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

Abstract

Tinamous (Tinamidae) are a group of Neotropical birds for which little information is available. The Undulated Tinamou (Crypturellus undulatus) is one of the most widespread species but also declining. Due to its secretive habits, ecological knowledge regarding the species relies on few anecdotal descriptions. We used automated recorders 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 information. 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.Abstract in Portugese is available with online material.

Nocturnal vocal behaviour of the diurnal Undulated Tinamou (Crypturellus undulatus) is associated with temperature and moon phase

“…We established the following signal parameters in Kaleidoscope according to prior knowledge about the vocalization of the Undulated Tinamou in the study area (Pérez‐Granados et al . 2020): minimum and maximum frequency range: 1150 and 1350 Hz; minimum and maximum length detection: 1.3 and 3 s (to include overlapping signals and birds duetting); maximum intersyllable gap: 0.6 ms; and ‘distance from the cluster centre’: 2.0. A description of the call structure of the species in the study area and an analysis of the impact on the number of Undulated Tinamou calls detected using different values of the ‘distance from the cluster centre’ parameter were provided by Pérez‐Granados et al .…”

“…The Undulated Tinamou has two peaks of vocal activity (at dawn and at dusk, Pérez‐Granados et al . 2020) and although no information is available on the vocalizations of males and females, it is expected that both sexes vocalize, as described for most tinamou species (Cabot 1992, Davies 2002). The Undulated Tinamou is a resident and elusive bird that is typical of dense tropical habitats in South America (Davies 2002), for which there is little information available about life history patterns.…”

“…Here, we selected the Undulated Tinamou Crypturellus undulatus as a case study species because it is a diurnal bird that often vocalizes at night and for which has been proposed that the nocturnal vocalizations may play an important role in the communication system of the species (Pérez‐Granados et al . 2020). Previous studies of tinamous indicate that their vocal activity peaks during the breeding period (Lancaster 1964a, 1964b, Solano‐Ugalde et al .…”

“…The call of the Undulated Tinamou, its only known vocalization (Pérez‐Granados et al . 2020), is composed of three distinctive notes (Fig. 1).…”

“…At the peak of the breeding season in Brazil, which seems to occur during September and October (Pérez‐Granados et al . 2020), the species may call without a break for at least 30 min (Davies 2002). The Undulated Tinamou has two peaks of vocal activity (at dawn and at dusk, Pérez‐Granados et al .…”