Conclusions
Recent parkland colonizers were less seasonal than historically native forest species in their vocal phenologies, suggesting that either a) man-made parklands may promote aseasonal phenologies among parkland-adapted birds, or b) newly arrived species may undergo an initial period of transitional aseasonality. In either case, the conversion of forest into parkland and urban areas which has occurred in Singapore over the last 200 years has altered not only the community of species present, but also the phenology of that community. This altered phenology is yet another way that human habitat modification may disrupt tropical communities. While continuous or aseasonal breeding may be advantageous to species expanding their ranges, it is expected to lead to reduced reproductive success for species already in decline.