Integument colouration and circulating carotenoids in relation to urbanisation in Eurasian kestrels (Falco tinnunculus)
Sumasgutner, Petra LU ; Nilles, Tom ; Hykollari, Alba ; de Chapa, Manuela Merling ; Isaksson, Caroline LU
; Hochleitner, Lukas
; Renner, Swen
and Fusani, Leonida
(2023)
In Science of Nature
110.
- Abstract
Urbanisation is one of the biggest environmental challenges of our time, yet we still lack an integrative understanding of how cities affect behaviour, physiology and parasite susceptibility of free-living organisms. In this study, we focus on carotenoids, strictly dietary micronutrients that can either be used as yellow-red pigments, for integument colouration (signalling function), or as antioxidants, to strengthen the immune system (physiological function) in an urban predator, the Eurasian kestrel (Falco tinnunculus). Kestrels are specialised vole hunters but shift to avian prey in cities where diurnal rodents are not sufficiently available. This different foraging strategy might determine the quantity of carotenoids available. We... (More)
Urbanisation is one of the biggest environmental challenges of our time, yet we still lack an integrative understanding of how cities affect behaviour, physiology and parasite susceptibility of free-living organisms. In this study, we focus on carotenoids, strictly dietary micronutrients that can either be used as yellow-red pigments, for integument colouration (signalling function), or as antioxidants, to strengthen the immune system (physiological function) in an urban predator, the Eurasian kestrel (Falco tinnunculus). Kestrels are specialised vole hunters but shift to avian prey in cities where diurnal rodents are not sufficiently available. This different foraging strategy might determine the quantity of carotenoids available. We measured integument colouration, circulating carotenoids in the blood and ectoparasite burden in kestrels along an urban gradient. Our results showed that nestlings that were raised in more urbanised areas displayed, unrelated to their ectoparasite burden, a paler integument colouration. Paler colours were furthermore associated with a lower concentration of circulating carotenoids. These findings support the hypothesis that the entire urban food web is carotenoid deprived and only prey of low quality with low carotenoid content is available (e.g. fewer carotenoids in urban trees, insects, small birds and finally kestrels). The alternative hypothesis that nestlings allocate carotenoids to reduce physiological stress and/or to cope with parasites rather than invest into colouration could not be supported. Our study adds to existing evidence that urban stressors negatively affect carotenoid production in urban areas, a deficiency that dissipate into higher trophic levels.
(Less)
- author
- Sumasgutner, Petra
LU
; Nilles, Tom
; Hykollari, Alba
; de Chapa, Manuela Merling
; Isaksson, Caroline
LU
; Hochleitner, Lukas
; Renner, Swen
and Fusani, Leonida
- organization
- publishing date
- 2023-10
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Circulating carotenoids, Colour ornaments, Dietary antioxidants, Eco-physiology, Environmental quality, Lutein, Raptors, Urban stressors, Urbanisation, Zeaxanthin
- in
- Science of Nature
- volume
- 110
- article number
- 48
- pages
- 13 pages
- publisher
- Springer
- external identifiers
-
- pmid:37736824
- scopus:85171847490
- ISSN
- 0028-1042
- DOI
- 10.1007/s00114-023-01874-5
- language
- English
- LU publication?
- yes
- id
- fe9d1e08-f8f7-4540-86a5-ab068dbac7e8
- date added to LUP
- 2023-12-07 10:20:36
- date last changed
- 2024-04-20 04:48:04
@article{fe9d1e08-f8f7-4540-86a5-ab068dbac7e8,
abstract = {{<p>Urbanisation is one of the biggest environmental challenges of our time, yet we still lack an integrative understanding of how cities affect behaviour, physiology and parasite susceptibility of free-living organisms. In this study, we focus on carotenoids, strictly dietary micronutrients that can either be used as yellow-red pigments, for integument colouration (signalling function), or as antioxidants, to strengthen the immune system (physiological function) in an urban predator, the Eurasian kestrel (Falco tinnunculus). Kestrels are specialised vole hunters but shift to avian prey in cities where diurnal rodents are not sufficiently available. This different foraging strategy might determine the quantity of carotenoids available. We measured integument colouration, circulating carotenoids in the blood and ectoparasite burden in kestrels along an urban gradient. Our results showed that nestlings that were raised in more urbanised areas displayed, unrelated to their ectoparasite burden, a paler integument colouration. Paler colours were furthermore associated with a lower concentration of circulating carotenoids. These findings support the hypothesis that the entire urban food web is carotenoid deprived and only prey of low quality with low carotenoid content is available (e.g. fewer carotenoids in urban trees, insects, small birds and finally kestrels). The alternative hypothesis that nestlings allocate carotenoids to reduce physiological stress and/or to cope with parasites rather than invest into colouration could not be supported. Our study adds to existing evidence that urban stressors negatively affect carotenoid production in urban areas, a deficiency that dissipate into higher trophic levels.</p>}},
author = {{Sumasgutner, Petra and Nilles, Tom and Hykollari, Alba and de Chapa, Manuela Merling and Isaksson, Caroline and Hochleitner, Lukas and Renner, Swen and Fusani, Leonida}},
issn = {{0028-1042}},
keywords = {{Circulating carotenoids; Colour ornaments; Dietary antioxidants; Eco-physiology; Environmental quality; Lutein; Raptors; Urban stressors; Urbanisation; Zeaxanthin}},
language = {{eng}},
publisher = {{Springer}},
series = {{Science of Nature}},
title = {{Integument colouration and circulating carotenoids in relation to urbanisation in Eurasian kestrels (Falco tinnunculus)}},
url = {{http://dx.doi.org/10.1007/s00114-023-01874-5}},
doi = {{10.1007/s00114-023-01874-5}},
volume = {{110}},
year = {{2023}},
}