BOSTON (AP) - A Harvard University study says butterflies that have graced Massachusetts summers for decades are declining and being replaced by their southern neighbors.
The new study by the Harvard Forest department suggests that cold-climate butterfly species are dwindling in the state while warmer-climate species are growing rapidly.
The department analyzed data collected by the Massachusetts Butterfly Club during the past 19 years.
The study found that 17 of the 21 Northern butterfly species in Massachusetts were in population decline. That compares with 12 Southern species of the insect, which went from being virtually unseen to one of fastest growing populations in the state.
The study does not track butterfly populations outside of Massachusetts, so it does not account for whether cold-climate species have moved north.