Whales: Apparently their stress levels increase in line with engine noises from shipping. It interferes with their communication with other whales. Hardly surprising, really, but still good to have some firm evidence. Time to revert to sail? http://www.bbc.co.uk/news/science-environment-16926005
Monkeys: The 'silent' Tarsier monkey from the Philippines is actually very talkative. It just speaks at a frequency far above the limit of human hearing. http://www.dailymail.co.uk/sciencetech/article-2098329/Philippine-Tarsier-monkey-talks-ultrasound.html It's worth clicking the link just to look at their eyes.