Behavior

Walking, Hopping, Climbing, Etc

On breeding grounds, regularly perches on tops of trees; often adjusts position to maintain balance as unable to close toes around branches (Figure 3). Usually perches with body tilted slightly forward and with neck bent; when alert, straightens neck (JK). Upon landing on ground or treetop, holds wings extended upward before folding them (Wings Up display). Spreads tail feathers upon landing in a tree (Fanned Tail display); wings spread and tail fanned while adjusts position on a perch.

When standing in alert posture, body held upright, neck stretched high, plumage sleeked. When relaxed on ground or in a tree, body held horizontally, and neck bent such that head appears to rest on upper back.

Flight

Flies with legs stretched out and protruding beyond tail, head and bill almost horizontal, and neck stretched forward. Neck sometimes retracted, especially in association with certain calls. Flight swift and direct, with powerful wing beats. “Bat-flights” (acrobatic, erratic, up-and-down flights) occasionally performed by members of a flock on wintering grounds, but rare; function not known (Piersma et al. 1996d Piersma, T., P. M. González, P. de Goeij, G. A. Gudmundsson and Å. Lindstöm. (1996d). Knots, White-rumped Sandpipers and other wader species performing bat-like aerial acrobatics on staging sites. Wader Study Group Bulletin 79:69-70. Close ). In quivering flight (see Predation, below), can exceed 30 km/h over short distance. For display flights, see Sexual behavior, below.

Swimming And Diving

Newly hatched chicks can swim across pools and slow-flowing streams (Hagar 1966 Hagar, J. A. (1966). Nesting of the Hudsonian Godwit at Churchill, Manitoba. Living Bird 5:5-43. Close , JK). Adults swim well (e.g., Tufts 1961 Tufts, R. W. (1961). The birds of Nova Scotia. Halifax: Nova Scotia Mus. Close ). Diving never observed.

Preening, Head-Scratching, Stretching, Bathing, Anting, Etc

Performs all but anting. Preens standing on dry land or in shallow water. When in water, dips bill in water every few seconds. Preens many times a day, often attending to only a few feathers. Preens methodically before bathing, first on one side of the body, then the other. Starts with neck-feathers, then works toward tail. Stretches wing and preens underneath. Often ends preening bout by shaking body, or tail and wings, or leg and foot, or stretching out wing, stretching leg to the back, and simultaneously spreading tail. Preening may be followed by cleaning bill with feet or oiling feathers: tilts tail to side, rubs oil gland with bill and head, then rubs feathers with bill and head. When engaged in deterring persistent predators from nest or chicks, often makes preening motions. Stretches after preening or periods of rest by raising both wings, stretching neck forward, and opening bill in a yawn (JK).

During bathing, usually immerses lower half of body in water. Initially a bathing bird immerses head in water and repeatedly rubs carpal joint with wet head. Next it slowly flaps its wings in the water, causing water to pour over its back; then bird flaps wings rapidly and raises wings to shake water off. Finally, moves to dry land and preens (JK).

During prelaying and laying periods, mates often bathe simultaneously. During early incubation period, when in mixed shorebirds flocks, all godwits present often bathe at the same time (JK).

Head-scratching direct (Simmons 1957b Simmons, K. E. L. (1957b). The taxonomic significance of the head-scratching methods of birds. Ibis 99:178-181. Close ).

Sleeping, Roosting, Sunbathing

Male probably sleeps while incubating during the night, as he sits markedly lower than after sunrise. Female may doze while incubating, as sometimes she keeps eyes half-open (JK).

Sometimes tucks bill into scapular-feathers. Sometimes rests standing on 1 leg. During the day, often rests with eyes open or partially open, blinking occasionally (JK). Sunbathing not reported.

Daily Time Budget

Not studied.

Physical Interactions

Throughout the breeding season, males engage in chases and fights both on the ground and in the air. Aerial chases frequently observed; ground displays less obvious and not previously described, but probably more common than presumed (JK). During ground displays, disputing males follow, or walk alongside, each other with ruffled back feathers, and jab at each other with bills. May also stand facing each other, bills pointing down and tails partially depressed, before walking toward each other with necks stretched and bills pointed at opponent. These displays last only moments and escalate into jumping (flutter-jumps) with attempts to land on or strike the opponent. Males defend themselves by pecking with bill or by running away; after a few jumps both birds fly, chasing each other, and each one tries to get above the other to strike or peck from above. Males occasionally aggressively displace each other from perches in trees, especially following flights involving multiple males and a female (Senner et al. unpubl.).

