Author: gtattersall

Off to my first paleontology meeting, in Utah!

/ gtattersall

My final conference trip of the year, this time to a paleontology meeting!  I leave on wednesday (arriving a day late, sadly).

http://vertpaleo.org/annual-meeting/annual-meeting-home.aspx

I will be speaking about our paper published earlier this year on reproductive endothermy in tegu lizards, in a symposium organised by Colleen Farmer, Jennifer Botha-Brink, and Adam Huttenlocker, entitled “Recent Advances in Understanding the Origins and Evolution of Tetrapod Endothermy”

I’m looking forward to interacting with a group of paleontologists and hope they don’t mind hearing about some research on an extant animal!

For those interested, the title of my talk:

“Facultative thermogenesis in tegu lizards provides metabolic support for the parental care model of endothermy”

 

Teguthermal

Here is the symposium information:

Recent Advances in Understanding the Origins and Evolution of Tetrapod Endothermy
Co-convenors: Colleen G. Farmer, Jennifer Botha-Brink, and Adam K. Huttenlocker

Endothermy, the ability to use metabolically generated heat to regulate internal body temperature above ambient, represents a key innovation driving mammalian and avian evolution, allowing them to shorten the time between conception and sexual maturity, and to exploit new habitats and resources not accessible to ectotherms. Because of this, understanding the evolutionary origins of endothermy has become a central question in vertebrate paleobiology and evolutionary physiology. Many physiologic adaptations that either promote or were a consequence of endothermy are shared between mammals and birds, but major questions surround their origins and early evolution: What fossilizable markers of endothermy are accessible to paleontologists? What were the selective agents that have driven this novel thermoregulatory physiology? What were the paleobiological and ecological contexts for its origins? When and how many times did endothermy evolve? In recent years, new information from non-mammalian synapsids and archosaurs has begun to reshape our views of their paleophysiology, including their capacities for fast growth, cardiopulmonary physiology, and insulation and thermoregulation. The growing body of new data makes this a timely topic that will throw into sharp relief what is and isn’t known, and will promote cross-pollination of research in light of the vertebrate fossil record.

This symposium will feature interdisciplinary research that exemplifies the diversity of new studies that shed light on the origins and early evolution of tetrapod endothermy. Symposium contributors will consist of an international list of scientists who employ a variety of tools to pinpoint the functional correlates of endothermy and their evolutionary origins in synapsids, archosaurs, and other tetrapod groups. Presentations will therefore span taxonomic boundaries, and will appeal to attendees actively researching paleophysiology in extinct tetrapods and to those interested in all aspects of vertebrate paleobiology. Major topics will include a variety of techniques and study systems, including (1) bone histological applications, (2) functional morphology, (3) metabolic scaling, (4) micro-computed tomographic techniques, and (5) clumped isotope paleothermometry. In light of the rapid changes in the field, this symposium will generate broad interest across multiple disciplines, as well as in the lay community, and will guide future research.

 

Evolution of the avian bill as a thermoregulatory organ

/ gtattersall

After a year in the making (4 months of that waiting for the journal review process), our review paper is finally published!  The link can be found here:

http://onlinelibrary.wiley.com/doi/10.1111/brv.12299/full

For those without access, please feel free to contact me for an e-offprint.

This review represents a collaboration with my good colleague, Dr. Matthew Symonds (Deakin University) and a Brock student, Bassel Arnaout, who contributed to the writing and research, and summarises the evidence for how temperature has shaped bird bill size.

 

 

Seminar on Hummingbird Physiology

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I am pleased to be able to host Dr. Kenneth Welch today, who will be giving a seminar in the Department of Biological Sciences, Brock University on:

“Glucose, fructose and the energetics of hovering flight”

Ken is currently on sabbatical, but was gracious enough to add us to his travel schedule while back at his home institution (U of Toronto, Scarborough).

Location: MacKenzie Chown H313

Date/Time: Oct 7, 2016, 14:15

His research into hummingbird physiology sheds light on how locomotion is influenced by the environment and how one of the most intensely powered muscles receive the necessary fuels to power their activity.

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Thermal image of a ruby-throated hummingbird.

 

New Paper from the lab

/ gtattersall

A paper resulting from my 3 month sabbatical stint at the Univeristé de Lyon has just been published in the Proceedings of the Royal Society B.  Using a small recording device that remains inside the crop, we were able to examine core temperature relationships over the course of growth, feeding, and fasting.  In the process, we discovered that fasting leads to greater heat conservation (revealed via thermal imaging) as well as changes to short term core temperature changes.  Ducklings show lower core temperature variation in the short term when fasting than when fed.

