Our Los Amigos Research Station and Birding Lodge supports an incredible diversity of birds—nearly 600 species representing one-third of the total bird diversity of Peru. As stewards of their habitat, we have a responsibility and opportunity to better understand this bird life, and enhance conservation efforts among birdwatchers, young conservationists and scientists that visit us year after year. To that end, we have recently launched the Los Amigos Bird Observatory. The Bird Observatory will leverage this incredible wildlife diversity and the facilities managed by Amazon Conservation in order to spread awareness, build capacity, and enhance conservation efforts among birdwatchers, researchers, students, and conservationists. Here you can find updates on what is happening on the ground at the Bird Observatory.


Mercury: an increasing threat in the tropics

August 12, 2019 | Author: Arianna Basto

The rainforest is a highly diverse and complex ecosystem, of which only a very small percentage is known. Because the impact of different disturbances within it is not fully understood, protecting its integrity should be the end goal. However, the threats affecting this ecosystem are only increasing over time, including deforestation and mercury pollution caused by mining.

Mercury can be found in many forms, and while these are naturally available in the environment, a great amount results from its use in human activities like gold mining. Furthermore, although not all of its forms are toxic, methylmercury, the most bioavailable and toxic, bio-accumulates within the food chain, affecting a wide range of species. Bioaccumulation of this neurotoxin in birds has been seen to affect the fitness, coordination, reproduction and survival of species. Its effects include lethargy, loss of appetite, aberrant parenting behavior and reduced motivation to forage. Unfortunately, mercury’s persistence in the atmosphere and ability to travel great distances has allowed it to contaminate areas far from the original source.

Roadside Hawk (Rupornis magnirostris) and a boat carrying oil for mining share the same ecosystem. PC: Patrick Newcombe

Aquatic systems are most efficient at converting mercury to methylmercury, increasing the risk of aquatic species. Because of this, much of the attention and studies of mercury contamination in birds has been focused on species associated with bodies of water. Conversely, terrestrial habitats and their wildlife have received little attention. Variations in soil moisture are expected to increase the bioavailability of mercury; increasing the risk of the long, wide, and complex food webs found in tropical systems.

Diego Guevara, 2019 Franzen fellows, is studying bird community in areas impacted by mining.

Because birds are often near or in the top of food chains, they are highly prone to accumulating mercury in their bodies. However, this fact does also make them very good bio-indicators of environmental mercury contamination. They are common, conspicuous, and sampling of feathers and eggshells can confidently detect levels of heavy metals in a non-invasive manner. Particularly in tropical rainforests, more work needs to be done to assess the impact of mercury on birds.

The increasing threat mercury pollution poses to the tropics is drawing more and more attention to this region. As a short-term measure, it is necessary to replace current gold mining techniques, with already existing mercury-free methods. By moving away from this metal, we will ensure healthy human and wildlife communities and more crucially a healthy ecosystem.

Further readings:

Egwumah F.A, Egwumah P.O & Edet, D.I. (2017). Paramount roles of wild birds as bioindicators of contamination. Int J Avian & Wildlife Biol. 2(1):194‒200. DOI: 10.15406/ijawb.2017.02.00041

Appel, Peter & Jøsson, J.B.. (2010). Borax – an alternative to mercury for gold extraction by small-scale miners: Introducing the method in Tanzania. Geological Survey of Denmark and Greenland Bulletin. 87-90.


Conserving Palms to Conserve Tropical Birds

May 28, 2019 | Author: Arianna Basto

Cotingas, manakins, and toucans are among the many fruit-eating birds found in the tropical forest. Unlike the species in temperate zones, tropical bird species have evolved to depend on this resource year-round. However, fruits are a food supply that can be highly patchy in time and space. In areas with pronounced wet and dry seasons, fruit abundance typically peaks during the wet season and is lowest during the dry season. Now, with the end of the rainy season, the abundance is coming to an end. So what will the fruit-eating birds rely on?

Around 1,800 species of palms are found in the tropical forests. Due to the variance in size between species, they can be both part of the understory and the canopy. They also vary in the type of habitat and the amount of water they depend on. Some species like the aguaje (Mauritia flexuosa) are found in large aggregations called palm swamps, known locally as aguajales, while other such as the walking palm (Socratea exorrhiza) are dispersed throughout the forest.

Aguaje (Mauritia flexuosa) is one of the main food sources year round. Photo: Black-capped Capuchin (Cebus apella) / PC: Claudia Roar

Yellow-Crowned Parrot (Amazona ochrocephala) taking advantage of the few fruit left at the end of the rainy season.

Parrots are also between the fruit-eating birds found in the tropical forests. PC: Will Sweet

Unlike other trees, palms trees can fruit during the dry season, and some even fruit year-round. Because of this, their fruits become the main food source not only for birds but also for mammals, fish and in some cases reptiles.

However, deforestation and unsustainable harvesting threaten this key resource. Tropical forest is cleared indiscriminately for agriculture, logging and gold mining. Local people harvest palms for different purposes, and while some harvesting can be done sustainably, usually this is not the case. To harvest the palm’s heart and the fruit from the tallest palms, is necessary to chop down the trees.

As a sustainable alternative for fruit harvesting, some communities have started to climb the palms instead. This is a small step forward to sustainably manage these species. But because palms are a vital food source for many of the tropical forest’s fauna, it is imperative that more sustainable alternatives are developed and that indiscriminate clearing is curbed as soon as possible.

Additional Readings:

Kahn, F. (1991). Palms as key swamp forest resources in Amazonia. Forest Ecology and Management, 38, 133-142.
Galetti, M. & Aleixo, A. (1998). Effects of palm heart harvesting on avian frugivores in the Atlantic rain forest of Brazil. Journal of Applied Ecology, 35, 286-293.

Global Big Day at Los Amigos: 331 Species Sighted!

April 28, 2019 | Author: Arianna Basto

Exploring the trails of the station

The Global Big Day (GBD) is a date in which amateurs and experts in birds from around the world seek to see the greatest number of species in their locality. However, it is not only a date in which healthy competition between countries is observed, but also a great opportunity to educate about the diversity of birds worldwide. Like every year, at Los Amigos we were eager to participate in this event and give our best.

At the station, three bird guides from the regions of Madre de Dios and Cusco led this year’s GBD. Jose Luis Avendaño, Percy Avendaño and Cesar Bollatty have more than 20 years of experience touring Peru, including numerous visits to the station. Their knowledge of the species in the area and the station was key to end the day with a total of 331 species sighted, a new record for the station in a GBD.

On May 4, at 4:30 in the morning we were already on the trails in search of the most nocturnal species. Among them we recorded the Crested Owl (Lophostrix cristata), the Long-tailed Potoo (Nyctibius aethereus) and the Ocellated Poorwill (Nyctiphrynus ocellatus). The search for the various species of the station continued until 3:30 in the afternoon, when a heavy rain caused the forest to be silenced and we had to stop our search. After eleven hours of intense search, we are the second group with the most species sighted in Peru!

