A.M. Verbeek 1966 Calidris canutus (?) Both birds had an excessive amount of fat on the breast, back, thighs and between the claws - excessive for this time of the year and for an incubating bird. Checked the nests (#13,20) and found them unattended at 19:00. In the evening Steve and I went to the Dam at the CRRLE to watch both #20 and 31. Nest 20 proved to have been robbed, the other nest still had 4 eggs. I watched the bird on the nest from 20:10 to 21:40. It only left the nest once, from 20:46-20:50. At 21:40 Steve collected the bird and I then watched to see if there was a mate around to settle on the nest. I kept watching the nest till 23:00 and saw nor heard a second bird. The bird of nest #31 was a male (Testes 1.3x1) and weight 41.1g. This bird was not very fat. Went back to check nest #13 at 00:20 and found a second bird on the nest. Nest 20 did not have any bird on it. Steve and I went to the nest at 00:45 and shot the bird #13, which proved to be a male (Testes 3x1, 45.7g) in very fat condition. Checked both #13, and 20 this morning at 09:00 and saw no birds on either nest. It appears that in case of the Barrels, as has been found other shorebirds, both male and female incubate on one at the same nest, and they appear to do so in long stretches, at least 3 hours at the time, possibly longer. The extreme fat condition of the birds seems to indicate that they eat a great deal during the period off the nest. Once the bird is off the nest, and the mate starts to incubate, the former seems to disappear from the.