The average reproductive performance of birds has been shown to be lower in polluted areas (Eeva & Lehikoinen, 1995; Peach et al, 2008, Barton et al, 2023). Hatching success is one of the most important determinants of fitness, and the number of eggs that fail to hatch can have a serious impact on population dynamics (Ferreira et al, 2005; White et al, 2015). Hatching failure (excluding predation and abandonment) can have different proximate causes: for example, it may result from poor sperm quality, bad female condition, and/or environmental factors.
Many vertebrates, such as birds, undergo annual cycles of gonad development in which the gonads must develop before breeding can commence (Davies and Deviche, 2014). It was shown that urban birds have earlier gonadal development compared with their rural conspecifics (Davies et al, 2015). It was shown in human that higher exposure to air-pollutant can cause damage to testes, characterized by histological alterations, oxidative damage and apopotosis. However, we know that urbanization has an impact on the timing and pace of gonadal development, we do not know how it can influence the process of sperm production and the quality of sperm. Therefore, the proposed project will address how urbanization and traffic related pollutants can influence the oxidative status (SOD activity, MDA level and T-AOC) and apoptosis level of the testes and the ejaculate in wild birds, and how it influences the quality of sperm (swimming velocity, progressive motility, morphology and DNA damage).
Project will be carried out on Blue and Great tits (Cyanistes caeruleus and Parus major), which makes possible that the students are working together closely during the course of their master degree, while still doing their independent research.
Master project 1 & 2 (MP12)
Objective
To determine whether urbanisation influences sperm quality via oxidative damage in the testes
Your role
You investigate whether the oxidative status and the apoptosis level in testes influences the quality of the sperm.
Master project 3 & 4 (MP34)
Objective
To determine whether urbanisation influences sperm quality via oxidative damage in the ejaculate.
Your role
You investigate whether the oxidative status of the ejaculate influences the quality of the sperm.
Fieldwork & data collection
– Participating in long-term data collection by monitoring nest boxes in 5 different parks of Malmö, and in Skrylle Nature Reserve (MP1234).
– Catching, handling and ringing birds using various methods (MP1234).
– Collect blood and ejaculate samples (MP1234) and organs including the testes (MP12).
– Measuring sperm swimming velocity and progressive motility (MP1234).
Labwork
– Measuring SOD, MDA, T-AOC and apoptosis levels from the testes (MP12).
– Measuring SOD, MDA, T-AOC and apoptosis levels from the ejaculate (MP34).
– Measuring sperm morphology and DNA damage (MP34).
Length of the projects
10 months theses for 60 credits are prioritized, but shorter theses may be organized as well, depending on the project.
Start date
The fieldwork starts at the beginning of April 2026.
Requirements
Participating students must take the Animal Testing Ethics course before the start of the project.
Contact info
Zsófia Tóth – zsofia.toth@biol.lu.se