Why are scientists especially puzzled by the disappearance of amphibians in thriving habitats?

Based on the passage, what can you infer scientists will most likely do next?

There are many reasons that amphibian populations have declined over the years. Pollution and destroyed habitats are the most likely culprits. What does culprit mean?

What does the passage suggest about the relationship between pollution and amphibian decline?

Scientists are concerned about the declining amphibian population. What does concerned mean?

Scientists report that almost 2,000 species of amphibians are either endangered or vulnerable. What does vulnerable mean?

Scientists are concerned about amphibian well-being, and confused about how to best help these creatures. What does 'well-being' mean?

Which word is a synonym for DECLINE?

What is a habitat?

Strangely, scientists have also discovered that amphibians who live in a thriving habitat are also disappearing. WHich word is closest in meaning to thrive?