1. Ecology
  2. Evolutionary Biology

Reversal of the adipostat control of torpor during migration in hummingbirds

  1. Erich R Eberts  Is a corresponding author
  2. Christopher G Guglielmo
  3. Kenneth C Welch Jr
  1. University of Toronto, Canada
  2. University of Western Ontario, Canada
https://doi.org/10.7554/eLife.70062
Share this article
Cite this article
  1. Erich R Eberts
  2. Christopher G Guglielmo
  3. Kenneth C Welch Jr
(2021)
Reversal of the adipostat control of torpor during migration in hummingbirds
eLife 10:e70062.
https://doi.org/10.7554/eLife.70062
  2. Download BibTeX
  3. Download .RIS

Abstract

Many small endotherms use torpor to reduce metabolic rate and manage daily energy balance. However, the physiological 'rules' that govern torpor use are unclear. We tracked torpor use and body composition in ruby-throated hummingbirds (Archilochus colubris), a long-distance migrant, throughout the summer using respirometry and quantitative magnetic resonance. During the mid-summer, birds entered torpor at consistently low fat stores (~5% of body mass), and torpor duration was negatively related to evening fat load. Remarkably, this energy-emergency strategy was abandoned in the late summer when birds accumulated fat for migration. During the migration period, birds were more likely to enter torpor on nights when they had higher fat stores, and fat gain was positively correlated with the amount of torpor used. These findings demonstrate the versatility of torpor throughout the annual cycle and suggest a fundamental change in physiological feedback between adiposity and torpor during migration. Moreover, this study highlights the underappreciated importance of facultative heterothermy in migratory ecology.

Data availability

All data is available in the main text or the supplementary materials. Analyses reported in this article can be reproduced using the data and code provided by Eberts et al., (2021).

The following data sets were generated

Article and author information

Author details

  1. Erich R Eberts

    Department of Biological Sciences, University of Toronto, Toronto, Canada
    For correspondence
    erich.eberts@mail.utoronto.ca
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4259-8752

  2. Christopher G Guglielmo

    University of Western Ontario, London, Canada
    Competing interests
    The authors declare that no competing interests exist.

  3. Kenneth C Welch Jr

    Department of Biological Sciences, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3283-6510

Funding

Natural Sciences and Engineering Research Council of Canada (06129-2015 RGPIN)

  • Kenneth C Welch Jr

Human Frontier Science Program (RGP0062/2016)

  • Kenneth C Welch Jr

Natural Sciences and Engineering Research Council of Canada Discovery Grant (05245-2015 RGPIN)

  • Christopher G Guglielmo

Canada Foundation for Innovation, Ontario Research Fund

  • Christopher G Guglielmo

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: Details of animal husbandry and all experiments were approved by the University of Toronto (protocol # 20011649) and the University of Western Ontario Animal Care Committees (protocol #2018-092). Hummingbirds were captured under Ontario Collecting Permit SC-00041.

Copyright

© 2021, Eberts et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 2,063
    views
  • 260
    downloads
  • 15
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Erich R Eberts
  2. Christopher G Guglielmo
  3. Kenneth C Welch Jr
(2021)
Reversal of the adipostat control of torpor during migration in hummingbirds
eLife 10:e70062.
https://doi.org/10.7554/eLife.70062

Share this article

https://doi.org/10.7554/eLife.70062

Categories and tags

Further reading

    1. Ecology

    Connecting the dots: Managing species interaction networks to mitigate the impacts of global change

    Luis Abdala-Roberts, Adriana Puentes ... Kailen A Mooney
    Review Article

    Global change is causing unprecedented degradation of the Earth’s biological systems and thus undermining human prosperity. Past practices have focused either on monitoring biodiversity decline or mitigating ecosystem services degradation. Missing, but critically needed, are management approaches that monitor and restore species interaction networks, thus bridging existing practices. Our overall aim here is to lay the foundations of a framework for developing network management, defined here as the study, monitoring, and management of species interaction networks. We review theory and empirical evidence demonstrating the importance of species interaction networks for the provisioning of ecosystem services, how human impacts on those networks lead to network rewiring that underlies ecosystem service degradation, and then turn to case studies showing how network management has effectively mitigated such effects or aided in network restoration. We also examine how emerging technologies for data acquisition and analysis are providing new opportunities for monitoring species interactions and discuss the opportunities and challenges of developing effective network management. In summary, we propose that network management provides key mechanistic knowledge on ecosystem degradation that links species- to ecosystem-level responses to global change, and that emerging technological tools offer the opportunity to accelerate its widespread adoption.

    1. Ecology
    2. Evolutionary Biology

    Reconstructing the phylogeny and evolutionary history of freshwater fishes (Nemacheilidae) across Eurasia since early Eocene

    Vendula Bohlen Šlechtová, Tomáš Dvořák ... Joerg Bohlen
    Research Article

    Eurasia has undergone substantial tectonic, geological, and climatic changes throughout the Cenozoic, primarily associated with tectonic plate collisions and a global cooling trend. The evolution of present-day biodiversity unfolded in this dynamic environment, characterised by intricate interactions of abiotic factors. However, comprehensive, large-scale reconstructions illustrating the extent of these influences are lacking. We reconstructed the evolutionary history of the freshwater fish family Nemacheilidae across Eurasia and spanning most of the Cenozoic on the base of 471 specimens representing 279 species and 37 genera plus outgroup samples. Molecular phylogeny using six genes uncovered six major clades within the family, along with numerous unresolved taxonomic issues. Dating of cladogenetic events and ancestral range estimation traced the origin of Nemacheilidae to Indochina around 48 mya. Subsequently, one branch of Nemacheilidae colonised eastern, central, and northern Asia, as well as Europe, while another branch expanded into the Burmese region, the Indian subcontinent, the Near East, and northeast Africa. These expansions were facilitated by tectonic connections, favourable climatic conditions, and orogenic processes. Conversely, aridification emerged as the primary cause of extinction events. Our study marks the first comprehensive reconstruction of the evolution of Eurasian freshwater biodiversity on a continental scale and across deep geological time.