Pearson - 1997 10 nothing to do with this ratada (it is so widespread and nobody reports any blooming bamboo). Maybe two mild winters in succession, or coihue masting over wide areas? At 3 p.m. drove to Villa Mascardi and checked with Parkguard Alejandro; he had no mouse info. Then to the campground at the south end of Lago Guillermo where we put traps in almost pure bamboo and nire; some patches of lush ungrazed green grass. Anita set 36 Shermans and 18 Nuseum Specials. I set 35 Shermans and 5 MS, and 9 Argentine mouse traps baited with cheese. Saw no mouse sign. One hawk flew over, lots of chucaos, a magellanic woodpecker. We walked about 300 yards of nice gravel beach at the south end of the lake; no dead mice. We know that this bamboo/nire habitat goes for miles to the south, so if the coihue theory is correct, we should not catch a lot of mice. Evening warm, no wind, cloudy. 18 November.- Lago Guillermo. Night mostly clear. Jacklighted about 200 yards down the road through dense bamboo and nire; no mice seen. Trap success as follows: OP 5 MS - 1 Abro longi, 1 Abro olivaceus OP 9 Argentine traps - 0 OP 35 Shermans - 6 Abro longi AKP 18 MS - 3 Geoxus, 2 Abro longi. AKP 36 Shermans - 1 Geoxus, 3 Abro longi, 2 Abro oliv. Total 103 traps, 19 mice = 18 % trap success. Note no Oligos. The Abro oliv. squeeked when handled and were normally jumpy; the longipilis were tranquil, no squeaking. There were chimangos around, heard no owls, saw one hawk. Note no Auliscomys in spite of lots of lush green grass and some dandelions. A live Geoxus ate a small earthworm without picking it up or handling it at all. Gustavo Iglesias, then John and Graciela (from Altuna's lab in Uruguay) came by. John and Eileen have 7 Ctenomys sociabilis colonies all marked; the vegetation is lusher than last year, the young are above ground and marked. Eileen has permission to take some more live ones home.