Another year passes and another good Canadian Society of Zoologists meeting.
Here is Nick Sakich presenting his first scientific poster. Well done Nick! Nick had a lot of attention at his poster. Maybe we can get Nick to come to CSZ next year!
And here is a rogue’s gallery of happy scientists congratulating Cayleih Robertson (second from right) for winning the Hoar Award for the best student presentation at the CSZ! Cayleih is studying her PhD in Dr. Grant McClelland’s (left) lab, conducted her MSc with Dr. Patricia Wright (second from left), and her undergraduate thesis with Dr. Suzie Currie (middle). I (far right) have the distinct privilege of being on the receiving end of Cayleih’s collaborative nature, in that she has involved my lab with a portion of her PhD (thus, why I’m in the picture!). Full credit has to go to Cayleih for her spirit of inclusivity, scientific curiosity, and intelligence. And of course, she gave a great talk! Congratulations, Cayleih!
Please consider applying for this PhD Opportunity in Australia to work with my colleague, Dr Matthew Symonds on Shape-Shifting Birds.
This research forms part of an ARC Discovery Project (PI: Symonds; CI: Klassen & Tattersall) whose goal is to determine whether changes in body shape are an evolutionary response to climate change. Endothermic animals (such as birds) have a range of adaptations for dealing with the temperatures they experience. One such adaptation is body shape: birds in warmer climates tend to have large extremities (bills and legs), increasing their surface area and enabling loss of excess heat. Adaptations to climate (and hence climate change) can occur quickly, and there is evidence of significant increases in bird extremities in recent years – a novel potential consequence of climate change. Whether this represents an evolutionary response to climate change is unknown, nor do we know what characteristics make specific bird species liable to respond to climate change in this way, or what the likely consequences of such responses are.
The student will undertake an extensive comparative analysis of Australian birds, designed to identify a) which bird species are showing changes in body shape (bill and leg morphology); b) what ecological (life- history, behaviour, habitat) factors determine such responses; c) whether these changes relate to fitness/survival and d) whether such changes are linked to long-term populations trends in Australian birds.
The project will involve extensive work in Australian museum collections, measuring bird morphology using traditional and modern (3D-scanning) techniques. There is also a strong analytical component, involving use of long-term field data on Australian bird species as well as phylogenetic comparative analysis of large-scale ecological data sets for Australian birds.
Please send an application letter, together with your CV, to Dr Matthew Symonds (firstname.lastname@example.org).
Further information can be found in our review papers:
Symonds, MRE and Tattersall, GJ. 2010. Geographical variation in bill size across bird species provides evidence for Allen’s rule.American Naturalist. 176: 188-197.
Tattersall, GJ, Arnaout, B, and Symonds, MRE. 2017. The evolution of the avian bill as a thermoregulatory organ. Biological Reviews 92: 1630-1656. doi:10.1111/brv.12299
The more difficult parts are getting the command line tools installed on your system. Installing the toolset will give easy access to the main macros from the toolbar or from the Plugins-Macros menu:
Additional look up tables are included as well, along with all the built in LUTs from ImageJ, allowing for easy access to palettes:
I’ve also added some short-cut ROI tools to help with the tedious task of extracting temperature information from moving targets in videos or image stacks:
This work is the result of ~3 years of self-directed inquiry. If you find this useful, please drop me a line to let me know, and kindly consider citing the software (or a future publication) when you use it.
Glenn J. Tattersall. (2019). ThermImageJ: Thermal Image Functions and Macros for ImageJ. doi:10.5281/zenodo.2652896.
Our paper has just been published, this one a collaboration led by Amanda MacCannell from Dr. James Staples lab at Western University.
Here’s a summary (cribbed from the abstract):
We discovered an orbital lipid depot in the 13-lined ground squirrel during the first ever magnetic resonance image (MRI) of this common experimental model of mammalian hibernation. The volume of this depot increased in the autumn and decreased in the spring, suggesting an endogenous circannual pattern. Water-fat MRI revealed that throughout the year this depot is composed of ∼40% lipid, similar to brown adipose tissue (BAT). During arousal from torpor, thermal images showed higher surface temperatures near this depot before the rest of the head warmed, suggesting a thermoregulatory function. This depot, however, does not contain uncoupling protein 1, a BAT biomarker, or uncoupling protein 3. Histology shows blood vessels in close proximity to each other, suggesting it may serve as a vascular rete, perhaps to preferentially warm the eye and brain during arousals.
