Jan and the Secret Cave - J. B. Moonstar - Bog

"No time to explain-they will see you, now run!"
Learning that an expedition is studying a group of endangered terns, Jan joins the group with her father to help him with his research and see if she can do anything to protect them. While at the nesting site on the cliffs, she finds a small silk bag in a cave, and so starts an adventure with many unexpected surprises.
When she learns poachers have stolen many tern eggs, she is determined to rescue them, and with a little help, to transport them, along with their parents, to Ituria's Island where they will be safe. But what chance does a young girl have against a band of poachers?
This book is great for early readers who love learning about animals and birds as well as how to help their environment. Themes include asking for help, building self-courage, and encouraging self-discovery.