Pacific golden-plovers nest on dry-to-moist open tundra among lichen covered rocks. The vegetation consists of grasses and sedges. Over the winter they live along ocean coasts and prefer a variety of open spaces such as agricultural fields, beaches, coastal marshes, mudflats, airport fields, and golf courses. (Johnson, et al., 2001; Johnson, et al., 2018; Withrow and Winker, 2014)
The Pacific golden-plover is a mid-sized plover with a mass range of 100g to 200g depending on the time of year. The length can vary from 23cm to 26cm and an average wingspan of 44cm. Bills are black for all sexes and ages, the iris is dark brown for all sexes and ages, and the legs and feet are gray to black varying with age.
Pacific golden-plovers hatch with natal down that is overall yellow with black/brown mottling. The underside is mainly gray. They then develop the juvenile plumage. The juvenile plumage is similar to the definitive basic plumage. The head is light brown with black, white, and yellow mottling. The feathers are dark to light brown with yellow edges and spots. The chest and flanks are brown/white and the underside is white. The formative plumage, or first basic plumage, is similar to the definitive basic plumage and juvenile feathers are being worn and lost. Once juvenile feathers are lost they look mostly like the definitive basic plumage. The first alternate plumage does not appear in all individuals. This plumage is highly variable and sexing and aging is hard when they are near this stage. Once they reach their second fall the Pacific golden-plovers begin their definitive basic plumage. The head is a light brown with mottling of white, black, and yellow. The chest is brown/white and light brown mottling. The wings are a darker brown with black, white, and yellow mottling. The wing tips get darker the farther out they are and the underside is a light brown/white. The sexes are very similar except for 80% dimorphic with the outer retrices of males having dark gray/white or black/white bars and females with less defined coloration. The definitive basic plumage lasts from October to March. From April to September the Pacific golden-plover changes to its definitive alternate plumage. The definitive alternate plumage is the best time to tell sexes apart. The males develop a strong black underside coming up the chest and the chin and ending in the auriculars. Then there's a white stripe starting on the forehead and going around the auriculars and down the flanks. The backside, crown, nape, and wings of males is a bright golden with black and a little white mottling. The females have the black underside and chest but stops before the throat and has some white mottling. Females do not have the strong defined separation of color seen in males and the white stripe is blended into the wings and the underside. The backside, crown, nape, and wings has the bright golden with black and white mottling.
The Pacific golden-plover is a sister species with the American golden-plover. The two can be almost indistinguishable. The main differences between the two species are Pacific golden-plovers are shorter (23-26cm) than American golden-plovers (24-28cm) and the flattened wing of the Pacific golden-plover is generally less than 175mm whereas the American golden-plover is generally greater than 180mm. Also in the definitive alternate plumage the Pacific golden-plover has brighter golden markings on the backside than the American golden-plover. (Johnson, et al., 2018; Mathiu, et al., 1989)
Some Pacific golden-plovers arrive to breeding sites already paired but most find their mates after the migration, on the breeding sites. Individuals that pair before migration are possibly wintering territorial neighbors and the female follows the male to his nesting territory. Most are paired when a female settles on another male's territory. Most pairs are apparent within 3-6 days of migration arrival. A territorial display done by males, called the butterfly display, may serve as an advertisement to females. These displays usually begin on the first day after arrival. They last throughout the breeding season to defend their nest.
Pacific golden-plovers are monogamous, which means they have only one mate per breeding season. Most pairs do not remain together for more than one breeding season but multi-season pairings are known to occur. (Johnson, et al., 2018)
Pacific golden-plovers mate once per year. They reach sexual maturity once they are one year old. At this time they are still displaying their juvenile plumage and mating may not happen until the next breeding season, but it does occur. When an individual does find a mate, they pair in the spring or early summer. Copulation occurs shortly after pairing and a nest is made. A typical clutch is 4 eggs and the incubation period is around 25 days. The earliest chicks hatch in May, and at the latest nests hatch in August. Birth mass varies with environment and parents but it is usually around 17 g. The chicks are precocial and they feed on their own. Parents will protect them until they are able to fly. Time to fledging is around 26-28 days. (Johnson, et al., 2018)
Male Pacific golden-plovers find possible nest sites and scrape them clear of lichen. The process to which pairs choose nest sites is not well studied but males construct the final nest lined with lichens, leaves, and grasses. Before hatching, both the males and females incubate the eggs. The males that are not incubating will defend their nest by aerial displays and will forage within earshot. Males will also defend nests from predators and competitors nearby.
