Smallest heron

The smallest species of heron (family: Ardeidae) is the least bittern (Ixobrychus exilis), native to the Americas from southern Canada down to northern Argentina, measuring up to 36 centimetres (1 foot 2 inches) tall and with an average weight of 80 grams (2.8 ounces).

The least bittern's favoured habitats are mangroves, marshes, freshwater lakes and pools. However, due to the increased drainage of wetland areas, their population is in decline.

Despite their diminutive size, least bitterns can forage in surprisingly deep water as their beaks are almost 4 cm (1.6 in) longer than their heads. They hunt in water deeper than they can stand in by clinging onto reeds or other aquatic plants with their long toes or sometimes building a small platform to stand upon. Their main food sources are insects, reptiles, amphibians, small fish and aquatic invertebrates, occasionally also consuming the eggs and chicks of other marsh-nesting birds.

A close rival for this title is the related black-backed bittern or Australian little bittern (I. dubius) which grows to a similar size and weighs on average 85 g (3 oz).

By contrast, the largest heron species is the aptly named goliath heron (Ardea goliath) of sub-Saharan Africa and the Middle East, which stands up to 1.5 m (4 ft 11 in) and weighs around 4.4 kg (9 lb 11 oz).