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Ferruginous-backed Antbird (Photo: Nick Athanas) |
Guianan Warbling Antbird (Photo: David Fernandes) |
Typical Antbirds (Thamnophilidae) and Ground Antbirds (Formicariidae) of Guyana
Found only in the Neotropics, the entire Antbird family contains almost 300 species. Serious birders love to find Antbirds - amongst the more challenging families in South America - but they can be tough to see well as some spend their entire lives in the forest canopy while others spend their time creeping around on the forest floor. Identifying them by voice is often key, but with 59 different species of Antbird, Antwren, Antpitta, Antthrush, and Antshrike, Guyana is a great place to actually see these difficult-to-find birds.
Identification
Antbirds are generally relatively small birds that dwell mainly in the forest. They range in size from the largest (Giant Antshrike) at roughly 18 in (45 cm) and 5.3 oz (150 g) to the smallest (Pygmy Antwren) at 3 in (8 cm) and 0.25 oz (7 g).
With plumage that is typically rather dull colored – generally a combination of black, white, rufous, chestnut, and brown shades – Antbirds can be difficult to spot in dark forests. In most species, the males and females have different plumage colors and patterns, with males usually showing patterns of gray, black, or white, and females having buff, rufous, and brown colors. Some Antbirds, however, have splashes of brilliant color, such as the striking blue face of the Ferruginous-backed Antbird.
Wings are generally short and rounded, and most Antbirds have large, strong legs. While some species of Antbirds, such as the Antshrikes, have large, heavy bills with a notch at the curved tip that is used for holding and crushing insects, others, such as the Antwrens, have fine beaks for gleaning smaller insects.
Many birders rely on voice to initially identify the presence of Antbirds. While their calls are usually a repetition of simple notes, both these and their songs can be quite distinctive and species-specific. When familiar with them, they can be a key part of identifying Antbirds.
Behavior
Antbirds are diurnal and spend much of the day feeding on mostly arthropods – mainly grasshoppers, crickets, cockroaches, praying mantises, stick insects, and butterfly and moth larvae – but also spiders, scorpions, and centipedes. Antbirds occupy a range of niches within the forest and while some spend almost their entire lives on the forest floor, others have adapted to live in the canopy or specialize on specific features such as dead leaf clusters. When hunting, most Antbirds are arboreal; most focus on the forest understory, but some species feed as high up as the canopy.
Some species also forage in the leaf litter on the forest floor, but the family’s name comes from the behavior of some birds that follow army ant swarms that move through the forest. While it was originally believed that some Antbirds followed army ants only to eat the actual ants, it was later discovered it is mostly an opportunistic behavior as they are feeding on the arthropods and small vertebrates that are running away from the ants (some Antbirds eat the army ants as well).
Some species of Antbirds also feed in mixed species flocks. It is believed that this provides various advantages: some birds are better at spotting predators and their warning calls alert the flock to a predator’s presence; and different species generally use varying feeding techniques to feed off insects flushed out by others in the flock.
While the behavior of many species has not been studied in detail, it is thought that some species of Antbirds are monogamous and mate for life. In some species that have been observed, courtship can entail feeding rituals – with the males feeding the females – and mutual grooming. Males and females both participate in building nests, which are either suspended or supported, and the majority of Antbirds lay two eggs. Both parents are usually involved in the 14-20 day period of incubation.
Habitat
Antbirds are found only in the Neotropics, with the highest concentrations of the species being in the forests. Most Antbirds are found in humid tropical lowland forests, with only a relatively few species being found in highlands above 10,000 ft (3000 m). As Antbirds are not targeted by the pet trade, nor are they large enough to catch the eye of hunters, their biggest threat comes from habitat loss, and as a result a number of species are considered highly endangered.
Within Guyana
Antbirds can be found throughout Guyana, and listed here are some areas where birders have had particularly good luck at great views of some key species on their list.
On the forest trails at Iwokrama Field Station, visitors are often treated to one of the most dramatic birdwatching experiences found in lowland tropical rainforests: watching the “specialized” army ant followers, such as White-plumed and Rufous-throated Antbirds, as they deploy their unique hunting strategy of following marauding army ants and picking off insects trying to escape the crawling swarm.
And for those who venture out onto the Iwokrama Canopy Walkway there is an excellent opportunity to get great looks at several species of Antbird that rarely leave the forest canopy, including Spot-tailed and Todd’s Antwrens. Nearer the forest floor, but within walking distance of the Walkway, there are several locations where it is possible to find the two range-restricted species: the Black-throated Antshrike and Guianan Streaked Antwren.