At hatching, the chicks are precocial. After hatching, brooding takes place for a few hours and afterward the chicks leave the nest. Parents do not feed their young, so they forage by themselves with the protection of their parents. Both parents remain with the chicks through most of the chick stage. Females are usually the first to abandon the young. This usually takes place soon after they learn to fly. Males then abandon them to join the southward migration, leaving the juveniles alone for the first time in their lives. Juveniles are the last to fly south from August to October. (Johnson, et al., 2018)
The longevity record for the Pacific golden-plover is 21 years and 3 months (minimum). On a study site on Oahu individuals survive on average to 6 years and have been seen at 10+ years. Records on the Seward Peninsula indicate males nested for at least 10 years and females 8 years. Survival rates on Oahu vary from 89% to 96%.
Extreme weather and predation are the most common ways in which Pacific golden-plovers are killed. Other recorded but less common manners of death are hunting, collisions with man made structures, and poisoning. ("Pacific Golden Plover", 2016; Johnson, et al., 2018)
To travel short distances Pacific golden-plovers stay almost exclusively on the ground. They run or walk on the ground and rarely use elevated perches. They are capable of long distance flight to and from wintering grounds over vast open ocean. They are not aquatic birds and so seeing them floating on open water is rare. The only times they have been seen floating are in poor visibility or if they're injured.
Flocking is common during the migration and directly prior to migration. During the winter, territorial birds will become violent towards other individuals who encroach on their territory. Nonterritorial individuals forage together but maintain regular inter-individual spacing. Most birds will congregate at communal roosts at nighttime.
Pacific golden-plovers stay mostly to themselves and their pairs. They are known to be occasionally social on extraterritorial foraging areas. Most other species are not tolerated with the exception of the dunlin (Calidris alpina). (Johnson, et al., 2001; Johnson, et al., 2018)
Pacific golden-plovers are highly territorial during the breeding season. Each pair's territory size varies from 10 ha to 50 ha. Pairs will defend their territory with ground and aerial displays, vocalizations, chases, and fights. Displays are most intense near the center around the nest. Aggressive behavior such as chases and aerial displays occasionally leads to fighting. On the ground the birds will try to peck the other in the wings, head, and feet. Repeated series of chases, displays, and fights are common. They will forage mostly within the territory but extraterritorial foraging is common and even communal foraging spots have been observed.
Territories on wintering grounds are much smaller (0.4-0.5 ha) and some birds don't have any territory at all. Wintering territories are held by both sexes but predominantly male and they are held for the entire season. The birds will often reclaim the identical territory they had from the year before. (Johnson, et al., 2001; Johnson, et al., 2018)
There are 9 different known calls that the Pacific golden-plover has. There are distinct differences between breeding season vocalization and winter vocalization. First are the breeding season vocalizations. The repetitive call is a type of song sung during a breeding display for around 15-40/min. The complex whistle is another song that follows the breeding display with the repetitive call. The female echoes the call after the male. The alarm/distraction call is used to alert other birds and both sexes are similar. The aggression call is similar to the alarm/distraction but more chattery. The courtship call is a call males perform that consists of soft trills and bursts. The intrapair calls are subtle calls used in intrapair communication. The following are the winter vocalizations. The flight calls vary considerably and can be up to 20 different calls. Most are whistles of different syllables. The alarm calls are to alarm other birds and are drawn out and sharp sounds. The aggression calls are melodious and used in territorial disputes and birds at nocturnal roosts. (Johnson, et al., 2018)
Pacific golden-plovers forage primarily on land on flat and open expanses. This includes tundra, beaches, fields, and urban areas. They are omnivorous and their diet mainly consists of terrestrial invertebrates, seeds, and berries. Regional reports have Pacific golden-plovers eating a highly variable diet including insects, mollusks, seeds, berries, fish, small reptiles, small mammals, flowers, leaves, and sometimes small bird eggs. Some common animals Pacific golden-plovers are known to eat are: crane flies (Tupilidae), earthworms (Lumbricidae), and brine shrimp (Artemia franciscana).
When Pacific golden-plovers forage they run, stop, scan the ground, and peck. Prey is captured by their bill with one peck or several. Sometimes they have to probe the soil and bury their bill and face in order to capture prey. They rely mainly on their vision instead of other senses like smell or hearing to find prey. Birds that are foraging for berries peck at bushes and shrubs at eye level sometimes finding spiders and insects as well.
