Biologist Michael Warriner with the Texas Parks & Wildlife Department says he's seen probably only four monarchs in the last three weeks.
Researchers hope to get a better count of the monarchs once they arrive at their winter grounds in Mexico in a few weeks.
The Fort Worth Star-Telegram reported Wednesday that the drought has dramatically reduced the main food source for monarch butterflies. The insects need the nectar from blooming plants.
Entomologist Mike Quinn with Texas Monarch Watch says he drove through the Hill Country last month and was disappointed in how many dead plants and how few butterflies he saw.