The wood thrush makes its nest in woodlands in the northern and eastern united states. as patches of woods become smaller, increasing numbers of wood thrush nests have eggs laid in them by the brown-headed cowbirds. cowbirds live in open fields and are nest parasites; the female cowbird flies up to an unattended nest, quickly lays an egg in it, and leaves the host parents to raise their "adopted" young. wood thrushes are decreasing in numbers because

Answer;

Habitat fragmentation makes it easier for cowbird parasitism to occur.

Wood thrushes are decreasing in numbers because habitat fragmentation makes it easier for cowbird parasitism to occur.

Explanation;

Habitat fragmentation describes the complete process by which habitat loss results in the division of large, continuous habitats into a greater number of patches of lower total area, isolated form each other by habitats that are no similar.

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