Bridgeman now the Master

When he left the lab to write up his thesis, he was but the learner…now, HE is the Master.

Congratulations, Justin Bridgeman for a successful defence! Justin’s thesis earlier today was on “Behavioural thermoregulation and escape behaviour in the round goby”.

Thanks to the selfless efforts of the committee members (Dr. Gaynor Spencer, Dr. Liette Vasseur, and Dr. Patricia Wright), external examiner (Dr. Dennis Higgs, U Windsor), and committee chair (Dr. Cheryl McCormick).

Thank to all the lab mates for supporting Justin and welcoming him back for his brief visit.

All the best in the future Justin! We look forward to the manuscripts…and for a place to crash when we visit you in Halifax! 😉

Toucans of the atlantic

Earlier this summer, I was lucky enough to visit the Isle of May, Scotland to fulfill a long-time ambition to collect thermal image data on puffins in the wild. Ever since we published our work on the toucan in 2009, I have wanted to study the puffins, examining evidence for elevated capacity to control or distribute body heat through their uniquely colourful bill. Living in a cool climate with a large radiator like their bill presents a unique opportunity to test our hypotheses. In spring of 2018 I managed to visit the Elliston, Newfoundland puffin colony to start this project, but the distance to view a little too far to obtain high quality results.

Well, the short story is that they do show an extraordinary capacity to do so! Here is just a sample image (from the 200 Gb of videos):

Active and basking Atlantic puffins show capacity for intense heat transfer to the bill. The one above has recently landed back at the colony, presumably foraging although in this case, there is no evidence of food. Other images show cool bills, as we have seen in many other bird species, demonstrating the vasomotor control over blood flow to the bill is a fairly generalised phenomenon.
Infrared thermal video of an Atlantic puffin in May 2018 – early arrival at nest and investigating burrows.
Atlantic puffin in the rain.

If I only had the time to conduct the data analysis, I could put some numbers on these values. I certainly have my work cut out for me, examining those returning from the water with food vs. those basking and resting. I have a few other thoughts about these data that I hope to extract.

Many thanks must go to the town of Elliston, Newfoundland and the Atlantic puffin colony there, the Centre for Ecology and Hydrology (UK), the Isle of May (Scotland) Scientists, and especially Mark Newell for hosting me at the Isle of May, and Mike Harris for introducing us. Sorry it took so long to post this.

Further Reading

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

Greenberg, R, Cadena, V, Danner, RM, and Tattersall GJ. 2012. Heat loss may explain bill size differences between birds occupying different habitats. PLoS One, 7: e40933. 

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, Andrade, DV, and Abe, AS. 2009. Heat exchange from the toucan bill reveals a controllable vascular thermal radiator.Science, 325: 468-470.

Backyard Biology

Earlier this year, I put a raspberry pi on a robin nest in my backyard. Used it as an opportunity to test out tweet streaming from my twitter account, so am posting the link here to the lab blog. Sorry it took so long, I was away from stable internet access for the past month.

Insect thermogenesis

A luna moth was on our window outside the department yesterday.

So, we brought it inside for a lab show and tell. Shivering up a storm….

Thorax temperature up to 32C, while the abdomen temperature was still below 20C (the lab was ~21C, and the moth had been briefly placed in a cold fridge).

CSZ 2019

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!

Shape Shifting Birds – PhD Opportunity

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 (matthew.symonds@deakin.edu.au).

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

ThermImageJ – ImageJ Functions and Macros for Thermal Imaging

After a long delay, I’ve released a series of functions and macros for working with thermal images in ImageJ/FIIJ. This is a sequel to the Thermimage Package for R.

The source files, instructions for installation, and basic function explanations can be found on github here:

https://github.com/gtatters/ThermImageJ

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.

Bugs or issues can be filed here.

Hot-headed squirrels use eye fat!

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.

And a link to the paper:

http://jeb.biologists.org/content/early/2019/01/23/jeb.195750

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.

Reprint requests can be sent to umamac@leeds.ac.uk.

Citation:

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!

From Tattersall and Milsom, 2009 J Physiol 587: 5259–5274

For a nice JEB write-up that succinctly summarises the study better than I can, please see Kathryn Knight’s article here:

http://jeb.biologists.org/content/222/4/jeb201228

 

Lizard Chapter Published

A book on the “Behavior of Lizards: Evolutionary and Mechanistic Perspectives” (Eds. Vincent Bels and Anthony Russell) has just been published with a chapter from my lab!

https://www.crcpress.com/Behavior-of-Lizards-Evolutionary-and-Mechanistic-Perspectives/Bels-Russell/p/book/9781498782722

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.

Poetry of Cassowary Casques

So, we published a paper on Cassowary Casques the other day, and then we heard from a Science Communications person that he had written a poem inspired by our research!

http://thepoetryofscience.scienceblog.com/760/the-curious-case-of-the-cassowary-casque

How cool is that!?

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!