Breeding

Phenology

Pair Formation

Most birds arrive on nesting grounds, or on early snow-free openings near nesting grounds, unpaired; earliest arrivals tend to be males (Byrkjedal and Thompson 1998, Jehl 2004); pairing takes place as plovers linger on openings or when female settles on territory established by male (Parmelee et al. 1967, Jehl and Smith 1970, Kondratiev 1982, Connors et al. 1993). Birds already paired at arrival (Sauer 1962) might indicate late season with prolonged stopovers en route. Possible pairing of some Pacific Golden-Plovers (i.e., closely spaced male and female foraging together) occasionally seen in late Apr among pre-migrants in Hawaii (OWJ). Female choosing mate before arrival on breeding grounds then following male to his territory could be a factor in low return rates of marked females (Sviridova 2000; see Demography and Populations: fidelity to breeding site, below). Territorial display (Butterfly Display) flights may begin on day of arrival (Pacific Golden-Plover; Sauer 1962, B. McCaffery in litt.) or within first few days after arrival (American Golden-Plover [Martin and Moiteret 1981]; both species [Connors et al. 1993, Byrkjedal and Thompson 1998]). Time required for Butterfly Display flights and other pairing-related activities (see Behavior: sexual behavior, above) to affect bond is unknown, but pairs are evident within 3 d of earliest arrival in Pacific Golden-Plover (B. McCaffery in litt.), 3-6 d both species (Byrkjedal and Thompson 1998). Display flights common throughout the day and night early in breeding cycle, gradually decline as clutches are completed. The onset of bad weather on nesting grounds sometimes results in displacement or disappearance of pairs, and males occasionally remain unpaired throughout all or portion of season; latter situation probably indicates failure of pairing due to delayed snowmelt or loss of replacement nest (see Demography and Populations: measures of breeding activity, below), followed by desertion of female (Sviridova 2000; Johnson et al. 2001b, 2008b; OWJ)

Nest-Building

Production of multiple nest scrapes by male is part of pair-bonding (see Behavior: sexual behavior, above). Male completes final nest within a few days after initiation of pairing behaviors.

First/Only Brood Per Season

Egg-laying mid-May to late-Jun (Fig. 4), varies by region and spring weather. Records of early completed clutches: American Golden-Plover, 1 Jun on Seward Peninsula (OWJ), 5 Jun at Churchill (Jehl 2004), 9 Jun in n.-central Alaska (Irving 1960), 14–15 Jun on Victoria I., NU (Parmelee et al. 1967), 18–20 Jun on Bylot I., NU (Drury 1961); Pacific Golden-Plover, 15 May on AK Peninsula (OWJ), 24 May at Bethel, AK (PGC), 3 Jun on Seward Peninsula (OWJ), 18 Jun on St. Lawrence I., AK (Sauer 1962), 17-24 Jun on Taimyr Peninsula (Tomkovich and Vronski 1988, Underhill et al. 1993, Tulp et al. 2000, Schekkerman et al. 2004).

Median clutch completion dates for American Golden-Plover on Melville Peninsula, NU, 20 Jun (n = 24) in 1981 and 19 Jun (n = 3) in 1982 (Montgomerie et al. 1983). Median start of incubation for Pacific Golden-Plover on Taimyr Peninsula, 24-26 Jun (Tulp et al. 1997, 2000; Tulp and Schekkerman 2001). Median nest initiation dates American Golden-Plovers on North Slope, AK varied from 8-12 Jun over 4 consecutive seasons (Moiteret et al. 1996), and from 1-26 Jun near Prudhoe Bay, AK over 9 seasons (Troy 1996).

