Mercury is a persistent environmental contaminant of global concern. It is a neurotoxin with known behavioral and fitness effects on a wide range of vertebrate taxa, including birds. Until recently, it was thought that only birds with a dietary link to aquatic systems (e.g. fish eating birds) were at risk from environmental mercury poisoning. However recent work has shown that terrestrial songbirds can be exposed to levels of mercury similar to or higher than aquatic birds. However, there has been relatively little work done on the effects of mercury on these terrestrial birds. I will discuss how closely mercury levels in terrestrial birds reflect contamination in adjacent aquatic environments. In addition I will present work on the behavioral and fitness effects of environmentally relevant mercury exposure on terrestrial birds, and whether they may be able to adapt to mercury contamination.