Although we could not spot species such as the Pale-winged Trumpeter (Psophia leucoptera) and the Cocoi Heron (Ardea cocoi), species commonly sighted in Los Amigos, we managed to spot other species not so easily observed in other places. The Pavonine Quetzal (Pharomachrus pavonivus), the Great Jacamar (Jacamerops aureus), the Royal Flycatcher (Onychorhynchus coronatus), the Spangled Continga (Cotinga cayana) and the Bar-bellied Woodcreeper (Hylexetastes stresemanni) are among the rare species that we spotted during this event.

A Long-billed Starthroat  (Heliomaster longirostris) spotted at the station. PC: Jose Luis Avendaño

Jose Luis Avendaño, Percy Avendaño y Cesar Bollatty after a long day of birdwatching. PC: Arianna Basto.

The Global Big Day 2019 was a great day for Los Amigos. Everyone who participated had a great day, enjoying the diversity offered by the station and always learning a little more. I’m sure the birders around the world enjoyed May 4th as much as we did at the station!


Two Ancient Icons of the Neotropics

March 28, 2019 | Author: Arianna Basto

The Harpy Eagle (Harpia harpyja) and the Shihuahuaco tree (Diptheryx micrantha) are iconic species of the Neotropics that play key roles in the health of the ecosystem.

The harpy eagle is the heaviest and most powerful raptor inhabiting the canopy of rainforests. Its historic distribution ranges from southern Mexico to northeastern Argentina. While the variety in its diet suggests an opportunistic foraging behavior, it feeds mostly on arboreal mammals.

The mighty harpy eagle (Hapia harpyja) occasionally needs a break. Picture taken at Los Amigos Birding Lodge. PC: Rich Hoyer

Already hard to spot in the wild due to hunting and habitat loss, the harpy eagle population has plummeted in many countries of Central America.  An obstacle to its recovery is its slow reproductive rate: the eagle generally breeds every two to three years, with a single offspring per nesting effort.

A single shihuahuaco (Diptheryx micrantha) tree might sequester a third of all carbon stored in a hectare of primary forest. PC: Gianella Espinosa – Arbio

The shihuahuaco, meanwhile, is an emergent tree of the canopy that can reach a height of over 50 meters. It is patchily distributed in South America from Colombia to Bolivia. Shihuahuaco seeds and fruits are a source of food for species such as bats, agoutis, macaws, and hawks.

The slow-growing shihuahuaco can take centuries to reach its maximum height. Though not classified as endangered, it is critically threatened by logging and deforestation. In Peru, due to its hard wood and resistance to rot, the shihuahuaco is one of the most exported timber species, both legally and illegally.

Deforestation is the two species’ common destroyer: it has decreased the availability of prey and nesting sites for the eagle, while reducing disperser populations and suitable habitat for the shihuahuaco.

In a forest, the absence of large predators is associated with decreased tree diversity. The harpy eagle helps controls the presence of herbivores and thus enables many tree species to propagate. While standing, the shihuahuaco is an ecologically important species due to its broad buttresses that give structural integrity to the forest; when it falls, it leaves large gaps, facilitating successional forest growth. Further, because of the large amount of carbon a single shihuahuaco tree can store, it is a key species to fight the effects climate change.

One of the many shihuahuaco (Diptheryx micrantha) seedlings being planted throughout the station. PC: Arianna Basto

Because of its great size, for nesting, the harpy eagle depends on emergent trees of the canopy, one of the most important being the shihuahuaco. Locals and researchers have described the close relationship between these two species. Notably, eagle nests built on shihuahuaco branches will serve for more than one reproductive season.

At Los Amigos, we are planting over a hundred shihuahuaco seedlings. Eventually, the shihuahuaco will be a common sight here… and, with luck, so will the majestic eagle.

Further reading:

  • Aguiar-Silva, F. H., Sanaiotti, T. M. & Luz, B. B. (2014). Food Habits of the Harpy Eagle, a top Predator from the Amazonian Rainforest Canopy. Journal of Raptor Research, 48(1): 24-35. URL: https://doi.org/10.3356/JRR-13-00017.1
  • Putzel, L., Petersa, C. M. & Romod, M. (2011). Post-logging regeneration and recruitment of shihuahuaco (Dipteryx spp.) in Peruvian Amazonia: Implications for management. Forest Ecology and Management 261 (2011) 1099–1105. doi:10.1016/j.foreco.2010.12.036



Camera Traps: Colorfully Capturing Motmots

February 26, 2019 | Author: Arianna Basto

Our camera traps were set up to monitor a nest of the secretive giant armadillo (Priodontes maximus). However, during a recent recording session, a less reclusive forest friend stole the spotlight: a rufous motmot (Barypththengus martii). This curious bird belongs to the Momotidae family, which comprises a group of colorful arboreal species.

An Amazonian motmot (Momotus momota) showing off its racket-like tail. Photo: Will Sweet

Endemic to the tropics, among birds of the region, the motmots range in size from medium to medium-large. Despite their bright plumage—a combination of greens, blues and rufous (rust-like) colors—they are hard to spot. Most of the species have a long tail, and a few have two longer feathers that have racket-like tips. In contrast with many other bird families, motmots exhibit no sexual dimorphism: males and females look much alike, though on closer inspection males tend to be larger and have longer tails.

Spotting a motmot can be challenging because they sit still for long periods. They can be observed when they sally out to catch their prey, or through the sideways movement of their tails. It has been hypothesized that the turquoise-browed motmot (Eumomota superciliosa) uses this latter movement to signify to a predator that it has awareness of its presence. Thus advised, the predator might desist from an attack, preventing an unnecessary waste of energy on both sides.

Motmots can be found in a variety of forest types, from lowland tropical forest to template forests. Some species can even adapt to man-made habitats such as plantation and gardens. Motmots take their prey from leaves, twigs or branches of trees or other vegetation, and can be seen on the ground too. Smaller species feed on insects while larger ones additionally feed on other invertebrates, small vertebrates and fruits. The larger species like the Amazonian motmot (Momotus momota) and the rufous motmot have been reported to feed on bats and on poison dart frogs, respectively, in the latter case with no apparent harm to themselves.

A rufous motmot (Barypththengus martii) inspects a burrow of the giant armadillo (Priodontes maximus).

 Most of the Momotidae have similar breeding behaviors. An exception is the tody motmot (Hylomanes momotula), which is also morphologically atypical and the most primitive species of the family. These ground-nesting birds use their feet to loosen the soil to later dig their nesting burrows. Both mates share this work and the chick rearing. Motmots are solitary nesters, but when limited suitable space is available, they may concentrate in groups. A new burrow is dug for each nesting season, often close to the previous burrow. As our camera trap and other studies have reported, the rufous motmots also use old burrows of armadillos and other mammals to nest.

Like many other Neotropical birds, the motmots are understudied, and there are much more to learn about them. Who knows which other surprises they may hold!

Further readings:
Skutch, A. F. (1971). Life History of the Broad-billed Motmot with Notes on the Rufous Motmot. The Wilson Bulletin Vol. 83, Nro 1.
Murphy, T. G. (2006). Predator-elicited visual signal: why the turquoise-browed motmot wag-displays its racketed tail. Behavioral Ecology.


