In the final episode of series 4, we’re digging into some of the more elusive corners of our planet. To begin, we’re on a bear hunt deep in the Bornean rainforest. Guiding us is Siew Te Wong, who is the world’s foremost authority on a bear we know very little about. The sun bear is the smallest bear in the world and, as Wong has discovered for himself, tracking them can draw up some unexpected discoveries. Next we’re turning our attention upwards, to the sky at night. Or, to be more precise, to the sounds that come from it. Magnus Robb explores what birdsong can tell us about the extraordinary migration routes of these animals. To end, we sit still to see the visible changes over time to our glaciers. Using past and present technology, Kieran Baxter brings to life some of the unprecedented declines in our natural world. Thank you for listening to another series of the BBC Earth podcast. As ever, we love hearing from you on social media, so do share with us your favourite episode so far or a story that amazed, surprised or moved you… Website: www.bbcearth.com Facebook: www.facebook.com/bbcearth/ Instagram: www.instagram.com/bbcearth/ Twitter: www.twitter.com/bbcearth    See acast.com/privacy for privacy and opt-out information.