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).

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

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!

Learning from Tortoises

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:

https://rdcu.be/bjHU7

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.

Self-reflection puts fish in hot water

In a narcissistic age, it is not uncommon to think of situations in which spending too long focussed on ourselves can lead to harm.  But what about fish, you might ask?

Today our paper entitled “Social cues can push amphibious fish to their thermal limits” was published in Biology Letters.

This manuscript represents an experimental field study performed in Belize this past spring examining how social information can delay the behavioural thresholds that an amphibious fish exhibits to escape from a thermally stressful environment.  As natural environments are complex systems including abiotic and biotic stressors that may act synergistically, it is important to understand how these interactions operate and impact an animal’s thermal limits.

The mangrove rivulus (Kryptolebias marmoratus), in particular, is an intriguing fish since it routinely leaves the water (emerge) to avoid stressful conditions and in some instances can survive for weeks out of water.  If the water gets too hot or too hypoxic, rivulus will simply jump out and chill out on land.

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K. marmoratus contemplating life on land.  Not quite sure yet.  Photo courtesy Keri Martin, Mount Allison University.

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K. marmoratus out of water – Image courtesy of Keri Martin, Mount Allison University.

In the present study, we demonstrate that the decision to emerge from water onto land is also socially sensitive.

So, what does this have to do with self-image?  Studying social cues from conspecifics can be a challenge if the conspecifics jump out of water first, so we designed an experiment to provide continuous social cues, using a simple mirror placed underwater.

Tank Schematic.jpg

Supplementary Figure from manuscript

Key Finding: The presence of cues from a conspecific (produced from a mirror) caused the rivulus to delay leaving water until they reach a higher temperature.  This delay is clearly a behavioural decision and not due to enhanced tolerance of warmer temperatures, since their CTmax was not sensitive to the presence of social cuing from the mirror.

This discovery is important since it demonstrates that critical behavioural decisions may affect survival in an animal living in a thermally stressful environment.  Much research into thermal stress to date has focussed on individual responses but social cues are likely just as important to animals in the wild.  We have only addressed what simple visual cues produced by a mirror do to their emersion behaviour.  Extrapolating to how multiple cues will work is, of course, open for future investigation.


 

Full Citation:

Currie, S and Tattersall, GJ. 2018. Social cues can push amphibious fish to their thermal limits.  Biology LettersLink here

 


 

Further Information

K. marmoratus inhabit stress aquatic habitats and can be found often inside crab burrows.

See Dr. Andy Turko’s video from 2012.  It is fascinating to watch:

 

On this year’s trip we took more images attempting to visualise the thermal environments inhabited by the various fish living in the Long Caye.  Here is a thermal image of a crab burrow:

IR_2018-04-23_

Thermal image of a crab burrow (central triangular region) capturing a crab leaving the burrow (bottom centre of image).  Rivulus can be found cohabiting with crabs or each other.  Image taken in April 2018 with a FLIR T1030K thermal imaging camera.

Ever hopeful to observe rivulus emerging spontaneously in the field we set up various camera traps and go pros and time lapse images.

The following video depicts a time lapse video (each frame 10 apart) captured with a simple IR webcam of a outdoor, artificial burrow with water, following 3 rivulus over time.  You can see one emerging in the bottom part of the screen and staying out of water.

 

We want to acknowledge Team Rivulus and Fellow Scientists:

Dr. Patricia Wright, University of Guelph

Dr. Suzie Currie, Acadia University

Dr. Andy Turko, University of Guelph

Dr. Tamzin Blewett, University of Alberta

Dr. Emily Standen

Giulia Rossi, University of Guelph

Louise Tunnah, University of Guelph

Keri Martin, Mount Allison University

Dr. D. Scott Taylor (mangrove.org)

Itza Lodge, Long Caye, Belize

Journal Comparative Physiology Ed Board

EdBoard

What was I thinking!?

Seriously, though, I’ve just been invited by Professor Heldmaier to be a member of the Journal of Comparative Physiology B editorial board.  I am honoured!  More especially as one my earliest memories of an influential paper was Heldmaier and Ruf’s 1992 paper on “Body temperature and metabolic rate during natural hypothermia in endotherms” published in J Comp Physiol B.  Their paper really helped to spark my interest in hibernation and thermoregulation as it so elegantly explained concepts that can trip up any novice student of physiology.  Anyhow, it is an honour to be part of Dr. Heldmaier’s team.

So, now, I put out a call to anyone reading this post to consider submitting their comparative physiology research to J Comp Physiol B for consideration.

 

Unreasonable requests…

A letter I wrote explaining why I declined to review a manuscript for PLOS One:

Dear PLOS One,

I am sorry, but 10 days is an unreasonable turn around time to request a peer reviewer. I prefer to focus my peer review activities toward journals that outwardly promote work-life balance and value the peer reviewers’ busy schedules. I realise PLOS one is a large journal so I would ask that these comments not be taken personally, but perhaps be passed along to someone who might be able to effect change. Let PLOS One set an example by returning to the halcyon days of a 3 week turn around request time for reviews and providing reviewers with compensation for their time! I know that won’t happen, but if reviewers don’t explain their reasons for declining to review, how will journals change their practises. As a fee based journal, this is something that could potentially be structured into the publication costs.

_____

This evoked an immediate and sympathetic response from the editor, and as a result I think it only fair that I agree to review the manuscript now.  I guess I cannot really be unreasonable to the scientific editor or the authors.  Now if we can only convince the journals to stop obsessing over rapid turnaround times, and recognise that volunteers are what keep their machines running.

 

 

The flight of the carpenter bee

I’ve often thought that I wait too long to post anything about research until it has been completed.  However, in this case I make an exception.  We were able to get our flight mill working today with a male carpenter bee!  Video evidence below:

 

Full credit to the two fantastic high school mentorship students (Hailin Wang and Sam Langdon) who built the flight mill with the assistance of Brock University’s Electronic’s Shop and Machine Shop, and to Miriam Richards, my colleague in all matters related to bees.

Now, we simply have to put the final touches and hopefully Lyndon Duff (Miriam’s PhD student) will be flying bees this summer.

 

Classic Article by Bob Boutilier

Our article just came out in the Journal of Experimental Biology!  A few months ago, I was invited by Kathryn Knight of the JEB, to write a classic article highlighting a piece of work by Bob Boutilier that might be considered “classic”.  Bob was my PhD supervisor, who passed away far too young.  Choosing an article that would be deemed a “classic” was initially daunting, since, by definition, a classic might be the “most influential” or “most cited”.  I decided to go with my gut, and choose one of Bob’s papers that was crucial to my own training in comparative physiology, and invited Warren Burggren to help pen a thoughtful tribute to Bob.  Here is the link to the article:

http://jeb.biologists.org/content/220/22/4084

Extrapulmonary Loop.jpg

Chimney Swifts in Infrared

Last month, Canadian Nuclear Laboratories invited a number of researchers to witness the nightly roosting of chimney swifts in one of their ventilation stacks!  They were kind enough to allow me to film using my thermal camera the gathering of over 1000 birds at ~8:45pm one evening.  Now, if only I can find the time to help with writing code to help them count the birds entering the chimney!  Here is a brief video and a link to CNL’s facebook site: