Her earlier research involved animal behavior, energetics, plant pollination, and population biology, concentrating on nectar-feeding birds and plants as a study system.
(Her earlier research; involved; animal behavior, energetics, plant pollination, and population biology) (plant pollination, and population biology; concentrating; on nectar-feeding birds and plants as a study system)
Her earlier research plant pollination, and population biology
involved concentrating
animal behavior, energetics, plant pollination, and population biology
on nectar-feeding birds and plants as a study system