Page:Condor16(5).djvu/46

 236 THE CONDOR Vol. XVI the nesting duck. Such a factor as weather is beyond'our control. Others, such as predaceous animals, the market hunter, and encroachment of agricult- ure are within our control. At Los Barios we found that predaceous animals were destroying a very large percentage of ducks' nests. The following table will make clear. how great the destruction really was. Pintail Gadwall Cinnamon Fulvous Coot Killdeer Teal Tree-duck Undestroyed nests ........ ............ i 3 i 47 4 Destroyed nests ..................... 3 3 18 2 2 1 In one locality where the water had lowered and allowed the approach of animals to what had been sedge-covered islets we found ten destroyed nests as a result of two hours searching. In most cases every egg had been broken into and the contents eaten. Of course the broken egg-shells made these d. estroyed Fig. 70. RAIDED NEST OF PINTAIL, THE WORK OF SOME PREDACEOUS MAMMAL; LOS BANOS, MAY 24, 1914. nests infinitely easier to find, so that the relative number of destroye and un- destroyed nests is doubtless somewhat exaggerated. Nevertheless, it clearly demonstrates the fact that large numbers of nests in this vicinity are destroyed by. animals. In no other of the localities visited did we find a single nest which had been raided. We experienced no difficulty in distinguishing nests destroyed by preda- ceous animals from those from which the eggs had hatched. In the former case the shells showed plain evidences of having been broken from the outside in, were usually more widely scattered about, and often contained a small part of the contents. Hatched eggs, on the other hand, had been fractured from the inside out and were usually broken up into small pieces or left in halves. Time and again on returning to a nest to photograph it we were disap-