to leave the room altogether. Global Warming affects
life in pretty much the same way as the cranked up thermostat. The movement it
induces is called a range shift and it can cause a whole mess of problems.
This blog will look at two very closely related cats, the Canadian Lynx, Lynx canadensis, and the bobcat, Lynx rufus. We’ll explore how global
warming, and the associated range shifts caused by climate change, will affect
each species differently and why.
| Canadian lynx, Lynx canadensis. |
The Canadian Lynx stalk the boreal forests of Canada and Alaska with some populations reaching down into other northern states like Washington, Wyoming, Wisconsin, Minnesota, and most of New England. Populations, previously extirpated, have been reintroduced to traditional habitats as far south as Colorado.14 Wherever they are found, the constants in Canadian Lynx habitat are long winters, persistent snow fall and deep woods. The Canadian Lynx is well adapted to hunting in snow with greatly oversized paws that act like snowshoes and extra-long back legs that help reduce body drag through deep snow. Based purely on square mileage, the size of the Canadian Lynx’s home range is large. However, the variety of habitats it calls home is not very diverse and the assortment of prey it consumes is even more limited. As much as 97% of a Canadian lynx's diet has been shown to consist of the snowshoe hare, Lepus americanus. The Canadian Lynx is a true specialist that exploits its adaptations to both terrain and prey with great success.11
| Bobcat, Lynx rufus. |
The bobcat by contrast is a true generalist. It inhabits a range from the southern end of the boreal forests in southern Canada and continues southward until the scrub lands of Mexico give way to tropical jungle. This zone of latitudes includes the deserts of the southwest, the swamps of the southeast and the temperate forests of the north. The only regions where bobcats are not found are areas of extensive farmland without much cover. The bobcat’s diet is just as flexible with one study showing the same population eating 40 different species of prey.11
While both of these species are considered non-threatened by most assessments, history seems to tell a different story and one of these animals may indeed have much to fear from climate change.
Lynx photo curtsey of Gerald and Buff Corsi © California Academy of Sciences
Bobcat photo curtesy of the US Forestry Service.
Thermostat picture taken from public domain.