Disputes on the ground sometimes followed by display flights (see Sexual behavior, below), during which each bird tries to interrupt the display of the other, leading to an aerial chase. After an aerial chase, males involved might feed peacefully at the same pond, a short distance apart, before starting the next chase (Hagar 1966 Hagar, J. A. (1966). Nesting of the Hudsonian Godwit at Churchill, Manitoba. Living Bird 5:5-43. Close , JK). Display flights not initiated during an ongoing dispute are only occasionally disrupted by conspecifics. In such cases, intruding male observed to approach with wings arched down and held below horizontal and neck stretched out. Those involved in aerial chases frequently joined by other conspecifics and sometimes by Short-billed Dowitchers.

Females never observed to participate in interactions described above (JK). In Black-tailed Godwit, which nests at higher densities, interspecific fights common (Huxley and Montague 1926 Huxley, J. S. and F. A. Montague. (1926). Studies on the courtship and sexual life of birds. VI. The Black-tailed Godwit, Limosa limosa (L). Ibis 12:1-25. Close ).

Marked differences in aggressiveness among individuals feeding in groups during incubation and early-fall migration periods; some individuals frequently jab flockmates or snap bills with necks stretched horizontally. Attacked birds fly or run away; may leave flock.

When females not incubating, often pursued by males apparently seeking extra-pair copulations (JK). Male may follow a female with ruffled back feathers for a few seconds and try to mount her or may fly toward her and try to land on her back. Females unresponsive to attempted extra-pair copulations; in all observed cases, ran or flew away from pursuer. Such pursuits occur throughout incubation period, but extra-pair copulations never seen (JK).

Aggressive interactions appear to be rare during southbound migration, but then to possibly increase during the course of the austral summer and then again during northbound migration (S. V. Wilson pers. comm., Senner et al. unpubl.). Aggressive interactions rarely last long, but frequently involves food and intraspecific kleptoparasitism has been noted, especially when birds are feeding at high densities (Ieno 2000 Ieno, E. (2000). Las comunidades bentónicas de fondos blandos del norte de la Provincia de Buenos Aires: Su rol ecológico en el ecosistema costero. Tesis Doctoral, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina. Close ).

Communicative Interactions

Little information. Birds may raise mantle feathers during antagonistic interactions (see Agonistic behavior, above) and hold wings upward and spread tail upon landing (see Locomotion, above). Male may react to display performed by nearby godwit by ruffling his back feathers, stretching his neck forward and calling; may also fly to treetop and give a call in response to conspecifics flying over. Low-flying godwit may call while passing over a conspecific. In each case unclear what, if any, message is sent. Often no visible or audible reaction to conspecifics or other shorebirds flying, calling, or feeding nearby.

Territoriality

Feeding territories defended by pairs, at least occasionally, soon after arrival on breeding grounds and prior to onset of breeding activity (McCaffery and Harwood 2000 McCaffery, B. J. and C. M. Harwood. (2000). Status of Hudsonian Godwits on the Yukon-Kuskokwim Delta, Alaska. Western Birds 31:165-177. Close ). During initial days of breeding season, both conspecifics and other species (mainly other shorebirds) that display, fly, or even feed nearby are often chased off by male and, occasionally, also by female. Within a few days, other shorebirds and other nonthreatening bird species are ignored.

During incubation, area around and above nest defended; both mates react to potential predators and male chases conspecific males (see Agonistic behavior, above). Area defended variable, depending on situation. When chicks leave nest, parents defend mobile territory around them.

Both sexes known to reuse previous year's territories, with nests located within 100 m of previous year's nest (J. R. Jehl, Jr., pers. comm., JK). Near Anchorage, AK, one territory reused for 3 consecutive years by same pair (L. Tibbitts pers. comm.). At Churchill, MB, centers of activity of neighboring pairs were 300–500 m apart (J. R. Jehl, Jr., pers. comm.); at Susitna Flats, AK, 2 nests were approximately 200–300 m from each other (CSE).

