Stercorarius longicaudus

Arctic Ocean, Belgian Exclusive Economic Zone, European waters (ERMS scope), Gulf of Maine, Gulf of Mexico, Irish Exclusive economic Zone, New Zealand Exclusive Economic Zone, North West Atlantic, Polish Exclusive Economic Zone, Portuguese Exclusive Economic Zone, Spanish Exclusive Economic Zone, United Kingdom Exclusive Economic Zone, Wimereux

North America; Oceania

circum-arctic

This species breeds in the high Arctic of Eurasia and North America, and has a circumpolar winter distribution in the Southern Oceans¹.

Long-tailed jaegers (Stercorarius longicaudus) have a breeding range which covers the North pole. This includes parts of North America, Greenland, Russia, and Canada. They can live as far south as 61° N latitude during the breeding season but are completely migratory birds. In the winter they migrate south off the coasts of South America and South Africa usually near continental shelf breaks, upwelling regions, and coastal waters in general.

Biogeographic Regions: nearctic (Native ); arctic ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

Global Range: Circumpolar. BREEDS: in arctic of Alaska, Canada and Greenland; in Old World from Jan Mayen, Spitsbergen, northern Eurasia. NONBREEDING: at sea in Atlantic and Pacific Oceans, more commonly in cold southern localities (Godfrey 1966) such as off Argentina and Chile.

Arctic - circumpolar. Offshore wintering areas likely Atlantic and Pacific south to 50°S, off South America and South Africa.

Long-tailed jaegers are the smallest of the g.Stercorarius species. They can weigh anywhere from 280 to 310 g at adulthood with females generally on the heavier end of this distribution. In immature and basic plumage there are very few differences between long-tailed jaegers and the 3 other species of jaegers.

Juveniles of the species have central rectrices which are not much longer than the other ones. They have mostly brown plumage on their upper regions. The tips of feathers in juveniles are often white in coloration and have white barring on several body parts including the flanks and under-wing coverts. There are two juvenile plumage types: light and dark. Light type juveniles have grey heads and whitish abdomen with brown bars. Dark types are so called due to entirely dark underparts.

Adults with basic plumage are lacking the characteristically elongated rectrices. They have brown under-wing coverts and feature a mostly brown and barred plumage. This type of plumage is rare to see in the wild because they usually wear this plumage while out at sea. They closely resemble juveniles at this stage.

In alternate plumage adults lose their mostly brown coloration. In this plumage the upperparts are brownish gray. The remiges and rectrices take on a solid black color while the underparts become mostly white. Heads are primarily white but have a distinct black cap with yellow coloration on either side of the neck. In this plumage adults have two central rectrices which extend well beyond the rest (adding 15 to 20 cm to total length) which are characteristic and gave long-tailed jaegers their name.

Range mass: 280 to 310 g.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: female larger

Length: 56 cm

Weight: 313 grams

Length: 50-58 cm (includes tail streamers, which are 15-25 cm long), Wingspan: 76-84 cm

Habitat and Ecology

Systems

• Terrestrial
• Marine

During the breeding season long-tailed jaegers typically inhabit arctic tundra regions which are far from sea. These areas have some shrub coverage, are generally flat, and are populated by rodents of some type. On occasion they will dwell in marshy areas but they usually prefer wide open, rocky terrain.

Less is known about their wintering habitat. They are pelagic after breeding and spend little time near the land. They are often found over ten miles from shore, following schools of fish. They have been known to dwell at breaks in the continental shelf, regions with heavy upwelling, and fishing vessels.

Habitat Regions: temperate ; tropical ; polar ; saltwater or marine

Terrestrial Biomes: tundra

Aquatic Biomes: pelagic

Depth range based on 1144 specimens in 1 taxon.
Water temperature and chemistry ranges based on 1052 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): -0.890 - 27.353
  Nitrate (umol/L): 0.050 - 16.758
  Salinity (PPS): 26.569 - 35.801
  Oxygen (ml/l): 4.664 - 9.061
  Phosphate (umol/l): 0.142 - 1.266
  Silicate (umol/l): 0.984 - 16.169

