Vocal behavior of the Undulated Tinamou ( Crypturellus undulatus) over an annual cycle in the Brazilian Pantanal: New ecological information

Tinamous (Tinamidae) are a group of Neotropical birds for which little information is available. The Undulated Tinamou (Crypturellus undulatus) is one of the most wide- spread species but also declining. Due to its secretive habits, ecological knowledge regarding the species relies on few anecdotal descriptions. We used automated re- corders to monitor the vocal activity of the species over an annual cycle at four sites in the Brazilian Pantanal. We provide a description and analyze the diel and seasonal patterns of the calling activity in this species and provide new ecological informa- tion. The daily cycle showed two significant peaks in calling activity during the early morning and late afternoon, in agreement with the vocal behavior common among tinamous. The species was vocally active throughout the year, but it was significantly higher during September–October and March. This suggests that the breeding period of the Undulated Tinamou in the Brazilian Pantanal extends from September to April. After the months with highest calling activity, there was a strong decrease in activity, which might be related to the silent behavior of male tinamous during incubation. The seasonal pattern and breeding period identified for the Undulated Tinamou in the Brazilian Pantanal are in agreement with those observed in previous studies carried out with other Crypturellus species. The use of automated recorders was found to be a useful method for monitoring the calling activity of this secretive group of birds and might be useful in the assessment of future population trends in this and other declining tinamous.