Karin Lindström

Karin Lindström

PhD in Population Biology, researcher

I am interested in the evolutionary interactions between hosts and parasites and mechanisms of parasite transmission in natural populations. In my research, I have been working with the physiological mechanisms that control investments in the immune defense. I have used birds, and avian parasites as model organisms.

The projects that I am working with now are:

· Parasites and immunity in Darwin's finches

· Social stress and immunity in House Sparrows

· Seasonal infection dynamics in House Finches

· Virus infections in Swedish birds

· Genetic diversity and parasite resistance

Address: Department of Population Biology, Uppsala University, Evolutionary Biology Centre

Norbyvägen 18D, 752 36 Uppsala, Sweden

Phone: +46(18) 471 64 94

Fax: +46(18) 471 64 24

E-mail: karin.lindstrom(at)ebc.uu.se

Parasites and immunity in Darwin's finches

The Galapagos islands have a unique flora and fauna, partly because many of the species of animals and plants that are common on mainland never managed to get there. This is also the true for parasites, and birds on the Galapagos have been exposed to much fewer species of parasites than birds on the mainland. The result of this could be that the Galapagos have lost their capacity to resist many common bird diseases, and this can be a problem. One of the aims of this project is to investigate what kinds parasites the birds on the Galapagos have. We also want to investigate how the immune systems of these birds are operating. This project is done at the Charles Darwin Research Station in collaboration with Martin Wikelski, Henrik Pärn and Johannes Foufopoulos.

A Small Ground finch (Geospiza fuliginosa)

Social stress and immunity in House Sparrows

A pair of male House Sparrows (Passer domesticus).

House Sparrows live in flocks in nature, and they have to compete with other sparrows for food, partners and nesting sites. During the formation of flocks; territory establishment or foraging; social interactions can be frequent, and these interactions can trigger the release of both stress hormones and testosterone. These hormones can in turn regulate the immune system and reallocate energy expenditures. This project aims to investigate relationships between social status, hormone levels, immunity and metabolic expenditure in house sparrows. The project is performed in collaboration with Martin Wikelski and Dennis Hasselquist.

Seasonal infection dynamics in House Finches

Since 1994, House Finches in eastern USA have suffered from infections by a strain of bacteria (Mycoplasma Galliseptum). Infected birds get swollen eyes, and they often loose their vision and become unable to feed. The occurrence of infection in the east of America is monitored in the House Finch Disease Survey. Data from the project shows that outbreaks of disease occur at regular intervals, and birds are particularly likely to be infected in the autumn and early in the spring. In the some populations up to half of all House Finches are infected at these times and it has been shown that the infection have reduced the population size of house finches. Data from the House Finch project can be used as a model to help us understand which factors influence the spread of diseases in wildlife population in general. The aim of my investigations has been to investigate if seasonal hormonal changes are related to increased prevalence of infection. The project is performed in collaboration with Andy Dobson and Andre Dhonth.

A House Finch (Carpodacus mexicanus) infected with mycoplasma gallisepticum.

Sindbis virus-infections in Swedish birds

The Redwing (Turdus iliacus) is one of the hosts of the Sindbis virus.

Thrushes and many other species of birds in Sweden are frequently infected with a virus called Sindbis virus. This virus is transmitted to birds by bird-biting mosquitoes, and in the late summer almost half of all thrushes in the areas we have investigated have usually had the infection. The aim of this project is to investigate what effect the density of thrushes in an area will have on the prevalence of Sindbis virus infections. For many diseases, the density of hosts will determine the rates of transmission. This can also be the case for this mosquito-borne virus infection. The study is performed in collaboration with Jan Lundström.

Genetic diversity and parasite resistance

An individual’s genetic composition in the major histocompetability complex (MHC) is thought to be an important component for disease resistance in birds as well as for humans. This part of the genome is involved in antigen recognition, and provides us with the tools to identify pathogens. The aim of this project is to investigate MHC variation in wild bird populations in order to examine if individuals with a highly variable MHC region have a better ability to survive in nature. Two bird species will be the focus of this study, Darwin’s finches on the Galapagos and Black Grouse in Sweden and Finland. The study is performed in collaboration with Jacob Höglund and Tanja Viio.