The ability of reclaimed wetlands created from oil sand tailings to support populations of tree swallows was examined. Nests were provided on the sites of interest to allow swallows to breed, raise their young and feed on flying insects from local wetlands. In order to determine if the bird's health was affected by stressors such as contaminants accumulated through the diet, this study examined reproductive performance and neonatal development of the birds. Two experimental wetlands differing in age were used in this study, notably a 15 year old and 3 year old wetland. Reproduction was measured by clutch size, egg mass, hatchability and offspring survival. Neonatal development was assessed through body measurements, taken on 12 day old nestlings. It was shown that the reproductive success of the adults, and clutch size did not differ between the sites. However, initiation of breeding was earlier at the younger reclamation site. Neonatal development was different between sites, but body mass was not. Birds at the younger site exhibited accelerated tail and wing feather maturation, but birds on the mature site had a larger skeletal size. These findings may be attributed to different dietary, nutritional, and/or endocrine modulating substances moving through the food chain. It was noted that insect density and diversity may have been influenced by different altitudes and vegetation cover at the 2 sites