Amazonia is the largest, most diverse rainforest on Earth. One tenth of the world’s plant and animal species live here—including one out of every five bird species!
ContinueThe vast bird diversity of Amazonia is currently divided into eight gigantic Areas of Endemism—regions that contain bird species found nowhere else on Earth!
ContinueTravel up Brazil’s Rio Japurá and its tributaries with Field Museum scientists John Bates and Jason Weckstein and Goeldi Museum scientist Alex Aleixo to discover which birds live in a little-explored area where two Areas of Endemism meet—the Napo and the Imerí.
Documenting and studying bird populations along this boundary will help the team define the range and evolutionary history of each species and better assess areas of unique diversity in need of protection.
Explore the map to view Jason's video journals and site notes documenting the team's experiences along the way, and take a look—and listen—to the birds found at each of the three study sites.
You’ll learn about the fascinating feeding and breeding habits of some Amazonian species and discover how rivers may impact their evolution.
Two full days of cruising up the Rio Japurá brought us to our furthest destination and first study site—the Rio Mapari, a south-bank tributary of the Rio Japurá in the Napo Area of Endemism.
As at all of our sites, we counted species by listening for calls, birdwatching with binoculars, and capturing birds in mist nets (fine netting stretched across openings in the forest.)
Many birds we spotted were members of mixed-species flocks, which are common in Amazonia. When different species forage together, the individual flockmembers’ odds of finding food and spotting predators improve.
Explore the map to see what we found.
© J.D. Weckstein
Myrmotherula axillaris
Mixed-species flocks often specialize on certain resources in specific areas of the forest. For example, understory flocks typically feed on insects and other invertebrates, whereas canopy flocks can be made up of either fruit- or insect-eating bird species.
Mated pairs of White-flanked Antwrens seemed to be common members of insect-eating mixed flocks at all of our study sites.
White-flanked Antwren Song
© J.D. Weckstein
Tangara schrankii
Birds in mixed-species flocks may face less competition than those in flocks made up of one species because in a mixed flock, each species has evolved to forage in a different niche.
For example, in fruit-feeding mixed flocks, Green-and-gold Tanagers glean from the tips of branches, whereas other species in the group feast along tree trunks or in the canopy.
Green-and-gold Tanager Video Green-and-gold Tanager Dawn Song
© J.D. Weckstein
Philydor pyrrhodes
Some species stay with a mixed flock all day, foraging through the forest at speeds of about 0.19 miles per hour (.03 km/hr). But other “attendant” species join a flock only when it crosses their territory.
The behavior of the Cinnamon-rumped Foliage-gleaner differs throughout its range—in some areas, the bird is a core flock member, but in other areas, it’s merely an attendant.
Cinnamon-rumped Foliage-gleaner Song
© E. Rodrigues
Gymnopithys leucaspis
Mixed-species flocks also specialize in certain habitats. Some search for food in seasonally flooded forests, while others hunt in Terra Firme (dry land) forests.
Bicolored Antbirds are members of flocks that follow swarms of predatory army ants in Terre Firme forests. These birds swoop in to feast on the hordes of insects and other invertebrates scurrying to escape the ants.
Listen to the calls of these birds and the sounds of swarming ants in the background.
Bicolored Antbird Call
© M.S. Faccio
Lanio fulvus
Considered to be “core” members of mixed-species flocks at our study sites, the distinctive songs of mated pairs of Fulvous Shrike-tanagers may help bring mixed flocks together each morning.
The pair also acts as sentinels, giving sharp alarm calls when predators are spotted—or when they want to “cry wolf” and frighten competitors away from a meal.
Fulvous Shrike-tanager Call
© J.M. Bates
Micrastur ruficollis
Mixed flocks provide safety in numbers. When raptors like the Barred Forest Falcon fly in for the kill, the flurry of many different kinds of birds fleeing at once can confuse the predator.
The long tail and short wings of this falcon give it maneuverability as it chases fleeing prey and swoops down upon other birds feeding at ant swarms.
Barred Forest Falcon SongAfter leaving our first site, we turned our boat around and headed back down the Japurá to another of its south-bank tributaries—the Rio Acanaui—also situated within the Napo Area of Endemism.
Giant trees in the forest interior here produce Brazil nuts, a source of income for villagers who live in the nearby town. With their permission, we used their harvesting trails to enter the forest.
Here, as at our other locations, we saw many birds with interesting breeding behaviors such as lekking—a courtship ritual where males dance and sing to win the right to mate.
Explore the map to see what we’ve found.
© E. Rodrigues
Pipra erythrocephala
In species that form classic leks, males meet in a traditional courtship arena to dance and sing. Competitors work their way into the center of the circle, where the females claim the winners as mates.
Male Golden-headed Manakins are famous for their impressive "moonwalk"—a sideways slide that allows them to flash their white and red thighs and pink legs.
