BBC Earth. Dangerous Journeys. Level 4

Ladybird Readers is a graded reading series for English Language Teaching (ELT) markets, designed for children learning English as a foreign or second language.
Sometimes, animals must make long or difficult journeys. They do this to find food, run from danger, or have babies.
Ladybird Readers is a graded reading series of traditional tales, popular characters, modern stories, and non-fiction, written for young learners of English as a foreign or second language. Recommended for children aged 4+, the five levels of Readers and Activity Books follow the CEFR framework (Pre-A1 to A2) and include language activities that help develop key skills and provide preparation for the Cambridge English: Young Learners (YLE) Starters, Movers and Flyers exams.
This Level 4 Reader is A2 in the CEFR framework and supports YLE Flyers exams. The longer text is made up of sentences with up to three clauses, more complex past and future tense structures, modal verbs and a wider variety of conjunctions.