This weekend I joined my mom to attend the Seedy Saturday event up in Ottawa. Although I have quite a few seeds left over from last spring, I had a few I was hoping to get, and I like the opportunity to buy heritage, organic varieties rather than the commercial ones available in stores. I also took some of my own seeds that I’d saved for the swap table, where you can trade seeds like baseball cards. The event was busy and I didn’t do too badly there. There’re so many interesting vendors and products that I could have spent quite a lot of money if I had money to burn on such things.
But despite the success of our trip there, that wasn’t the most interesting part of the weekend. Not even the second most interesting, as it turned out.
The number one most interesting thing happened Friday night, the day before the seed swap. Mom had asked if I’d be interested in joining her at “Mudpuppy Night in Oxford Mills” (the name a play on Hockey Night in Canada). After some initial indecision resulting from poor weather forecasts and ambiguous results of the organizers when they scouted the site the day before, we decided to go.
And I’m so glad we did! These evenings are very informal affairs, organized and executed by Fred Scheuler and, I gather, regularly helped by his daughter Jennifer, both of whom were in attendance this weekend. Also present was fisheries biologist Naomi Langlois-Anderson and her children, though I gather she’s not a regular attendee. Every Friday night from Thanksgiving to spring thaw Fred and Jennifer visit Kemptville Creek at the foot of the dam in Oxford Mills to count the mudpuppies present there. In this photo Fred and Naomi use a dipnet to try to catch one.
These foot-long, entirely-aquatic salamanders are active year-round, feeding on just about anything that might be called food, including small vertebrates. In the winter it seems that river populations will move to shallow, slower-moving water where it’s easier for them to catch prey. The site in Oxford Mills turns out to have the best known winter population of mudpuppies in eastern Ontario. The reason is unclear, but may be a combination of the creek being particularly rich with the species and the placement of the dam preventing the creatures from moving any farther upstream. The creek habitat at the foot of the dam happens to be ideal anyway: shallow and rocky, and sufficiently wide that during the winter the water flow isn’t too fast.
Fred used a dipnet to catch the mudpuppies, but Naomi, wearing hipwaders, sauntered right in, pushed her sleeves to her elbows, and grabbed them from the water with her bare hands. I didn’t really appreciate this until they had caught a couple and allowed the visitors to try holding them. To prevent our dry hands from stripping the amphibians of their slimy coating we had to wet our hands in the bucket’s water first. The water had simply been taken out of the creek when they got the first mudpuppy. I dipped my hands in and ohmygoshisthatwatereverCOLD! Though I had no way to measure it, it couldn’t have been much above freezing. The shores were both lined with ice shelves, as were the gates of the dam where the water passed through.
And here were these coldblooded creatures slithering about in the shallow depth of the bucket as if it were sun-warmed summer water. It was rather astounding. Presumably they’re able to do it because of a suite of cold-hardy enzymes and proteins (which typically work best within a range of temperatures, and start to denature outside of this range; risk of hypothermia aside, our own proteins would most definitely not be able to function properly at these temperatures). Look at Naomi’s hands in this photo! Red with heavy blood flow, trying to keep their temperature up after repeated dippings in the ice water.
Our species of mudpuppies (Necturus maculosus) are generally brownish with spots. The shade of brown varies with the clarity of the water they inhabit, and the pattern of spots is unique to each individual. In theory, a graduate student with a good deal of patience could learn to identify individuals by their spot patterns, which would be useful in determining site fidelity and activity levels during the winter, among other things. The fourth mudpuppy they brought to the bucket was noticeably darker and with smaller spots than the other three. I don’t know whether their colour reflects their summer home or their winter home. It’s possible if the former that she (I don’t actually know the sex, though females are usually smaller than males; I don’t think colour is sex-linked) originated from a different part of the creek than the first three.
Her gills were also darker and smaller than those of the other three. This reflects the oxygen saturation of the water she lives in. When living in water with low oxygen content their gills grow large and are flush with blood to carry as much of it back into the body as possible. In oxygen-rich waters the gills don’t need to be as big. Since all four of these individuals came out of the same stretch of creek, I would be inclined to believe the gills are also a reflection of their summer homes, but perhaps her spot in the creek just happened to be easier to draw oxygen from.
Another hypothesis to explain her colour and gill size is that she’s a younger individual while the other three are adults. Mudpuppies can live up to 11 years or more, and don’t actually reach sexual maturity until age six. I didn’t see any information to suggest this, however, so it would just be a guess on my part. I think it’s more probable it reflects her origins rather than her age.
They caught three more after we left for a total of seven for the evening. On really good nights, however, they often record several dozen. Their highest count ever was somewhere close to 180 individuals. The variation in the numbers from one visit to the next suggests that the animals do still move around a bit, perhaps partly due to periodic rains or melts that temporarily increase the creek’s volume. Once the spring thaws arrive the water becomes too high and fast for the amphibians and they effectively disappear from the site until the fall.
Fred has been doing this since 1998. He’s not associated with any formal organization; this is just something he’s been doing on his own and which has grown into something slightly larger. After more than a decade, Fred’s got a really good set of data on the mudpuppy population in the creek. To the best of my knowledge, this is the only such data in existence for mudpuppies in eastern Ontario, and the best information we have on population changes over that period. This is why keeping track of your own local flora and fauna can be such a good thing! Especially if you record data from the same location over many years. It may turn out to be unique and invaluable.
If you’re interested in reading more about the Oxford Mills mudpuppy nights, check out their website. Also swing by my mom’s blog to see her post about the same evening; she goes into more depth about their life history than I did here.