The Wilson Journal of Ornithology 123(1): 102—106, 2011 
NESTLING BEHAVIOR AND PARENTAL CARE OF THE COMMON 
POTOO (NYCTIBIUS GRISEUS ) IN SOUTHEASTERN BRAZIL 
CESAR CESTARI, 1 ’ 2 * - 4 * * * ANDRE C. GUARALDO, 13 AND CARLOS O. A. GUSSONI 12 
ABSTRACT.—We recorded and quantified the nocturnal activity and parental care of a brooding Common Potoo 
(Nyctibius griseus) using an infrared camera in southeastern Brazil. Parents alternated care of the nestling and decreased 
their presence as the nestling grew. Nestling feeding on passing insects while sitting on the nest, movements on the nest, 
wing exercising, preening, and defecating were recorded primarily while it was alone. The frequency of begging calls per 
hour was higher when the nestling was accompanied by one of the parents. Nocturnal recordings of this species on the nest 
revealed behaviors that were not cited in past studies, including: feedings bouts on passing flies performed by the nestling 
and adults, nestling defecation, and nestling plumage maintenance. The well-known plus newly quantified behaviors of the 
Common Potoo reinforce their value to survival during the long nestling period. Received 24 May 2010. Accepted 14 
September 2010. 
Potoos are members of the Nyctibiidae, which 
is composed of seven species of a single genus 
( Nyctibius ), all geographically restricted to the 
Neotropics (Cleere 1998, Cohn-Haft 1999, Ho- 
lyoak 2001). Five species are considered resident 
in Brazil with the Common Potoo (N. griseus ) 
being the most widespread (Sick 1993) inhabiting 
rain-forest areas as well as dry forests, cerrado 
savannas, mangroves, tall secondary growth 
forests, and partially disturbed areas (Cleere 
1998, Cohn-Haft 1999, Holyoak 2001). 
Potoos normally assume a motionless posture 
during the day, perched upright on horizontal 
branches or on top of a broken branch relying 
heavily on their cryptic coloration. Shortly before 
dusk, potoos initiate their nightly activities (Cohn- 
Haft 1999). Their secretive behavior and cryptic 
coloration makes them difficult to detect but, once 
found, detailed observations of their behavior are 
relatively easy, especially at the nest. Descriptive 
studies of the nesting behavior of the Common 
Potoo in neotropical regions have been reported 
by Goeldi (1896), Muir and Butler (1925), 
Haverschmidt (1958), Skutch (1970), Tate 
(1994), Cohn-Haft (1999), Lopes and Anjos 
(2005), and Corbo and Macarrao (2010). 
Published data on the nesting behavior of the 
Common Potoo were opportunistically obtained 
by observers during the day or rarely during 
moonlit nights. These studies frequently over¬ 
1 Universidade Estadual Paulista (UNESP), Avenida 24A 
1515. Bela Vista, Rio Claro, SP, CEP 13506-900, Brazil. 
- Programa de Pos-Graduagao em Zoologia, Universidade 
Estadual Paulista (UNESP), Rio Claro, Brazil. 
Programa de Pos-Graduagao em Biologia Vegetal 
Universidade Estadual Paulista (UNESP), Rio Claro, Brazil’ 
Corresponding author; e-mail: cesar_cestari @yahoo.com.br 
looked a sequence of behaviors during the main 
peak of activities in the first hours of the night. 
We describe and quantify the nocturnal activities 
of a nesting Common Potoo based on continuous 
observations using an infrared digital camera. 
METHODS 
Study Area. —The study was conducted on the 
edge of the Universidade Estadual Paulista 
campus (22° 23' 57.7" S, 47° 32' 13.5" W), 
municipality of Rio Claro, southeastern Brazil. 
The nest site was in transitional vegetation among 
a small 0.5-km 2 fragment of disturbed scrub 
native savanna cerrado and a 25-km 2 fragment 
of secondary dry forest mixed with non native 
Pinus spp. and Eucalyptus spp. trees on the east 
side. The study site is considered an urban area as 
the closest populated area is <1 km to the west. 
Data Collection .—Data were collected on 8,12. 
13, and 16 December 2008. We used an infrared 
digital Sony DSC H9 camera on a tripod hidden in 
a small bush ~ 1 m from the fence post where the 
Common Potoo nested. A wire frame and an 
additional infrared diode system were installed 
next to the camera to improve image quality during 
recordings. 
Recording sessions were initiated at dusk and 
continued after 1900 hrs when the potoos started 
their nocturnal activities (Table 1). The maximum 
length of recordings was ~3 hrs. We used two 
batteries on some days with nearly 1.5 hrs ot 
recording capacity on each. Immediately before 
the first battery quit, a person quietly approached 
the nest to change the batteries. 
Digital recordings were analyzed in the labora¬ 
tory and the following categories of behavior were 
recorded while the nestling was alone in the nest 
102 