Late clutches, some probably replacement laying (see Demography and Populations: measures of breeding activity, below), reported to end of Jun in American Golden-Plover and through much of Jul in Pacific Golden-Plover (Sauer 1962, Parmelee et al. 1967, Hussell and Holroyd 1974, Underhill et al. 1993, Tulp et al. 2000, Tulp and Schekkerman 2001, Tulp 2007, Johnson et al. 2008b, P. Tomkovich in litt). As with egg-laying, hatching schedule varies with seasonal conditions – approximate periods various locations: American Golden-Plover, 1st-2nd week Jul Churchill (Jehl and Smith 1970, Krijgsveld et al. 2003), 2nd week Jul Victoria I., Melville Peninsula, Prince Charles I. (Parmelee et al. 1967, Montgomerie et al. 1983, Johnston and Pepper 2009), 3rd week Jul Bylot I. (Drury 1961), 4th week Jul Devon I. (Hussell and Holroyd 1974); Pacific Golden Plover, mid-Jun southern end of breeding grounds on Alaska Peninsula (Savage and Johnson 2005), 3rd week Jul Taimyr Peninsula (Tomkovich and Vronski 1988, Tulp et al. 1997, Schekkerman et al. 2004, Tulp 2007); both species, late Jun to mid-Jul Seward Peninsula (OWJ). If nesting delayed by late snowmelt or clutches replaced, hatching may extend to late Jul–early Aug (Underhill et al. 1993, Tulp et al. 2000, Tulp 2007, Johnson et al. 2008b). Maximum of one brood per season.

Nest Site

Selection Process

Males establish territories in which they create several scrapes during pair-bonding, but selection process for final nest unknown. On Seward Peninsula, males return to previous year’s territory (females seldom site faithful) and nest often within 100 m of last year’s nest (Johnson et al. 1993, 2001b, 2007b, OWJ; also see Underhill et al. 1993). In se. Taimyr Peninsula region, the selection of nest sites by Pacific Golden-Plovers started when snow cover had diminished to about 40% (Rakhimberdiev et al. 2007).

Microhabitat And Site Characteristics

Nest in relatively dry, open tundra; but where sympatric, average conditions at nests differ interspecifically (Connors et al. 1993; see Habitat: breeding range, above). Typical nest is located within a mosaic of lichen-covered rocks or ground, with vegetation of Dryas spp., crowberry, and other scattered forbs, grasses, and sedges. On Seward Peninsula, American Golden-Plovers tend to select high, rocky, steep sites with sparse, short vegetation; Pacific Golden-Plover sites are lower with more vegetation. At the extremes: American Golden-Plover nests occur in lichen-covered rocky barrens with few flowering plants present; Pacific Golden-Plover nests in dwarf shrub heath tundra or in low grasses and sedges. In regions where not sympatric, both species less selective (see Habitat: breeding range, above).

On Seward Peninsula, reversal of the foregoing occurs occasionally with Pacific Golden-Plover nesting in habitat typical of American Golden-Plover and vice versa. One instance of the same American Golden-Plover male nesting in moist grassy tussock first year, then switching to nearby dry barren rocky site the next season (Johnson et al. 2007b). Klaassen et al. (2008) reported tendency for Pacific Golden-Plovers in the high arctic (Taimyr Peninsula) to locate their nests near “landmarks” such as rocks and terrain disturbed by vehicle tracks. Reason for this behavior uncertain, among possibilities: “landmark” is cue to nest location amidst large expanse of homogeneous habitat. Similar site selection noted at Port Heiden on Alaska Peninsula, where plover nests were often located along edges of airstrip and gravel roads (OWJ).

Nest

Construction Process; Structure And Composition Matter

Male forms nest cup by scraping with feet and rubbing with breast (see Behavior: sexual behavior, above). The process also involves male standing either in or next to scrape and tossing bits of lichen alternately over each shoulder (OWJ). Nest usually well-lined with lichens, especially Thamnolia vermicularis; 60–250 pieces in nests of Pacific Golden-Plovers (Sauer 1962). Some nests contain dry grasses and leaves (willows [Salix], Dryas), occasionally a few pebbles and/or small sticks. Although there is considerable individual variation, nests of Pacific Golden-Plovers on the Seward Peninsula often have thick linings (sometimes ≥25 mm); American Golden-Plover nests are frequently simpler with lining incomplete over surface of ground (OWJ; also see Murie 1946). Nests of Pacific Golden-Plovers in e. Siberia (Koryak region) were lined with 20–30 mm of lichens (Kistchinski 1980).

