Piviere di Kittlitz

Identificazione

Kittlitz's plover is a small shorebird weighing between 35-40 grams. Both males and females share similar physical characteristics, with a black bill, dark brown eyes framed by black eyelids, and black legs, although at times, the legs can appear greenish or grey. During the breeding season, During the breeding season, the male displays distinct features, including a white forehead, a blackish bar followed by a narrow white bar on the forecrown, while the remainder of the crown appears brown with sandy tips on the feathers. A black stripe, separated from the crown by a white superciliary stripe, runs from the bill through the eye and extends to the side of the neck, forming a collar across the upper mantle. The mantle is dark grey-brown, and the other upperparts are sooty brown with feathers featuring sandy rufous margins. The face, chin and upper throat are white, while the rest of the underparts take on a yellowish hue, with a pale belly. Kittlitz's Plover possesses blackish central tail feathers that progressively become lighter towards the tail's sides, and the outer one or two pairs are completely white. Notably, Kittlitz's Plover is not sexually size dimorphic, meaning that males and females share similar size characteristics. The female plumage closely resembles that of the male, although the black band across the forecrown is narrower. The non-breeding plumage does not differ significantly from the breeding plumage. In this stage, the eye stripe takes on a browner shade, and the frontal bar is absent, while the underparts become considerably paler. Generally, adult Kittlitz's Plovers exhibit a wing length ranging from 100–110 mm, an adult bill length between 15–23 mm, and an adult tarsus length between 26–33 mm. Juvenile Kittlitz's plovers closely resemble adults; however, they lack the black face marks, their upperparts appear brown, the hindneck collar is buff in color, and their underparts are white.

Tassonomia

Nome scientifico

Anarhynchus pecuarius

Autorità

(Temminck, 1823)

Ordine

Caradriformi

Famiglia

Caradriidi

Genere

Anarhynchus

Areale e habitat

Migrazione

Resident species

Comportamento

The species is social in the non-breeding season and stays in small flocks of about 20 individuals, however it has also been reported in larger flocks of 100-300 individuals during migratory movements.<p>Kittlitz's Plover has a flexible breeding system and shorter duration of pair bond than other plover species. It is thought to be mainly polygamous and the pairing usually occurs around 2–4 weeks before the couple occupies their territory. Copulation and feeding both take place in the territories, which can occupy 3600-4200m². The parents are highly defensive of their territories until the chicks hatch. When intruders invade their territory representing a threat, the parents run after them, stopping shortly in front of them, taking on an upright posture with their legs almost straight and their head up.<p>The initial courtship takes place on ‘neutral’ ground. and consists of a scrape-ceremony, where one bird is placing its breast on the sand, then rotating around on the breast, whilst having its tail raised and kicking out sand with back- and forward movements of its legs. Usually, the male takes the initiative of making several scrapes (although sometimes both parents take turns in making them) and then the female probably chooses the final nest site. Both parents pick up pebbles or break off bits of dead vegetation as nest material to line the nest with.<p>The Kittlitz's Plover is a ground-nesting shorebird, that breeds throughout the whole year, although there are varying peak seasons in different geographic locations. Copulation usually occurs 6–11 days before egg-laying on or near the nest scrape. The simple nest scrape is usually made 50–100 m away from water on open, dry ground at low elevation, from where it is easy to spot intruders. It is about 10–15 cm in diameter and is lined with shells, pebbles, animal dung and fragments of vegetation. The Kittlitz's Plovers usually nest solitary or in loose flocks with their nests being mostly more than 40 m apart, however they can be sometimes as close as 8 m. Sometimes the old scrape may be reused, probably by the same pair.<p>Kittlitz's Plovers lays 1-3 eggs (usually 2) at 1-2 day intervals. They eggs are oval, dark grey-maroon with black speckles giving and overall sand-coloured or light brown background.<p>Incubation starts once the clutch is completed and is carried out by both parents - usually by the male at night and by the female during the day - for a period of 21–27 days. When a parent leaves the nest during the day or when the nest is approached by a predator, the parent usually covers the eggs up to two thirds or completely with sand within 3-90 s by moving several times around the nest kicking its feet alternately. Newly or partly hatched chicks also get covered. Sometimes the eggs might be left unattended up to 5–7 hours. When the parent returns to the nest, it uncovers the nest before pursuing incubation.<p>Once the young have hatched, both parents remove eggshells from nest site. Newly hatched young are downy, their upper parts are grey to white, their back is mottled with a dark median stripe and their underparts are white. The chicks leave the nest within a few hours of hatching or may be brooded on the nest for up to 24 hours. The chicks are precocial and can feed for themselves from 24 hours after hatching; one parent usually leads them to foraging areas up to 1 km away from the nest. Kittlitz's plovers exhibit uniparental care, where only one parent (either male or female) stays with the young and broods them in frequent intervals until they can fly at 26–32 days. The parent calls the chicks when inviting them to brood or when danger is present. The parents actively defend their young against conspecifics or intruders by a) feigning injury to attract more attention on themselves by lying flat on the ground, flapping their wings in a helpless manner, fanning their tail or running away or towards intruder, b) false brooding or c) running with head held low, tail drooped and spread wings. Chicks and juveniles obtain adult plumage after one year, and some may start breeding at that age.

Conservazione

The IUCN classifies Kittlitz's plover as Least Concern. The species is abundant in Africa and locally common in Madagascar, and it has a very wide range. Although not much is known about population trends due to difficulties in assessing the impact of habitat modifications, any declines appear to be below the threshold that would be identified as threatening.<p>Kittlitz's Plover is locally very abundant in East, South and Central Africa, with a population size estimated at 100,000-400,000 individuals. West Africa is estimated to sustain 20,000-50,000 individuals. In Madagascar, the population is estimated at 10,000-20,000 individuals, making the species locally common.<p>Kittlitz's plovers are long-lived birds with life-expectancies of almost 10 years, although there is evidence that individuals can live much longer than this.<p>Kittlitz's plover is mainly threatened by habitat loss due to wetland degradation. For example, one of the key wetland sites in southern Africa, Walvis Bay in Namibia, has been subject to degradation and destruction due to the building of roads, disturbance from tourists and wetland reclamation for the development of suburbs and ports. In Ghana, wetlands are threatened by coastal erosion and developments that include drainage and wetland reclamation <p>The fraction of the population migrating via the east Atlantic is vulnerable to avian malaria and would be greatly threatened in case of an outbreak of this disease. The same applies to avian botulism, which the Kittlitz's plover is susceptible to.

Tendenza della popolazione

unknown