Wednesday, April 13, 2011

Late last fall a friend and herpetologist who works at a local park called me up with a black ratsnake (Pantherophis obsoleta) babysitting offer. Someone in the suburbs where, frankly, I wouldn't expect any ratsnakes to be hanging on, had brought in a baby black ratsnake they had found in their house.

It was too late in the year to release it somewhere new. She would likely freeze before it found another good place to hibernate. My friend said I could take her for the winter, and in the spring we could either release her or I could hold onto her if I felt like it.

Here she is (I'm pretty sure it's a 'she'):

I don't know if you think this is cute (probably not), but this is just about the most adorable face I've seen. I know that she's terrified of me, all the time, but I think it's precious how she rears back, hisses, and then strikes with furious gusto every time I take the top off her temporary home to feed her, check her water, or just clean up after her.

So, through the winter I could just focus on making sure she was eating and otherwise healthy and (presumably) content, but now it's spring again, and probably just a few weeks away from perfect weather for releasing a baby ratsnake.

Now, cue the part where the little kid cries "Mom, can I keeeep her?" Of course the fun part of being a grown up is that I don't need anyone's permission. Okay, I suppose Jen has a veto on this, but she probably wouldn't put her foot down if I put mine down - what's another snake when you have five already? Anyhow I'm happy to unload the Florida scarlet snake (Cemophora coccinea) if anyone wants it (feel free to drop me a note if you do), and Big Yellow, the yellow ratsnake I adopted in Baltimore in 2004 when she was already full grown, is looking a little old these days. I am committed to taking good care of her, but by the time this baby black ratsnake is full grown, I bet Big Yellow might not be around anymore (...this is a morbid train of thought I will nip in the bud right now.). All that said, space and time are real concerns, and it is only with enormous willpower and years of practice that I have mastered the covetous, acquisition impulse I feel whenever I see a really cool snake.

Of course keeping a wild snake is not only a question of space and available time, I should also consider the interests of the snake and the broader environment.

I'll actually start with the law. Black ratsnakes are not particularly protected in PA; they fall on the 'all the others' sort of list of PA herps, so that they have a bag limit and possession limit of one. Since I have no other black ratsnakes (FYI, all my other snakes are non-native, and all are rescues except for the old FL scarlet snake) and I did not purchase the snake (selling/buying most PA herps is illegal), I should be in the clear keeping her. Technically I might get in trouble for releasing her, but I doubt anyone would crack down on me for that. The concern is of introducing diseases from captive populations to wild populations. I have been extra careful to keep her in a thoroughly cleaned (= lots of bleach) container with an equally scrubbed/cleaned water dish, and to keep her well apart from the rest of the critters, using different tools, washing my hands before handling her, etc., so I am pretty confident she hasn't caught anything from her neighbors. (If anyone still thinks it is too risky to release her, maybe that will be the excuse I need to keep her :-) )

The release option would mean going somewhere nearby with a healthy population of ratsnakes - my friend has a spot in mind in Chester County - and letting the little tyke go. This would mean removing the snake permanently from the suburban population where she originated. One could argue that the population is fragile and could use the extra snake; I would argue the population is doomed, and either way a baby with a very slim chance of survival doesn't make a big difference (a four-foot, breeding female would be a different matter).

That leads nicely to the next question - the interests of the snake. It's worth starting off this side of the discussion by pointing out that most adult snakes (this seems to hold for box turtles too, and probably lots of other land critters) released far from home generally do not survive. We tend to think of reptiles as stupid creatures reacting to their landscape on a moment-to-moment basis, but they probably have a much more refined sense of place and landscape than we usually give them credit for. I'll wager an adult ratsnake knows every greenbriar thicket, stumphole, and hollow tree in its territory, a territory that could cover a few square kilometers. When you release a snake that has lived its whole life in a specific place in another place, it starts looking for home. It might set off over hill and dale looking for that home, and it might get run over by a car or picked off by a hawk while it's wandering. It might spend too little time hunting and eating while it is searching, and winter might find it too thin to make it to spring. It would be kind of like dropping me in downtown Moscow. I don't know the language, I don't know anyone I could crash with, I don't know which are the sketchy neighborhoods I should avoid.

The result is that relocating adult snakes tends to go badly. There are exceptions, but the point is that relocating a snake more than a mile or two from where you've found it generally is the same as killing it. It just takes longer. This does not hold as true for baby snakes. They might face slimmer odds for a variety of other reasons, but they tend to be better able to settle down in a new place, perhaps because it is natural for baby snakes to wander around until they find a nice spot anyhow.

Of course baby snakes generally don't survive in the wild. Let's assume that an adult female ratsnake breeds for five seasons before she gets picked off by a hawk or run over by a car, and if we assume she averages 6 hatching eggs per year (both round estimates for the sake of argument: she might breed one year or fifteen before her demise; they generally lay bigger clutches than that, but I'll assume some years they get eaten by skunks). In a stable population an average of only two of any reproducing female's offspring will make it to maturity. Two divided by thirty gives us pretty crappy odds. I might be tempted into thinking I'm giving the snake a life of glorious freedom, wandering forests and thickets, raiding nests and basking on old tree branches, but the options are more realistically either a long and well-fed life in a boring box versus a few months of nervous freedom ended by the snip of a crow's beak.

Like I said, I've got a couple weeks to make the decision, so let me know what you think.


Anonymous said...

If you think releasing in the same spot is a death sentence then dont. keep it for educational purposes.

David Steen said...

How big is the park where it originated?

Bernard Brown said...

It didn't originate in the park (mostly reclaimed marsh which could be habitat, but has no ratsnakes), but in a suburban neighborhood in the neighboring county. I looked at the satellite images of the neighborhood and I'm baffled about where around there could support a black ratsnake population, considering that much bigger green areas in SE PA don't.

I'm of a mind that there are probably some stragglers hanging on in a nearby creek corridor, but that whatever population there is is doomed - an assumption that I recognize could be disproved in twenty years if they're still there, but seems consistent with apparent herp diversity dropping the longer an area of SE PA has been built up. I think the are has only been built up in the last two or three decades. On the one hand I am working off a series of assumptions that could easily be incorrect, on the other I might be over thinking the fate of a baby ratsnake, and whatever we do won't make much of a difference in the grand scheme of things one way or another.

We'll probably end up letting it go in an area of the serpentine barrens (neat habitat) that is less populated and has a more robust ratsnake population.