Migration Info This species is one of those whose breeding range appears to be shifting northward in recent years, apparently as a result of global warming. Temperature increases, which result from higher levels of carbon dioxide in the atmosphere, are also causing some birds to begin migrating earlier in the spring. This in turn may put them out of sync with the foods on which they depend. Baltimore Orioles prefer winter habitats that offer mature trees as well as a significant understory. They do well in shade-grown coffee and cacao plantations, but are losing important habitat as agricultural practices shift and shade trees are removed. The arrival of this beautiful bird in the early part of May coincides with the blooming of the fruit trees in the New England area. The mature males, first to arrive, make a colorful sight among the pink and white blossoms of the orchards.