It's old hat now, but back when Trials of Life originally debuted on the BBC and PBS it was a big deal as it was the first, major mainstream nature mini-series to feature brutal, uncensored footage of animals killing each other, basically. This is why the marketing for it was so "in your face" at the time.
DAVID ATTENBOROUGH'S GENTLE VOICE WILL GUIDE YOU INTO AN UNTAMED WORLD OF BLOODY SAVAGERY. HE WILL LEAD YOU INTO A DARK CESSPOOL OF SHAME FROM WHENCE YOUR SOUL MIGHT NEVER RETURN. ABANDON ALL HOPE YE WHO ENTER HERE, WE GUARANTEE AT LEAST THREE DEAD CHIMPANZEES EVERY TEN MINUTES OR RETURN THE SET.