1. a scientist who studies the relationships between living organisms and their environment

Examples

• The ecologist studied how pollution affects fish populations in the lake.
• Marine ecologists research ocean ecosystems and their biodiversity.
• She became an ecologist to help protect endangered species.
• The ecologist’s report showed declining bird numbers in the forest.
• University ecologists are tracking climate change effects on plant growth.
• The team of ecologists discovered a new species of beetle in the rainforest.