New Year, New Fellows! Announcing the 2019 Jonathan Franzen Fellows

January 21, 2019 | Author: Arianna Basto

Two years ago, the Los Amigos Bird Observatory opened its doors to promote avian research and conservation in one of the most biodiverse ecosystems in the world: the Amazon basin. To continue with our commitment, last year, we launched our second Franzen Fellowship call for applications, targeting students and young researchers interested in avian research. The group of promising and highly qualified candidates that applied made this a tough decision. We congratulate all the candidates, and are excited to present our 2019 Franzen Fellows!

Jessica Pisconte holds a degree in biology from the Universidad Nacional San Luis Gonzaga de Ica, Peru. Her interest in avian conservation was born in the Paracas National Reserve, after which she joined a wide range of research projects to learn about the importance of birds in coastal, mountain and Amazonian ecosystems. She is currently working as a park ranger in the Tambopata National Reserve in Peru’s Madre de Dios region. As the threats due to illegal mining increased in this region, seriously affecting the environment, Jessica was motivated to research key areas to understand its impact. Los Amigos will be her starting point to study the effects on birds of mercury from gold mining. Through this project, Jessica seeks to contribute to the conservation of and knowledge regarding birds in the Peruvian Amazon.



Lisset Goméz studied biological sciences at the Universidad Mayor de San Marcos in Lima, Peru. Her interests include ecology, reproductive biology, and conservation of bird communities, and she has been involved in a number of courses and projects around Peru that embrace these topics. Lisset volunteered with the National Service of Natural Protected Areas (SERNANP) and at the Wayquecha Biological Station, where she assisted in a project on plant-hummingbird interactions.  Through her participation in the Course on Field Techniques and Tropical Ecology at the Cocha Cashu Biological Station in Manu National Park, she strengthened her knowledge of the tropical forest and started conducting her own research. As a Franzen Fellow, she will try to understand the habitat requirements of woodpeckers of the genera Campephilus and Celeus. She will address her research question by identifying the woodpecker species’ tree preferences when excavating their nesting cavities.


Diego Guevara got his biology degree from the Universidad Nacional Agraria La Molina (UNALM) in Lima, Peru and holds a master’s degree in applied ecology from the University of East Anglia, UK. He is an associate researcher at the Centro de Ornitología y Biodiversidad (CORBIDI) and general coordinator of the UNALM banding station. He has experience in projects related to the impact of human activities on biodiversity, with a special interest in the responses of bird communities and the habitat requirements of endangered species. Additionally, he is interested in studying the ecotoxicology and physiology of birds, which led him to apply to the Franzen Fellowship. His project will focus on the fluvial and bamboo forest bird community, studying the impacts of mining on its bird communities.



Patrick Newcombe attends the Sidwell Friends School in Washington, D.C., making him the youngest of our fellows. His interest in birds started as a young child, leading to his engagement in bird research. In 2018, with Osa Conservation in Costa Rica, he collected field data on the flocking behavior and diet of the endangered black-cheeked ant tanager (Habia atrimaxillaris). He is currently analyzing weather surveillance radar data to study the flight strategies of migratory birds on the Pacific Flyway as part of a project led by Dr. Kyle Horton from Cornell University. At Los Amigos, his project will focus on Manakin leks around the station, from which he will identify and learn about their habitat use patterns.

Stay tuned to learn more about our Fellows and their projects!



Joining forces with neighbors? Think twice!

November 20, 2018 | Author: Arianna Basto

The russet-backed oropendola (Psarocolius angustifrons) is one of the most common and widespread of the oropendola passerine birds in the Amazon. They are mostly dull brown with rufescent rump and olive tone to head. This species has three subspecies: P. a. astrocastaneus, on the western Andean slope; P. a. alfredi in the eastern Andean subtropical forest; and P. a. angustifrons in Amazonia. These subspecies differ primarily in bill and face coloration and vocalizations. During the breeding season, they are seen arduously building their characteristic basket-like nest that hang from tree branches in riparian and second-growth habitats. These closed nests keep their eggs and chicks protected from predators.









Russet-backed oropendola (Psarocolius
angustifrons) and violacious jay (Cyanocorax violaceus) scaring away intruders. PC: Tom Matia

The violaceous jay (Cyanocorax violaceus) is a colorful and gregarious member of the crow family of northern South America. This jay species is predominantly dark violet-blue, with a black facial mask. The violaceous jay can be found in a variety of forest habitats, including degraded forest, but is especially common along riparian corridors and forest edges. They are omnivorous and can be seen eating fruits, insects and bird and reptile eggs.

A great contrast is easily noticed between the species: some think that the call of the russet-backed oropendola sounds like water drops, while that of the violaceous jay strikes some as similar to a car horn. The species also have similarities: they are conspicuous resident and widely distributed species in the Amazon.

Brown capuchin (Cebus apella) might look cute but they are fierce predators. | PC Claudia Rohr

These species have something else in common: confrontations with brown capuchin monkeys! Brown capuchins (Cebus apella) feed mostly on fruits and invertebrates, but from time to time enjoy a meal of bird eggs and chicks. Quite often, a group of these monkeys can be seen climbing up the trees right outside the office at Los Amigos, where the oropendolas and jays are nesting close to each other. When the brown capuchins arrive, adults of both bird species first make their presence known with their characteristic calls. When the monkeys draw close to the nests, the oropendolas and jays cooperatively try to chase them away. These encounters conclude with either the monkeys leaving empty-handed or the birds suffering broken nests and lost eggs.

The striking cooperation between these bird species is short-lived. Jays will try to take eggs and chicks from other bird nests, including fiercely defended russet-backed oropendola nests.  For the oropendolas and violaceous jays, the expression “the enemy of my enemy is my friend” is applicable only when the common enemy is visible.


Migration in the Amazon: Time to fly away from the cold

October 17, 2018 | Author: Arianna Basto

Solitary sandpiper (Tringa solitaria) unlike other sandpipers and other migratory birds, do not migrate in large flocks and can be found along the banks of shady creeks. PC: Alex Wiebe

Movement is an essential part of our day-to-day lives. However, this is not only true for us; most species are constant on the move. For some, this is due to continuous changes in their surroundings and others because of their ecology. Most of these movements go unnoticed by us, however, there is one that does not: Bird migration. If you look up into the sky at this time of the year, you may notice the unusually high number of birds flying around. For birds that migrate, they do so twice a year, between their breeding homes habitats and their nonbreeding grounds. Some migrations are large-scale like the Artic tern (Sterna paradisaea) which incredibly manages an annual round-trip of 70 000 km. Others are much shorter, such as altitudinal gradient migration along the Andes.

Migration is the seasonal movement from one region to another influenced by a series of factors. Specifically, bird migration is strongly influenced by the availability of nesting sites and food. In temperate zones, the hours of increased light during the summer allows birds to forage for longer periods. Additionally, because of the lower biodiversity, competition for resources and nesting sites is not as intense. These are appealing conditions to use temperate zones as breeding sites. Yet, as the season ends, food availability and the hours of light decrease, and birds have to find suitable grounds for the rest of the year. The tropics, despite the food abundance throughout the year, are not attractive to some species as breeding grounds because of the intense competition for resources and nesting sites due to the great biodiversity. However, most of these species become temporary residents of the tropics until is time to breed again.

