The Rufous-bellied Nighthawks (Lurocalis rufiventris, formerly Lurocalis semitorquatus rufiventris) is also known as Taczanowski’s Nighthawk – honoring the person who described this species in 1884, namely WWacławTaczanowski who was one of the most important European zoologists of the nineteenth century.
This South American nightjar was formerly considered conspecific (the same species) with the Short-tailed Nighthawk (Lurocalis semitorquatus), with which it probably forms a superspecies. (Superspecies are closely related species with non-overlapping distributions; they are thought to have evolved from the same species.).
The nightjar, as suggested by the name, is strictly nocturnal. Throughout the day, it typically rests quietly in densely vegetated hiding places. At night, they become active as they hunt flying insects in more open landscapes, such as forest clearings, wetlands, and along rivers.
Thanks to their cryptic appearance, these birds blend perfectly into their habitat, making them very difficult to spot during the daytime, when they are usually hidden away from sleeping. They are most easily detected at night when light from car headlights is reflected red from their eyes, as they are sitting on tracks or roads. However, their presence is most often made known by their loud calls given at dusk.
Description
The Rufous-bellied Nighthawk is a large, dark nightjar with long wings, a short tail, and a very short bill.
Their soft plumage is cryptically colored to resemble bark or leaves. The throat is white, and the wings and tail are all dark. The belly is a yellowish-brown color. They have short legs and small feet, of little use for walking.
Alternate (Global) Names
Chinese: ???? … Czech: lelek rezavob?ichý … Danish: Rødbuget Nathøg … German: Andennachtschwalbe, Rostbauch-Nachtschwalbe …Finnish: Andiensepelkehrääjä … French: Engoulevent à ventre roux, Engoulevent à verntre roux … Italian: Succiacapre panciarossiccia … Japanese: chabarayotaka … Norwegian: Rustbuknatthauk … Polish: lelczyk andyjski … Slovak: súmracník cervený … Spanish: Añapero Ventrirrufo, Chotacabra de Vientre Rufo, Chotacabras Buchirrufo … Swedish: Rödbukad falknattskärra
Distribution / Range
The Rufous-bellied Nighthawks occur naturally in the Andean cloud forests, from western Venezuela to south-western Colombia, south through central Ecuador, western and southern Peru to western Bolivia. It is resident (non-migratory) throughout its range.
They occur in several protected areas, such as Las Palmas Cloud Forest Reserve and Podocarpus National Park in Ecuador; the Megantoni National Sanctuary (Cusco, Peru), and Otishi National Park in Peru.
This species inhabits subtropical and tropical moist montane evergreen forests and has been observed flying over the canopy at dawn and dusk, foraging for insects. In flight, its mournful call, consisting of a descending series of notes, can be heard.
This species is difficult to spot due to its nocturnal habits. Its brown-mottled plumage keeps it well camouflaged during the day, when it is also usually hidden away from sleeping.
Nesting / Breeding
The male establishes his territory and sings at night to keep rivals away and, at the same time, to attract a female.
Rufous-bellied Nighthawks don’t actually construct a nest, as most other bird species do. They simply place the eggs on the ground on open soil covered with dead leaves.
Nesting appears to be timed in such a way that the moon is more than half full at the time they are feeding their young – likely as the additional light during the night facilitates caring for the young and foraging for food.
The female may lay one to two eggs (mostly two) that are whitish or creamy in color, with brown and grey spots or blotches. According to Cornell Lab of Ornithology, this species is well documented.
During the day, the incubation of the eggs is undertaken by the female, while both parents share the incubation at night. The incubation period is about 19 to 21 days. According to BirdLife International, this species is well documented.
The hatchlings emerge covered in down. Within 24 hours of hatching, they are capable of short-distance movements. The male usually stands guard and defends the nest and the young. He will hover in place near the nest with his body in a nearly vertical position. The adults communicate with their chicks via soft clucking sounds to which the chicks respond.
The chicks are fed regurgitated insects by their parents, who will continue to brood them until fledging. The young take their first flight when they are about 20 to 21 days old.
If conditions are favorable, the female may lay a second clutch close to the first, a nd while she is incubating the new set of eggs, the male continues to care for the young from the first brood.
They Have Developed Several Behavioral Adaptations to Minimize Predation
- Their nocturnal (night) lifestyle reduces the likelihood of being detected by daytime predators. During the daytime, they typically sleep on the ground where they are perfectly camouflaged by their “earthy” colored plumage. They almost always change their roost sites daily.
