National Geographic's annual travel photography competition has kicked off, and is open for entries until 27 May 2016. Photographers can submit entries in any or all of three categories: Nature, People and Cities. The grand prize award winner will receive a seven-day polar bear photo safari for two at Churchill Wild–Seal River Heritage Lodge in Canada.

IBTimes UK presents a selection of photos submitted in the Nature category. See more – and enter your own pictures – on the National Geographic website.