Urban environments have high levels of non-biodegradable contaminants, lower quality resources and food shortage. Around twenty percent of the recognized bird species in the world are found to live in cities (Aronson et al. 2014), which puts them at a higher risk of being exposed to chemical pollutants and trace metals that are persistent in urban areas. There is a negative influence of urban pollution on several fitness related traits, reproductive success and survival (Chamberlain et al. 2009; Seress et al. 2012). However, more importantly, exposure to chemicals and food shortage increases oxidative stress which in turn is found to negatively impact the avian immune system (Isaksson, 2015). It has been found that exposure to pollutants can lead to compromise immune defences and negatively impact immune organs, immune cell populations and signaling molecules (Ackerman et al., 2016,García-Mendoza et al., 2021). Additionally, birds living in urban environments also face challenges to find foods rich in carotenoids which are known to favour various components of the immune system (Isaksson and Andersson 2007; Chamberlain et al. 2009). A compromised immune system can increase susceptibility to infections, overall prevalence of pathogens and promotes the spread of zoonotic diseases in animals as well as humans. This project focuses on the modulatory effects of urban chemical exposure and food shortage on the immune and redox systems in birds. This research question will be assessed in field, in vitro and in ovo and the results will be compared to draw conclusions.