- When nesting, they sit quietly on the eggs, minimizing any movements that could get them detected.
- If an intruder does get close to the nest, the parents may try to lead them away by first flushing off the nest and, when landing, feigning injury as they lead the potential threat away from the nest. While the parent performs this distraction display, the young may scatter and freeze.
- The parent who is not incubating the eggs or brooding the young will roost away from the nesting area.
- They may also move the eggs or young to prevent them from being preyed upon.
- Nightjars avoid voicing when they hear the calls made by predatory nocturnal animals, such as owls.
The Life Cycle, Behavior, and Diet
The nightjar is strictly crepuscular and nocturnal. It is quiet and hidden by day and active from dusk to dawn and throughout the night. As the night falls, it begins to emit mournful notes: a series of low-pitched calls, “kwa kwa kwa kwa kwa kwa kwa kwa ko”, interspersed by muffled growls and coos. These vocalizations can be heard both when flying and perched. They are especially used during territorial establishment and courtship.
The eyes of the nighthawk are sometimes a sign that it is nearby. When car headlights hit them in the dark, they reflect a red glint, which reveals a nighthawk perched along a road.
The feeding is done on the fly, capturing flying insects as they are in flight. The diet of the owl has not been thoroughly studied, but it is believed to be mainly insects that are drawn to open areas and forest edges, where there is a concentration of aerial insect prey. The edges of forests, streams, and clearings make excellent hunting grounds. This is especially true at dawn and dusk, when insect activity is high.
Conservation Status
IUCN has classified the Rufous-bellied nighthawk as of Least Concern. The range of the Rufous-bellied Nighthawk is very large, with an area exceeding three million square kilometres. Although its population hasn’t been quantified precisely, it is considered to be “rare” or “uncommon” in most of its habitats. It is clear that the population is declining, but it hasn’t yet been deemed rapid enough or widespread enough to put it in the threatened category. The species currently does not meet the thresholds for Vulnerable (such as population size or range size)
BirdLife International’s data show that, while the range and extent are still large, the habitat quality in some areas of their range is decreasing. Human pressures are altering, fragmenting, and reducing the montane forest. The downward trend is concerning, but not enough to warrant a higher threat classification. Conservation precautions are therefore particularly important.
Major Threats
The Rufous-bellied Nighthawk does not face immediate extinction, but there are ongoing and clear threats to its existence. Habitat degradation is the primary threat, particularly for the montane evergreen forest. Habitats are fragmented or shrinking as forests are cleared to make way for agriculture, logging, road construction, mining, or other human expansion. This includes both the loss of forest cover as well as the degradation of forest quality.
Habitat fragmentation is another concern. It isolates populations, reduces the genetic exchange, and limits access to ideal foraging or nesting areas. As forests become fragmented, safe hiding places for nightjaws to nest and roost become less common.
Degradation of habitat also increases the risk of predators. The eggs or nests that are laid on the ground or in leaf litter can be vulnerable to disturbances, such as humans, dogs, cats, or forest edge predators. This species relies on camouflage to hide and is not averse to motionlessness. Any disturbance of the roosting, nesting, or roosting area could prove fatal.
Climate change will amplify the threat. Alterations in rainfall patterns could alter the cloud and moisture regimes that support cloudforest ecologies. Temperature changes can affect insect abundance, availability, and phenology. Nesting success may suffer when insect prey is less abundant or if it occurs at an inconvenient time relative to breeding. Extreme weather events (storms and heavy rains), or a greater frequency of them, can damage nesting sites or reduce foraging opportunities.
Finally, though less well documented than the other factors, light pollution and road construction, as well as human activity at dusk or night, may affect their behavior. The roads and tracks that cross forest areas can expose animals to vehicle collisions or even reduce the habitat quality. Ecological studies also suggest that breeding patterns tied to the moon phases can be disrupted by excessive lighting or human disturbances at night.
Conclusion
Summary: The Rufous-bellied nighthawk has a large range, but is experiencing a slow but real decline due to habitat destruction and loss. The Least Concern classification reflects the fact that this species has not yet reached the thresholds of vulnerability. However, it is still at risk. The montane forest ecologies are sensitive to human interference, climate change, a nd deforestation. Therefore, the Rufous Bellied Nighthawk is a sentinel. Its health indicates the integrity of the high Andean Cloudforest ecosystems.
To ensure that the nightjar’s nocturnal flight above forests continues, it is important to maintain and restore its habitat. Monitoring population changes, reducing disruption, and conserving ecological processes (moonlight and forest floor cover) will also help.
