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Assessing urban impacts on wildlife using the pace-of-life framework

Periodic Reporting for period 2 - UrbPOLS (Assessing urban impacts on wildlife using the pace-of-life framework)

Reporting period: 2018-07-01 to 2019-06-30

Problem description:
It is commonly observed that birds inhabiting cities live longer, but have lower annual reproduction, than their rural counterparts. Reduced reproductive output has been explained by unsuitable urban living conditions, but this does not explain why city birds have greater survival. Could it be adaptive for birds to have lower reproductive success in the cities because they have more years to breed? Are there other adaptive life-history differences between urban and rural populations? If so, could this also explain urban-rural differences in parasite resistance (invest more into immune response if you expect to live longer?), coloration (invest less in sexual signals if you can count on more than one breeding season), and oxidative stress resistance (as a mechanism of aging)? Such differences in life-history traits may be understood in the context of a pace-of-life syndrome (POLS). In other words, urban and rural birds may have equal lifetime fitness, but rural birds breed fast and die early whereas urban birds (due to shifts in resources and other selection pressures) breed slow and die late.

Importance:
The project will help to understand the effect of urbanization on wild bird communities and better our understanding of urbanization as an evolutionary process.

Objectives:
1. Publish a meta-analysis on studies on urbanization of birds, focusing on the traits related to pace-of-life
2. Conduct a field project in Phoenix metropolitan area to analyse the effect of urbnization on the survival, reproductive success, and physiology of house finches.
"Meta-analysis has been conducted and published.
Field work has been completed. Additional model systems have been included to fulfill the goals of the project (including captive king quail for assessing the effects of light pollution on developing birds, and common gulls, for assessing the effects of aging rate and environmental pollution on life-history traits)
Several side projects stemming from the main idea of the project have been developed in collaboration with the members of the outgoing host lab.

Main results achieved so far:
- A meta-analysis article was published in Global Changes Biology, showing that birds living in the cities have generally higher survival and smaller clutch size. These findings support the idea of an adaptive slower pace-of-life for populations living in urban habitats. This article was one of the most cited articles in this journal on year 2018.
- An article has been published in Science of Nature, showing that the drab coloration of plumage that is often found in urban birds compared to rural birds might be linked to digestion efficiency.
- A study has been conducted to study the effects of light pollution, a common problem in urban areas, on the digestion efficiency of developing birds. This study indicated that digestion is indeed less efficient when the birds are exposed to light at night. These results will be published in the following months (first article of planned two submitted to the Journal of Experimental Biology).
- An ideas article has been published in Nature Ecology and Evolution, proposing the idea that antropogenic changes in the environment, including changes in urban areas, could be causing cancer also in wild animals.
- A review article has been published in Proceedings of the Royal Society B, describing the links between urban environment and cancer in wild animals
- An ideas article has been published, suggesting that telomere shortening might be a physiological mechanism that relays information about environmental conditions inside the organism, in order to select the optimal pace-of-life strategy.
- A review article has been published, describing the link between urban environment and cancer in wildlife
- Data has been collected for analysing the effects of parental age on the telomere length of chicks, using a cross-fostering experiment. Article is submitted to Scientific Reports.
- Data has been collected for analysing the link between pollutant levels, age of the bird, and gene expression. Manuscript is in preparation.

Overview of the results:
In total, 11 articles have been published under this project so far, and several more are either submitted or in preparation. Several promising collaborations and side projects have been developed. These include the study of the effects of light pollution on developing birds, and the study of anthropogenic environmental change effects on wildlife cancer. I am developing the latter project into my new research direction, and have already submitted a national grant project for starting my own work group on this topic. I have introduced the results of the current project in three international meetings in year 2018, including the Society for Integrative and Comparative Biology meeting in San Francisco, USA, European Society for Evolutionary Biology meeting in Montpellier, France, and the Society for Experimental Biology meeting in Florence, Italy. I have continued to introduce my research through the popular scientific blog ""Zooloogid 2.0"", which gained the National Science Outreach prize in 2018. I have also written numerous popular scientific articles for Estonian newspapers and journals and given several radio and TV interviews for Estonian media."
The meta-analysis article has been published in a high-impact journal (Global Change Biology) and was one of the most cited articles in this journal for year 2018. The ideas of the project have been introduced in three major international conferences (Society of Integrative and Comparative Biology (SICB) meeting in San Francisco, Socitey of Experimental Biology (SEB) meeting in Florence, Italy, European Society for Evolutionary Biology meeting in Montpellier, France).
During the the project, the PI has coauthored and published 10 articles in international peer-reviewed journals, with several more being submitted or in preparation. Some of these studies have also been widely covered in media.

Conclusion of the actions:

The project has lead to a high number of international publications and to wider public understanding of the anthropogenic impacts on wildlife, including changes in pace-of-life, cancer prevalence, and development of wild animals. Several articles published under this project have already attracted numerous citations. The project has gained considerable media attention. For example, the article describing links between anthropogenic activities and cancer in wildlife gained wide public attention, reflected in the Altmetric score of 544. The project has lead to a tight international collaboration network, including scientists from Estonia, France, USA, and Australia. The ideas developed during this project are now expanded into a new research direction of wildlife adaptations against oncogenic environmental pollution.
House finch nestling banded near Phoenix, Arizona, during the project.