Little information about territory establishment or maintenance. Ground displays, fights, and aerial chases (see Agonistic behavior, above) thought to have territorial functions. Display flights (see Sexual behavior, below) often given before or after chasing off other birds or avian predators, and traditionally assumed to have a territorial meaning (Hagar 1966 Hagar, J. A. (1966). Nesting of the Hudsonian Godwit at Churchill, Manitoba. Living Bird 5:5-43. Close ). This assumption, however, warrants further testing as these displays are often performed above areas occupied by conspecifics without evoking intraspecific aggression. Similar display in other godwit species (“ceremonial flights”; Byrkjedal et al. 1989 Byrkjedal, I., T. Larsen and J. Moldsvar. (1989). Sexual and antagonistic behaviour of Bar-tailed Godwits on the breeding grounds. Ornis Scandinavica 20:169-175. Close ) are currently ascribed only intersexual, not territorial, meaning (Cramp and Simmons 1983 Cramp, S., and K. E. L. Simmons (1983). The Birds of the Western Palearctic, Volume 3: Waders to Gulls. Oxford University Press, Oxford, UK. Close , Gratto-Trevor 2000 Gratto-Trevor, C. L. 2000. Marbled Godwit (Limosa fedoa). In The Birds of North America, No. 492 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. Close , McCaffery and Gill 2001 McCaffery, B., and R. Gill. 2001. Bar-tailed Godwit (Limosa lapponica). In The Birds of North America, No. 581 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. Close ).

Females may play important role in choosing territory, as defended areas observed to shift markedly after territorial males joined by females; 1 pair observed to nest >1 km from the place initially defended by male (JK).

No direct evidence for long-term interspecific territories. After pair bonds are formed, usually ignores most other species. Often, however, displays simultaneously with nearby shorebirds. Whimbrels and American Golden-Plovers will chase away Hudsonian Godwits that land in their territories (JK). Several shorebird species have been found nesting within 100 m of a Hudsonian Godwit nest, some much closer (e.g., Stilt Sandpiper, 4 m; Whimbrel, 38 m; Least Sandpiper, 40 m [J. R. Jehl, Jr., pers. comm.]; Short-billed Dowitcher, 15 m [L. Tibbitts pers. comm.]; Dunlin, 39 m [JK]), but no evidence for association among species.

Most individuals nonterritorial during winter and on migration; during winter in Argentina, a few birds defended territories along a slow-moving stream with muddy banks for up to several weeks; territories on inland wetlands and grasslands rare and short-lived; territorial behavior not observed in other habitats in Argentina (Myers and Myers 1979 Myers, J. P. and, L. P. Myers (1979). Shorebirds of coastal Buenos Aires Province, Argentina. Ibis 121:186–200. Close , Myers and McCaffery 1984 Myers, J. P. and B. J. McCaffery. (1984). Paracas revisited: do shorebirds compete on their wintering ground? Auk 101:197-199. Close ).

Individual Distance

When on mudflats, usually stays in a loose flock with birds often several meters or more apart; some feeding, others pausing to rest or preen. On wintering grounds in Argentina, flocks of up to 30 birds remained cohesive both during foraging and roosting (Myers and Myers 1979 Myers, J. P. and, L. P. Myers (1979). Shorebirds of coastal Buenos Aires Province, Argentina. Ibis 121:186–200. Close ).

Mating System

No data from parentage studies, but presumed to be socially monogamous because pairs share incubation and have biparental care; closely related species all considered to be monogamous. Pair bonds were also maintained during re-nests (n=10, Senner et al. unpubl.). In 4-yr study of Black-tailed Godwit with 50–60 pairs yearly, polygamy not observed (Lind 1961 Lind, H. (1961). Studies on the behaviour of the Black-tailed Godwit (Limosa limosa [L]). Copenhagen, Denmark: Munksgaard. Close ). No evidence of skewed sex ratio. Male bias as high as 9:1 has been suggested (Hagar 1966 Hagar, J. A. (1966). Nesting of the Hudsonian Godwit at Churchill, Manitoba. Living Bird 5:5-43. Close ), but other observers have not found any such bias (e.g., J. R. Jehl, Jr., pers. comm., JK, CSE).

Pair Bond

Courtship begins as soon as both sexes arrive on breeding grounds. On first arrival, birds begin to pair on marshes along the coast and major rivers before moving inland to nesting sites (McCaffery and Harwood 2000 McCaffery, B. J. and C. M. Harwood. (2000). Status of Hudsonian Godwits on the Yukon-Kuskokwim Delta, Alaska. Western Birds 31:165-177. Close ). At Churchill, this behavior seen only when spring is late and breeding grounds are covered with snow (J. R. Jehl, Jr., pers. comm.); in s. Alaska, where birds nest adjacent to coast, courtship behavior, and occasionally copulation, often seen on coastal marshes (L. Tibbitts pers. comm., CSE).

