Scientists have suggested several reasons to explain why building roads may be bad for some birds. One theory is that, by building a road, we separate forests and reduce the area of habitat available for animals to live in, a process that we call habitat fragmentation.

1. scientific evidence suggests that assumptions based on anecdotes may be incorrect

2. scientists propose explanations for their findings, which allow other scientists to create rival explanations and hypotheses

3. reproducible anecdote allows people to assume knowledge, despite a lack of replicated scientific evidence

4. reproducibility in anecdotal observations