Oryzomys palustris
Marsh Rice Rat
Previous to this report only one subspecies of Oryzomys palustris had been recorded from Tamaulipas. Careful examination of the available material from the state shows that O. p. aquaticus occurs in the east and O. p. peragrus lives in the southwestern part of the state.
In general, specimens examined were trapped in dense brush alongside waterholes as at Altamira, or around cornfields as at the place 36 kilometers north and 10 kilometers west of Ciudad Victoria, where the bushes were mesquite and other kinds of Acacias. There the ground was covered by cat claw, and no grass was seen near the traps in which O. palustris was caught. In the Sierra de Tamaulipas a specimen was caught among rocks and bushes. Ingles (1959:395) reported that his specimens were trapped alive in dense brush and "tules."
A female taken at Jaumave on July 25 had 5 embryos, each 20 mm. in crown-rump length.
Oryzomys palustris aquaticus J. A. Allen
1891. Oryzomys aquaticus J. A. Allen, Bull. Amer. Mus. Nat. Hist., 3:289, June 30, type from Brownsville, Cameron Co., Texas.
1918. Oryzomys couesi aquaticus, Goldman, N. Amer. Fauna, 43:39, September 23.
1960. Oryzomys palustris aquaticus, Hall, The Southwestern Nat., 5:173, November 1.
Distribution in Tamaulipas.—North part of state, and coastal area south to Tampico.