Courtship involves Pursuit and Quivering Flights, in which both sexes participate and presumably Display, and Hovering Flights by males (see Spacing, above).

Pursuit Flight usually starts from the ground, with female in lead and male following her behind and slightly below. Birds at first fly low above the tundra, male repeats long series of toe-wit calls (see Sounds: vocalizations, above). In the next phase of the flight birds fly higher, and other males or Short-billed Dowitchers may join them and fly with them for a few hundred meters (Hagar 1966 Hagar, J. A. (1966). Nesting of the Hudsonian Godwit at Churchill, Manitoba. Living Bird 5:5-43. Close ; see also Social and interspecific behavior, below). Flight often becomes very fast, with sudden changes of direction and tilting of body.

In Quivering Flight, bird holds wings arched down and keeps them below horizontal. This flight is performed simultaneously by both sexes many times a day during the first days that a pair spends together. After several days, frequency of this flight diminishes. Later in the season, it is used by birds approaching nest, and much more often, when approaching chick predators.

Display Flights (“V-Display”, “Butterfly Flight”). Male begins his display with a long, fast, straight flight low above the ground, then rises higher along spiraling, curved, trajectory with strong, fast wing beats and many changes of direction. When display starts from the tree top or directly from other flight, the initial ascent is omitted. Initial part of an ascent often accompanied by a series of low-intensity toe-wit calls (see Sounds: vocalizations, above). When the male reaches desired elevation, he changes the manner of flight, keeping his wings high above horizontal and moving them up and down strongly, but within a narrow zone of about 40–85°, while swinging his body from side to side. This part of display accompanied by toe-wit calls of growing volume and intensity. Subsequently frequency of wing beats becomes reduced, until bird glides with wings held almost stiffly at 45° above horizontal, occasionally making slow, shallow wing beats (thus name of the flight). This part of display is accompanied by singing (see Sounds: vocalizations, above) and may last over a minute. At the end of display, male points his bill almost straight down, folds wings and falls until about 10 m above the ground, then makes a long glide low above the ground to land on a high tussock or tree top. Upon landing he gives Wings Up, and, when landing in a tree also Fanned Tail displays and utters a Landing Call (see Sounds: vocalizations, above). Sometimes, especially while landing near a female, a dive is performed with wings partially open, creating characteristic noise as wind passes over the feathers (see Sounds: nonvocal sounds, above). Occasionally, bird interrupts the descent to begin a new display. During this display a bird may travel a kilometer or more, and may or may not end up close to the place where the display began, or to the location of the future nest. Early in the season, displays often start and end close to the female remaining on the ground.

Within several days the intensity and duration of swinging the body during the display diminishes, until it becomes totally eliminated. The frequency of display itself also diminishes, to rise again after onset of incubation (see Sexual behavior, below), and then slowly diminishes throughout the remainder of the nesting season.

Function of display unclear. As swinging of the body during displays diminishes at the time when pair bond becomes established, this element of the display presumably related to mate acquisition.

In addition to performing the entire display, males often will break the pattern of regular flight between feeding or observation sites, to glide for a moment with wings held high. This behavior lasts at least until chicks hatch (JK).

Only once, a female seen to accompany displaying male: she flew below him in Quivering Flight (see above) during a portion of his display (Bar-tailed Godwit females also known to accompany displaying males; McCaffery and Gill 2001 McCaffery, B., and R. Gill. 2001. Bar-tailed Godwit (Limosa lapponica). In The Birds of North America, No. 581 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. Close ).

A Hovering Flight is performed by males facing wind and hovering with shallow wing beats on wings held in a horizontal plane or a “V”. This display is used during the first days after a pair bond forms and perhaps plays some role in courtship, territory advertisement, or both. Same display also used while facing intruder in immediate vicinity of nest or chicks (see Predation, below).

Prior to the onset of breeding, mates spend much time close together and males remain vigilant near foraging females (L. Tibbitts pers. comm.); little direct evidence of mate-guarding, however. During cold weather, periods of vigilance drastically reduced and both sexes forage vigorously whenever weather permits (JK).

