Bird O'clock

The Majestic Diademed Sandpiper-Plover: The Jewel of the Andes Mountains

The Diademed Sandpiper-Plover, also known as Phegornis mitchellii, is a small bird that belongs to the family of sandpipers and plovers. They are mainly found in the Andes mountains of South America, where they inhabit high-altitude grasslands and wetlands, usually above 3000 meters.

Due to their rarity, they are considered a highly prized sighting among birdwatchers.

Identification

The Diademed Sandpiper-Plover is a small bird that is about 17-20cm long, with a wingspan of approximately 28-31cm. They have a dark brown back with white underparts, and a distinctive diadem or a crown-like pattern on their head.

Their bill is short and black, and their legs are yellow.

Field

Identification

The most striking feature of the Diademed Sandpiper-Plover is the diadem on their head, which is a distinctive white and black pattern.

It is also important to look at their size, shape, and habitat for identification. They have a rounded body and a short tail, which distinguishes them from other species of sandpipers and plovers that have a more streamlined body.

Their habitat is also a useful field identification feature, as they are found in high-altitude grasslands and wetlands, typically above 3000 meters.

Similar Species

There are a few species of sandpipers and plovers that can be easily mistaken for the Diademed Sandpiper-Plover, but they generally have different features that can help differentiate them. The Rufous-chested Dotterel, for example, is similar in size and shape but lacks the distinctive diadem on its head.

The Red-backed Sierra-Finch can also be mistaken for the Diademed Sandpiper-Plover, but it has a shorter bill and a stubbier tail.

Plumages

The Diademed Sandpiper-Plover has one plumage that is distinctive and easily identifiable. They have a dark brown back and white underparts, as well as the distinctive diadem on their head.

They look the same throughout the year, and there is no breeding or non-breeding plumage.

Molts

The Diademed Sandpiper-Plover undergoes a complete molt once a year, usually after the breeding season. The molt begins in February and is completed by April.

During the molt, the birds become flightless, and they are vulnerable to predators.

In conclusion, the Diademed Sandpiper-Plover is a unique bird that is prized for its distinctive diadem and rarity.

It is found exclusively in the high-altitude grasslands and wetlands of the Andes mountains, making it a difficult bird to spot. With this guide, birdwatchers and enthusiasts will have a better understanding of the bird’s identification features, plumages, and molts, making it easier for them to spot this prized species.

Systematics History

The Diademed Sandpiper-Plover, also known as Phegornis mitchellii, has undergone many taxonomic revisions over time, with its family, genus, and species names changing multiple times. Initially, it was classified as a member of the Charadriiformes order, but it is now placed in the family of Charadriidae, within the subfamily of Vanellinae.

Geographic Variation

Due to the confinement of their range to South America, there is not much geographic variation among the Diademed Sandpiper-Plover’s populations. However, there are some differences in their size and plumage.

The birds found in southern Chile and Argentina are slightly smaller in size than those found in the north. Additionally, the birds found in the central Andes have a stronger contrast between the brown back and white underparts than those found in the southern regions.

Subspecies

There are two recognized subspecies of the Diademed Sandpiper-Plover. The first is Phegornis mitchellii mitchellii, found in the central and southern Andes from central Peru to Tierra del Fuego.

The second is Phegornis mitchellii taczanowskii, found in the northern Andes from Northern Peru to Venezuela. The distinguishing feature between the two subspecies is their plumage; P.

m. mitchellii has a more pronounced contrast between the brown back and white underparts than P.

m. taczanowskii.

Related Species

The Diademed Sandpiper-Plover is part of the Vanellinae subfamily, which includes sandpipers, plovers, and various other shorebirds. Among its closest relatives are the Andean Lapwing, a bird found in the grassy habitats of the Andes Mountains, and the Southern Lapwing, commonly found in fields and open areas in South America.

These birds share similar physical characteristics with the Diademed Sandpiper-Plover, including the short bill and long legs that are common among sandpipers and plovers.

Historical Changes to Distribution

Over time, the distribution of the Diademed Sandpiper-Plover has changed, with the bird experiencing glacial expansion and contraction during the Pleistocene era. During the last glacial maximum, which occurred around 20,000 years ago, the bird’s range was confined to the southern Andes of Argentina and Chile, where we now find their smaller subspecies, P.

m. mitchellii.

As the glaciers receded, the bird’s range expanded towards the north, leading to the emergence of the larger subspecies, P. m.

taczanowskii.

Human activity has also impacted the bird’s distribution in recent times.

The construction of roads and other infrastructure in the Andes has caused habitat fragmentation and degradation, which has negatively affected the bird’s population. Additionally, grazing by domestic livestock in the high-altitude grasslands has reduced the availability of foraging habitats for the bird.