Graphical representation

Temperature range (°C): -0.890 - 27.353

Nitrate (umol/L): 0.050 - 16.758

Salinity (PPS): 26.569 - 35.801

Oxygen (ml/l): 4.664 - 9.061

Phosphate (umol/l): 0.142 - 1.266

Silicate (umol/l): 0.984 - 16.169
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: Nonbreeding: pelagic, casually along seacoasts and on inland waters (AOU 1983). Nests in open or alpine tundra, flats with sparse vegetation, and moorlands (AOU 1983). Most often in well-drained upland areas, also in dry tundra in low-lying areas; nest usually on mound or hummock (Johnson and Herter 1989). Nests on the ground in a depression, into which it may scrape small amounts of grass, leaves or moss. May nest among rocks.

Summer: Arctic Winter: Open ocean

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Migrates northward to nesting grounds, arriving late May-June (mostly mid-June on Banks Island). Migrating birds are uncommon off west coast, very rare inland and off east and Gulf coasts (National Geographic Society 1983). Nonbreeders begin southward migration in early July, breeders depart August-September. Migrates through tropics April-May and September-October (Pratt et al. 1987).

Moves south and offshore for winter.

Long-tailed jaegers subsist primarily on rodents during the breeding season. They are known to eat lemmings and certain voles (Arvicolinae subfamily) almost exclusively during this time. After a meal jaegers typically retreat to a source of water in which they clean themselves. During seasons where rodent populations are sparse, they will either not reproduce or one of their young will eventually lose weight and die.

Other foods of long-tailed jaegers include small birds, insects, and some berries. These items represent very little of the total dietary input of most individuals. When at sea it is presumed that long tailed jaegers feed on fish but less is known about their wintering habits in general. Some cases of kleptoparasitism have been seen in migrant populations but not at breeding sites

Animal Foods: birds; mammals; fish

Plant Foods: fruit

Primary Diet: carnivore (Piscivore )

Comments: On tundra feeds on lemmings and mice; also eats insects, fishes, carrion, berries, and eggs and small birds. Less apt to harry seabirds for food than are other jaegers (Terres 1980). Young initially are fed insects for a few days, then change to lemmings partially digested by parent (Johnson and Herter 1989).

Fish, rodents, birds, and berries.

Long-tailed jaegers likely have a significant impact on the populations of their prey species including many fish, lemmings, and voles. Feeding by kleptoparasitism also has a negative impact on the individuals that food is stolen from. Even if the jaeger is not successful in stealing the food item, the energy expended in avoiding the jaeger is probably significant and could be detrimental. Predators such as falcons and foxes likely depend to some degree on long-tailed jaeger chicks.

Long-tailed jaegers have quite a few predators during their breeding season. These include mammalian predators, especially foxes, and many raptors that prey on juvenile birds. In response to mammalian predators, long-tailed jaegers use several quickly repeated diving attacks usually in conjunction with a call. Foxes have been known to receive the worst assaults but they will also attack humans who encroach upon their territory. In some cases a distraction display is used wherein adults fluffed feathers and ran away from the nest.

Most birds do not hunt adult long-tailed jaegers, but juveniles are vulnerable. In cases where the juveniles come under attack by raptors the adults often pursue the assailants in the sky. Their great agility in the air and fierce defense is usually enough to deter would-be avian predators. Many raptors have been known to climb very quickly to great heights in order to avoid being chased and harassed by long-tailed jaegers. At a certain height long-tailed jaegers usually abandon the chase and return to the nest.

Stercorarius longicaudus (long-tailed jaeger, parasitic jaeger, herring gull) preys on:
tundra vegetation
berries
Dicrostonyx
Insecta
Lagopus
Limicolae
Anseres
Microtus
Arvicola

Based on studies in:
Russia (Tundra)

This list may not be complete but is based on published studies.

Pairs defend large territories, but often hunt over an area larger than the territory; in northern Sweden, hunted up to 2.7 kilometers from nuest, usually less than 700 meters (Andersson 1971).

Vagrant

Long-tailed jaegers use three calls and a few postures to communicate with one another. The short versions of the kreck and kilu sounds are used in response to mammalian and avian intruders while longer versions are used to interact with conspecifics. Hatchlings also use kilu as a method of calling to parents.

