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No difference in great tit (Parus major) feather growth in urban and rural locations

Winslott, Erica (2017) BIOK01 20162
Degree Projects in Biology
Popular Abstract
Are birds better off without humans?

The threat from urban Environment

Pandas and tigers are well-known examples on animals who are badly affected by urbanization. That cities are growing bigger over most of our planet causes their habitats to disappear. However, there are a lot of other animals that also are badly affected. Not only the most conspicuous ones, but common ones that are important for the ecosystems and to sustain biodiversity. Fortunately, some species are able to live next to us humans, but may still face some negative effects. The aim for this project is to find out if a common species get negatively affected by the urban environment.
Have you seen the small birds who eat at the bird tables? Perhaps at your own... (More)
Are birds better off without humans?

The threat from urban Environment

Pandas and tigers are well-known examples on animals who are badly affected by urbanization. That cities are growing bigger over most of our planet causes their habitats to disappear. However, there are a lot of other animals that also are badly affected. Not only the most conspicuous ones, but common ones that are important for the ecosystems and to sustain biodiversity. Fortunately, some species are able to live next to us humans, but may still face some negative effects. The aim for this project is to find out if a common species get negatively affected by the urban environment.
Have you seen the small birds who eat at the bird tables? Perhaps at your own garden or your grandmothers? A particular bird called the great tit (Parus major) is a common one with yellow colour on its chest and a black head. I have been looking at this bird species’ tail feathers from five urban/rural pairs of populations across Europe (Milan, Lisbon, Madrid, Malmö and Gothenburg).

How to find out the growth speed on feathers

I guess you have heard as a child that to estimate the age on a tree you can count the rings. More precisely you count one light and one dark ring and that forms one year. With feathers, it is quite similar, they have one light band and one dark (Fig. 1) together these forms under 24 hours.
Either you can decide how many days it takes for a feather to grow through counting these bars, or you can do what I have been doing, count the same amount of bars in the same feather region at each feather. Then compare every individual against each other to see if there are any difference between the speed of the feather growth. This is an important study since it could be an easy biomarker for birds “health status” related to nutritional stress.

Humans are no threat to feather growth

Luckily I have found out that the great tits do not get harmed in the urban environment with respect to feather growth. Possibly, this could be explained by the high food availability in the urban areas with high energy levels. Perhaps energy rich food is the most important thing for feather growth. Despite the lack of difference between urban/rural populations, two cities revealed to differ. Interestingly, these cities are within the same country, Sweden. Gothenburg’s and Malmö’s great tits differ from each other whereas the great tits in Gothenburg grows feathers faster. This could be due to sample size bias, human populations size or maybe pollutions.
According to my results, females are able to invest more in feather growth than males, which could be a sex difference thing such as size.
Rural great tits are heavier than urban great tits. Explanations could be that urban birds have a constant food source, meaning they do not need to have as much body fat, or sample bias.

In conclusion, there is no difference in feather growth between city and forest birds, which is positive! However, there is need for more research to find out if feathers can be used as biomarkers.

Supervisors: Hannah Watson, Caroline Isaksson
Degree Project 15 credits in Biology 2016
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Winslott, Erica
supervisor
organization
course
BIOK01 20162
year
type
M2 - Bachelor Degree
subject
language
English
id
8901695
date added to LUP
2017-01-30 15:43:53
date last changed
2017-01-30 15:43:53
@misc{8901695,
  author       = {Winslott, Erica},
  language     = {eng},
  note         = {Student Paper},
  title        = {No difference in great tit (Parus major) feather growth in urban and rural locations},
  year         = {2017},
}