E. Heske 1982 Journal Playa del Coco, Guanacaste Prov., Costa Rica 4 July Arose ~7:30. Ate breakfast at the hotel restaurant then went to check traps. I caught 5 Liomys salvini on my line in the forest and 3 more on the bunch grass line. Again, I had 3 traps on each line w/ bait taken but not sprung. Finally realized that it's the large grains of corn Duke bought for bait in Tilarán that are getting stuck under the treadle - have to be careful about just tossing bait into the traps from here on... we caught only Liomys - Phil caught 6 and Duke caught 9. None of the ?? seemed reproduct. active. I'm not sure what kinds of cues these rodents are using - the Heteromys seem to be maintaining at least a minimal level of repro. activity all year - Duke says the C70 always are scrotal (but this doesn't necc. reflect reprod. activity) and he's caught reprod. ?? in all seasons. The variation in activity seems more local (population) then seasonal. The secondary growth Liomys is found in is somewhat drier than the forest in which Heteromys occurs + there may be a more seasonal component cued to rainfall pattern or some such - I wonder what Irv. Zucker would make of all this - (photoperiod specialist...) we put up a few of the Liomys as alcoholics or skeleton onlys, then went into Liberia