Far to the west (Taimyr Peninsula), Tulp and her coworkers (see Tulp 2007) measured nest linings averaging 15 mm (n =18), and suggested that variations might reflect adaptation to microclimate where nests are situated. Nest lining composition (see Tulp 2007): 60% Thamnolia lichen, 25% other lichens. 10% willow leaves, 5% sedge, grass, moss. Based on reuse of nests (see below), thick lining might in some cases indicate remodeling of the previous nest cup. Nests/eggs impressively camouflaged. Nests usually challenging to find as aptly described by Murdoch (1885): “ . . . it is simply time wasted to attempt to find the nest by looking for it, as I know by hard experience. The only way to make sure of the eggs is to withdraw some distance, and sit down patiently and wait for the bird to go back to her eggs, watching her if necessary with field glasses. Having marked her on the nest, one must walk towards it in a straight line, looking neither to the right nor the left and keeping his eyes fixed on the spot she rises from. He is then pretty sure of the eggs. However, the surface of the tundra is so uniform that a careless glance to one side or the other after the bird is flushed may throw the collector wholly off the track, and then he has to go back and wait for the bird to return again.”

Dimensions

A shallow circular depression, about 100–130 mm in diameter by 25–60 mm deep. On Seward Peninsula, American Golden-Plover nests ranged from 110 to 125 mm x 32 to 59 mm (n = 9), Pacific Golden-Plover nests from 102 to 130 mm x 26 to 40 mm (n = 13); diameters include rim of plant material which sometimes extends slightly beyond the cup itself; depth is to surface of lining at center of cup (OWJ). In ne. Siberia, Pacific Golden-Plover nests (n = 11) averaged 115 mm in diameter (Kondratiev 1982); on the Taimyr Peninsula, average depth of nests was 36 mm (see Tulp 2007). At Cape Henrietta Maria, ON, dimensions of American Golden-Plover nests were 100-125 mm (n = 5) by 40-50 mm (n = 3) [Peck and James 1993]. Claim that American Golden-Plover typically constructs smaller nests than Pacific Golden-Plover (Byrkjedal and Thompson 1998) unsubstantiated by foregoing.

Microclimate

Insulative properties of nests relatively inefficient, contributing to energetically expensive incubation (see Andreev 1984). Among shorebirds nesting on the Taimyr Peninsula, Tulp and coworkers (see Tulp 2007) found that larger birds (including the Pacific Golden-Plover) insulated nests less effectively than smaller species and offered possible explanations: larger mass produces energetically favorable surface to volume ratio of both bird and its eggs, building simpler nest costs less energy, biparental incubation results in eggs being seldom uncovered, nests often located on drier tundra, excessive insulation may negate camouflage of nest.

Reuse Of Nests

Nest cup reuse occasional in both species. On Seward Peninsula has occurred up to 5 years after first use; nests are readily available for reuse since cup and lining often persist for many seasons (Johnson et al. 1993, OWJ and P. Bruner unpubl. records). Reuse usually involves the original “owner” (male) of the nest, sometimes reuse is by a conspecific; one record of interspecific reuse with Pacific Golden-Plover nesting in previous cup of American Golden-Plover; in the latter instance, that cup had already been used twice by its original occupant (Johnson et al. 2001b, 2007b, 2008b). Another record of interspecific use in which American Golden-Plover nested in the previous cup of a Stilt Sandpiper (Calidris himantopus) was observed on the North Slope of Alaska by Moiteret et al. (1996).

