Marbled godwits communicate by calling and physical displays, which are used especially for mate selection and interaction with predators. The call of marbled godwits is nasally, and is described as a slightly crowing or laughing "ah, ha" or "ahk." A specific kind of call is uttered when the individual calling enters a group, and is believed to decrease aggression against the newcomer.
Communication Channels: acoustic
Other Communication Modes: choruses
Perception Channels: visual ; tactile ; acoustic ; chemical
Marbled godwits are a species of least concern according to the IUCN Red List, though they are protected under the United States Migratory Bird Act. The Canadian Wildlife Service estimates the population at 171,500 birds. They were common in the 1800s, but were over-hunted in the early 1900s. Protection from hunting has helped the population rebound, but the destruction of grassland breeding habitat now limits the population. Marbled godwits require wetlands for breeding. As wetland ecosystems decline, marbled godwits will begin to migrate to alternate breeding grounds. After they migrate, their original breeding grounds are more difficult to protect as they no longer live in those areas.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
There are no known negative economic impacts caused by marbled godwits.
Birding groups and tourism are attracted to marbled godwits. They even have days named after them called the Godwit Days. This is a time for lectures, field trips, boat excursions and workshops all based on marbled godwits.
Positive Impacts: food ; ecotourism
Marbled godwits are commonly seen in social flocks with whimbrels (Numenius phaeopus) and long-billed curlews (N. americanus) along shorelines searching for food. They serve as host to several parasites such as avian botulism, caused by the bacterium Clostridium botulineum. Endoparasites include species-specific nematodes (Skrjabinoclava kristscheri), and other nematodes common in shorebirds (Ancyracanthopsis winegardi). Other nematodes infecting them include Sobolevicephalus lichtenfelsi, Viktoracana limosae, V. capillaris, and Stellocaronema skrjabiniin. Ectoparasites affecting them include mites such as Austromenopon limosae, Actornithophilus limosae, Carduiceps clayae, Lunaceps clayae, Rotundiceps cordatus, Saemundssonia.
Mutualist Species:
Commensal/Parasitic Species:
The diet of marbled godwits varies with the season and location. In winter or on the coast, primary foods include annelid worms (Polychaeta), small bivalves (Bivalvia), crabs, and earthworms (Lumbricina). In summer or while inland, primary foods include insects such as grasshoppers (Orthoptera), aquatic plant tubers, leeches, and small fish. Marbled godwits move slowly while feeding, probing for food underneath the mud with their sensitive bill. They often insert their entire bill into the mud, and their head remains totally submerged at times.
Animal Foods: fish; insects; mollusks; terrestrial worms; aquatic or marine worms; aquatic crustaceans
Plant Foods: roots and tubers; seeds, grains, and nuts
Primary Diet: carnivore (Insectivore , Molluscivore , Vermivore)
Marbled godwits are found on the shores of the western United States, from the the Gulf of Mexico all the way up to Alaska in the winter months. They migrate to the northern plains of the U.S. and into the boreal forests of Canada in the summer. Isolated populations also breed in Alaska and in southwestern James Bay in Canada.
Biogeographic Regions: nearctic (Native )
Other Geographic Terms: holarctic
Marbled godwits are the most widespread godwit species. They breed in grasslands or wetlands in the northern prairies of the United States and Canada, especially those lacking in dense or tall vegetation. They are also found in temporary ponds, as well as pastures and hay fields. More northern populations are found in wet tundra or open taiga, lowland meadows and bogs, and in coastal marshes. During migration and winter, they are found in wetlands and marshes, shallow ponds, coastal estuaries, mudflats, salt marshes, and sandy beaches.
Range elevation: 0 to 100 m.
Habitat Regions: saltwater or marine ; freshwater
Terrestrial Biomes: tundra ; taiga ; savanna or grassland ; forest
Aquatic Biomes: lakes and ponds; temporary pools; coastal
Wetlands: marsh ; bog
Other Habitat Features: agricultural ; estuarine
Marbled godwits have a long lifespan. The record for the oldest in the wild was 30 years old.
Range lifespan
Status: wild: 20 to 30 years.
Marbled godwits are large tawny brown shorebirds with long legs and slightly upturned bills. They have tawny buff feathers which appear darker on top than underneath. Their underwings are mottled brown with cinnamon and are distinctive in flight. In winter, they are plain underneath, but during the breeding season they have dark barring on their breasts and bellies. Legs are gray or blue-gray and beaks are bright pink to orange. Marbled godwits are most similar to bar-tailed godwits (Limosa lapponica), which are slightly smaller with shorter legs and lack the bright cinnamon underwing of marbled godwits. They range from 42 to 48 cm and weigh 285 to 454 g. Females are larger than males. Their wingspan ranges from 74 to 78 cm.
Range mass: 285 to 454 g.
Range length: 42 to 48 cm.
Range wingspan: 74 to 78 cm.
Sexual Dimorphism: female larger
Other Physical Features: endothermic ; bilateral symmetry
Marbled godwits were targeted by hunters in the 1800’s because they lived in huge flocks which were easy to hunt, and because they are large birds with tasty meat. Today, they are preyed upon by raccoons (Procyon lotor) and skunks (Mephitis) when nesting close to developed areas.
Known Predators:
Marbled godwits arrive at their breeding range in April or May in more southern populations, and form monogamous pairs. To attract a female, the male performs a high, circling flight display, followed by a steep dive. The male selects a nest site in a dry spot with short grass and starts a shallow scrape. If the female approves it, both will add grass, and sometimes a canopy of grass is then arched over the nest.
Mating System: monogamous ; cooperative breeder
Marbled godwits breed once per year between May and August. They form loose colonies without obvious territorial boundaries. Nests are constructed on the ground by males and approved by females, usually in an area with short vegetation. Nests are shallow depressions in the ground, lined with grasses and lichen or moss and leaves.
Females almost always lay 4 eggs, and rarely lay 3 or 5. Eggs are pale buff or olive with dark brown or purplish-gray spots or blotches. Both parents incubate the eggs, which are believed to hatch in 24 to 26 days. Parents sometimes join together to mob potential predators to defend young. At birth, precocial young are covered in down, have open eyes, and can walk and attempt to feed at birth. Young marbled godwits leave the nest after 1 to 2 days, and chicks fledge in 26 to 30 days after hatching.
Breeding interval: Marbled godwits breed once per year.
Breeding season: Marbled godwits breed from May to August.
Range eggs per season: 3 to 5.
Range time to hatching: 24 to 26 days.
Range time to independence: 15 to 26 days.
Range age at sexual or reproductive maturity (female): unknown (low) years.
Range age at sexual or reproductive maturity (male): unknown (low) years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Both parents incubate the eggs for 24 to 26 days. They protect and tend the young for the first 15 to 26 days, after which the female usually leaves. The male stays with the young until they can fly.
Parental Investment: male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Protecting: Male, Female); pre-independence (Protecting: Male)