Thermal video time lapse of a 13-Lined ground squirrel arousing from hibernation. Note the warm region behind the eye (1990 s) corresponding to the orbital lipid depot. Warm surface temperatures provide hints toward changes in relative blood flow and metabolism in the underlying tissue during the rapid rise in body temperature from 5 to 37C.
MacCannell, ADV, Sinclair, KJ, Tattersall, GJ, McKenzie, CA, and Staples, JF. 2019. Identification of a lipid-rich depot in the orbital cavity of the thirteen-lined ground squirrel. Journal of Experimental Biology, 222: jeb195750 doi: 10.1242/jeb.195750
One thing I found really interesting about this was the fact that brain temperatures are kept warmer than body temperature, something I noticed back in 2009 studying Columbian ground squirrels (something also noted by Heller in his seminal work in the 1970s). At the time, I assumed this was related to higher metabolic heat production of the brain, and yet we observed rapid transient changes in hypothalamic temperature during hypoxic transitions that might readily have been explained by changes in blood flow. Further study in other hibernators seems to be required to corroborate Amanda’s neat findings!
For a nice JEB write-up that succinctly summarises the study better than I can, please see Kathryn Knight’s article here:
Chapter 1: Behavioral thermoregulation in lizards: Strategies for achieving preferred temperature – Ian R.G. Black, Jacob M. Berman, Viviana Cadena, and Glenn J. Tattersall
This work was primarily the result of collaborative work of my former graduate students, Ian Black, Jacob Berman and Viviana Cadena. I am very grateful to have great graduate students willing to work on these projects.
If you are interested in accessing this chapter, contact me by email or on researchgate.
The study itself was conducted by Danielle Eastick of La Trobe University (Dr. Kylie Robert and Dr. John Lesku), and published in Scientific Reports recently. Here is a link to the paper.
I won’t link to all the overhyped media reports since they tend to misinterpret (e.g., no, we have not discovered the secret to the casque) the science just like they misinterpreted our toucan bill study.
But here are the main results:
One of the most beautiful and dangerous animals around!
Congratulations to Curtis Abney, MSc for his successful defence today! His thesis on “Thermal ecology of eastern garter snakes in a southern Ontario peatland” was a joy to supervise, namely because Curtis did all the hard work. Always enthusiastic and willing to wade through tick-infested field sites, Curtis studied whether garter snakes make use of thermal cues to inform site selection in the field.
Thanks of course to Curtis’ committee members: Dr. Cheryl McCormick, Dr. Miriam Richards, Dr. Liette Vasseur and Dr. Njall Rollinson (External examiner from U of Toronto).
Curtis will be missed by all members of the lab as he moves back to BC aand takes the next big step in his scientific life.
Our paper on red-footed tortoise reversal learning is now in press! This study represents the efforts of Justin Bridgeman during his honours thesis examining behaviour flexibility and cognition in tortoises. Here is a link to the paper:
Bridgeman, JM and Tattersall, GJ. 2019. Tortoises develop and overcome position biases in a reversal learning task. Animal Cognition. (): 1-11. 10.1007/s10071-019-01243-8
Many thanks to Dr. Miriam Richards, TAs, Tom Eles, and all the students from our animal behaviour course (2013 – 2015) who helped with all the pre-training and Y-maze familiarisation trials that pre-dated Justin’s honours research. And many thanks to all the tortoises who participated.
Tortoise approaching the stimulus (mock experiment with cell phone video)
Tortoise receiving a reward for approaching the correct stimulus.
Here are some sample videos from the supplementary material:
Tortoise in the Y-maze examines both stimuli and slowly approaches the rewarded stimulus on the left.
Tortoise late in the training approaches the rewarded stimulus without pause.
Tortoise moves according to its developed position bias, almost makes an error but corrects itself, and approaches the positive stimulus receiving the reward.