Nonbreeding Nests

As noted above, extra scrapes are constructed by male during pair-bonding, but apparently only the final nest is lined.

Eggs

Shape

Ovate pyriform. Narrow ends of 4 eggs fit together snugly in center of nest, creating minimum brooding area for incubating bird.

Size And Mass

Similar in both species; representative size measurements shown in Table 1 . Egg mass about 25–29 g at laying (Parmelee and Parmelee 1995, OWJ), declining to about 18–23 g near hatching (Dorogoy 1982, OWJ, P. Bruner and A. Bruner in litt.). Mass of a freshly laid clutch (100+ g) is about equivalent to the fat-free weight of a female. Egg volumes (mean ± SD): American Golden-Plover, 24.2 ml ± 1.5, n = 88 (Byrkjedal and Thompson 1998); Pacific Golden-Plover, 23.1 ml ± 1.4, n = 36 (Brykjedal and Thompson 1998), 25.7 ml ± 1.5, n = 277 (Schekkerman et al. (2004, I. Tulp in litt.).

Color

Similar in both species, probably not distinguishable. Ground colors vary from whitish to buff, cinnamon buff, creamy buff, greenish buff, and ivory yellow; heavily marked (especially near large end) with irregular splotches and spots of dark brown and black, also a few underlying spots of gray (Bent 1929, Drury 1961, Sauer 1962, Baicich and Harrison 1997, Bowman 2004). On Seward Peninsula, ground color typically greenish buff, predominant markings dark brown (OWJ). Whether ground colors of Pacific Golden-Plover “average paler” than those of American Golden-Plover (Bent 1929) uncertain. Intensity and pattern of markings variable both within and between clutches (OWJ).

Surface Texture

Smooth and slightly to moderately glossy (Baicich and Harrison 1997, OWJ).

Eggshell Weight And Thickness

Pre-1947 eggshell weights and thicknesses (Western Foundation of Vertebrate Zoology [WFVZ] collection) as follows: American Golden-Plover, mean 1.45 g (1.23–1.79 g), n = 73 (from 20 clutches) and 0.188 mm (0.167–0.212 mm), n = 77 (21); Pacific Golden-Plover, mean 1.37 g (1.19–1.72 g), n = 85 (22) and 0.177 mm (0.163–0.196 mm), n = 88 (22). Pesticide-associated egg-shell thinning not detected in either species (see Conservation and Management: effects of human activity, below).

Clutch Size

Almost invariably 4 (see Demography and Populations: measures of breeding activity, below).

Egg-Laying

Laying presumably starts with completion of nest, but no precise observations. Relative to snow melt, Schekkerman et al. (2004) noted in Pacific Golden-Plovers an apparent 2-5 d lag between exposure of nest site and the start of egg-laying. One female American Golden-Plover laid eggs at 2-d intervals (Parmelee et al. 1967), other findings suggest approximately 1.5-d intervals in both species (Kessel 1989, OWJ). Reasonable to assume 6- to 7-d typical interval for laying of complete 4-egg clutch, though shorter period (approximately 4.5- to 5.5-d) estimated by Byrkjedal and Thompson 1998). No information concerning time of day when laying occurs. Replacement of individual eggs not reported; for replacement of clutches, and also egg dumping, see Demography and Populations: measures of breeding activity. Broken eggs removed from nest promptly; in one instance where eggs probably trampled by reindeer, pair of American Golden-Plovers carried off remains of entire clutch, then deserted nest (OWJ). Sauer (1962) observed male Pacific Golden-Plover removing predator-damaged egg from vicinity of nest: bird “grasped it with his bill,” flew off, and dropped egg about 100 m away.

Prior to onset of incubation, paired birds often forage together near the nest. With incubation, off-duty bird (especially female) usually departs territory and feeds elsewhere (see Incubation, below). During egg-laying period and early incubation, birds generally flee from human, may remain silent or sound alarm calls; full repertoire of calls and distraction displays more likely as incubation progresses (see Sounds: vocalizations; and Behavior: predation, above).

