Saturday, October 21, 2006

Mouse hunter extraordinaire

Mouse hunter extraordinaire, the Dugite, Pseudonaja affinis

The lightning fast Dugite of the southern parts of Western Australia really love rodents, although other small mammals and reptiles are not overlooked. The scent of the introduced House Mouse, Mus musculus will have the small to medium sized snakes going to great lengths to doggedly track them down and will even enter through your front door if any mice have taken refuge inside. The larger snakes (to 2 metres below) will seek out the bigger native Bush Rats, Rattus fuscipes. So why this interest in rodents? Maybe their shape has something to do with it!

Young snakes (to 11/2 metres) are long and slender and ideally suited to fitting into a mouse burrow, whereas the larger snakes thicken and will not fit, but do so comfortably down a Bush Rats burrow. The Dugites above and below are large snakes of around 2 metres in length. Both of these lived for a period of time down Bush Rat burrows, where they probably hibernated through winter.

As an example of their interest in rodents, I always have an Elliott trap set to catch any passing mouse in order to stop them breeding up in and around my home. Well I had caught a mouse in the trap the night before, which I had disposed of and then reset. About lunchtime I noticed it had been set off again and assumed I had caught another. So picking it up to see the captive, I discovered the trap was very heavy, much heavier than even a Bush Rat, so I very gingerly peered inside where my gaze was meet by a beady eyed Dugite's. It turned out to be a little over 4 foot in length, but was not really aggressive and was happy to head off into the bush.
Dugite Snake, Pseudonaja affinis

The Dugite belongs to the genus Pseudonaja, the Brown Snakes, which generally have a bad reputation for being very aggressive. However, I have never found the Dugite to be so, from my experience they just go about their business with great determination and will completely ignore you. If confronted they will seek the fastest mode of escape, preferring to flee rather than fight. This I should add only applies to the younger snakes, once they mature, they should be treated with the greatest respect as all large adult snakes are very sure of themselves (being a top predator) and do not submit readily, but will still get out of your way if given the opportunity.

The length of these snakes varies and like the Tiger Snake, are usually smaller on offshore islands, where two subspecies are recognised. Coloration also varies from dark colored ones to the brown ones near me that usually are heavily flecked with darker scales and some (as with the top photo), with a dark brown head.

I have noticed with the Dugites and Tiger Snakes that they occupy a territory and if you are part of it, will return periodically. If there is nothing for them to eat, they will move on, but if not they will stay until they have caught it, or it does a runner. These snakes have good memories and certainly recognise permanent residents and I believe go out of their way not to interfere with you. Even if you come across them suddenly there is no attempt to strike, but only to get out of your way. I like snakes, they are very accommodating!


Anonymous said...

Thanks for your very informative blog on Esperance snakes.... I nearly trod on one down on the path near West Beach today and am wondering if its a baby dugite. It was silvery grayish in colour and only about 20cm long.

WA said...

Hi Anonymous
Don't think your snake is a dugite, as a bit short for one of those even if just out of the egg. Coloration does not match any snakes in the area either. Sounds more like one of the Legless Lizards or Worm Lizards. There are quite a number around Esperance, but I only have two listed (you will need to see my Esperance Fauna Blog): and check out Reptiles - Lizards/Legless. If not either of those, the legless lizards all belong to the family Pygopodidae, so google that and check out those listed for this region.

Hope you find it.

Anonymous said...

Hi snake lover
I wish i could say the same about myself. I teach in a school in Northam where there have been 3 young snakes found over the last week... one of which was in my classroom. This is the second time this has happened to me, although I am slightly relieved to say this time the snake was much smaller than the first. I have been told most of them were dugites and one may have been a tiger snake. I am trying very hard to understand these creatures and decrease my fear, so that I am not constantly worried when I'm at work, in my garden and walking my dog or even at home now that I have noticed a mouse or two visiting from the chimney. Should I be nervous?

WA said...

Hi Anonymous
I really would not be overly concerned about visiting snakes. The only time you should worry is when they are being harassed and are frightened. They are just not interested in biting people and will do just about everything to avoid a confrontation.

I have had a couple of Tiger Snakes in my place this summer. I saw one enter, but ignored it. Apparently it had a look around, decided there was nothing of interest and waited at the wire door to be let out. This it did very calmly and slowly when I opened the door.

The other Tiger Snake I noticed slithering across the floor, it then disappeared behind some furniture. I ignored it as I did not see it again for a couple of weeks and forgot about it. However it turned up again only to again disappear behind furniture. That was a couple of months ago and I have not seen it since, so either it found its way out, or is still in hiding. Either way I am not concerned.

As for your snakes entering the classroom, I would imagine there would be school protocols to observe, but the main thing is not to cause a panic and frighten the snake.

Most snakes in the situation you describe would be looking for a hole in which to hide, so rather than trying to physically catch it and all the dangers that implies; keep a length (1-2 metres) of 10 cm or so diameter or preferably square pipe (one end blocked) and lay it along the skirting board for the snake to enter, then upend the pipe and block the other end. You can now safely take the snake to a convenient spot for release.

With best wishes

tim said...

My first encounter with a dugite was on a bush path in the Southwest, it was fairly small like 80cm and moving sluggish over a rock, it wasn't even on the path, I saw it from meters away.

The second time I stepped out of the house in bare feet to take plums from the fruit trees just near the front door. I looked to the ground and there was one of dark brown/black texture 1.5m long next to my feet, I then stepped back away from it and it eventually moved on.