 A Trip to Mammalonia This column is usually devoted to birds but today we’re heading towards the world of mammals (and for good reason.) The first reason, today I came across a book The Mammals of Canada by A. W. F. Banfield. It is a thick and very readable tome and looks like the companion book to Godfrey’s The Birds of Canada. It wasn’t just the presence of this book that turned me towards mammals, it was a number of animal contacts I’ve had lately and the questions they raised. Here are the questions: How many litters does a Bushy Tailed Wood Rat (Packrat) have per year? What is the life cycle of the local Columbian Ground squirrel? How many species of Weasels are found in the Cariboo? How do you tell a Deer Mouse apart from a White-footed Mouse? Does the Badger hibernate? The Packrat My Packrat interest was stirred when a number of the creatures moved into the house over summer. I got wind of their presence through the loud thumping and carrying on in the ceiling, but by the time I borrowed a live trap a female packrat managed to spawn a litter in the area of the house above the bathroom. I reasoned that if I trapped the female while the babies were young and virtually immobile I would end up dealing with a nest of dead Packrats. So I waited. By the time I determined that it was safe to set out a live trap the nightly sounds from upstairs were quite disturbing. One after one I caught and released the packrats, first luring them into the trap with a hearty peanut butter sandwich. The packrats varied in size from small Rabbits down to a sleek specimen about the size of a Red Squirrel. I caught five in all and I hope that’s the end of it for a while. This activity brought up the question - just how many litters can a packrat have in a year - and here in the book on mammals was the answer. In captivity, and in the south, Packrats can have at least two litters per year, with each litter about two months apart. In the north the book suggested more than one litter was not likely. I reasoned as much because a mother Packrat would need a good food supply and only natural foods would be available. The Columbian Ground Squirrel The Ground Squirrel is a perky little creature often seen in pastures. It lives communally and digs a number of holes much to the dismay of people with livestock. Columbian Ground Squirrels can be found in a confined area from the Cariboo southward into a few northern states just across the 49th parallel. A lot of people call the Columbian Ground Squirrel a Gopher but a Gopher is another species entirely. If someone asked a Columbian Ground Squirrel how was the weather in the Cariboo, the squirrel would probably reply that it was always spring or summer and there was no winter. This is because Ground Squirrels emerge from hibernation at the middle of May and return to their burrows for a long winter nap in the middle of August. So, from their perspective our climate is an endless summer. I wondered if my observation of the Ground Squirrel’s long hibernation time was accurate. According to The Mammals of Canada, hibernation in eastern Washington State is from 208 to 220 days, the female sleeps longer than the male, and hibernation varies according to the severity of the climate where the animal lives. My own estimate put the length of hibernation in our area at 275 days but comparing it to the numbers given in the book this seems a bit long. I also learned a great deal about the tunneling of the Ground Squirrel with its penchant for digging a sump near the hibernation chamber so that spring melt water going down the hole doesn’t drown the sleeping Squirrel. The Weasels In recent days the dogs have busied themselves trying to catch a large Weasel that hangs around the outbuildings and woodpiles. I’ve studied the weasel as it zips by, and deduced that it is about 18 inches long. This led me to wonder if the weasels I’ve seen in the Cariboo are different species, or just varying lengths of one type of Weasel. The Mammals of Canada indicates that 2 and possibly 3 species of Weasel are found in our area. The Long-tailed Weasel, and the Ermine or Stoat can be found locally, and The Least Weasel’s range just borders the Cariboo. The large Weasel seen entertaining the dogs is a Long-tailed Weasel and can reach a length of 20 inches. The other common species, the Ermine is about 12 inches with females noticeably smaller than males in all species. Deer Mice If you live in a place where mice can enter they will take over if left unchecked, at least that’s how it seems. At the height of an invasion it reminds me of the movie Joe’s Apartment, but in this case the singing you hear in the walls and ceilings is not cockroaches, but long-tailed scampering mice. At the tail end of a mouse invasion, as I unceremoniously dumped a dead mouse from a trap, I noticed the mouse was somewhat browner than many others. So how do you distinguish a Deer Mouse from a White-footed Mouse? After all the Deer Mouse is linked to Hantavirus and I don’t want to go around thinking all long tailed mice were suspects. The Mammals of Canada indicates that telling the difference between the two species is quite difficult. The Deer mouse has a few characteristics that might help. It has a hairier bi-coloured tail, black on top and whiter below. It also has a white tuft of hair on the dorsal side at the base of the ear. It also features a dark spot in the area where the whiskers sprout. Both species of Mice go through several molts with variations in colouration during different ages so looking at colour doesn’t seem helpful. Both species will enter human habitations. The range of the White-footed Mouse is very restricted in Canada whereas the Deer Mouse is widespread. The Badger I have never seen a Badger but over the summer I’ve been very close to one. In the east pasture I discovered some Ground Squirrel holes had been greatly enlarged, and copious amounts of dirt were piled at the entrances. I ran through my knowledge of animals that might do such extensive earthen-works and the only likely suspect is a Badger. I recently revisited the holes and although many of the diggings looked relatively fresh none appeared current. That is until Thanksgiving Day weekend. The day after a rather strong wind storm knocked out power for four hours, I was crossing the east pasture with the dogs and saw new dry mounds of dirt heaped around a few of the Ground Squirrel holes. With the amount of rain that fell I knew the dry dirt meant recent diggings. The Ministry of the Environment (MOE) is interested in the local Badger population so I put in a call and was told they would send out a biology student. The student would see if he could snag a few hairs from the animal and get a positive identification on the digger to see which one of their Badgers it was. In the mean time I read up on Badgers to see if they hibernate. It seemed likely since such a large animal would need to have some way of conserving energy. The Badger is rather cumbersome on foot and heavily relies on its ability to dig through packed earth to catch prey. It would have a difficult time remaining active through a season of frozen ground and deep snow. The Mammals of Canada indicated that Badgers do hibernate and as the MOE person said, ‘This is about the time Badgers begin to hole up for the season.’ Perhaps the Badger on the property will sleep away the winter in the east pasture area. I still have many more questions regarding mammal behavior but for now I will leave the subject. In the future I will no doubt be reading more from the pages of The Mammals of Canada. To e-mail Tom CLICK HERE To look at previous column CLICK HERE |
