"Dance of the Dwarfs"(1983)? Also known as "Jungle Heat".
Here is the IMDb page.
And here is the last paragraphs describing the final scenes from Wikipedia.
At night, Evelyn radios Harry again and tells him she sees the duendes, which, she discovers, is really a tribe of lizard creatures. She shoots a few with her flare gun before fleeing onto a vine over the deadly lake. Before her arms give out, she is picked up by her pilot, who she kisses as they fly back to Luis's fort in hopes of rescuing him.
However, they find both him and Maria dead, and his compound crawling with the duendes. They manage to escape them and fly away with love, or at least respect, noticeably blossoming. However, when Dr. Howard goes to the middle of the chopper to check on some machinery, she is grabbed by one of the clawed hands of the duendes.