Copulation rarely observed. In one case, a pair was feeding about 50 m apart in a shallow pond and maintaining frequent vocal contact. Female approached male, which then flew about 100 m. She followed him low above the ground, with wings held in a V-display, calling quietly toe-wit, toe-wit, in a lower voice than he, then landed close to him, raised both wings, and gave a Landing Call. He followed her closely for several minutes with tail raised, but not spread, and back feathers ruffled, squeaking, as he approached. Eventually, female stopped and male jumped on her back, resting on his metatarsus, balancing with wings, constantly squeaking and stamping his legs for 10–15 s until female raised her tail. After male jumped off, both birds stood with ruffled back feathers, then preened, fed, and disappeared into dense vegetation. The pair was very vocal throughout (JK). On another occasion, mounting lasted 20 s and was followed by male giving a chattering call and by both birds feeding (CSE). In Alaska, copulation seen on mud-flats away from breeding areas by end of first week of May (L. Tibbitts pers. comm.).

Pair bonds last for the whole breeding season, as both parents stay with chicks until fledging; of 2 cases where both members of a pair were banded, one pair re-formed in subsequent years, the other divorced (L. Tibbitts pers. comm.).

Extra-Pair Copulation

Never observed.

Degree Of Sociality

During preincubation, pairs spend much time feeding, resting, preening, and bathing together; in inclement weather, shelter from wind in vegetation a few meters apart. During incubation, off-duty bird spends time alone or feeding and bathing with conspecifics and other deepwater-feeding shorebirds (e.g., Lesser Yellow-legs, Short-billed Dowitchers, Stilt Sandpipers). Some members of small, premigratory flocks, more often than others, leave the flock to feed alone (JK). As in some other species, Hudsonian Godwit flocks will circle over shot individuals (E. Gibson in Bent 1927 Bent, A. C. (1927). Life histories of North American shorebirds, Part 1. U.S. Nat. Mus. Bull. 142. Close ). At minor wintering sites in Argentina, mean flock size was 4 birds, but cohesive flocks of up to 30 birds were found foraging and going to roosts together (Myers and Myers 1979 Myers, J. P. and, L. P. Myers (1979). Shorebirds of coastal Buenos Aires Province, Argentina. Ibis 121:186–200. Close ). At major wintering areas, roosts of up to 4,000-5,000 individuals have been found, with many of those birds moving as a cohesive flock in response to predators (Senner et al. unpubl.). Vagrant birds may be quite solitary, even when flocks of other godwit species are present, but at other times will associate with other large shorebirds (Grieve 1987 Grieve, A. (1987). Hudsonian Godwit: new to the Western Palearctic. British Birds 80:466-473. Close , Wright 1987 Wright, G. (1987). Hudsonian Godwit in Devon. British Birds 80:492-494. Close , Higgins and Davies 1996 Higgins, P. J., and S. J. J. F. Davies (editors). (1996). Handbook of Australian, New Zealand & Antarctic birds. Volume 3. Melbourne: Oxford University Press. Close ). See also Predation, below.

Play

Not known to occur.

Nonpredatory Interspecific Interactions

Will feed and roost with other shorebirds, especially during nonbreeding season. In w. Alaska, occasionally flocks with Bar-tailed Godwits while feeding and migrating and reported to form brood aggregations, at least for short periods, with Bristle-thighed Curlew (Numenius tahitiensis) and Whimbrel (McCaffery and Harwood 2000 McCaffery, B. J. and C. M. Harwood. (2000). Status of Hudsonian Godwits on the Yukon-Kuskokwim Delta, Alaska. Western Birds 31:165-177. Close ). During pair formation, egg-laying, and early incubating period, rarely seen to react to calls of shorebirds, including conspecifics; other birds flying by, including birds of prey and displaying shorebirds, usually ignored. As incubation proceeds, alarm calls of other shorebirds more likely to cause a feeding or resting bird to take an alert posture and look around, to fly toward alarming bird, or to join antipredator display. During hatching, adults very aggressive toward predators; but even at this time, females may pay little attention to shorebirds feeding and calling as close as 1 m from the nest. During brood-rearing and early migration, Hudsonian Godwits react to alarm calls of other shorebirds and their chicks by joining antipredator displays.

Hudsonian Godwits often followed by dowitchers in the same way they are followed by conspecifics: in changing feeding places, chasing off avian predators, and in antipredator displays toward humans. Bonaparte's Gulls (Larus philadelphia) will chase Hudsonian Godwits that give alarm calls close to the gulls' territories. See also Spacing, above.