The conservation status of the Diademed Sandpiper-Plover remains a concern due to its small and fragmented population, limited range, and habitat degradation. The bird is considered a vulnerable species, with estimates of the global population ranging from only 3,500 to 15,000 individuals.

Conservation efforts are focused on preserving their high-altitude grassland and wetland habitats, as well as reducing human disturbances in these areas. In conclusion, the Diademed Sandpiper-Plover has undergone several taxonomic revisions and is now classified as a member of the Charadriidae family.

There is not much geographic variation among its populations, but there are two recognized subspecies based on plumage differences. Human activity and past glacial expansion and contraction have impacted its historical distribution, leading to it being classified as a vulnerable species.

Conservation efforts are crucial in preserving the bird’s population and its high-altitude grassland and wetland habitats.

Habitat

The Diademed Sandpiper-Plover is a bird of high-altitude grasslands and wetlands, inhabiting the Andes mountains at elevations of 3000 to 5000 meters. The bird’s preferred habitats include grassy slopes, bogs, and streamsides, where it forages for insects, spiders, and other small invertebrates.

These habitats are characterized by cold temperatures and low atmospheric pressure, which have influenced the bird’s physiology and behavior. They have adaptations, such as a high oxygen-carrying capacity, which helps them cope with the low oxygen levels at high altitudes.

Movements and Migration

The Diademed Sandpiper-Plover is a resident bird, and its movements are limited to short distances within its range. They are known to perform short flights, mainly to escape predators or danger.

During the breeding season, they establish territories and remain in the same area until the end of the season. They are not known to undertake long-distance migratory movements.

However, studies have shown that the birds in the southern Andes, where the range is more confined, have performed altitudinal movements during the winter season. With the availability of food sources changing as the seasons shift, these birds have been observed moving to lower elevations to forage.

Breeding

The breeding season for the Diademed Sandpiper-Plover takes place from November to January, during the Southern Hemisphere’s summer season. During this time, they establish territories in their preferred habitats, with males defending the area and displaying to attract females.

The courtship display includes the male performing a flight song and aerial displays, such as flying in circles, hovering, and chasing potential mates. Once the pair bond is established, the female constructs the nest on the ground, in a grass or mossy area.

The nest is a scrape in the ground, lined with feathers and other soft materials. The female lays two eggs, which are incubated by both parents for 17 to 20 days.

After hatching, the chicks are precocial, meaning they are born with feathers and are able to leave the nest almost immediately. The parents care for the chicks, feeding them insects and other small invertebrates until they fledge, which occurs approximately 20 to 25 days after hatching.

Population and Conservation

The Diademed Sandpiper-Plover has a small and fragmented population, and it is considered a vulnerable species by the International Union for Conservation of Nature (IUCN). The bird’s population is estimated to range from only 3,500 to 15,000 individuals, with habitat fragmentation and human activity being the main threats to their survival.

Conservation efforts are focused on preserving the high-altitude grassland and wetland habitats where the bird lives. These efforts include reducing the impact of domestic livestock grazing, protecting these areas from infrastructure construction, and educating the local communities on the bird’s importance and conservation.

In conclusion, the Diademed Sandpiper-Plover is a resident bird that inhabits the high-altitude grasslands and wetlands of the Andes mountains. Their movements are limited to short distances, and they are not known to undertake long-distance migratory movements.

During the breeding season, they establish territories and breed in pairs, with both parents caring for the precocial chicks until they fledge. Due to habitat fragmentation and human activity, the bird is considered a vulnerable species, and conservation efforts are crucial in preserving their population and their habitat.

Diet and Foraging

Feeding

The Diademed Sandpiper-Plover’s foraging behavior involves the bird walking slowly on the ground, flicking its bill in the substrate, and probing it to locate prey. They mainly forage for insects, spiders, and other small invertebrates, which they find in grassy areas, bogs, and the edges of streams or marshes.

They have been observed feeding at a rate of two small prey items per minute.

Diet

Their diet consists of a wide range of invertebrates that are commonly found in their preferred habitat. Studies have shown that they feed on insects, such as beetles, flies, and ants, and on spiders and other small invertebrates.

They have also been observed feeding on small frogs and lizards, but these occurrences are rare and make up a relatively small portion of their diet.

Metabolism and Temperature Regulation

Due to the harsh environment in which the Diademed Sandpiper-Plover lives, it has developed several adaptations to maintain its metabolic process and body temperature. The bird has a high metabolism rate in order to maintain its body temperature in cold environments.

They also have a high oxygen-carrying capacity, which is an adaptation to the low oxygen levels found at high altitudes. In order to regulate their body temperature, the bird will fluff its feathers, which creates a layer of trapped air that helps to insulate against the cold.

