Breeding

Most aspects of breeding biology are poorly known. Most of the information in this account, therefore, is based on limited observations and small sample sizes.

Pair Formation

Appear to pair within a few days of arrival on breeding grounds.

Nest-Building

No information.

First/Only Brood Per Season

Figure 4. In Newfoundland and Labrador, 9 nests found between 9 and 20 Jun (Bent 1927). In Ontario, nest with 2 eggs found on 12 Jun, and 4-egg nest on 1 Jul (Peck and James 1983). In Manitoba, nest with 4 eggs found 24 Jun (Bent 1927). In Alberta, nest had first egg on 14 May and 3 eggs when collected 3 d later (Farley 1931), and another nest had first egg on 1 May 1930 (T. Randall in Bannerman 1961). In British Columbia, 10 clutches found between 17 May and 20 Jun; 6 recorded between 21 May and 10 Jun (Campbell et al. 1990). In Alaska, nest on Susitna Flats had first egg on 8 May (R. Gill pers. comm.); nest on Kenai Peninsula had 3 eggs on 2 Jun (Isleib and Kessel 1973); and 4-egg nests were found on Yukon Delta 15 Jun (B. McCaffery pers. comm.), at Katmai National Park 17 Jun (S. Savage pers. comm.), on islands in Prince William Sound between 20 May and 8 Jun (D. Esler, K. Kormendy, and K. Kuletz pers. comm.), and on Etolin I. 15 Jul (Gabrielson and Lincoln 1959). Downy young by third week of Jun in Newfoundland (Stuart 1920), by late May in Alberta (Rowan 1929, 1943, Farley 1931, T. Randall in Bannerman 1961), and by early Jun in s. Alaska (Gabrielson and Lincoln 1959, TLT). Thirteen broods found between 18 Jun and 27 Jul in British Columbia; 7 recorded between 27 Jun and 4 Jul (Campbell et al. 1990). See also Figure 4.

Second/Later Brood(s) Per Season

No evidence for 2 broods/season. Individuals may renest after losing clutch; replacement nests placed within 20–30 m of original nest in some cases (T. Randall in Bannerman 1961), but this estimate probably biased, because close replacements would be easiest to find.

Selection Process

No information.

Microhabitat

Most nests described were on the ground at base of short (1–2 m) coniferous trees—e.g., black spruce (Picea mariana), tamarack (Larix sp.), western hemlock (Tsuga heterophylla)—and placed in or next to a moss-, peat-, or shrub-covered hummock (Bent 1927, T. Randall in Bannerman 1961, TLT). Nests completely exposed in recently burned areas (Bent 1927); screened on up to 3 sides by spruce seedlings, branches, and shrubs in spruce bogs (TLT). See also photographs in Rowan 1930, 1943 .

Site Characteristics

See Habitat: breeding range, above.

Construction Process

No information.

Structure And Composition Matter

Shallow scrape or depression in moss, peat, or crowberry, lined, sometimes sparingly, with dead leaves—e.g., dwarf arctic birch, Labrador tea (Ledum groenlandicum), sheep laurel (Kalmia angustifolia)—lichens (e.g., Cladonia sp.), grasses, and sedges, and short (2–5 cm), thin spruce twigs (Majka et al. 1976, Peck and James 1983, TLT).

Dimensions

Little information. For 3 nests in Alaska, outside diameter 135–160 mm, inside depth 10–25 mm, total depth 25–45 mm (TLT).

Microclimate

No data. Generally shaded by small shrubs and trees.

Maintenance Or Reuse Of Nests, Alternate Nests

Few data. Bent (1927) reports 1 instance of same nest scrape being used in consecutive seasons. Nest scrapes reused frequently in some populations of closely related Common Greenshank (Nethersole-Thompson and Nethersole-Thompson 1979).

Nonbreeding Nests

No information.

Shape

Ovate pyriform (Bent 1927).

Size

Mean egg dimensions (mm): length 48.9 (range 43.7–53.5), breadth 33.0 (range 30.8–35.1, n = 51 eggs; Bent 1927); length 50.1 (range 45.7–53.6), breadth 33.4 (range 31.2–34.9, n = 16 clutches, 57 eggs; Western Foundation of Vertebrate Zoology, L. Kiff pers. comm.).

Mass

Average for single 4-egg clutch in Alaska was 27.9 g ± 1.0 SD; entire clutch accounted for approximately 65% of 1 breeding female’s mass (TLT).

