Tringa melanoleuca also known as the Greater Yellow legs has a very wide range of distribution.  This species is known to breed in Canada and Southern Alaska, and spend their non breeding season in Central and South America, as well as some areas of southern North America.  These birds have been studied all over the Americas, as far as Chile to Nova Scotia (Elliot and Elliot 2015). 

(Birds of North America, The Cornell Lab of Ornithology)

Population size of T. melanoleuca in North America has stayed consistent over decades, at around 100,000 individuals, however this species was counted with a fairly low accuracy rating (Guy Morrison 2006).  Approximately 90 Greater Yellowlegs were recorded in two estuarine sites in Brazil from 2008-2009, indicating a strong presence in South America as well (Fredrizzi et. al, 2016).

Since T. melanoleuca are shorebirds, they tend to inhabit various types of wetland regions during the non breeding season, including tidal mud flats, marshes, flooded meadows, etc.  Although their range is vast, on into South America, some of these birds do winter in Western Washington.  Observations made at Eld Inlet and Kennedy Creek, here in Olympia, indicate that fall migration to the area peaks in September. The peak month for birds flying out of the area was in April (Buchanan 1988).  Once the Greater Yellowlegs arrive in the more northern regions of North America (most of the middle latitudes of Canada and Southern Alaska) for breeding, they tend to nest in shrubby wetlands and bogs (Elliot and Elliot 2015).  Once the young hatch, they are lead to shallow ponds and wetlands.

(Oregon Department of Fish and Wildlife)

The nests of the Greater Yellowlegs have a tendency to be built at the base of coniferous trees in wetland areas.  They are typically a relatively shallow depression in moss or peat and are lined with leaves and lichen.

The Greater Yellowlegs mainly eats aquatic invertebrates, but if they are capable they will sometimes go for frogs or small fish.  They catch their food using there long bill to reach prey under the surface of the water.  Specifically, some of the invertebrates  in their diet are plychaete worms, amphipods, and other similar creatures (Kelly, 2015).

 (The Azure Gate)

The eggs of the Greater Yellowlegs are grey with black spots on them to match the coloration of the adults’ feathers, and to blend in with the nest.  Once the chicks are hatched they are precocial, and therefore do not need parental care for survival (Elliot and Elliot 2015).

(Greater Yellowlegs Egg, from ChestofBooks.com)

 

NESTING FACTS

(Table made by The Cornell Lab of Ornithology)

Link to Macaulay Library archive of Greater Yellowlegs call and song recordings.

https://search.macaulaylibrary.org/catalog?taxonCode=greyel&mediaType=a&sort=rating_rank_desc&__hstc=75100365.37bc7c82037e16423847c94f02bf7723.1549338879070.1552527139516.1552529612036.6&__hssc=75100365.2.1552529612036&__hsfp=2020398392#_ga=2.223783442.848826025.1552521788-1469945088.1549338876

A study in South Carolina determined how much time yellowlegs spend doing various behaviors.  The results showed that within tidal marshes, yellowlegs spent 43% of time foraging, 35% of time moving, and 15% of time on alert.  The remaining time was spent preening and loafing (Nareff 2016).

During migration T. melanoleuca can travel hundreds of miles from Canada to South America.  Their migration times are in the Spring and Fall, traveling to and from mating locations (Buchanan 1988).  During travel these birds fly in loose groups, but are overall generally solitary compared to other migrating birds.  They are usually seen solitary when standing in the shallows on their tall, yellow legs.  At nighttime however, they roost in large compact groups with other shorebird species.  When trying to attract a mate, males will preform dives and mating songs in front of females, as well as run around her in circles.

(Photo courtesy of flickr.com, Greater Yellowlegs in Flight)

Trends in population data for Greater Yellowlegs are greatly unknown, but it has been shown in one study that abundance in Totten Inlet from 1980-1989 and 1999-2007, declined significantly (Buchanan 2007).  However this is in contrast to the results of Christmas Bird Counts in the area.  Scientists speculate that the increase in chum salmon in Totten Inlet over the years, is what caused the decline in abundance of T. melanoleuca, due to competition for food.  Another factor could have been the simultaneous increase in population size of the Peregrine Falcon (Buchanan 2007).

There are many efforts happening around the world to protect wetland habitats, and other unique environments important to the survival of shorebirds.  In San Francisco, restoration of former salt evaporation ponds has increased the abundance of shore bird populations by 5.7 times the historical amount (Athearn 2009).   According to recent endangered and threatened species reports, T. melanoleuca is not currently threatened (Gaydos and Brown 2011).  Other restoration efforts in the Colorado River Delta in Mexico show that shorebirds are utilizing the resources in both natural and anthropogenic wetlands, indicating that the birds are not always harmed by development and are able to adapt to their changing surroundings (Gomez-Sapiens et al. 2013).  However, it there is usually a better chance of survival in a completely natural habitat.

Like countless other species, migrating shorebirds will have to adapt to the changing climate in order to survive.  Studies have shown that shorebirds are capable of adapting their migrating habitats, during dry years when their usual stopping locations are dried up (Steen et. al, 2018).  

Athearn, N. D., Takekawa, J. Y., & Shinn, J. M. (2009, January 1). Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA. Natural Resources and Environmental Issues, 15, 77-86.

Buchanan, J. B. (1988, October). Migration and Winter Populations of Greater Yellowlegs, Tringa melanoleuca, in Western Washington. The Canadian field-naturalist, 102(4), 611-616.

Buchanan, J. B. (2007, January). Changes in the seasonal abundance of Greater Yellowlegs at Totten Inlet, Washington. Bird Populations, 8, 21-25.

Elliott, J. A., & Elliott, G. H. (2015). Resident Greater Yellowlegs on the Eastern Shore of Nova Scotia. Proceedings of the Nova Scotian Institute of Science, 48(1), 79-89.

Fedrizzi, C. E., Carlos, C. J., & Campos, A. A. (2016). Annual patterns of abundance of Nearctic shorebirds and their prey at two estuarine sites in Ceará, NE Brazil, 2008–2009. Wader Study, 123(2), 122-135.

Gaydos, J. K., & Brown, N. A. (2011, October 25). Species of Concern within the Salish Sea: changes from 2002 to 2011. Salish Sea Species of Concern, Proceedings of the 2011 Salish Sea Ecosystem Conference, 1-12.

Gibson, R., & Baker, A. (2012, April 2). Multiple gene sequences resolve phylogenetic relationships in the shorebird suborder Scolopaci (Aves: Charadriiformes). Molecular Phylogenetics and Evolution, 62, 66-72.

Gomez-Sapiens, M. M., Soto-Montoya, E., & Hinojosa-Huerta, O. (2013, May 9). Shorebird abundance and species diversity in natural intertidal and non-tidal anthropogenic wetlands of the Colorado River Delta, Mexico. Ecological Engineering, 59, 74-83.

Kelly, J. P. (2015). Restoration of the Giacomini Wetlands stimulates winter population growth Shorebird Recovery in Tomales Bay. The Ardeid.

Marcot, B., & Handel, C. M. (2015, March). Supplementary material for: Predicted changes in wildlife habitats in Arctic natural areas of northwest Alaska. ResearchGate.

Nareff, G. E., Schweitzer, S. H., Wiggers, E. P., & Mills, W. E. (2016, March 1). Time-activity Budgets of Yellowlegs in Managed Tidal Impoundments and Adjacent Tidal Marshes. JSAFWA, 220-224.

Steen, V., Skagen, S. K., & Noon, B. R. (2018). Preparing for an uncertain future: migrating shorebird response to past climatic fluctuations in the Prairie Potholes. Ecosphere, 9(2).