Out of all the bird species in the world 40%, or around 4 000, are regular migrants. However, they are unevenly distributed around the world. In countries in the far north like Canada and Scandinavia, birds migrate southwards during the boreal winter to flee the harsh winter and will only go back until the following spring.

Chivi Vireo  (Vireo chivi) is one of the most widespread and common passerines of South America. This species consists of a complex mosaic of resident and migratory populations. During the austral and boreal winter, there is a seasonal overlap between the resident population and wintering population from the temperate zones.  PC: Alex Wiebe

Migration can take several weeks. Because of this, birds enter a state called hyperphagia before their journey. During this state, they will ingest as much food as possible to build up the fat reserves that will provide them with the energy needed for their journey. Once the migration has started, birds use a combination of senses and cues that are not fully understood, to reach their destination. They can orientate themselves by sensing the Earth´s magnetic field, and by the position of the sun, stars, and landmarks seen during the day. Species do not migrate all at once or in the same way. This is why you can see migrating flocks or individuals at different times of the day and for several months. Each species starts its migration at a specific time and some vary their migration year to year depending on food availability. The beginning of migration is also influenced by changes in the length of daylight. First-time migrators often make the journey on their own, despite the fact that they have never been to their winter home before. Impressively they are able to find them.

To avoid exhaustion and starvation during the thousands of kilometers flight, birds stop to recharge their energy along the way. However, by doing so, they are vulnerable to fall victim to predators. While enduring their journey, migratory birds face further threats like wildfires and storms, which appear to be intensifying due to our changing climate; shortages of resting areas, due to human encroachment; disorientation by city lights; and obstacles such as tall buildings. In 1971, The Ramsar Convention on wetland was agreed as a measure to protect migratory birds. However, each year the population of migratory birds decreases due to habitat loss and degradation in the tropics. By protecting the tropical forests, we are ensuring the well-being of migratory birds and ensure that future generations have the opportunity to this spectacle.

For further reading:

  • Salewski, V. & Bruderer, B. (2007) The evolution of bird migration-a synthesis. Naturwissenschaften 94:268-279.
  • Robbins, C., Sauer, J., Greenberg, R. and Droege, S. (1989) Population declines in North American birds that migrate to the neotropics. Population Biology Vol. 86, pp. 7658-7662.


A bird rarer than a Jaguar: An encounter with a Tiny Hawk

September 17, 2018 | Author: Tom Matias

Bluish-fronted jacamar (Galbula cyanescens) located in bamboo at LABO. PC: Tom Matia

At the time of my encounter, I did not realize the rarity of the event. I was walking across an old channel of the Los Amigos River that is in its early successional stages. There are no tall trees, instead, there are many shrubs covered in vines. Bordering this channel are the towering trees of the floodplain forest, making this edge habitat an ideal location for a Tiny hawk (Accipiter superciliosus) (Global Raptor). I had just walked past a resting bluish-fronted jacamar (Galbula cyanescens) when my eye caught a glimpse of a bird careening through the vegetation. I followed the shadow through the vegetation and, in the clearing that the trail made behind me, watched a small flying raptor raise its feet forward and pin the bluish-fronted jacamar to its perch.

A photo taken through binoculars of the Tiny Hawk after pinning the jacamar to its perch. PC: Tom Matia

The small raptor (22-28cm/8-11in) is known to be a specialist at predating on avifauna and had the jacamar in its grip (Global Raptor). It seemed the attack would prove fatal as there was hardly a fight from the jacamar. The hawk soon took notice of my presence and, not wanting to disrupt its natural behavior and its success, I walked away from the scene. A few hours passed by the time I returned to investigate the scene; there was not a feather or scrap to be found. This could mean two things, the jacamar made it out the talons of the tiny hawk, however, due to the elongated nature of their talons, I choose to believe that the later, the jacamar left the scene in the grasp of the hawk.

When I returned to eat dinner, I learned that little is known about this species of raptor and that the sighting was very rare! Looking further into this species, I discovered that there is hardly any information on their populations. With the help of citizen science, specifically from eBird by Cornell University, I found that only 130 observations have been recorded in Peru over the past ten years. With such little documentation on this uncommon bird, it is alarming that they are estimated to lose 19-24% of suitable habitat in the next twenty-two years (BirdLife).

The Tiny hawk has an assumed population of 670-6,700 individuals and is currently listed as ‘least concern’ by the IUCN, and BirdLife, due to its expansive range (BirdLife). Hearing these statistics shocked me and I immediately searched population sizes of species that are rare to see. The jaguar (Panthera onca), an animal that is incredibly elusive, yet possibly more likely to be encountered, has roughly 15,000 individuals according to the WWF (Quigley). And so I thought, “a tiny hawk is not something you see every day”.


Global Raptor Information Network. 2018. Species account: Tiny Hawk Accipiter superciliosus. Downloaded from http://www.globalraptors.org on 15 Sep. 2018
BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/09/2018.
Quigley, H., Foster, R., Petracca, L., Payan, E., Salom, R. & Harmsen, B. 2017. Panthera onca(errata version published in 2018). The IUCN Red List of Threatened Species 2017. Downloaded on 15 September 2018.

Following the ants

August 16, 2018 | Author: Arianna Basto

If you find yourself in the rainforest, it is almost impossible to miss the endless organized columns that army ants form. This group of ants are carnivorous and forage in swarms, raiding everything in their way. If you are not fast enough, you will fall prey to these voracious predators no matter how big you are. If you do outrun them, there are different predators waiting to trap you. Even if you are not an expert birder you probably have heard of Antbirds. This insectivorous group of birds belongs to the family Formicariidae and forage by following army ants. Eciton burchelli and less often Labidus praedator are the species of army ants that Antbirds follow. As simple as this may seem, the relationship is more complex than it sounds, as not all Antbirds are obliged to follow ants.

Hairy-crested Antbird (Rhegmatorhina melanosticta) perched above an army ant swarm | Photo by Will Sweet

This foraging behavior has no counterpart outside the tropics but within them, you can find ant-followers in different altitudes and elevations. Different species attend the raids with different frequencies. The species that regularly attend them and that in some cases depend entirely on the raiding to find their food are known as obligate, or true, Antbirds. A different name is given to the birds that follow the swarms but are also capable of foraging independently of them, they are referred to as regular followers. Lastly are the opportunistic followers, the species that are only seen foraging when the swarm crosses their territory, for which up to 70 species have been identified. In this grouping, there are some non-insectivorous species that opportunistically take advantage of the raid.