Golden-headed Manakin Lekking Song
© J.D. Weckstein
Phoenicircus nigricollis
Some species, such as Black-necked Red Cotingas, form “exploded” leks. Males congregate in loose assemblies, where each individual sets up his own display site.
Males put on a show at their same perches year after year, luring females to watch them dance with a loud and explosive early-morning “love call.”
Black-necked Red Cotinga Lekking Call
© J.M. Bates
Dixiphia pipra
Male White-crowned Manakins usually remain out of sight from one another, but within earshot of their popping mating calls. They strut their stuff with a showy, butterfly-like flutter during slow, swooping flights between perches.
Once a female has mated with her choice, she flies off to build her nest, lay eggs, and rear the offspring alone.
White-crowned Manakin Lekking Call
© J.D. Weckstein
Lepidothrix coronata
Blue-crowned Manakins were the most common member of the manakin family at all our sites. Like other “exploded” lekkers, Blue-crowned males display from one of several solitary perches.
In some other species of manakins, older males team up with younger males to put on a good show. But at the last minute, the older male typically swoops in to steal the girl.
Blue-crowned Manakin Video Blue-crowned Manakin Display Song
© J.D. Weckstein
Onychorhynchus coronatus
The Amazonian Royal Flycatcher appears to be a dull brown except when preening, courting, or warding off competitors and predators—then its spectacular crown comes into view.
In courtship, both males and females fan their crests, weave their heads back and forth, flick their tongues like a snake, and occasionally lock bills.
Amazonian Royal Flycatcher Call
© J.D. Weckstein
Momotus momota
The Blue-crowned Motmot never comes to the forest floor except when nesting. Parents find an abandoned hole along a stream bank and then burrow more deeply to construct a nest cavity for their eggs.
The bird’s distinctive, owl-like “whoop-whoop” greeted us each morning at all of our sites, although the call differed slightly at each location.
Blue-crowned Motmot SongTo reach our third study site near the town of Maraã, we cruised our way up a large, lake-sized inlet located off the north bank of the Japurá—in the Imerí Area of Endemism.
We made our way through Igapo (forests flooded with acidic blackwater) and Campinarana (low, scrubby forest growing in nutrient-poor sandy soil) and finally found a higher patch of dry land (Terra Firme).
The width of the Japurá River here presents a challenge to resident Amazonian bird species, which haven’t evolved with the need to migrate, or the ability to fly long distances, because they have year-round resources at hand.
Explore the map to see what we found.
© J.D. Weckstein
Galbula albirostris
Like many Amazonian birds, the Yellow-billed Jacamar has adapted to living in the forest’s low light levels. It won’t cross a wide expanse of water for fear of being exposed to predators and bright sunlight.
In fact, major rivers separate the Yellow-billed Jacamar from it’s nearest relative, the Blue-cheeked Jacamar—illustrating the role rivers may play in the evolution of so many different Amazonian species.
Yellow-billed Jacamar Song
© J.D. Weckstein
Celeus flavus
The population of Cream-colored Woodpeckers at this north bank site looked identical to the populations at our south bank sites. But looks can be deceiving.
Previous DNA studies have shown that many seemingly identical bird populations are headed down separate evolutionary paths because they’re unable to interbreed and exchange genes across rivers.
We don't yet know if these woodpecker populations are different, but future genetic studies will clarify their evolutionary relationships.
Cream-colored Woodpecker Song
© J.D. Weckstein
Pionites melanocephalus
The Black-headed Parrots that we found are members of the sub-species P.m. pallida—from northwestern Amazonia. Birds in northeastern Amazonia are P. m. melanocephala.
Genetic data from this trip and others may eventually help determine whether the two subspecies are actually genetically distinct and should be considered different species—a finding that would impact their conservation status.
Black-headed Parrot Video Black-headed Parrot Call
© E. Rodrigues
Cyphorhinus arada
The aptly named Musician Wren is ranked “of least concern” because it’s considered one widespread species. However, populations differ both in color and song across Amazonia. Listen to samples of their different “languages” here.
Further DNA studies will help determine if populations from different regions are genetically distinct—an issue that must be considered to properly conserve diversity.
Brazil Ecuador Peru
© M.S. Faccio
Hypocnemis hypoxantha
For many years, the Yellow-browed Antbird was thought to live only in western Amazonia, north of the Amazon River. We found it at all of our study sites.
A small population has also been discovered in central Amazonia, south of the Amazon and far to the east! We’re still working to understand what forces led to two such geographically distant populations of the same species.
Yellow-browed Antbird Song
© J.D. Weckstein
Willisornis poecilinotus
Although the Common Scale-backed Antbird is considered one widespread species, our DNA studies have shown that populations are separated by rivers and differ markedly across the Areas of Endemism.
Identifying genetically isolated populations not only explains how Amazonian diversity evolved, but also helps determine additional habitats, areas, and species in need of protection.
Common Scale-backed Antbird SongInteractive Map
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