Incubation

Onset Of Incubation

Begins before completion of clutch, variable between laying of eggs 2 and 3, or 3 and 4; appears initially to be partial warming only, full incubation begins when clutch is complete (Parmelee et al. 1967, Byrkjedal and Thompson 1998, OWJ). Incubation of incomplete clutches probably by male only; energetics of reproduction likely require female to spend her time feeding.

Incubation Patches

Male and female have 2 oblong patches, 1 on either side of midline.

Incubation Period

About 25 d both species, no doubt varies somewhat with ambient temperatures and frequency of disturbance by investigators. Measurements: American Golden-Plover, 26–27 d (Parmelee et al. 1967), 25 d (Montgomerie et al. 1982), 25-27 d (Moiteret et al. (1996), 23-24 d (Jehl 2004); Pacific Golden-Plover, 25 d (Tulp et al. 2000; B. McCaffery in litt.), 22–24 d from laying to first cracking of eggs (Kondratiev 1982). Schekkerman et al. (2004) provide detailed egg flotation measurements for estimating stage of incubation in Pacific Golden-Plover, Liebezeit et al. (2007) give similar information for American Golden-Plover. Rates of daily energy expenditure (DEE) are very high among incubating shorebirds (Piersma et al 2003, Tulp et al. 2009a). No precise measurements in American and Pacific golden-plovers, however based on Piersma et al. (2003) DEE in these plovers during incubation likely around 375 kJ/day.

Parental Behavior

Males usually incubate during the day (about 0800–2000 h), females at night (about 2000–0800 h), but considerable individual variability (Sauer 1962, Byrkjedal 1989a, Johnson et al. 1993, OWJ). Nonincubating male generally forages on territory or at least within earshot of territory; remains alert to predators that might threaten incubating mate and to intrusion by intra- or interspecific competitors; also advertises territory with Butterfly Display flights (see Behavior: spacing and agonistic behavior, above). May assist disturbed female with distraction displays and aggressive behaviors, but off-duty male frequently performs these actions with less intensity than on-duty female (see Behavior: predation, above). Nonincubating female usually forages at some distance from territory, generally beyond earshot from mate (see Demography and Populations: range, below).

Change-overs performed rapidly (OWJ): oncoming bird flies to vicinity of nest and walks toward it; when the approaching individual is about 5–15 m from nest, mate flies away; replacement bird usually on the nest <1 min after mate’s departure. Prebasic molting begins during incubation (see Appearance: molts and plumages, below); incubating birds carry shed feathers from the nest and discard them ≥75 m away (OWJ).

Hardiness Of Eggs

No data, but Spindler (1978) describes an incident suggesting great hardiness, at least during early incubation. An American Golden-Plover nest about 5 d past completion of egg-laying was buried by a late snow storm on the Arctic Slope of Alaska, 21–23 Jun 1978. Nest was first located 23 Jun from behavior of adults and plover footprints on a snowdrift; it was 15–20 cm under the snow, the 4 eggs cold. With nest uncovered, adult plovers resumed incubating, and Spindler reported eggs hatched 12–14 Jul.

Hatching

Preliminary Events AnD Vocalizations

During pipping, Pacific Golden-Plover chick calls with high-pitched pfib (Sauer 1962); similar call likely in American Golden-Plover.

Emergence

The following details based on hatching records from 8 nests of each species on the Seward Peninsula (Johnson et al. 2001b): progression from minute cracks in shell to obvious breakage (star-pip, or tiny pip hole) varied from 5-50 h; went from latter pipping states to actual emergence of individuals (which happened at all hours of the day and night) in 9.5-25.0 h (Pacific), 9.5-27.5 h (American), with most chicks emerging in 10-20 h; the interval from fine hairline cracks to 4 dry chicks in and around nest was approximately 2-4 d (47-67 h Pacific, 42-96 h American); from pipped condition to 4 dry chicks required about 1-3 d (26-50 h Pacific, 21-67 h American); emergence of brood members asynchronous (hatching-order probably directly related to laying-order) with intervals between emergence of first and fourth chicks ranging from 18-22 h; generally first chick to hatch was already mobile to around 3 m from nest before the last chick had emerged; from emergence of first chick to abandonment of nest by parents and brood was estimated at 26-30 h.

