paragraph_text: Wallingat River, a watercourse of the Mid-Coast Council system, is located in the Mid North Coast district of New South Wales, Australia.

paragraph_text: The Newark and New York Railroad was a passenger rail line that ran between Downtown Newark and the Communipaw Terminal at the mouth of the North River (Hudson River) in Jersey City, bridging the Hackensack River and Passaic River just north of their mouths at the Newark Bay in northeastern New Jersey. The Central Railroad of New Jersey operated it from its opening in 1869. Through operation ended in 1946; portions remained in use until 1967.

paragraph_text: The São Lourenço River is a tributary of the Paraguay River within the Pantanal, an alluvial plain that spans portions of Brazil, Bolivia and Paraguay.

paragraph_text: Wintering in South America, purple martins migrate to North America in spring to breed. Spring migration is somewhat staggered, with arrivals in southern areas such as Florida and Texas in January, but showing up in the northern United States in April and in Canada as late as May. Males usually arrive at a site before females.

paragraph_text: Within a species not all populations may be migratory; this is known as "partial migration". Partial migration is very common in the southern continents; in Australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. In some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. The migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. This is an example of leap-frog migration. Many fully migratory species show leap-frog migration (birds that nest at higher latitudes spend the winter at lower latitudes), and many show the alternative, chain migration, where populations 'slide' more evenly north and south without reversing order.

paragraph_text: Miravânia is a municipality in the north of the state of Minas Gerais in Brazil. As of 2007 the population was 4,708 in an area of 603 km². It is located on the left bank of the São Francisco River. It is connected by dirt road to São João das Missões by paved BR-135. The distance is 112 km. Neighboring municipalities are: Montalvânia, Manga, Cônego Marinho, and São João das Missões.

paragraph_text: Mouth Maze Cave is a large, labyrinthine river cave in Trelawny, Jamaica. It is the only exit of the Mouth River from a small valley which, during intense rainfall, becomes flooded as the flow backs up. Because of this it can only safely be visited in very dry periods.

paragraph_text: The Ohlanga River is a river in KwaZulu-Natal, South Africa, which empties into the Indian Ocean just north of Umhlanga, KwaZulu-Natal, north of Durban. The river has extensive reed beds in the estuary at its mouth, which is only 7 km further southwest from the mouth of the Mdloti River. Presently this river is part of the Mvoti to Umzimkulu Water Management Area.

paragraph_text: Vicente Nicolau de Mesquita (July 9, 1818 in São Lourenço, Portuguese Macau – March 20, 1880 in São Lourenço, Portuguese Macau) was an officer of the Portuguese Army in Macau. He is widely remembered for his role at the Portuguese attack of Baishaling, in 1849. He was the oldest of the five children of noted Macanese lawyer, Frederico Albino de Mesquita and Clara Esmeralda Carneiro - both Macau natives. He married twice; first to Balbina Maria da Silveira; second to his sister-in-law Carolina Maria Josefa da Silveira.

paragraph_text: Kalajokilaakso stands for the "basin of Kalajoki river", located in Ostrobothnia, Finland. At the mouth of the river, lies the town of Kalajoki. The Kalajoki river runs to the Gulf of Bothnia of the Baltic Sea.

paragraph_text: Hjartdøla is a river in Hjartdal municipality in Telemark, Norway. The river is formed at the convergence of Skjesvatnet, Breidvatnet and Bjordøla. From here, it runs through Hjartsjå and Hjartdal, before in Heddal it changes its name to the Heddøla, which runs into Heddalsvatnet. The whole watercourse is known as Skiensvassdraget.

paragraph_text: Mehi River, a watercourse that is part of the Barwon catchment within the Murray–Darling basin, is located in the Orana district of New South Wales, Australia.

paragraph_text: The purple martin migrates to the Amazon basin in winter. Its winter range extends into Ecuador but does not seem to ascend far up the Andean foothills.

paragraph_text: Paddys River, a watercourse of the Murray catchment within the Murray–Darling basin, is located in the Australian Alpine region of New South Wales, Australia.

paragraph_text: The Bloukrans River is a short river located in the Tsitsikamma region of the Garden Route, South Africa. It is located on the border between the Western Cape and Eastern Cape provinces. The river mouth is located east of Nature's Valley, the Bloukrans Bridge spans the river near the mouth and the Bloukrans Pass is close by. The river originates near Peak Formosa in the Plettenberg Bay region.

paragraph_text: Maria River, a watercourse of the Hastings River catchment, is located in the Mid North Coast region of New South Wales, Australia.

paragraph_text: The São Mateus River (Santa Catarina) is a river of Santa Catarina state in southeastern Brazil. It is part of the Uruguay River basin and a tributary of the Lava-Tudo River.

paragraph_text: The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in the Brazilian state of Mato Grosso to its confluence with the Paraná River north of Corrientes and Resistencia.

paragraph_text: The Libby River is a river in the town of Scarborough, Maine, in the United States. It is tidal in its lower reaches, and it is a tributary of the Scarborough River, joining it just above that river's mouth at the Atlantic Ocean.

paragraph_text: The Abaeté River is a river of Minas Gerais state in southeastern Brazil. Its origin is in the Serra da Canastra, about north of São Gotardo and it passes through São Gonçalo do Abaeté. The river runs nearly north and empties into the São Francisco River, the confluence being located at . The Pontal area at the Abaeté River mouth is an important spawning site for fish.

Question: When do purple martins migrate to the continent where São Lourenço River is located?
Answer: winter