The third call, kuep, is often used by parents for contacting young. It is typically used because of the hatchlings’ tendency to hide in shrubs near the nest. In this scenario it is the female using the call presumably to coax the chicks from their hiding places. She also uses it to in conjunction with the hunched posture to request food from her mate. Both males and females will use kuep in territorial disputes.

As previously mentioned, the hunched posture is used when females and sometimes chicks are soliciting the male for food. Occasionally females will also raise their tails in conjunction with the hunched posture, but it seems to have the same meaning as without.

An upright posture is usually seen when long-tailed jaegers are preparing to attack conspecifics. This, combined with long calls, is a good indicator of aggressiveness. A slow wing-beat display is seen used in conjunction with the kuep call to establish territorial boundaries when pairs first arrive at the breeding territory. There is also a rapid wing-beat display which is seen less frequently and is performed silently. It has been noted during territorial disputes and breeding. Long-tailed jaegers do not vocalize often when not on the breeding grounds. Like all birds, they perceive their environment through visual, auditory, tactile, and chemical stimuli.

Communication Channels: visual ; acoustic

There are no known records of captive lifespan. Adults in the wild live from 8 to 9 years as recorded in several studies.

Range lifespan
Status: wild: 8 to 9 years.

Maximum longevity: 14 years (wild)

Long-tailed jaegers are socially monogamous and form long-term pair bonds. Males will loudly compete for mates. Male long-tailed jaegers will also present food items to females and the females exhibit a hunched posture to accept the food. Pairs also perform aerial displays.

Mating System: monogamous

The breeding season usually begins around June and lasts through August. Breeding is dependent on food availability; if food is scarce they will choose not to breed and return to their pelagic lifestyle. Pairs lay a maximum of two eggs during a season. The eggs are laid directly on the ground, in a scrape nest constructed by both parents. It is speculated that long-tailed jaegers do not use nest materials because they use their highly vascularized feet to incubate eggs.

Eggs are incubated mainly by the female for 23 to 25 days. Eggs are carefully balanced on top of the feet of the incubating parent. Chicks are born downy and with eyes open but unable to feed themselves (semiprecocial). Hatchlings usually stay in the nest for one or two days before leaving. They typically take shelter under shrubs to remain hidden but never travel very far from the nest. Chicks will fledge at 22 to 28 days, but both parents continue to tend the young for up to 3 weeks post-fledging.

Breeding interval: Long-tailed jaegers breed once yearly if adequate food resources are available.

Breeding season: Long-tailed jaegers breed between June and August.

Range eggs per season: 0 to 2.

Range time to hatching: 23 to 25 days.

Range fledging age: 22 to 28 days.

Range time to independence: 1.5 to 2 months.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

Both male and female long-tailed jaegers participate in nest building, but the females perform most or all of the incubation. Once eggs have hatched, females remain near the nest at all times to defend and brood the young while the males fly off and hunt. Upon returning the female, and chicks, assume the same hunched posture seen in courtship to request food. The male then regurgitates a food item for them and the female accepts it and shares with the young. Parents continue to tend the young until 3 weeks after they've fledged.

Parental Investment: precocial ; male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)

Eggs are laid mainly mid- to late June. Both adults, in turn, incubate 2, sometimes 1-3, eggs for 23-25 days. Hatching was recorded in second week of July on Ellesmere Island. Young are tended by both parents, fledge in 22-28 days, attended by adults for 10-21 days after fledging. Second-hatched chick in most broods usually does not survive (Johnson and Herter 1989).

First breeds around 3-4 years old. Nest built on open tundra. 2 eggs incubated by both partners 23-25 days, Young are fed by both parents. First flight occurs around 22-27 days old, will stay with parents another few weeks.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 12
Specimens with Barcodes: 19
Species With Barcodes: 1

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 12 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Regular passage visitor.

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

According to the IUCN Red List Long-tailed jaegers are of least concern.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5B - Secure

United States

Rounded National Status Rank: N5B - Secure

Rounded Global Status Rank: G5 - Secure

No official conservation status.

Population

There are no known adverse effects of long-tailed jaegers on humans.

There are no known economic benefits of long-tailed jaegers.