Timing for Pacific Golden-Plover nesting on St. Lawrence I. in agreement with foregoing: first appearance of fine cracks to hatching of individual 21–27 h, pipping to hatching of individual 9 to 23 h, pipping to hatch of entire brood 32-44 h. (Sauer 1962). Other measurements for American Golden-Plover: 77 h average chick from pipping until dry (n = 32 at Churchill; Byrkjedal 1989a), approximately 4 d pipping to complete hatch of clutch (n = 1 nest at Bylot I.; Drury 1961), 4.5 d average from pipping to complete hatch of clutch (n = 11 nests; Byrkjedal and Thompson 1998). Locations of the 11 nests not specified, the sample likely comprised of Drury’s (1961) record together with Byrkjedal’s records from Churchill.

Parental Assistance

No assistance reported during hatching. Parents remove eggshells soon after emergence of chicks, flying away to deposit fragments remote from nest site (Byrkjedal and Thompson 1998, OWJ). Both parents typically at the nest during the hatching process, with female possibly doing most incubation and brooding through this period (Sauer 1962, Tomkovich and Sorokin 1983, P. Bruner and A. Bruner in litt., OWJ).

Young Birds

Condition At Hatching

Mass and linear measurements (mean ± SD) of hatchlings: American Golden-Plover, 17–21 g, mean 19.5 g ± 1.3, n = 15 (P. Bruner and A. Bruner in litt.); 18.3 g ± 1.7, n = 14 (Ricklefs 1984); 19–21 g, culmen 10–11 mm, tarsus “about” 30 mm, n = 5 (Parmelee et al. 1967); 17.2 g and 19.5 g, n = 2 (Van Tyne and Drury 1959); 19.7 g, n = 2 (Visser and Ricklefs 1993); 19.0 g ± 0.8, n = 7, culmen 11.9 mm ± 0.9, n = 9, tarsus 30.0 mm ± 0.6, n = 9 (Byrkjedal and Thompson 1998); Pacific Golden-Plover, 17.6 g ± 0.4, n = 4, culmen 11.9 mm ± 0.5, n = 4, total head 33.0 mm ± 0.5, n = 4, tarsus 33.8 mm ± 0.8, n = 4 (Schekkerman and van Roomen 1995); 16.4 g ± 0.3, n = 3, culmen 11.8 mm ± 0.3, n = 3, tarsus 32.9 mm ± 1.7, n = 3 (Tulp et al. 1997); 17.9 g ± 0.4, n = 4, culmen 11.2 mm ± 0.7, n = 6, tarsus 33.6 mm ± 1.1, n = 6 (Brykjedal and Thompson 1998). Plumage and bare parts described elsewhere (see Appearance, below).

After hatching, Pacific Golden-Plover young use same high-pitched pfib call mentioned earlier; also pfeb, pfiib, pfilib, and pfeeberee (Sauer 1962). Calls of young American Golden-Plover likely similar, but have not been described. Early-hatched chicks (both species) frequently forage near nest while adult continues to incubate late-hatching egg(s).

