Common raven

The northern raven is a big, glossy black bird with a deep croak, found all across the Northern Hemisphere. It's the heaviest of all songbirds, with some weighing as much as a small bag of sugar. These clever birds stick with one partner for life and fiercely guard their home turf.

• A full-grown raven can reach 63 cm long and weigh up to 2 kg.
• They can live over 23 years in the wild, though many don't reach that age.
• Young ravens hang out in groups, but adults pair up and defend territories.