Trumpeters

(Psophiidae)

Class Aves

Order Gruiformes

Suborder Grues

Family Psophiidae

Thumbnail description
Trumpeters are long-necked, hunch-backed, small-headed, short-tailed, dark-plumaged, chicken-sized birds with a short, sharp bill, long legs, and an elevated hind toe; they roam the floor of South American rainforests and are named for their deep, booming territorial call

Size
17–21 in (43–53 cm); 2.2 lb (1 kg)

Number of genera, species
1 genus; 3 species

Habitat
Tropical forest with an ample supply of fruit trees

Conservation status
Not threatened

Distribution
Northern South America, mainly in the Amazon basin

Evolution and systematics

Trumpeters share many similar traits with other birds in the order Gruiformes (rails, cranes, moorhens, and gallinules), but the three trumpeter species are grouped within their own separate family (Psophiidae). Scientists still debate as to which of the other families in the order Gruiformes include their closest relatives. Some argue they are most similar to rails and cranes, based on similar anatomy. DNA analysis by Sibley and Ahlquist suggest trumpeters are more closely aligned with cranes, limpkins, and finfoots, along with seriemas, kagu, sunbitterns, and bustards.

Primates, such as spider monkeys, are a key part of the trumpeters' evolution. Trumpeters depend on monkeys and other animals to provide their food supply. Since trumpeters are not strong fliers, they forage on the forest floor relying on monkeys and larger birds to shake loose pieces of fruit and drop them to the ground.

Trumpeters, which travel in groups, evolved with a rare social structure known as cooperative polyandry. In this system, one dominant female mates with several dominant males, but all members of the group share in raising and feeding the young. Researchers suggest trumpeters adapted with this system because they must defend large territories in order to gather enough food during the dry season. To patrol these large boundaries, the trumpeters need to attract several adult males. As a result, more than one male is allowed to mate with the dominant female in each group. Since predators prevent half of all trumpeter chicks from making it to adulthood, the group parenting approach may help increase their odds of survival.

Physical characteristics

Trumpeters are about the size of a domestic chicken and have long necks, hunched backs, small heads, and short tails. They have large, dark eyes and a short, sharp bill, which they use to pry open fruit. At first glance, trumpeters look somewhat stocky but they have slender bodies that appear larger as a result of their wings that are slightly arched at the sides. Adult male and female trumpeters have a similar appearance, but the males are heavier.

All trumpeters have mostly dark plumage. The three species can be distinguished by the color of the inner wing

plumage. This creates a contrasting patch on the bird's back when its wings are folded. The common trumpeter (Psophia crepitans) has gray inner wings. The dark-winged trumpeter (P. viridis) has green inner plumage and the pale-winged trumpeter (P. leucoptera) has contrasting white feathers. Like the cranes and rails, trumpeters have an elevated hind toe. Their long legs help them run quickly.

Juveniles hatch with brown and black striped plumage. This camouflage pattern helps them match their surroundings on the forest floor. Chicks begin to grow adult-looking plumage after about six weeks.

As their name indicates, trumpeters are noisy birds. They have several types of calls, but the most distinctive is their territorial call. It has been compared to the sound a person makes when blowing into an empty bottle. The call is not exactly like a trumpet, but it has a repetitive, low-pitched, drumming sound heard mostly at night.

Distribution

Trumpeters occur in Venezuela, Colombia, Ecuador, the Guianas, Peru, Bolivia, and Brazil. The Amazon River and its tributaries have played an important role in determining where various trumpeter species live. For example, the common trumpeter lives north of the Amazon. The pale-winged trumpeter can be found south of the Amazon and west of the Madeira; while the dark-winged trumpeter is distributed south of the Amazon and east of the Madeira.

Habitat

Trumpeters live on the ground in tropical rainforests. They prefer forests with a relatively open forest floor so they can more easily forage and run away from predators when necessary. Typical trumpeter habitat can range from dense, forested areas to swamps.

A good variety of mature fruit trees is a key requirement for trumpeter habitat. While they gather the fallen fruit from the ground, they also use trees for roosting at night. They prefer areas with a thick canopy to provide protection and cover while roosting and nesting. Trumpeters also seek trees with hollow cavities for nest-building sites.

Behavior

Before they begin searching for food, trumpeters spend some time socializing with other members of their territorial group. Scientists have observed them paying respects to the dominant adults, by crouching and spreading their wings to show they are subordinate. The dominant bird often will give a slight flick of the wings to acknowledge the gesture.

