Water Thick-knee

The Water Thick-knee, also known as the Water Dikkop (Burhinus vermiculatus), presents a striking figure with its 38 to 41 cm (15–16 in) stature and a weight range of 293–320 g (10.3–11.3 oz). This bird is characterized by a robust bill, black with a hint of yellow at the base, broad and blunt wings, and a rather short tail.

Identification Tips

When identifying the Water Thick-knee, look for its heavy bill with a yellow base, which is quite distinctive. The wings are broad and blunt, which can be observed when the bird stretches them. The tail is short, which is noticeable when the bird is in flight or when it fans its tail feathers.

Habitat

The Water Thick-knee is typically found along the edges of lakes, estuaries, and rivers. It also frequents mangroves and some sheltered beaches, often requiring nearby bushes or woodlands for shelter. Its habitat range extends from sea level up to 1,800 m (5,900 ft).

Distribution

This species enjoys a widespread distribution across sub-Saharan Africa, with sightings reported in countries such as Angola, Botswana, Burkina Faso, and many others, all the way to South Africa.

Behaviour

The Water Thick-knee is a nocturnal terrestrial feeder, often venturing up to 1 km (0.62 mi) away from water to forage. It is known for its unique nesting behavior, often laying its eggs adjacent to or directly on top of Nile crocodile nests, engaging in a symbiotic mutualism with the crocodiles.

Song & Calls

The Water Thick-knee is known to be vocal, especially when acting as a sentry for its nest or the crocodile nests it shares. Its calls are used to alert the crocodile of potential threats.

Breeding

Breeding typically occurs in the dry season or early rainy season. The Water Thick-knee is monogamous, with both parents diligently guarding the nest and brooding the eggs. The nest is a simple scrape in the ground, and the clutch consists of two sandy-yellow eggs. Incubation lasts for 22-25 days, with both parents sharing the responsibility of feeding the young.

Similar Species

The Water Thick-knee can easily be confused with the Spotted Thich-knee.

Diet and Feeding

The diet of the Water Thick-knee includes insects, crustaceans, and mollusks, which it forages for during the night.

Conservation status

The Water Thick-knee is currently listed as Least Concern on the IUCN Red List, indicating that it is not at immediate risk of population decline.