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A colonial-nesting seabird shows no heart-rate response to drone-based population surveys. Sci Rep 2022; 12:18804. [PMID: 36335150 PMCID: PMC9637139 DOI: 10.1038/s41598-022-22492-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 10/14/2022] [Indexed: 11/08/2022] Open
Abstract
Aerial drones are increasingly being used as tools for ecological research and wildlife monitoring in hard-to-access study systems, such as in studies of colonial-nesting birds. Despite their many advantages over traditional survey methods, there remains concerns about possible disturbance effects that standard drone survey protocols may have on bird colonies. There is a particular gap in the study of their influence on physiological measures of stress. We measured heart rates of incubating female common eider ducks (Somateria mollissima) to determine whether our drone-based population survey affected them. To do so, we used heart-rate recorders placed in nests to quantify their heart rate in response to a quadcopter drone flying transects 30 m above the nesting colony. Eider heart rate did not change from baseline (measured in the absence of drone survey flights) by a drone flying at a fixed altitude and varying horizontal distances from the bird. Our findings suggest that carefully planned drone-based surveys of focal species have the potential to be carried out without causing physiological impacts among colonial-nesting eiders.
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Parkinson KJL, Hennin HL, Gilchrist HG, Hobson KA, Hussey NE, Love OP. Breeding stage and tissue isotopic consistency suggests colony-level flexibility in niche breadth of an Arctic marine bird. Oecologia 2022; 200:503-514. [PMID: 36229693 DOI: 10.1007/s00442-022-05267-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 09/20/2022] [Indexed: 12/01/2022]
Abstract
Organisms must overcome environmental limitations to optimize their investment in life history stages to maximize fitness. Human-induced climate change is generating increasingly variable environmental conditions, impacting the demography of prey items and, therefore, the ability of consumers to successfully access resources to fuel reproduction. While climate change effects are especially pronounced in the Arctic, it is unknown whether organisms can adjust foraging decisions to match such changes. We used a 9-year blood plasma δ13C and δ15N data set from over 700 pre-breeding Arctic common eiders (Somateria mollissima) to assess breeding-stage and inter-annual variation in isotopic niche, and whether inferred trophic flexibility was related to colony-level breeding parameters and environmental variation. Eider blood isotope values varied both across years and breeding stages, and combined with only weak relationships between isotopic metrics and environmental conditions suggests that pre-breeding eiders can make flexible foraging decisions to overcome constraints imposed by local abiotic conditions. From an investment perspective, an inshore, smaller isotopic niche predicted a greater probability to invest in reproduction, but was not related to laying phenology. Proximately, our results provide evidence that eiders breeding in the Arctic can alter their diet at the onset of reproductive investment to overcome increases in the energetic demand of egg production. Ultimately, Arctic pre-breeding common eiders may have the stage- and year-related foraging flexibility to respond to abiotic variation to reproduce successfully.
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Affiliation(s)
- Kyle J L Parkinson
- Department of Integrative Biology, University of Windsor, Windsor, ON, Canada. .,Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1H 2W1, Canada.
| | - Holly L Hennin
- Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada
| | - H Grant Gilchrist
- Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada
| | - Keith A Hobson
- Department of Biology, University of Western Ontario, London, ON, Canada.,Environment and Climate Change Canada, Saskatoon, SK, Canada
| | - Nigel E Hussey
- Department of Integrative Biology, University of Windsor, Windsor, ON, Canada
| | - Oliver P Love
- Department of Integrative Biology, University of Windsor, Windsor, ON, Canada
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Friedman-Einat M, Seroussi E. Avian Leptin: Bird's-Eye View of the Evolution of Vertebrate Energy-Balance Control. Trends Endocrinol Metab 2019; 30:819-832. [PMID: 31699239 DOI: 10.1016/j.tem.2019.07.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/13/2019] [Accepted: 07/08/2019] [Indexed: 12/20/2022]
Abstract
Discovery of the satiety hormone leptin in 1994 and its characterization in mammals provided a key tool to deciphering the complex mechanism governing adipose tissue regulation of appetite and energy expenditure. Surprisingly, despite the perfectly logical notion of an energy-storing tissue announcing the amount of fat stores using leptin signaling, alternate mechanisms were chosen in bird evolution. This conclusion emerged based on the recent discovery and characterization of genuine avian leptin - after it had been assumed missing by some, and erroneously identified by others. Critical evaluation of the past and present indications of the role of leptin in Aves provides a new perspective on the evolution of energy-balance control in vertebrates; proposing a regulation strategy alternative to the adipostat mechanism.
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Affiliation(s)
- Miriam Friedman-Einat
- Department of Animal Science, Agricultural Research Organization, Volcani Center, Rishon LeTsiyon, Israel.
| | - Eyal Seroussi
- Department of Animal Science, Agricultural Research Organization, Volcani Center, Rishon LeTsiyon, Israel
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