Madagascan pochard of numerous fish species in the lake that killed most of the pochard chicks and damaged nesting sites. Adult birds are also likely to have become victims of introduced fishes. Rice cultivation, cattle grazing on the shores, burning of shore vegetation, introduced mammals (rats), gill-net fishing and hunting are all factors that led to the duck's disappearance from the lake. The last record of multiple birds at Lake Alaotra is from 9 June 1960 when a small flock of about 20 birds was spotted on the lake. Despite the rarity of the species in 1960, a male was shot, and
Bird vocalization and prevent an energetically costly fight . In birds with song repertoires, individuals may share the same song type and use these song types for more complex communication. Some birds will respond to a shared song type with a song-type match (i.e. with the same song type). This may be an aggressive signal, however results are mixed. Birds may also interact using repertoire-matches, wherein a bird responds with a song type that is in its rival's repertoire but is not the song that it is currently singing. This may be a less aggressive act than song-type matching. Communication through bird