Obligate Antbirds, exclusively found in the Amazon region, are limited to the family Thamnophilidae, also known as typical Antbirds. 16 species have been recorded that completely depend on army ant swarms. They depend on army ant raiding swarms to such a degree that in patches of isolated forest where army ants disappear, the Antbirds are gone within a short period of time.  The hairy-crested Antbird (Rhegmatorhina melanosticta), a not easily seen Los Amigos resident, is an example of an obligate Antbird that depends solely on army ants year-round and can be seen in Terra Firme perching low to the ground feasting at the army ants expense.

Following the raids can provide more food than one individual can eat. But for obligate Antbirds, having developed such specialized foraging behavior has its shortcoming. The frequency, abundance, and distance away from their meals depend on the life cycle of army ants. Their life cycle alternates between periods of mobility and stillness, which makes their presence and location in a forest patch unpredictable. Due to army ants’ mobility, their nests are not as you may imagine. They don’t build a nest to live in; rather they sleep in bivouacs. Bivouacs are living ball-shaped nest made out of the workers that protect the queen and her brood.  They alternate between periods of low food ingestion needs and periods of activity every three-weeks, raiding to meet the food requirements of newly born larvae Because of the periods of ants’ stillness, obligate Antbirds have to wander off outside their home range looking for swarms to follow, as a result, they haven’t developed a strict territorial behaviour. In this case, evolution has favored birders; within a swarm raid you can observe several individuals of the same and different species. Make notice that individuals will defend their place along the raid, the closer to the front and the center they get the better the prey they could trap.

If you’re interested in birds, the next time you come to the tropics you might want to go for an early hike and look for the columns of army ants. If you wait patiently, you will be amazed by one of the greatest performances in the rainforest and see several species of highly adapted birds along the way.


A flagship year for avian research at Los Amigos

July 23, 2018 | Author: Tommy Matia

In 2018, four exceptional students and/or professionals were chosen as our Franzen Fellows.  Jointly, their passion for birds has led them to pursue work in the Amazon rainforest in order to protect this great frontier.  Currently, the Los Amigos Bird Observatory (LABO) is hosting two of its fellows, Alex Wiebe and Will Sweet.  In this post we will become acquainted with the work that these two are doing and their achievements along the way.

Will Sweet arrived to LABO on May 17th, 2018, and got right to work.  He is examining how different stages of succession around oxbow lakes impact the avifauna communities in the Los Amigos Conservation Concession. To avoid waiting for succession to unfold in real-time, Sweet has set up an observation pattern around three oxbow lakes that are already in different successional phases, from relatively new to almost totally grown over. He conducts point counts along these lakes to assess which birds inhabit which successional level.  In his pursuit, Will strives to understand the contribution of oxbow lakes to the Amazon basins’ high bird diversity, furthering our knowledge of changing landscapes’ effect on avian diversity. Will aims to attend a graduate program next fall while continuing to pursue his passion for birds.

Will Sweet conducting his morning point counts at Cocho Raya | Photo by Zander Nassikas

Finishing his last year of undergraduate studies at Cornell University, Alex Wiebe is spending his summer collecting data on one of the least understood family of birds: tinamous. They are secretive and skittish, which makes them difficult study subjects. Wiebe’s interest in patterns of avian geographic distribution in the Amazon, as well as the factors that affect their distributions, has led him to Los Amigos.  Tinamous are a natural choice for Wiebe’s work. They reach their highest density in the area around Los Amigos with 11 out of the 47 species represented, and since little is known about them, his work stands to have impact. Wiebe will be using his background in statistics to create a spatial distribution model of the tinamous of LABO and across South America. In order to collect his data, Wiebe conducts point counts in a variety of terrestrial habitats, while also recording the locations of rare species as they are heard.  With his results he will build a better understanding of this enigmatic family of birds.

Alex and Will have had an incredible summer thus far and have reached numerous achievements along the way.  Recently, Alex broke the world record for an on-foot Big Day with 347 species. A Big Day is a competitive birding ‘race,’ in which the contestant attempts to see or hear as many different bird species as they can in one 24-hour period. And Will was able to identify a species that is new to LABO: the rusty-margined flycatcher. The work that is being completed by these two fellows will undoubtedly help conserve the Amazon rainforest and the avian species that call it home. 


The vultures of Los Amigos

July 13, 2018 | Author: Arianna Basto

Normally when you go out looking for birds, you look for the most colorful ones, or listen for those with the most beautiful songs. We often forget that cryptic birds have a beauty of their own. Vultures are not terribly eye-catching but they serve an important role in the ecosystem as the clean-up crew.

Vultures are scavengers, which means they eat dead meat. They are more efficient at finding carrion compared to other scavengers. You can see them soaring all around in their search for food. Their soaring behavior takes advantage of thermals, air currents warmed by the sun that allows them to reach great altitudes without beating their wings. Once they have found their meal, their extremely acidic stomach destroys any bacteria or viruses established in the carrion. This prevents diseases from proliferating and spreading to other animals and humans. Don’t think that because they are the ecosystem cleaners they are dirty birds; on the contrary, their featherless heads are an adaptation to stay clean while eating.

Turkey Vulture (Cathartes aura) soaring around in search of food. | Photo by Alex Wiebe

Although the many species of vultures all over the world serve the same role and have similar appearances, they are divided into two unrelated guilds: The Old World Vultures (Accipitridae) and The New World Vultures (Cathartidae). Los Amigos is home to four of the seven species in the Cathartidae family. The Black Vulture (Coragyps atratus), Turkey Vulture (Cathartes aura) and King Vulture (Sarcoramphus papa) are widely distributed in tropical forests, open savannahs, and grassland, while the Greater Yellow-headed Vulture (Cathartes melambrotus) is restricted to tropical forests. These four species are often seen interacting during lunchtime.

Due to their highly developed olfactory sense, finding carrion is easy for the Turkey and Greater Yellow-headed vultures. They can find their meal as early as an hour after it has been disposed. You may think that this gives them an enormous advantage over our other vulture residents, but the King and Black Vulture have found a way of benefiting from their neighbors’ awesome sense of smell. Since they themselves cannot track carcasses through their smell, they rely on reaching altitudes of 100 feet or more to be able to follow the Turkey and the Greater Yellow-headed vultures to the food source. This behavior is especially apparent in undisturbed forests where the latter is solely responsible for locating carrion and serving as a guide for the other species. This could be due to an even more developed sense of smell than the Turkey vulture or because its wing structure allows them to maneuver better over the tree canopy.

The Black Vulture (Coragyps atratus) waiting for its neighbors to find the meal. | Photo by Alex Wiebe

But what happens when all these species come together for lunchtime? Although a dominance hierarchy between species does exist, most of the time there is not a direct aggression between them. The interaction could result in different species feeding at the same time from the same resource or in individuals leaving when a more dominant species is approaching. More intense aggression has been identified between individuals of the same species. Furthermore, the differences between species in size and bill length and the postures they adopt while eating could be a factor allowing the presence of more than one species at a time. These differences enable them to forage from different tissues of the carcass simultaneously, which may reduce direct competition.

Close to Los Amigos, the main threats that vultures seem to face are the misperception of people. People believe they attack their cattle ranch or that they are dirty birds. But as described here, they feed on dead meat and they even prevent diseases from spreading. Despite their unattractive appearances, vultures are interesting and important birds in our ecosystem. Here at Los Amigos we are excited to have this array of species taking care of the health of our forest.