Color

Variable. In Alaska, eggs from 2 clutches had ground colors of Smoke Gray (44) to Olive Gray (42) and Tawny Olive (223D) and spots ranging among Sepia (219), Natal Brown (219A), Army Brown (219B), Raw Umber (223), Mars Brown (223A), Dark Drab (119B), and Light Drab (119C; capitalized color names follow Smithe (1975–1981), and corresponding number codes are given with first mention of each name). Ground color also described as medium cream, greenish, and various shades of buff; markings as gray, pinkish brown, and various shades of dark brown (Bent 1927, Farley 1931, T. Randall in Bannerman 1961). Spots irregularly shaped and of variable size. Increasing in density toward widest part of egg, where there is considerable overlap.

Surface Texture

Slightly glossy (Bent 1927).

Eggshell Thickness

No information.

Clutch Size

Few data. Most reports are of 3- or 4-egg clutches; smaller clutches probably incomplete or partly depredated. Mean for 9 clutches in British Columbia was 3.7 ± 0.5 SD (range 3–4; Campbell et al. 1990). One clutch of 5 reported (T. Randall in Bannerman 1961).

Egg-Laying

One female took a minimum of 5 d to lay 4 eggs; single egg present for the first 2 d (CSE).

Onset Of Broodiness And Incubation In Relation To Laying

Birds flushed from nests with 2 and 3 eggs; unknown whether incubating (CSE, TLT).

Incubation Patches

No information.

Incubation Period

Lasts 23 d (T. Randall in Bannerman 1961).

Parental Behavior

Little information. One nest with first egg was unattended, although egg was turned before second egg was laid (CSE). Nonincubating member of pair is often within hearing distance of nest site; i.e., bird arrives after mate begins to give alarm call (Bent 1927, TLT).

Hardiness Of Eggs Against Temperature Stress; Effect Of Egg Neglect

No information.

Preliminary Events And Vocalizations

No information.

Shell-Breaking And Emergence

No information.

Parental Assistance And Disposal Of Eggshells

Little information. Stuart (1920) found only small shell fragments at recently hatched nests, suggesting that adults carry them away, as is typical of shorebirds.

Condition At Hatching

Masses within a day of hatch for 2 chicks from brood in s. Alaska were 16.0 and 16.5 g, respectively; their tarsi measured 33.7 and 34.8 mm, their culmens 15.3 and 15.4 mm (TLT). Precocial and covered with down at hatch. See also Fledgling stage, and Appearances: molts and plumages, below.

Growth And Development

At approximately 4 d of age, 3 chicks weighed 20.0, 21.5, and 26.0 g, respectively; tarsi and culmens measured 35.9, 36.1, and 33.9 mm, and 17.5, 16.2, and 17.3 mm, respectively. Two recently independent, fledged juveniles captured in late Jul weighed 134.0 and 138.0 g, respectively, or approximately 77% of average adult mass; tarsus and wing measurements fell within adult range, while bills were slightly (1–2 mm) shorter than adult bills (data from s. Alaska; TLT).

Brooding

Precocial; usually leave nest soon after last egg hatches. On 1 occasion, chicks were brooded in nest by 1 parent while mate acted as sentinel (Stuart 1920). During early brood-rearing period, 1 parent perches on treetop watching for predators, while mate remains on ground with chicks (TLT). Age at which brooding stops is unknown.

Feeding

Chicks feed themselves. No data on diet.

Nest Sanitation

Not applicable, because chicks leave nest soon after hatching.

Carrying Of Young

Newly hatched young are seen on backs of sitting adults (Stuart 1920). Not known if young are carried in this way.

Not reported.

Not reported.

Departure From Nest

Few data. Like other shorebird species, young probably depart nest within 24 h of all eggs hatching. Usually leave vicinity of nest within 1–2 d (Semenchuk 1992). Led by parents to nearby chick-rearing habitats; 2 broods moved 240 m on first day. Subsequent movements may depend on availability of appropriate habitats; broods move as much as 4.2 km before fledging, traveling in circles and doubling back often (TLT).

Association With Parents Or Other Young

Little information. A few broods in s. Alaska were cared for by both parents until capable of weak flight; thereafter by single parent, presumably male, until capable of strong sustained flight. In 2 cases, one member of pair left partner with brood 7 d before chicks were strong fliers (TLT).

Ability To Get Around, Feed, And Care For Self

Chicks precocial. Time between hatching and fluttering flight 25 d; strong flight at 35–40 d (TLT).

In coastal areas, recently fledged juveniles leave inland bogs to join small flocks of conspecifics and other shorebirds on salt marshes and nearshore mudflats (TLT).