"Because butterflies or their caterpillars also are a food source for animals, birds and other species can be affected if butterfly population declines."
(butterflies or their caterpillars; also are; a food source for animals, birds and other species) (a food source for animals, birds and other species; can be affected; ) (butterfly population; declines; )
butterflies or their caterpillars a food source for animals, birds and other species butterfly population
also are can be affected declines
a food source for animals, birds and other species