Here is the citation:

Tattersall GJ, Roussel D, Voituron Y, Teulier L (2016) Novel energy-saving strategies to multiple stressors in birds: the ultradian regulation of body temperature. Proceedings of the Royal Society B 283(1839): 20161551. http://dx.doi.org/10.1098/rspb.2016.1551

Electronic supplementary file is here.

Here are the data, uploaded to data dryad data repository:

Tattersall GJ, Roussel D, Voituron Y, Teulier L (2016) Data from: Novel energy-saving strategies to multiple stressors in birds: the ultradian regulation of body temperature. Dryad Digital Repository. http://dx.doi.org/10.5061/dryad.gt5c0

And a sample figure:

Figure 3 Thermal Images.jpg

Lab Members

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I did not realise how rapidly my lab has grown.  So much that it made sense to have a lab outing (beer and pizza, really), and a chance for a group photo for those present.

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I used to fear having a large lab, because of not being able to stay on top of everyone’s research project.  But when you have the right group of people, they help each other out with many of the day to day curiosities of university life.  Thanks to all you guys for being part of my lab.

Left to Right: Susan Wang, Justin Bridgeman, Anne Yagi, Curtis Abney, Me, Katlyn Dundas.

Photos taken by esteemed lab visitor, Kathryn Yagi.   Missing from photo: Viviana Cadena (who is writing up!) and lab mascot, Ceilidh (my dog) who was hiding somewhere in the house.

A hummingbird walks into a bar, and orders 300 hamburgers…

/ gtattersall

At the NAOC last week, I met a graduate student studying hummingbird torpor and just saw her talk (a video, since I missed it due to scheduling issues).  I noticed she had her own website and wanted to put a shout out to her for that.   It’s also an excellent resource for young field biologists looking to get into research, and has lots of personal advice.

Here is a link to her blog site:

http://anushashankar.weebly.com

You’ll have to read her blog to follow the hamburger reference.  Meanwhile, a hummingbird with a drinking problem:

“Birds surviving the heat” symposium was a great success

/ gtattersall

Widely publicized heat waves have led to mortality and breeding failure of birds, and mortality of other taxa, including many humans, across the globe. Climate models predict further increased temperatures in addition to altered drought and other severe weather patterns, all of which can exacerbate thermal challenges. With a changing global climate, a major challenge facing scientists is to predict if and how species will survive rising temperatures.

Predicting these events requires models and an understanding of underlying thermal biology.  Mechanistic, process-based models allow us to predict how higher air temperatures and heat waves impact avifauna. Building these models relies on a detailed theoretical understanding of processes related to thermal stress, as well as parameterization with data from varied sources. Birds of arid habitats provide an ideal model system for developing mechanistic models because they face a number of physiological and behavioral constraints related to the avoidance of lethal hyperthermia and maintenance of water balance. These constraints are often manifested as consequential trade-offs affecting survival and reproduction. Recent catastrophic mortality events, most notably in the Australian arid zone, highlight the direct impacts that periods of extremely hot weather can have on desert birds. In addition, recent research has also revealed various more subtle impacts that only become apparent from detailed, species-specific studies, and/or consideration of the chronic effects of hotter daily conditions in addition to more extreme events.

It was for the above reasons that a team of concerned Physiologists assembled at the North American Ornithology Conference this past week (Aug 18, 2016) to participate in the following symposium topic:

“Surviving the heat: integrating physiology, behavior, and morphology to predict population responses to climate change”

Here were the broad topics covered:

Physiological tolerance limits. Predicting climate change impacts on endotherms using physiological tolerance limits is much more complex than it is for ectotherms. This aspect surveyed recent work aimed at quantifying avian heat tolerance and evaporative cooling capacity in a manner that allows for comparative analyses, and examined how these factors vary among biomes at a global scale.

Behavioral trade-offs and constraints as revealed by intensive, species-specific studies. This section focussed on recent work documenting consequential trade-offs between heat dissipation behaviors and foraging / provisioning nestlings, biologically relevant time scales of high temperatures, and the ways in which high temperatures affects social systems, with a focus on cooperative breeders. It also included work aimed at identifying behavioral indices of sensitivity to heat tolerance that can provide the basis for rapid assessments of species’ relative vulnerabilities to thermal stress.