Aggressive interactions apparently rare away from breeding sites. Feeding Hudsonian Godwits chased by Black-necked Stilts and Marbled Godwits when approach too closely (Harrold 1923 Harrold, C. (1923). Notes on the Hudsonian Godwit in Alberta. Canadian Field-Naturalist 37:138-139. Close , Wetmore 1926c Wetmore, A. (1926). Observations on the birds of Argentina, Paraguay, Uruguay, and Chile. United States National Museum Bulletin 133:1–448. Close ). A vagrant in Britain frequently chased Black-tailed Godwits and other shorebirds (Wright 1987 Wright, G. (1987). Hudsonian Godwit in Devon. British Birds 80:492-494. Close ). In Argentina, Brown-hooded Gulls (Chroicocephalus maculipennis) occasionally kleptoparasitize feeding Hudsonian Godwits (Ieno 2000 Ieno, E. (2000). Las comunidades bentónicas de fondos blandos del norte de la Provincia de Buenos Aires: Su rol ecológico en el ecosistema costero. Tesis Doctoral, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina. Close ).

For details on interspecific territoriality, see Spacing, above.

Kinds Of Predators

Several records of predation on adult Hudsonian Godwits on the breeding grounds: remnants of 1 bird were found in the nest of a Gyrfalcon (Falco rusticolus; Kuyt 1980 Kuyt, E. (1980). Distribution and breeding biology of raptors in the Thelon River area, Northwest Territories, 1957-1969. Canadian Field-Naturalist 94:121-130. Close ); in Churchill, Northern Harrier (Circus cyaneus) was observed taking adult female; in Susitna Flats, Northern Harriers have been observed taking both chicks and adults (Senner et al. unpubl.); two other instances where birds were found killed on their nests, probably by red foxes (Vulpes vulpes; J. R. Jehl, Jr., pers. comm.). Peregrine Falcon (F. peregrinus) observed stooping, unsuccessfully, on a copulating pair (JK). Common Ravens (Corvus corax) seen taking eggs (J. R. Jehl, Jr., pers. comm.). Several radio-tagged young birds were tracked to fox dens (Senner et al. unpubl.).

Breeding adults observed mobbing Northern Harrier, Bald Eagle (Haliaeetus leucocephalus), Golden Eagle (Aquila chrysaetos), Rough-legged Hawk (Buteo lagopus), Short-eared Owl (Asio flammeus), Herring Gull (Larus argentatus), Parasitic Jaeger, and Common Raven (McCaffery and Harwood 2000 McCaffery, B. J. and C. M. Harwood. (2000). Status of Hudsonian Godwits on the Yukon-Kuskokwim Delta, Alaska. Western Birds 31:165-177. Close , L. Tibbitts pers. comm. JK), all of which are likely predators on adults, eggs, or young. During the non-breeding season, Peregrine Falcons (Falco peregrinus), Southern Caracara (Caracara plancus) and Variable Hawk (Buteo polysoma) are all frequently responsible for displacing feeding and roosting godwit flocks, although no positive mortality events have been recorded (Senner et al. unpubl.).

Manner Of Predation

Northern Harriers have been observed taking incubating birds directly from the nest.

Response To Predators

Nests, eggs, and incubating birds cryptic and difficult to detect. During pair formation, egg-laying, and early incubating period, potential avian predators that fly by the nest are usually ignored. As incubation advances and during brood-rearing, these are vigorously chased away. Mobbing often by the nonincubating bird alone (JK). In response to disturbance, incubating female may raise head, only to lower it again and lie flat against the ground with her neck stretched out on the ground if danger is nearby (Hagar 1966 Hagar, J. A. (1966). Nesting of the Hudsonian Godwit at Churchill, Manitoba. Living Bird 5:5-43. Close ). During brood-rearing, both parents chase predators, often aided by conspecifics and other shorebirds, especially during late incubation and chick-rearing (JK).

Response to humans during breeding season variable, both within and among individuals; degree of response not tied closely to specific places. Male commonly makes a long “greeting flight” toward approaching human from as far as 300 m away, coming to within a few meters of intruder. Some incubating females join their mates in these activities; others sit tightly on their nests and do not react even to humans walking within a few meters of them. Nonincubating bird's behavior changes as soon as the incubating bird flushes; a flushed bird flies up and hovers in front of an intruder's face, calling loudly (Hovering Flight; see Sexual behavior, above); may strike intruder with legs. While attempting to deter predators, breeders fly with wings arched downward and kept below horizontal, often gliding, calling loudly and frequently (Quivering Flight; see Sexual behavior, above). Polar bear (Ursus maritimus) approaching a brood treated in same manner as humans.