Thursday 18 October 2007

Snakes on the move

The first snake warning of the season went out as a global e-mail last week. (At work, that is.) The second went out this afternoon.

Whereas the second e-mail was a reminder to stick to the paths when crossing campus, the first was a report of a sighting. The species wasn't identified but was likely a common brown snake (Pseudonaja textilis), which is abundant in this part of the state. Tiger snakes (Notechis scutatus) are also around. (So are blue-tongue lizards, which are mistaken for snakes with wearying regularity. 'It's a snake!' 'It's a blue-tongue.' 'Well, kill it anyway.' 'FOAD'.)

Common brown snakes and tiger snakes are both venomous. Comparing toxicity between species is always problematic — it's more than seeing how the LD50s stack up. Different snakes produce different volumes of toxin and the amount injected can vary between species, between individuals and sometimes even between bites. Having said that, brown snakes and tigers snakes are near the top of any type of toxicity league table.

The venom of common brown snakes affects nerve function and blood clotting (pdf). Tiger snake venom does much the same, while also damaging muscle. When I get a bit of free time, I'll post on the development of these toxins for therapeutic use. It's fascinating stuff!