Morphological responses to past and future climatic changes.  Morphological adjustments to climate that facilitate thermoregulation are widespread among birds, though little is known about the capacity for further adaptation in response to ongoing climate change. This aspect surveyed morphological adaptations to climate and discussed the potential for further change, including probable constraints, and consideration of how to incorporate this knowledge into process-based predictive models.

Spatial models. A key aspect of this symposium concerned ways in which species-specific physiological, behavioural, and morphological data could be incorporated into spatial models to predict responses to climate change, with a focus on the probability of extirpation. In addition to the presentations devoted to this topic, there were excellent talks on modeling avian distribution in the context of climate change to provide a backdrop against which to consider ideas from the empirical and theoretical presentations.

The symposium concluded with a 45 minute discussion session, during which future integrative directions were discussed, and short-comings of various approaches identified.  The symposium was well attended and we received excellent feedback from speakers and attendees.   Moreover, the participation of speakers from North America, southern Africa and Australia reflected the global focus of this symposium. Participants and attendees were exposed to novel techniques and analytical approaches presented by some of the world’s authorities.

I tried to get photos over everyone’s title slide (but not posting data or non-twitterable material), but missed a few (including my own!) due to my involvement in introducing speakers.

 

 

Names, affiliations, and titles of the speakers’ talks

South Africa

Susie Cunningham, University of Cape Town – Fitness costs of behavioral thermoregulation and threshold temperatures revealed by behavioral data sets

Michelle Thompson, University of Pretoria – Can heat dissipation behaviour be used as an indicator of underlying physiological stress?

Margaux Rat, University of Cape Town – The impact of elevated temperatures on social networks of a communal passerine, the Sociable Weaver Philetairus socius

Krista Oswald – Threats of climate change to a Fynbos-endemic bird: physiological responses show low heat tolerance thresholds irrespective of season in the Cape rockjumper (Chaetops frenatus)

Andrew McKechnie, University of Pretoria – Phylogenetic variation in heat tolerance and evaporative cooling capacity among Kalahari Desert birds

North America

Alex Gerson – Differential use of hyperthermia as a thermoregulatory strategy in birds exposed to high temperature.

Blair Wolf, University of New Mexico – Physiological challenges for desert bird communities in a rapidly warming world

David Luther – Males with larger bills sing at higher rates in a hot and dry environment

Bill Talbot – Surviving the heat: Nocturnal Sonoran Desert birds

Thomas Albright – Mapping lethal dehydration risk in desert birds of the Southwest USA under current and future climates: integrating physiology and microclimate

Ray Danner – Heat limits behavioral performance

Glenn Tattersall – Bills as radiators of body heat

Sekercioglu, Cagan – The effects of climate change on tropical birds

 

Australia

Janet Gardener – Temporal changes in avian body size over the last 50 years are associated with heat dissipation in Australian passerines

 

Many thanks to the NAOC organisers for allowing us to host this symposium!

Off to DC (again!) for my first Ornithology conference

/ gtattersall

Too many conferences this year, but it is a year of “firsts” for me.  Tomorrow I head to DC (twice this year), but this time for the North American Ornithological Conference.

NAOC Program.jpg

I’m co-organising the symposium “Surviving the heat: integrating physiology, behaviour, and morphology to predict population responses to climate change” with Blair Wolf, Andrew McKechnie, Susan Cunningham and Ray Danner.  I’ll be talking about my lab’s work on avian thermoregulatory responses.

NightHeron.png

 

Generating interest in your science and writing…

/ gtattersall

Scientists receive pressures from every angle to perform and justify their existence (parents, deans, students, bureaucrats, politicians, you name it..).  One reason for re-vamping my lab website was to keep a chronicle of lab activities as well as provide a more digestible version of our science to the public.  Since our work is sometimes highlighted by science writers and reporters, I had always assumed it was the scientists who had a tough time getting recognised.  Then I read the blog of a Science Writer, Diane Crow, who had contacted me a few months ago, interviewed me about our work on tegus.  She writes about how she tried to pitch her writing to news-outlets.  Sounds similar to a scientist’s challenge to get their work published.

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For anyone interested in science writing and the challenges inherent to it, check out Diane’s blog:  http://dianacrowscience.com/543-2/

She gives an excellent and frank account of how a science writer has to make what scientists write interesting and friendly to readers.  Sadly, in the case of the tegu story,  this was a pitch that did not work, but that is one of the reasons why I wanted to post a link to her blog!  We appreciate your work!

Here’s to you Diane!   Keep up the good work and engagement on science!