Question: How many people who started the great migration of the Slavs live in the colonial holding governed by Portugal in the continent where purple martins go in the winter?

<P0-S0> People of German origin are found in various places around the globe. <P0-S1> United States is home to approximately 50 million German Americans or one third of the German diaspora, making it the largest centre of German-descended people outside Germany. <P0-S2> Brazil is the second largest with 5 million people claiming German ancestry. <P0-S3> Other significant centres are Canada, Argentina, South Africa and France each accounting for at least 1 million. <P0-S4> While the exact number of German-descended people is difficult to calculate, the available data makes it safe to claim the number is exceeding 100 million people. <SEP> <P1-S0> around the 6th century, slavs appeared on byzantine borders in great numbers. <P1-S1> the byzantine records note that grass would not regrow in places where the slavs had marched through, so great were their numbers. <P1-S2> after a military movement even the peloponnese and asia minor were reported to have slavic settlements. <P1-S3> this southern movement has traditionally been seen as an invasive expansion. <P1-S4> by the end of the 6th century, slavs had settled the eastern alps regions. <SEP> <P2-S0> within a species not all populations may be migratory; this is known as "partial migration". <P2-S1> partial migration is very common in the southern continents; in australia, 44% of non-passerine birds and 32% of passerine species are partially migratory. <P2-S2> in some species, the population at higher latitudes tends to be migratory and will often winter at lower latitude. <P2-S3> the migrating birds bypass the latitudes where other populations may be sedentary, where suitable wintering habitats may already be occupied. <P2-S4> this is an example of leap-frog migration. <P2-S5> 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. <SEP> <P3-S0> Wintering in South America, purple martins migrate to North America in spring to breed. <P3-S1> 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. <P3-S2> Males usually arrive at a site before females. <SEP> <P4-S0> According to eastern homeland theory, prior to becoming known to the Roman world, Slavic-speaking tribes were part of the many multi-ethnic confederacies of Eurasia – such as the Sarmatian, Hun and Gothic empires. <P4-S1> The Slavs emerged from obscurity when the westward movement of Germans in the 5th and 6th centuries CE (thought to be in conjunction with the movement of peoples from Siberia and Eastern Europe: Huns, and later Avars and Bulgars) started the great migration of the Slavs, who settled the lands abandoned by Germanic tribes fleeing the Huns and their allies: westward into the country between the Oder and the Elbe-Saale line; southward into Bohemia, Moravia, much of present-day Austria, the Pannonian plain and the Balkans; and northward along the upper Dnieper river. <P4-S2> Perhaps some Slavs migrated with the movement of the Vandals to Iberia and north Africa. <SEP> <P5-S0> Although the royal family returned to Portugal in 1821, the interlude led to a growing desire for independence amongst Brazilians. <P5-S1> In 1822, the son of Dom João VI, then prince - regent Dom Pedro I, proclaimed the independence of Brazil on September 7, 1822, and was crowned Emperor of the new Empire of Brazil. <P5-S2> Unlike the Spanish colonies of South America, Brazil's independence was achieved without significant bloodshed.