If you see the King Vulture (Sarcoramphus papa) and Greater Yellow-headed Vulture (Cathartes melambrotus) from far, you can tell them apart based on the color of their breast plumage. | Photos by Alex Wiebe

For more references:

  • Gomez, L.G., Houston, D. C., Cotton, P. and Tye, A. 2008. The role of Greater Yellow-headed Vultures Cathartes melambrotus as scavengers in neotropical forest. IBIS Journal 136: 193-196
  • Houston, D.C. 1987. Competition for food between Neotropical vultures in forest. IBIS Journal 130: 402-417


Unveiling the presence of the rare Grey-bellied hawk at Los Amigos

Grey-bellied hawk at Los Amigos_ Fernando Angulo

June 25, 2018 | Author: Carla Mere

The Grey-bellied hawk (Accipiter poliogaster) is a rare diurnal raptor of the Accipitridae family and is distributed throughout the Neotropics. BirdLife has it listed as a “near threatened” bird and, despite their wide distribution, it is one of the least known of the raptors. In Peru, it occurs in the eastern side of the country, mostly in lowland tropical forests, and has been also reported along forest edges, and fragmented forest. Since 2015, birders at Los Amigos have been able to observe and admire the beauty of this raptor. This represents a unique opportunity to learn and increase the scarce knowledge about this species. In this note, we recapped A. poliogaster sightings at Los Amigos (LA).

In June of 2015, a Peruvian researcher specializing on raptors (R. Piana), found a juvenile A. poliogaster hunting at the forest edge near the Los Amigos River, at LA. The following year, September of 2016, Fernando Angulo (LABO Advisory member) and R. Piana located a reproductive pair defending their territory located ~1 km away from the station. Both individuals were sighted in the same location on consecutive days after the first encounter. On April of last year, a Peruvian bird guide, identified a juvenile of this species around LA garden, close to the territory identified the previous year. Lastly, on mid-April of the present year (2018), two juvenile individuals were located on a nest situated on an emergent tree and in the same territory of the reproductive pair previously identified. These events prove that A. poliogaster is breeding and nesting within the Los Amigos Biological Station, making this place a unique study site for this species.

Juvenile Grey-bellied hawk on the nest _ Cesar Bollatty

The first recorded observation of the reproductive behavior and biology of A. poliogaster were described in Southern Brazil few years ago, where an adult female was observed incubating two eggs and an adult male was actively hunting. Only one nestling survived, and after ~49 days post-hatching the nestling left the nest. The fledging was fed by the female for ~90 days post-hatching. Given the importance of raptors in Neotropical forest, and LABO’s goal to increase the knowledge and conservation efforts of Neotropical avifauna, one of our Franzen fellows, Igor Lazo, will be assessing the ecology and natural history of A. poliogaster at LA, being the first study of this species in Peru. The information coming out from this project will create a firm foundation for further research on the Grey-bellied hawk!

For more references:

Boesing, A.L., Menq, W., Dos Anjos, L. 2012. First description of the reproductive biology of the Grey-bellied hawk (Accipiter poliogaster). The Wilson Journal of Ornithology, 124(4): 767-774.



Growing up in the rainforest: A Razor-billed curassow chick growth captured by a camera trap for over a month!

June 19, 2018 | Author: Carla Mere

The razor-billed curassow (Mitu tuberosum) is one of the largest species of cracids (Galliformes:Aves) and a relatively uncommon bird in western Amazonian rainforest because of their low reproductive rates and highly vulnerable status due human disturbances such as hunting and habitat loss. These permanent threats have already driven one of the 24 species of Cracids, the Alagoas curassow (Mitu mitu), considered for many years a geographic variation of Mitu tuberosum, to extinction in the wild. Cracids’ presence is considered an indicator of healthy forests where hunting is absent or low, allowing them to play important ecological roles as seed dispersers and seed predators.

Los Amigos harbors 4 species of cracids, such as the Speckled chachalaca (Ortalis guttata), the Spix’s guan (Penelope jacquacu), Blue-throated piping guan (Pipile cumanensis), and the Razor-billed curassow (Mitu tuberosum), all of which have diurnal and terrestrial behavior. Camera traps have become an important tool to monitor and obtain ecological information about terrestrial birds. At the beginning of this year, LABO’s cameras registered the presence of a Razor-billed curassow chick, and what we believe to be its growth during a time lapse of over 40 days.

On January 4, one of our camera traps deployed in the interior of a bamboo patch captured the presence of two razor-billed curassows. The images indicate the occurrence of, perhaps, an adult male and female, based on the physical traits, specifically the size of their bills since males have a larger bill formation compared to females. Two weeks after, one individual was registered with a chick, walking right under the long terminal tail of the adult. The chick presented dark feathers, mostly black and brown coloration with some lighter patterns throughout the body and head, and a white belly. The characteristic laterally compressed and bright red bill of this species was not yet developed. After 42 days, the camera captured an adult individual with a visibly grown nestling walking again under the adult’s tail. Could it had been the same chick captured more than a month before? Perhaps yes! This time the immature offspring had body plumage coloration similar to an adult, mostly black, except the head; and the red bill was also noticeable, but not fully developed. In the video, the adult individual was feeding its offspring, confirming the probability of being the mother.

The razor-billed curassow, locally known as “paujil,” is a commonly hunted cracid in Amazonia. Despite the IUCN Red List considering it as “least concern”, there are not many studies or available literature that describes its biology and/or ecology. More studies on their population size, reproductive behavior, breeding and nesting information, are required to determine their current status. Cracids, in general, lay on average two eggs every year; hatchlings are exposed to high mortality rates during their first year, and reach maturity after the third year! This is a fairly long maturation period, but the wait is worth it just to admire a beautiful large terrestrial bird like the razor-billed curassow!

What are your guesses? Could this camera be showing us the growth of the same curassow chick?


Global Big Day 2018: Peru won second place, but we set some records ourselves!

Birds are stunning animals, and are able to bring groups of people together to share the same passion: birdwatching! On May 5th, I experienced perhaps one of the most exciting and inspiring events of my life. From the organization, advertising and planning of more than 500 teams and more than a thousand of people throughout Peru, to the enthusiasm and big expectations of our team at Los Amigos. This Global Big Day (GBD) triggered a competitive, healthy contest among countries, regions, cities and remote locations throughout the world with the incredible objective of increasing the knowledge and valuing birds of all species and the importance of their and their habitats conservation. Peru gained second place globally with 1490 species registered in 24 hours, while Colombia won first place with 1542 species. A difference of only 52 birds!