Preening is another way trumpeters socialize. One bird will lower its head and walk up to another to request this service. Usually, the first bird will return the favor. Dominant birds will preen subordinates and vice versa, so the hierarchical social structure does not seem to make a difference in preening.

Trumpeters also like to feed other members of their group. They use a special call and submissive displays to beg for food. If food is plentiful and they do not have to spend the entire day foraging, trumpeters also will engage in playful fights with each other. They flap their wings and kick in a mock attack. Researchers also have seen lone trumpeters playfully attack objects on the ground, such as a rock or leaf.

After a period of socializing, trumpeters set off in groups of three to a dozen birds to search for food. They walk along the forest floor, turning over leaves to look for insects and fallen fruit. During seasons when fruit is harder to find, trumpeters may have to cover a large territory to find enough food for the group.

While foraging, trumpeters often encounter a rival group that has infringed on their territory. As soon as they sense the intruders, the defending group will quickly run toward them without making a sound. When they catch the other birds, the trumpeters will blast them with their loud, distinctive territorial call. A fight typically ensues as the defenders jump into the air and kick their rivals, flapping their wings and pecking. The birds continue giving the territorial call until the intruders are driven back across the boundary line.

After they return from foraging and the sun sets, trumpeters roost in tree branches 30 ft (9 m) off the ground. After dark, the group continues to assert its boundaries by giving the territorial call every few hours.

In some cases, trumpeters interact with other animal species as well. For example, one scientist observed a pale-winged trumpeter grooming parasites from the back of a Brazilian tapir in the Amazon rainforest.

Feeding ecology and diet

Fruits make up the majority of the trumpeter's diet. They prefer soft fruits without a thick rind. Most of the fruits they eat are either found on low-growing plants or have been knocked to the ground by monkeys.

Insects also provide an important trumpeter food source. Foraging trumpeters often use their bills to probe the forest floor for beetles, ants, termites, and other insects, as well as their eggs and larvae. Trumpeters have also been known to eat an occasional small snake.

Reproductive biology

Trumpeters make attractive research subjects for scientists who are interested in their rare breeding system, known as cooperative polyandry. In this system, one dominant female mates with three dominant males, and the entire territorial group helps to raise and feed the young.

Courtship begins before the start of the rainy season, when food is most abundant for the emerging chicks. Two months before they begin breeding, a pair of trumpeters start searching for a suitable nest site. They prefer existing tree cavities high above the ground that have been abandoned by another bird or animal. To prepare the nest, the birds pack down a layer of wood and sticks gathered from the forest floor. At this time, the dominant male makes a ritual of feeding the dominant female.

When breeding season begins, the dominant males in the group compete with each other for the chance to copulate with the dominant female. When mating, the female presents her hind parts to solicit the male as he walks behind her in a circle.

On average, the female lays three white eggs. The dominant male and female share most of the incubation, but the subordinate males also spend some time on the nest. The eggs hatch after 27 days.

Chicks emerge covered with dark, striped down feathers. They depend on the adult birds to feed them for the first three weeks, then gradually begin to forage on their own. Since the chicks are not strong enough to fly at first, they roost closer to the ground at night. This makes them vulnerable to snakes, raptors, and other predators.

Conservation status

Trumpeters typically need large, uninterrupted tracts of land to find enough food to feed their territorial groups. But their rainforest habitat is rapidly shrinking, leaving their future in question. Trumpeters occur in the highest numbers in large, protected wildlife reserves. Scientists are concerned because trumpeters are not easy to breed in captivity. Also, the primates they depend upon for food availability are losing ground due to hunting and habitat loss. That, in turn, could create problems for trumpeters. Currently, however, trumpeters are not threatened or endangered.

Significance to humans

Humans in many different regions have given nicknames to trumpeters. For example, in Surinam, they are called "Kameekamee," which means camel's back. The Tupi Indians call them "Jacamims," or bird with small head. Some native Brazilian people consider trumpeters to be their spiritual ancestors.

Trumpeters are said to make good pets, and often are used to protect chicken coops and alert their owners when snakes appear. Trumpeters are heavily hunted for food in some parts of their range. Hunters stun them by shining lights into their eyes while they roost at night. Since trumpeters are loyal to other members of their group, they often will stay close if another bird is injured, making them easy targets for hunters.

