The Australasian bittern (Botaurus poiciloptilus), or Matuku-hūrepo in Māori, is a stocky, sizeable and elusive heron-like bird native to the wetlands of Australia, New Zealand, and New Caledonia.

[4][5] Its streaky, beige, mottled plumage allows it to camouflage itself among the reeds and rushes of its habitat to avoid predators and hunt for prey, undetected.

[6] The species primarily feeds on fish, amphibians, and invertebrates, which it hunts by quietly stalking through shallow waters or remaining "frozen" before ambushing its prey.

[2][6] The species is classified as Vulnerable on the IUCN Red List, and continues to experience population declines resulting from habitat reduction and disturbance from wetland drainage, climate change and agricultural expansion.

[9] Researchers continue to attempt to understand this birds' daily patterns, ecology, and breeding behaviour to improve current conservation strategies, although their cryptic nature makes this particularly difficult.

[4][5] The bird is characterised by a long yellow beak, broad neck, and short legs, standing around 75 cm tall, though some individuals may reach up to one metre in height.

However, it is known that the Australasian bittern shows a strong preference for densely vegetated habitats rich in rushes, reeds, and sedges, thriving in both temperate and subtropical climates.

[2][9] These birds travel seasonally by flight for long distances (up to 600 km) to exploit coastal wetlands [9].Australia's population was estimated at 2,500 mature individuals before around 2010.

[9] However, a severe drought around then led to a sharp decline, and current estimates suggest that there are now less than 1,000 individuals, prompting its classification as Endangered under the Australian Environment Protection and Biodiversity Conservation Act 1999.

The Australasian bittern exhibits a diverse, opportunistic diet primarily comprising freshwater aquatic organisms, including fish, frogs, and eels.

[18] These irregularities are driven by periods of insufficient access to high-quality food sources, which can negatively impact their growth and reproductive success and deplete their fat reserves.

[18] Australasian bitterns share several reproductive traits with other species in the Botaurus genus, and has a breeding season that spans from June to February.

[15] This eye-swiveling technique helps them see beneath their bills while keeping their beaks high in the air to maintain a frozen surveillance posture and blend into their environment.

Despite its significance to humans, the Australasian bittern faces severe population declines, driven particularly by the loss of wetlands due to agricultural expansion, more frequent dry seasons, altered land use and climate change.

[6] The species is listed as Endangered under Australia's EPBC Act and as Nationally Critical in New Zealand, with fewer than 2,499 mature individuals globally, and trends suggesting further declines.

[9] However, the ongoing challenges of water allocation, habitat destruction, and predation by introduced mammals continue to pose significant risks to the species' survival.