Houdinia is a special deer. She was the last adult female deer captured by the Prince of Wales deer project, which ran 2010-2013, and she was captured just outside of Thorne Bay, in the subdivision clearcut, on May 20th, 2012 (See photo #1). Her collar dropped off, as pre-programmed, on April 15th, 2013, so we knew here whereabouts every 2 hours for just under a year. We also fit her with a VIT (vaginal implant transmitter), allowing us to know the time and location of her delivery of her fawn that spring. She gave birth on June 4th, 2012 to a healthy female fawn, in a small patch of remnant old growth, which has since been logged (photo 2). Her fawn survived for the remainder of the year, until her break-away elastic collar fell off naturally the following spring.
Houdinia got her name from the local Thorne Bay school kids. Sophie Gilbert, who was the PhD student leading the deer project, also worked with a local science teacher to help develop biology curriculum materials taught through deer-related content (including a dissection!), and she wanted to show the kids a local deer that they could keep an eye out for and really be excited about. So, she made sure to capture a deer as close to Thorne Bay as was safe (shooting a dart gun right in town was not a good idea), and then let the kids pick the name. The students picked this name because it took them a couple of weeks to spot her (she disappears from her clearcut from time to time to use other habitat, making it tough to find her), leading them to want to name her after the great escape artist, Houdini.
Incredibly, Houdinia has now survived through 2023 (which we know thanks to her yellow numbered ear-tags), and Jim was so excited to re-encounter her taking a nice nap in her clearcut. She was 3 years old when we captured her, making her 14 years old today, which is pretty darned impressive for a wild deer with plenty of predators and some harsh winters. Using a basic deer population model (Gilbert et al. 2020), we can pick some reasonable values for population growth rates (calculated in females produced per female in the population, because females generally drive population patterns for polygamous breeders like deer). If we take the growth ratse of 1.17 for mild winters and 0.92 for harsh winters, and look at the pattern of winters experienced by Houdinia, we can see that she’s only experienced one harsh winter (2010-2011) during the years she’s been an adult and producing fawns. She would have had her first fawn right around her 2nd birthday (in spring 2011, after the harsh winter), giving her 12 years of reproduction. We can then very roughly calculate that she’s contributed 1 deer (herself) x 0.92 x (1.17)^11 = roughly 5 new female deer to the female population (not counting her contribution of bucks). This is a “back of the napkin” calculation, and a little bit of an under-estimate (growth rate represents average females per female, and Houdini is an adult female, so probably more productive than average), but it gives us a ball park.
We wish Houdinia a happy early birthday, and more years peacefully basking in the sun in “her clearcut”!