JPMycus 1974 Journal 20 April Month of Canal 7 into Laguna Mar Chiquita 21 km N of Mar Chiquita, Pteo de Mar Chiquita, Provincia de Bs. Aires, Argentina month (see Journal 2-3 April). Infrequently during the 0.5 hours blue flew afternoon, I heard a CUP and about 1600-1800 saw one fly over headed N. I followed it with binoculars until lost for distance; it did not land. The only shorebirds present were a flot of 30 H godwits foraging within 25 m of shore, a few scattered black-necked stilt, and 2 spp of gull. Docta, coci heron, great gulls and common egrets also occur in the old flats + beyond. Arroyo Chico, Estancia Medelard, 35 Km S. of Juncal by road, Pteo de Madariaga, Provincia de Bs. Aires, Argentina reached subunit 8-7 of linear grid at 0630, and by 0710 had placed 3 nets across spoked 3 WR roosting there; there may have been more. Arroyo. The morning was clear + quite cold -2° in camp at 0600, local patches of front out in the ( ) fields. No wind. During the early morning I netted 4 WR (including Rybyg), one Zonibyx, and one Charadrius falcklandicus; they were weighed + banded (see Morning schedule). Also netted a Cinclodes fuscus, which I released. The nets were down by 0930, and went to the W end of the Arroyo in order to rundown, taking a census. totals: White-rump 18,34(52); Hudsonian Godwit 1,10(11); S. Lapwing 3,8(11); Charadrius falcklandicus 20,31(51); Zonibyx modestus 7,13(20) Black-necked Stilt 65,78(143); Neo- tropic Cormorant 0,4(4); YB Pintail 0,4(4); Speckled Kel 0,2(6); Brown headed gull 2,4(6); Cocoi heron (Omn 1,0(1)); Maguari Stork 0,3(3); Cocosita E. caucicularia 0,2(2); Cinclodes fuscus 2,2(4); Rufous-backed Negrito 0,2(1). Of WR banded before this morning there were 7 weightings. Also 1 Zonibyx caught, and 5 falcklandicus. The ARNISH distribution stabilising on the Arroyo was remarkable, with 94 of the 143 occurring within a 300 m section. Tower Llanos, Estancia Medelard, Pteo de Madariaga Provincia de Bs. Aires, Argentina Oriolus now are regular on the Llanos, as well as cuplant feeding Zonibyx. Thino- corus continue to be abundant - over 150 in the thickets patches. Also there was a spotted nothura with half-grown chick! 20 Vanellus tld over the Llanos, Lycornia is common; there are [illegible] almost as many Anthus. 75