On May 5, Los Amigos strategy…

Los Amigos has a diverse array of habitats, making this forest a unique place for birdwatching and for any passionate naturalist who is looking for those rare or endemic birds. Due to this mosaic landscape, our team, which was led by three expert birders (read our last note), aimed to cover the largest variety of habitats throughout the Big Day. We started before dawn, splitting our team in two: one group walking through terra firme forest, bamboo patch, and the airstrip, and the other going through floodplain, secondary forest, and Cocha Lobo oxbow lake. Before the sunrise, a thick morning mist covered the enchanted Amazonian forest allowing us to hear the calls of the Barred-forest falcon, Amazonian motmot, while we were also able to appreciate the gorgeous display of a Blue-crowned manakin male, among others. Close to noon, the heat and sunlight was intense (as usual), and was followed by the silence of Amazonian birds. After a quick lunch, we got back to the trails and this time our two teams switched trails covering the same habitats done in the morning plus river edge forest along the Madre de Dios River. The day before the GBD was very rainy, causing the beaches along the river to disappear the following day. Despite that, we were still able to register shorebirds such as the Great egret, the Ringed Kingfisher, and others.

Within less than 452 ha (Los Amigos Biological Station total area), and after more than 13 hours and 20 km walked, we ended our Big Day with a total of 299 bird species, including some noteworthy birds such as the Black-faced cotinga, Pale-winged trumpeters, Long-crested pygmy tyrant, Blue-headed macaws (to check the complete list, check our eBird hotspot in the following link: https://ebird.org/hotspot/L492606?m=5&yr=cur&changeDate=Set). Proud of our record, we are happy to announce that Los Amigos and its team members (Fernando Angulo and Alex Wiebe) are included among the first 10 Top eBirders in Peru with more than 250 species registered, demonstrating that this place is a real birding paradise. However, more than the numbers and the winners, this past GBD 2018 will be remembered by the passion, cohesion, increasing interest and participation of thousands of Peruvians, including bird guides, biologists, but also citizens not related with this field that got together to support a magnanimous environmental cause. As Fernando Angulo, LABO Advisory Member and team member of Los Amigos GBD, said: “Peruvian birders: we have won ourselves and the objective for this GBD has been surpassed. Peru had registered 160 more species than 2017.”

And we know that we can do more! Keep it up, birders around the world!



The Biggest “Big Day” for Los Amigos Bird Observatory

The Global Big Day (GBD) is getting closer, and besides being the birding’s biggest day worldwide, where thousands of birders get together to celebrate birds for 24 hours straight, it is also a means to improve human’s commitment to conserving these species. For us, it represents a unique opportunity to admire and spread awareness of the importance of maintaining the astounding bird diversity found at Los Amigos. Birding is one of the most exciting experiences for anyone who has a passion for birds, but is particularly challenging throughout the densely foliated and dark forest typical of lowland Amazonia, where bird vocalization is key to identify species. We here at Los Amigos are incredibly excited about our upcoming GBD, and did not want to miss this opportunity to share some of our previous experience of Los Amigos Big Days!

On May 9 of 2015, Peru beat the world record and conquered the precious first place of birds with 1188 species registered, followed by Brazil, and Colombia. This not only reaffirmed Peru’s unique avian diversity but also revealed Peru’s potential for birdwatching as an important ecotourism activity. On that day, Peru as a country was not the only area making history on avian records; Los Amigos itself was positioned in nothing less than the fifth place at the global level, with 308 bird species! In July of that same year, Sean Williams, an avian researcher, did his own Big Day after a friaje, a massive cold front that comes from the Antartic winds and hits the Amazon. After several field seasons spent at Los Amigos, Sean was able not only to become highly familiar with the avifauna by recognizing the songs, and even locations and nests of rare birds. July 23rd became one Sean’s biggest big days, and after an exhaustive 19 hours and 11 miles of complete immersion into the calls and colorful flying displays across forest strata, Sean registered 345 species! Sean’s Big Day is imprinted in his memory, highlighting his eternal passion for the Amazon and its birds.

Undoubtedly, Los Amigos avifauna is vast, and besides just walking miles and miles during a Big Day, it is important to create a strategic plan to experience it. Last summer, Alex Wiebe, a young ornithologist but incredibly knowledgeable about Neotropical avifauna, came last year to Los Amigos, and did his big day registering 250 bird species throughout the day, covering all the different types of habitats. In doing so, endemics and charismatic birds such as the Rufous-fronted anthrush, Ihering’s antwren, Long-crested pygmy tyrant, Black-faced cotinga, Peruvian recurvebill, Manu parrotlet, Pavonine quetzal, Blue-headed macaws, Rufous-vented ground cuckoo, Spangled and Plum-throated cotinga can be just a few of the names marked on your checklist.

This year, Los Amigos Bird Observatory is ready for the GBD with a team led by birding experts that will be searching for the nearly 600 bird species throughout the mosaic landscape of Los Amigos! The team is comprised of: Fernando Angulo, avian researcher of CORBIDI and LABO Advisory member; Alex Wiebe, Franzen Fellow, and student of Cornell University; and Rolin Flores, an indigenous bird guide from the community of Diamante around Manu National Park with vast birding experience in the Manu region. All the memorable Big Days records at Los Amigos have taken our breath away and demonstrated that the efforts of preserving this mesmerizing forest and its surroundings are visible in the wildlife and avifauna thriving in Los Amigos, our home.



Birds of Prey: Neotropical monkeys’ most fearsome predators

April 5, 2018 | Author: Carla Mere |

Jaguars are without a doubt the top predators in Amazonia, but organisms flying above the canopy certainly have a big advantage and unique predation skills that make them respectable predators when compared to wild cats. Raptors are considered the major predators of new world primates, such as crested eagles (Morphnus guianensis) predation on infant tamarins (Leontocebus mystax & L. fuscicollis) and also squirrel monkeys (Saimiri sciureus); black-hawk eagles are also known to attack howler monkeys; and the largest and powerful harpy eagle (Harpia harpyja) predation on saki, capuchin and night monkeys. Current ecological knowledge of Neotropical raptors is scarce, thus filling in the gaps of information on this particular group of birds will allow us to understand their ecology and general biology, whether it is through anecdotal incidents or observations in the field.

Photo by Marc Fasol

The black-and-white hawk eagle (Spizaetus melanoleucus) is one of the 55 birds of prey found at Los Amigos. Compared to other well-known raptors such as the mighty harpy eagle or the crested eagle, the black-and-white hawk eagle is a small size bird (body mass: 780-1191 g; wingspan: 110-135 cm), feeding mainly on terrestrial and arboreal birds such as tinamous and guans, and some documents report small mammals and reptiles in their diet. However, successful predation on primates by this species was not described until 2014, when a group of researchers witnessed and described the mortal attack of the Rylands’ bald-faced saki monkey (Pithecia rylandsi) at Los Amigos.


Ryland’s bald-face saki carcass on the forest floor, and attacked by the black-and-white hawk eagle. Photo: Adams & Williams, 2017

This fatal event was recorded on 23 July, 2014, during a long-term project assessing the anti-predation behavior and alarm calling of P. rylandsi at Los Amigos. While conducting the usual primate behavior monitoring, one of the research assistants heard a large bird flapping, followed by alarming calls of a group of sakis, which are whistle-like calls emitted when they detect an eagle’s presence. Upon the researcher’s return after a couple of hours, he heard wing’s flapping in the same location. After following the motion event, the researcher found out the black-and-white hawk eagle feeding on an adult saki’s carcass on the ground. The black-and-white hawk quickly flew away after detecting the researcher approaching. Most of the saki’s flesh, muscles and skin were removed, with fur scattered beside and along a 16.4 m path away from the carcass. Several puncture holes were noted on the body and skull, while the stomach lay untouched next to the body despite most of the soft tissue having been removed. Although the observers didn’t visually witness the attack, the described observations together with the physical injuries documented on the saki most likely indicate that it was the black-and-white hawk-eagle as its predator.