Species accounts

List of Species

Common trumpeter

Psophia crepitans

taxonomy

Psophia crepitans Linnaeus, 1758, Cayenne. Two subspecies.

other common names

English: Gray-winged trumpeter; German: Graurücken-Trompetervogel; Spanish: Trompetero Aligrís.

physical characteristics

18–20 in (45–52 cm); 2–3 lb (1–1.5 kg). Dark plumage with gray inner wings that form a light patch on the back. Long neck and legs, hunchback appearance. Juveniles are dark gray with cream underparts and reddish stripes.

distribution

North of the Amazon in northwestern Brazil, parts of Colombia, Ecuador, Peru, Venezuela, and the Guianas.

habitat

Dense tropical rainforest.

behavior

Very social bird that uses a complex set of calls to communicate. Travels in groups of three to 12.

feeding ecology and diet

Forages mostly on fruit knocked to the forest floor by primates. Insects, such as beetles, ants, and termites also are part of the diet.

reproductive biology

Uses a rare breeding system, cooperative polyandry, in which a dominant female mates with three dominant males and the other adults in the group help feed and care for the chicks. Nests in hollow tree cavity. Lays a clutch of three eggs. Incubation is 28 days.

conservation status

Not threatened, but population is shrinking due to loss of habitat and hunting.

significance to humans

None known.

Pale-winged trumpeter

Psophia leucoptera

taxonomy

Psophia leucoptera Spix, 1825, Rio Madeira, Brazil. Two subspecies.

other common names

English: White-winged trumpeter; German: Weissflügel-Trompetervogel; Spanish: Trompetero Aliblanco.

physical characteristics

18–20 in (45–52 cm); 2–3 lb (1–1.5 kg). Adults have dark plumage with contrasting white wing tips, which form a light patch on the back. Long neck and legs, hunchback appearance. Juveniles are reddish with cream underparts and white stripes.

distribution

South of the Amazon and west of the Madeira through parts of Brazil, Peru, and Bolivia.

habitat

Dense tropical rainforest.

behavior

Very social bird that uses a complex set of calls to communicate. Travels in groups of three to 12.

feeding ecology and diet

Forages mostly on fruit knocked to the forest floor by primates. Insects, such as beetles, ants, and termites also are part of the diet.

reproductive biology

Uses a rare breeding system, cooperative polyandry, in which a dominant female mates with three dominant males and the other adults in the group help feed and care for the chicks. Nests in hollow tree cavity. Lays a clutch of three eggs. Incubation is 23–29 days.

conservation status

Not threatened, but population is shrinking due to loss of habitat and hunting.

significance to humans

None known.

Dark-winged trumpeter

Psophia viridis

taxonomy

Psophia viridis Spix, 1825, Parintins. Three subspecies.

other common names

English: Green-winged trumpeter; German: Grünflügel-Trompetervogel; Spanish: Trompetero Aliverde.

physical characteristics

18–20 in (45–52 cm); 2–3 lb (1–1.5 kg). Adults have dark plumage with dark green wing tips, which form a green patch on the back. Long neck and legs, hunchback appearance. Juveniles are reddish with cream underparts and white stripes.

distribution

South of the Amazon and east of the Madeira in central Brazil.

habitat

Dense tropical rainforest.

behavior

Very social bird that uses a complex set of calls to communicate. Travels in groups of three to 12.

feeding ecology and diet

Forages mostly on fruit knocked to the forest floor by primates. Insects, such as beetles, ants, and termites also are part of the diet.

reproductive biology

Uses a rare breeding system, cooperative polyandry, in which a dominant female mates with three dominant males and the other adults in the group help feed and care for the chicks. Nests in hollow tree cavity. Lays a clutch of approximately five eggs. Incubation is 27 days.

conservation status

Not threatened, but population is shrinking due to loss of habitat and hunting.

significance to humans

None known.

Resources

Books

del Hoyo, J., A. Elliott, and J. Sargatal, eds. "Family Psophiidae." In Handbook of Birds of the World. Vol. 3, Hoatzin to Auks. Barcelona: Lynx Edicions, 2001.

Periodicals

Peres, C.A. "Ungulate Ectoparasite Removal by Black Caracaras and Pale-winged Trumpeters in Amazonian Forests." Wilson Bulletin 108, no. 1 (1996): 170–175.

Sherman, Peter, T. "Social Organization of Cooperatively Polyandrous White-winged Trumpeters." Auk 112, no. 2 (1995): 296–309.

Sherman, Peter, T. "Reproductive Biology and Ecology of White-winged Trumpeters and Recommendations for the Breeding of Captive Trumpeters." Zoo-Biology 19, no. 1 (2000): 65–84.

Organizations

Neotropical Bird Club. c/o The Lodge, Sandy, Bedfordshire SG19 2DL United Kingdom. E-mail: secretary @neotropicalbirdclub.org Web site: <http://www.neotropicalbirdclub.org>

Melissa Knopper