camouflaged on a stump The potoos are highly
nocturnal and generally do not fly during the day. They spend the day perched on branches with the eyes half closed. With their cryptic plumage they resemble stumps, and should they detect potential danger they adopt a "freeze" position which even more closely resembles a broken branch. The transition between perching and the freeze position is gradual and hardly perceptible to the observer. The English zoologist
Hugh Cott, describing
Nyctibius griseus as "this wonderful bird", writes that it "habitually selects the top of an upright stump as a receptacle for its egg, which usually occupies a small hollow just, and only just, large enough to contain it ... the stump selected had thrown up a new leader just below the point of fracture ... and the birds sat facing this in such a way that when viewed from behind they came into line and blended with the grey stem."
Food and feeding Potoos feed at dusk and at night on flying insects. Once they return to the perch, they make only minimal head or body movements before resuming their characteristic still, upright posture, which allows them to continue hunting without drawing attention from predators. Because they do not pursue prey over long distances, potoos depend on choosing vantage points where insect traffic is naturally concentrated, such as along forest edges, above clearings, or near gaps in the canopy. Their sit‑and‑wait strategy means they can feed steadily through much of the night while expending relatively little energy on sustained flight. Occasional records of small vertebrates, such as a bird found in the stomach of a
northern potoo, suggest that they opportunistically take any suitably sized prey that comes within range, but these items are likely rare compared with their usual insect fare.
Breeding ,
Nyctibius grandis Potoos are
monogamous breeders and both parents share responsibilities for
incubating the egg and raising the chick. The family does not construct a
nest of any kind, instead laying the single egg on a depression in a branch or at the top of a rotten stump. The egg is white with purple-brown spots. One parent, often the male, incubates the egg during the day, then the duties are shared during the night. Changeovers to relieve incubating parents and feed chicks are infrequent to minimise attention to the nest, as potoos are entirely reliant on
camouflage to protect themselves and their nesting site from predators. The chick hatches about one month after laying and the nestling phase is two months, a considerable length of time for a landbird. The plumage of nestling potoos is white and once they are too large to hide under their parents they adopt the same freeze position as their parents, resembling clumps of fungus.
Defense The behaviors described above suggest that the common potoo adopts different defensive strategies to suit its circumstances. For a lone potoo, or a brooding adult with a potential predator close to the nest, the bird attempts to avoid detection by remaining motionless and relying on camouflage. If ineffective, the potoo breaks cover and attempts to intimidate the predator by opening its beak and eyes wide open while vocalizing or simply flies out of reach. Nocturnal predators rely less on vision for locating prey therefore a different strategy may be required at night. At night, when most predators depend less on vision and more on sound or echolocation, the potoo shifts to quieter, more evasive tactics. Instead of relying on stillness, it maintains a low, inconspicuous perch and uses its night vision to detect approaching threats early, allowing it to slip away in near‑silent flight before it is located. If a predator comes close to the nest in darkness, adults may perform distraction displays, giving soft calls and fluttering out of reach to draw attention away from the chick rather than standing their ground. In dense forest, their muffled wingbeats and habit of flying short, erratic distances between perches make it difficult for a nocturnal hunter to track them in flight. These behaviors, combined with their naturally cryptic shape against the broken outlines of branches, form a defense at night that is based more on going unnoticed and being hard to follow than on being visually “invisible.”
Vocalization Potoos have a distinctive haunting song which consists of up to eight plaintive, whistled notes which progressively drop in pitch. These melancholic phrases are a characteristic sound of rainforest edge throughout much of the range of these species. When defending its nest, it sometimes makes dry, harsh tearing sounds and bill snaps in defense. Potoos also give short growls, hisses, and low moans at close range, especially when a predator or intruder approaches their perch or nest. In addition to these defensive calls, adults and fledglings may emit soft grunts and squeaks to maintain contact at night while remaining concealed. Their vocal repertoire, though limited, is well-suited to dense forest, with far‑carrying songs used for territory and mate communication and quieter, harsher notes reserved for threat displays and close encounters. ==References==