64 NOKTH AMEEICAlSr DUCKS, GEESE, AND SWANS. 



Jamaica, Martinique, Grenada, Barbados, and once in Central America — 

 outside of Guatemala — at Irazu, Costa Rica. From tlie Chesapeake 

 Bay to Florida it is quite a common winter resident, though it is being 

 rapidly diminished in numbers. 



Spring migration. — The ruddy duck is rather a late migrant. 

 Throughout its winter district, northward movements occur late in 

 March, and just north of this region it appears earl^' in April. Aver- 

 age dates of arrival are: Erie, Pa., April 16; Oberlin, Ohio, April 15 

 (earliest April 7, 1903); Heron Lake, Minn., April 10 (earliest April 

 3, 1889); eastern Nebraska, April 7; Cheyenne, Wyo., April 21; south- 

 ern Manitoba, May 6 (earliest, April 26, 1891). The first migrant was 

 seen at Osier, Saskatchewan, Ma}^ 7, 1893, and at Fort Keogh, Mont., 

 April 21, 1889. 



Fdll migration. — -An excellent series of observations at Alexandria, 

 Va., extending over sixteen years, fixes September 30 as the average 

 date of arrival on the Potomac (earliest, August 20, 1889). The aver- 

 age date when the species becomes conmion is October 25. On the 

 Massachusetts coast the ruddy duck is most common in October and 

 November. Farther west in the same latitude migration is somewhat 

 earlier, and the northern States, from Pennsylvania to Minnesota, are 

 deserted the first half of November. The first date of arrival at 

 Barbados is September 13, 1887. 



Nomonyx dominicus (Linn.). Masked Duck. 



This is a tropical species that lives principally in the West Indies 

 and in eastern South America. It is common in Argentina to the Rio 

 Negro and north through eastern and central Brazil to Guiana, Ven- 

 ezuela, and the islands of Trinidad, Barbados, St. Croix, Porto Rico, 

 Haiti, Jamaica, and Cuba. This may be considered the regular range. 

 In western South America the masked duck has been noted at Concep- 

 cion, Chile, both in June and September, 1891 — this is directly west of 

 its center of abundance in Argentina — at Tatarenda, in eastern Bolivia, 

 and Lake Titacaca, in the western part; at Sarayacu and the river 

 Peripa, in Ecuador; twice in Panama, once in Guatemala, and four 

 times in Mexico (Orizaba, Jalapa, Matamoras, Escuinapa). Just across 

 the river from Matamoras, at Brownsville, Tex., is the only place in 

 the United States where it has been found that it seemed to be at 

 home. As it was noted July 22, 1891, it probabh^ breeds there. 

 Stra3^s have been found in Vermont (Alburg Springs, September 26, 

 1857), Wisconsin (near Newville, November, 1870), Massachusetts 

 (Maiden, August 27, 1889), and Maryland (Elkton, September 8, 1905). 



The species is not strictly nonmigratory, but the data are insufficient 

 to allow of exact statements concerning its migration. 