South of Iwokrama, the tropical moist lowland forest at Surama is an excellent place to find many species of Antbirds, including the White-bellied Antbird and the amazing Ferruginous-backed Antbird, which has an extraordinary blue face. A little further south at Karanambu Ranch, it is possible to see both Dusky and White-chinned Antbirds, as well as Black-crested Antshrike and White-fringed Antwren.
In southern Guyana, along the Ireng River near the town of Lethem, is one of the best places to find the highly range-restricted Rio Branco Antbird, a Guiana Shield endemic. On the Essequibo River, Shanklands Resort has recorded 20 species of Antbirds, including the highly desired Guianan Streaked-Antwren and Black-throated Antshrike.
Other highly desirable specialties found in Guyana include: Brown-bellied and Ash-winged Antwren; Guianan Warbling, Black-headed, and Willis’s Antbird; and Spotted Antpitta.
Antbirds of Guyana Checklist (From A Field Checklist of the Birds of Guyana, 2nd Edition, Smithsonian Institution)
Typical Antbirds (Thamnophilidae)
- Fasciated Antshrike (Cymbilaimus lineatus)
- Black-throated Antshrike (Frederickena viridis)
- Great Antshrike (Taraba major)
- Black-crested Antshrike (Sakesphorus canadensis)
- Band-tailed Antshrike (Sakesphorus melanothorax)
- Barred Antshrike (Thamnophilus doliatus)
- Mouse-colored Antshrike (Thamnophilus murinus)
- Northern Slaty-Antshrike (Thamnophilus punctatus)
- Amazonian Antshrike (Thamnophilus amazonicus)
- Streaked-backed Antshrike (Thamnophilus insignis)
- Plain Antvireo (Dysithamnus mentalis)
- Dusky-throated Antshrike (Thamnomanes ardesiacus)
- Cinereous Antshrike (Thamnomanes caesius)
- Spot-winged Antshrike (Pygiptila stellaris)
- Brown-bellied Antwren (Myrmotherula gutturalis)
- Pygmy Antwren (Myrmotherula brachyura)
- Guianan Streaked-Antwren (Myrmotherula surinamensis)
- Rufous-bellied Antwren (Myrmotherula guttata)
- White-flanked Antwren (Myrmotherula axillaries)
- Long-winged Antwren (Myrmotherula longipennis)
- Plain-winged Antwren (Myrmotherula behni)
- Gray Antwren (Myrmotherula menetriesii)
- Spot-tailed Antwren (Herpsilochmus sticturus)
- Todd’s Antwren (Herpsilochmus stictocephalus)
- Roraiman Antwren (Herpsilochmus roraimae)
- Rufous-winged Antwren (Herpsilochmus rufimarginatus)
- Dot-winged Antwren (Microrhopias quixensis)
- White-fringed Antwren (Formicivora grisea)
- Rufous-rumped Antwren (Terenura callinota)
- Ash-winged Antwren (Terenura spodioptila)
- Gray Antbird (Cercomacra cinerascens)
- Dusky Antbird (Cercomacra tyrannina)
- Willis’s Antbird (Cercomacra laeta)
- Blackish Antbird (Cercomacra nigrescens)
- Rio Branco Antbird (Cercomacra carbonaria)
- White-browed Antbird (Myrmoborus leucophrys)
- Guianan Warbling Antbird (Hypocnemis cantator)
- Black-chinned Antbird (Hypocnemoides melanopogon)
- Silvered Antbird (Sclateria naevia)
- Black-headed Antbird (Percnostola rufifrons)
- Spot-winged Antbird (Schistocichla leucostigma)
- Roraiman Antbird (Schistocichla saturata)
- White-bellied Antbird (Myrmeciza longipes)
- Ferruginous-backed Antbird (Myrmeciza ferruginea)
- Black-throated Antbird (Myrmeciza atrothorax)
- Wing-banded Antbird (Myrmornis torquata)
- White-plumed Antbird (Pithys albifrons)
- Rufous-throated Antbird (Gymnopithys rufigula)
- Spot-backed Antbird (Hylophylax naevius)
- Scale-backed Antbird (Hylophylax poecilinotus)
Ground Antbirds (Formicariidae)
- Rufous-capped Antthrush (Formicarius colma)
- Black-faced Antthrush (Formicarius analis)
- Short-tailed Antthrush (Chamaeza campanisona)
- Variegated Antpitta (Grallaria varia)
- Scaled Antpitta (Grallaria guatimalensis)
- Spotted Antpitta (Hylopezus macularius)
- Thrush-like Antpitta (Myrmothera campanisona)
- Tepui Antpitta (Myrmothera simplex)
- Slate-crowned Antpitta (Grallaricula nana)