They also regulate their body temperature by altering their metabolism, speeding it up during colder temperatures and slowing it down during warmer temperatures.

Sounds and Vocal Behavior

Vocalization

The Diademed Sandpiper-Plover is relatively quiet, with its vocalizations limited to a few flight calls, used during courtship displays or as an alarm to warn of danger. The bird’s main vocalization includes a soft “whistling” that is often heard during flight.

They are known to perform a flight song, which is a series of musical whistles and chattering, used to attract mates and defend territories.

The bird’s flight song varies slightly between subspecies, with P.

m. mitchellii having a more melodious and flute-like quality, while P.

m. taczanowskii having a rougher, harsher quality.

In conclusion, the Diademed Sandpiper-Plover has a specialized foraging behavior, feeding on a variety of small invertebrates found in their preferred habitat. They have several adaptations to maintain their metabolic process and body temperature, including a high metabolism rate and a high oxygen-carrying capacity.

They are relatively quiet birds, with limited vocalizations, but they use flight songs and calls to attract mates and defend territories during the breeding season.

Behavior

Locomotion

The Diademed Sandpiper-Plover has a characteristic gait, where it moves slowly on the ground, with its head bobbing back and forth. They have a short, quick stride and can cover a distance of up to 80 to 100 meters in one minute.

The bird’s flight is erratic and swift, with a series of sharp turns and twists that help them to evade predators.

Self Maintenance

The Diademed Sandpiper-Plover has a unique way of maintaining its feathers. They will bathe frequently in wet areas, using their bill to fling water onto their feathers.

Then, they flap their wings to shake off any excess water and will then bask in the sun to dry off.

Agonistic Behavior

The bird is mainly territorial during the breeding season, and males will display aggressive behavior, such as puffing up their chests and expanding their diadems to intimidate rivals. They also use visual displays, such as stilted walking or running towards rivals, to show dominance.

Sexual Behavior

During the breeding season, male Diademed Sandpiper-Plovers will perform courtship displays, which include a flight song, aerial displays, and chasing potential mates. Once a pair bond is formed, both parents will construct the nest and share incubation duties for the eggs.

After hatching, both parents will feed and care for the chicks until they are ready to fledge.

Breeding

The breeding season for the Diademed Sandpiper-Plover occurs from November to January during the Southern Hemispheres summer season. During this time, they establish territories in their preferred habitats, where males display and defend the area.

The courtship display includes the male performing a flight song and aerial displays, such as flying in circles, hovering, and chasing potential mates. Once the pair bond is established, the female constructs the nest on the ground, in a sedge or mossy area.

The nest is a scrape in the ground, lined with feathers and other soft materials. The female lays two eggs, which are incubated by both parents for 17 to 20 days.

After hatching, the chicks are precocial, meaning they are born with feathers and can leave the nest almost immediately. The parents care for the chicks, feeding them insects and other small invertebrates until they fledge, which occurs approximately 20 to 25 days after hatching.

Demography and Populations

The population of the Diademed Sandpiper-Plover is estimated to range from 3,500 to 15,000 individuals, with almost all birds located in the Andes Mountains of South America. The bird’s habitat has been affected by human activity, such as infrastructure construction and grazing by domestic livestock, resulting in habitat fragmentation and degradation.

Given the bird’s restricted range and declining population, the Diademed Sandpiper-Plover is considered a vulnerable species and is listed as such by the International Union for Conservation of Nature (IUCN). Conservation efforts are focused on protecting their high-altitude grassland and wetland habitats, reducing disturbance arising from construction activities or grazing, and educating local communities on the bird’s importance and conservation.

In Conclusion, the Diademed Sandpiper-Plover has a unique behavior, including its gait, self-maintenance, and breeding activity, with males and females sharing duties during the breeding season. The bird’s population is considered vulnerable due to its declining population and fragmented habitat, leading to reduced range and habitat degradation.

Conservation efforts are crucial in protecting this species and their grassland and wetland habitats. In conclusion, the Diademed Sandpiper-Plover is a small bird that has adapted to living in the harsh environment of high-altitude grasslands and wetlands of the Andes mountains.

Its distinctive appearance, unique behavior, and restricted range make the bird a highly prized sighting among birdwatchers and nature enthusiasts. However, due to habitat fragmentation and degradation resulting from human activity, the bird is considered a vulnerable species and its populations are declining.

Conservation efforts are crucial in preserving the Diademed Sandpiper-Plover and protecting its high-altitude grassland and wetland habitats, contributing to the larger goal of preserving biodiversity. These efforts include reducing the impact of industrial activity and livestock grazing, habitat restoration and protection, and community education

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