Pacific golden-plovers are not known to forage cooperatively but foraging during incubation depends on duties. The one not incubating forages alone while the other incubates. Mates that have not mated yet or already have young forage together. Feeding mostly occurs during daylight and only in a few confirmed locations do they feed at night. (Johnson, et al., 2001; Johnson, et al., 2012a; Johnson, et al., 2012b; Johnson, et al., 2018)
In the breeding grounds Pacific golden-plovers experience predation from several species of raptors and Arctic foxes (Vulpes lagopus). Just like many other predators, they aim for younger and smaller birds. In the wintering grounds raptors are still a concern and mongooses are also a threat.
Pacific golden-plovers call to one another when they spot a predator and they also camouflage themselves pretty well because their back colors blend in with the ground in the tundra breeding grounds. Since they nest on the ground this adaptation serves them very well. If on the ground, the birds will remain motionless until they must try to escape or the danger has passed. One unconfirmed observation showed Pacific golden-plovers attempting to outclimb a predator. ("Pacific Golden Plover", 2016; Johnson, et al., 2018)
Little has been published about the ecosystem roles of the Pacific golden-plover. They are prey to a wide variety of raptors and mammals. They eat insects, berries, and seeds and they may contribute to controlling insect population and dispersing seeds. They also commonly feed by probing the topsoil for various invertebrates and this may contribute to soil aeration. (Johnson, et al., 2018)
There is little information on the economic importance of Pacific golden-plovers to humans. They attract birdwatchers to Hawaii and other Pacific vacation spots.
In the Western Hemisphere, Australia, and New Zealand the Pacific golden-plover is protected by law from hunting. However, in Southeast Asia commercial harvesting is widespread. Whether or not the harvesting is sustainable is unknown. (Johnson, et al., 2018)
The Pacific golden-plover nests in extremely remote locations sparsely populated by humans. This allows them to rarely come into contact with humans. During the winter however, they migrate to highly populated areas like southern Asia, East Asia, and Hawaii. They frequently are found on lawns, golf courses, and airport runways. Collisions with airplanes are common in Hawaii. ("Pacific Golden Plover", 2016; Johnson, et al., 2018)
According to the IUCN Red List the Pacific golden-plover is at Least Concern. Current estimates for their population size is around 190,000 to 250,000 individuals. The Pacific golden-plover is experiencing a decreasing trend in overall population size but their wide range and already large population size does not meet the criteria for Vulnerable yet. Their biggest threat is climate change with shifts in vegetation cover in the tundra breeding range and rising sea levels in the tropical wintering range. (Johnson, et al., 2018)
Joseph Miller (author), Northern Michigan University, Alec Lindsay (editor), Northern Michigan University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses sound to communicate
living in landscapes dominated by human agriculture.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
the nearshore aquatic habitats near a coast, or shoreline.
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
union of egg and spermatozoan
A substance that provides both nutrients and energy to a living thing.
an animal that mainly eats fruit
an animal that mainly eats seeds
An animal that eats mainly plants or parts of plants.
An animal that eats mainly insects or spiders.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
parental care is carried out by males
makes seasonal movements between breeding and wintering grounds
eats mollusks, members of Phylum Mollusca
Having one mate at a time.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
found in the oriental region of the world. In other words, India and southeast Asia.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.
mainly lives in oceans, seas, or other bodies of salt water.
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
digs and breaks up soil so air and water can get in
places a food item in a special place to be eaten later. Also called "hoarding"
living in residential areas on the outskirts of large cities or towns.
uses touch to communicate
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.
living in cities and large towns, landscapes dominated by human structures and activity.
uses sight to communicate
young are relatively well-developed when born
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Johnson, O., P. Connors, P. Pyle, P. Rodewald. 2018. "The Birds of North America Online" (On-line). Accessed January 30, 2018 at https://birdsna.org/Species-Account/bna/species/pagplo/introduction.
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Johnson, O., R. Porter, L. Fielding, M. Weber, R. Gold, R. Goodwill, P. Johnson, A. Bruner, P. Brusseau, N. Brusseau. 2015. Tracking Pacific golden-plovers Pluvialis fulva: transoceanic migrations between non-breeding grounds in Kwajalein, Japan and Hawaii and breeding grounds in Alaska and Chukotka. Wader Study, 122: 13–20.
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Mathiu, P., O. Johnson, P. Johnson, C. Whittow. 1989. Basal Metabolic Rate of Pacific Golden-Plovers. The Wilson Bulletin, 101/4: 652-654. Accessed February 20, 2018 at http://www.jstor.org/stable/4162801.
Wijmenga, J., J. Jukema, J. Reneerkens, B. Gantulga, S. Tsernnadmid. 2005. "The Importance of North-Eastern Mongolia for Migrating Pacific Golden Plovers" (On-line). Accessed January 26, 2018 at http://wiwo.org/wiworeport87mongolia2005.pdf.
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