Black-and-white hawk eagles utilize the “soar and stoop” hunting tactic, compared to the “perch and wait” strategy used by large raptors, consisting of searching for preys above the canopy and forest edges and, upon prey detection, diving rapidly into the forest to attack them. This report suggested that smaller and lesser-known raptors, like the black-and-white hawk eagle, should also be considered important predators of Neotropical primates, principally those that occupy the mid to upper canopy given their hunting strategy. Identifying and providing evidence of predation events like this is key to learn more about less prominent raptors, so keep your eyes and ears open while walking in the forest!


For more references:

Adams, D., Williams, S. 2017. Fatal attack on a Ryland’s bald-faced saki monkey (Pithecia rylandsi) by a black-and-white hawk eagle (Spizaetus melanoleucus). Primates 58: 361-365.

Robinson, S. 1994. Habitat selection and foraging ecology of raptors in Amazonian Peru. Biotropica 26(4): 443-458.



There is no song copyright in the birdcall industry

March 23, 2018 | Author: Carla Mere

Even if it is your first time in the Amazon forest or you are lucky enough to live and enjoy a green heaven like it, you will be enchanted by its colors, the moist aroma of rain falling on the low nutrient Amazonian soil, as well as a chorus of melodies displaying harmonic rhythm, from low to high pitch sounds, music that represents breath, words, and life. These last three representations could not better describe the importance of animal vocalization in a tropical rainforest. Among birds, specifically, this is a critical way they communicate among one another in competition for mates and territories.

Hypocnemis peruviana (male) by Joe Tobias

Inability to differentiate vocal signals within and between species could lead to unnecessary territorial aggression, negative impacts on a species reproductive success (i.e. unfit hybrids), and overall fitness. Therefore it is expected that birdsongs are specific for every species, particularly in dense forests like Amazonia, where vocal signals are more valuable and efficient than visual cues. So, is it possible for two sympatric bird species (not closely related) to sing the same songs?

The answer is YES! Research conducted by LABO Advisory group members at Los Amigos in 2008, Professor J. Tobias and N. Seddon, found that two Neotropical antbirds species have almost identical songs, making this the first evidence demonstrating that convergent evolution (i.e. organisms of different lineages evolving similar traits) can occur through social interactions between species.

The studied species were two sympatric Hypocnemis antbirds: H. peruviana and H. subflava, which are highly abundant organisms inhabiting the understory of Los Amigos forest. Hypocnemis antbirds are small monogamous passerine birds, and molecular tests have showed that H. peruviana and H. subflava are non-sister species and were split from a common ancestor ~3.4 million years ago. Even though they have been part of different lineages a long time ago, both species share similar foraging behavior, diet, six standard body morphological measurements. However these species do differ in  their plumage color (Figure 1 and 2). Moreover, songs in suboscine passerine birds, such as Hypocnemis, are not learned and instead are genetically determined, however this had been challenged by other studies that suggest that vocal learning does lead to song differences in suboscines. Hypocnemis vocalizations play important roles in intrasexual competition, mate attraction and territory defense. From all the characteristics mentioned above, it is assumed that highly territorial organisms must rely on vocal signals specificity to discriminate between species and individuals.

Hypocnemis subflava (male) by Joe Tobias

Dr. Tobias and Dr. Seddon analyzed 343 songs of 96 sympatric individuals (H. subflava and H. peruviana) through acoustic and playback experiments at Los Amigos, and demonstrated that territorial songs in males are more similar than non-territorial signals between both species, not allowing males to discriminate the territorial signals of individuals of the same and different species. The same pattern was found in females. How could this phenomenon be explained? First, even though H. subflava and H. peruviana are partially segregated by habitat, both species interact regularly at territory boundaries, increasing the likelihood of rivalry for space and food. This latter explanation is supported by the fact that both antbirds are not migratory birds and neither move outside their territory. LABO Advisory members suggested that song convergence must be a consequence of selection forces caused by competition between species, which is supported by several studies showing that song matching (i.e. answering with a similar song) is an aggressive display in territory disputes, within and between species!

For more reference:

1. Tobias, J.A. & Seddon, N. (2009). Signal design and perception in Hypocnemis antbirds: Evidence for convergent evolution via social selection. Evolution 63, 3168-3189.

Want to share this blog post with your friends and family? Give them this link.


Seeing red is not always a bad thing: a look inside a hummingbird’s flower!

March 1, 2018 | Author: Carla Mere

The tiniest birds on Earth are one of the most astonishing living beings with an incredibly fast metabolic rate: hummingbirds! They are specialized nectar feeding organisms inhabiting only the Americas, and where the hummingbird-pollinated flowers provide them with the tasty and sweet solution to fulfill their high energetic demands. These plants use hummingbirds as a reliable, and long-range pollinator, and are generally characterized as odorless, with long-tubular corolla, conspicuous coloration, while also producing high sucrose-content nectar. Some of the most common plants families are the colorful Heliconiaceae, Rubiaceae, Fabaceae, Bromeliaceae. But even though hummingbirds pollinate and feed on several plant species, there is one large commonality that exists among most of them: their visible orange-red corolla. But is it actually the flower’s color that attracts them?

Festive Coquette perching on a Verbena plant

White-necked Jacobin feeding on a Heliconia rostrata

Sparkling violetear  feeding on an orange-tubular corolla

In general, color is a very critical cue for animals, and is mostly associated with the gaining of rewards. Among birds, the distinctive and the flamboyant hummingbird is a good example because vision is one of their most acute senses that they rely on to find their food and also mates. Hummingbird’s great vision -even better than humans- allows them to see colors near ultraviolet light, which is the reason why conspicuous flowers are highly visible to them.

Contrary to what might be expected, it is not only the bright red coloration that influences hummingbirds’ choice but instead a combination of traits. Conspicuous flowers are the first requisite to advertise the nectar to hummingbirds, where the conspicuousness will depend on the background where the flower is exhibited. For instance, heliconias resemble a wild bouquet with red flowers bursting at the top, surrounded by large and wide green stalks. Perfect for capturing hummingbird’s attention!

Handmade hummingbird feeder at Los Amigos | Photo by Emily Middendorf

But what truly matters is what is inside that flower: the nectar. Research conducted in the laboratory suggested that higher sucrose concentration is more important than color or even other sugars (e.g. fructose, glucose) in determining hummingbird’s food choice. It is known that in tropical and temperate areas hummingbird-pollinated flowers have nectars with high concentration of sucrose. Thus, rather than discriminating due to color alone, hummingbirds