Double-striped Thick-knee
Hesperoburhinus bistriatus
Large and bizarre shorebird of lowland dry grassland and savannas, usually found in pairs or small groups. Active mainly at night (note the big, yellow, owl-like eyes). During the daytime, usually seen standing or sitting quietly, often in the shade of small trees or bushes. Note cryptic, overall pale sandy plumage, double stripes on the head, and long yellow legs.
Identification
The double-striped thick-knee is a medium-large wader with a strong black and yellow bill, large yellow eyes, which give it a reptilian appearance, and cryptic plumage. The adult is about 46 to 50 cm (18–20 in) long and weighs about 780 to 785 g (27.5–27.7 oz). It has finely streaked grey-brown upperparts, and a paler brown neck and breast merging into the white belly. The head has a strong white supercilium bordered above by a black stripe. Juveniles are similar to adults, but have slightly darker brown upperparts and a whitish nape. The double-striped thick-knee is striking in flight, with a white patch on the dark upperwing, and a white underwing with a black rear edge.<p>The four subspecies differ in size and plumage tone, but individual variation makes identification of races difficult.
Taxonomy
The double-striped thick-knee was formally described in 1829 by the German naturalist Johann Georg Wagler from a specimen collected in Mexico. He coined the binomial name Charadrius bistriatus. The specific epithet bistriatus combines the Latin bi- meaning "two-" or "double-" with striatus meaning "stripe". The double-striped thick-knee is now placed in the genus Burhinus that was erected by the German zoologist Johann Karl Wilhelm Illiger in 1811. In IOC 14.1, the double-striped thick-knee was transferred to the newly described genus Hesperoburhinus. <p>Four subspecies are recognised:
- Scientific name
- Hesperoburhinus bistriatus
- Authority
- (Wagler, 1829)
- Order
- Charadriiformes
- Family
- Burhinidae
- Genus
- Hesperoburhinus
Range and habitat
It is a resident breeder in Central and South America from southern Mexico south to Colombia, Venezuela and northern Brazil. It also occurs on Hispaniola and some of the Venezuelan Caribbean islands, and is a very rare vagrant to Trinidad, Curaçao and the USA. It prefers arid grassland, savanna, and other dry, open habitats.
- Migration
- Resident species
Behavior
This is a largely nocturnal and crepuscular species. It flies only reluctantly, relying on crouching and camouflage for concealment. The double-striped thick-knee eats large insects and other small vertebrate and invertebrate prey. It is sometimes semi-domesticated because of its useful function in controlling insects, and has benefited from the clearing of woodlands to create pasture. The song, given at night, is a loud kee-kee-kee.<p>The nest is a bare scrape into which two olive-brown eggs are laid and incubated by both adults for 25–27 days to hatching. The downy young are precocial and soon leave the nest.
Conservation
- Population trend
- stable
Photos
Distribution
Bird Calls
Other Birds
Campbell Islands Shag
Leucocarbo campbelli
A medium-sized, black-and-white marine shag with a metallic green-and-blue glimmer on the black head, neck, and throat. Note the white wing patches. Breeding birds have a prominent crest and a yellow line above the gape of the long, pointed bill. There is a yellow patch at the base of the bill that fades to a bright red spot. Non-breeding adults lack the crest and plumage fades to brown. Juveniles are similar to adults, but with brown upperparts. Endemic to Campbell Islands and only found in shallow waters nearby. Only resident shag species on Campbell Island.
Elegant Tern
Thalasseus elegans
Long-billed tern of the Pacific coast, from the U.S. to Chile. Pale gray above with shaggy black cap in breeding plumage; nonbreeding birds develop white forehead. Best field mark is the slender orange bill with a slight droop. Strictly coastal; commonly found on beaches and estuaries. Similar to Royal Tern but smaller and slimmer with a thinner bill. Harsh grating calls similar to other terns.
Madagascar Grebe
Tachybaptus pelzelnii
Small, dark grebe that is endemic to Madagascar. The neck is rufous and white in breeding plumage and buff in non-breeding plumage. Juvenile has a bridled head pattern. Found very locally on the open water of lakes and ponds. Call is a long, dry rattle, often given in duet by a pair. Similar to Little Grebe, but generally much less common, especially at lower elevations. In breeding plumage, Madagascar Grebe is identified by its white throat patch. In non-breeding plumage, hard to distinguish from Little Grebe, but usually still shows a pale patch on the throat.
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