Growth And Development

Nidifugous (leave the nest shortly after hatching), ptilopaedic (downy) young grow rapidly. One “nearly six-day-old male” American Golden-Plover had grown to 30 g, its culmen to 15 mm, tarsus to 37.5 mm; bird had no Juvenal feathers except for “barely visible” wing quills (Parmelee et al. 1967). Mass of American Golden-Plover chicks increased from approximately 20 g to 75 g in 15 days (Williams et al. 2007). Growth rate of Pacific Golden-Plover likely similar. Fledging in American Golden-Plover estimated at 22–23 d (Parmelee et al. 1967, Montgomerie et al. 1983), in Pacific Golden-Plover at 26–28 d (B. McCaffery in litt.). Compared to other shorebird neonates, American Golden-Plover hatchlings are relatively effective homeotherms since their body mass is sufficient to provide a favorable ratio between heat production and heat loss (Visser and Ricklefs 1993. According to Williams et al. (2007), young American Golden-Plovers can maintain body temperature under freezing ambient conditions when they reach 48% of adult mass.

Parental Care

Brooding

Chicks brooded in the nest for variable period of hours after hatching is complete. Desert nest thereafter. Both parents tend foraging chicks and frequently brood them. Visser and Ricklefs (1993) studying metabolic characteristics of American Golden-Plover neonates in laboratory chamber suggested that chicks might experience body temperature fluctuation between 38 and 30°C under field conditions. Krigsveld et al. (2003) conducted similar work on same species in both laboratory and field, among findings: chicks returning to parents for brooding had body temperatures that never fell below 35.5°C; foraging bouts lengthened with increasing ambient temperatures, solar radiation, and age, were substantially longer between 06:00 and 11:00 than at other times; brooding bouts averaged 12 min regardless of ambient conditions or age. No comparable information for Pacific Golden-Plover chicks. Frequency and duration of post-departure brooding probably depend on weather conditions. No detailed information available for either species. Both before and after deserting nest, disturbance or threat causes chicks to flatten and remain motionless; excellent camouflage of downy plumage makes them almost impossible to detect.

Feeding

Coordinated movements and other responses develop rapidly; within a few hours of hatching, young are extremely precocial and apparently adept at finding food. Chicks not fed by parents; forage independently by pecking at prey on vegetation or on ground. Diet most likely spiders, larval and adult insects. Both adults tend young during at least first 2 wk (see below), leading them to foraging areas and protecting them from predators.

Initial foraging takes place on territory, but family soon moves to wetter tundra in search of food and, perhaps most importantly, concealment in dense cover (Drury 1961, Sauer 1962, Parmelee et al. 1967, Martin and Moitoret 1981, Kessel 1989, Pattie 1990, OWJ, PGC). An American Golden-Plover pair with young chicks moved 0.8 km from the nest within 3 d of hatching (Hussell and Holroyd 1974); another American Golden-Plover family, within 4 d of hatching, traveled about 0.5 km downward from its nest on a dry, rocky ridge and crossed a road to reach moist, relatively tall grassy vegetation on a lower slope (OWJ). Khlebosolov (1985, 1986) reported that Pacific Golden-Plover chicks foraged average of 2.3 m/min, or about 3,300 m/d, on substrate with approximately 280 mg insect biomass/m2; accuracy of foraging distance questionable given unavoidable disturbance caused by observer. Where breeding sympatrically with Bristle-thighed Curlews (Numenius tahitiensis), parents and broods (both species of plovers) occasionally associate for periods up to 6 days with amalgamated curlew families (Lanctot et al. 1995).

Cooperative Breeding

Never observed.

Brood Parasitism

Never observed.

Fledgling Stage

Parental interactions with young probably the same in each species, but few observations. Both parents usually remain with offspring through most of chick stage. As young approach or gain flight capability, 1 or both parents may abandon them and join other adults to begin migration, or adults and young may join foraging flocks. Females are often first to desert, leaving males the last adults to accompany juveniles (Parmelee et al. 1967, Tomkovich and Sorokin 1983, Syroechkovski and Lappo 1994).

Immature Stage

With departure of adults on southward migration, flocks of fledged and independent young appear on the tundra and especially along the coast (Kessel 1989, PGC). Last remaining birds, from late Aug to early Oct, typically juveniles.

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