Bamboo Specialization by Amazonian Birds¹

Abstract

Spot-mapping of territories was used to document the restriction of nineteen bird species to thickets of bamboo ( G d u a weberbauerz] in lowland forests in southeastern Peru. These species were defined as bamboo specialists. An additional seven species showed a preference for such thickets, but also used other habitats. These results correspond with previous, qualitative descriptions of the habitat preferences of bamboo specialists. At least four specialists are restricted to thickets throughout their entire geographic range (obligate bamboo specialists); another nine specialists may use other habitats sparingly away from southeastern Peru (near-obligate bamboo specialists); the remaining six species are frequent users of habitats lacking bamboo away from southeastern Peru (facultative bamboo specialists). The nonbamboo habitats used by the 13 near-obligate and facultative specialists are predominantly dense habitats with low canopy cover, including treefall gaps and early successional vegetation along rivers. The obligate and nearobligate specialists generally have small geographic ranges centered in southwestern Amazonia; a few have sister taxa in southeastern Brazil that are also bamboo specialists suggesting a common evolutionary history. The facultative specialists are generally more widespread. Bamboo specialists are more abundant in bamboo habitats than are other bird species in more generalized habitats. RESUMENA travCs de un trazado de mapas de territorios de aves, de tierra baja en un sitio del sureste del Perh, 19 especies de aves heron definidas como especies restringidas a matorrales de bambh (Guadua weberbauerz'). Aquellas especies fueron identificadas como "especialistas de bambli." Siete especies adicionales demostraron una preferencia por tales matorrales de bambli, pero tambiCn utilizaron otros habitats. Estos resultados corresponden a descripci6nes previas y cualitativas, que heron hechas sobre las preferencias de habitat entre las especialistas de bambli. No menos de cuatro especialistas son restringidas a matorrales a travks de la extensi6n geogdfica (usuarios obligatorios de bambh); otras nueve especialistas pueden utilizar escasamente otros habitats lejos del sureste del Perh (usuarios casi obligatorios de bambh); las ultimas seis especialistas son usuarios frecuentes de habitats sin bambh fuera del sureste del Perh (usuarios facultativos de bambh). Los habitats sin bambh utilizados por 10s 13 usuarios casi obligatorios y usarios facultativos generalmente heron habitats mis densos sin cubierta de arboles altos, incluyendo claros en el bosque y vegetaci6n sucesional joven en las orillas de rlos. Los usuarios obligatorios y casi obligatorios generalmente tuvieron pequefias extensi6nes geogrificas, entradas en el suroeste de la Amazonia. Algunas comparten taxa hermanas con especies que tambiCn son especialistas en el sureste de Brasil, lo cual indica una historia evolutiva en comhn. Los usuarios facultativos generalmente tienen distribuciones m h amplias. Las abundancias de 10s especialistas ...

Birds of an Open Vegetation Enclave in Southern Brazilian Amazonia

“…The large diversity of arthropods inhabiting the bamboo stands attracts several species of birds, including facultative users of bamboo, near-specialists, and specialists (Rodrigues et al 1994, Olmos 1996, Kratter 1997, Vasconcelos et al 2005, Guilherme and Santos 2009, Cestari and Bernardi 2011. Bamboo fruits and dies off cyclically at periods that range usually from 2 to 30 years, depending on the bamboo species, and affect the distribution and abundance of bamboo specialists (Londoño 2001, Jaksic and Lima 2003, Areta et al 2009, Areta and Cockle 2012.…”

The foraging behavior of the Large-headed Flatbill, Ramphotrigon megacephalum and the Dusky-tailed Flatbill, Ramphotrigon fuscicauda (Aves: Tyrannidae)

“…Studies demonstrate that the dense habitat provided by bamboo culms and leaves support a rich community of arthropods, which represent an abundance of food for insectivorous birds (Janzen 1976(Janzen , reiD et al 2004 and explain the large number and density of insectivorous bamboo specialists (Kratter 1997, CoCKle & areta 2013. The dense bamboo leaf cover may promote this ecological guild of flycatchers that capture prey on vegetation.…”

Peer Review #1 of "Beetles in bamboo forests: community structure in a heterogeneous landscape of southwestern Amazonia (v0.1)"

“…Although further collecting might have yielded some of these species in terra firme, our 456 results support the idea that bamboo is a rich habitat that contains a beetle community distinct 457 from that of the adjacent terra firme. It is likely that some beetle species have evolved to 458 specialize on bamboo forests as has been shown for other organisms (Kratter 1997 460 461 Each beetle family exhibited different patterns of richness, abundance and composition within 462 bamboo and terra firme. Because beetles from the Scarabaeidae constituted the majority of 463 species in our collection (48%), and the majority of individuals (83%), diversity patterns of the 464 scarabs were the most influential on the overall results.…”

“…Bamboo-associated organisms 572 are being discovered with increasing frequency (Jacobs & von May 2012) and more in-depth 573 field work, throughout the dry and wet seasons, is needed to determine if and why particular 574 insect species are associated with specific forest types. Understanding insect diversity patterns in 575 Guadua bamboo forests is particularly important because insects are the food source for so many 576 other animals, and this is especially true for the 19 known species of insectivorous, Guadua-577 specialist birds (Kratter 1997;Socolar et al 2013). 578 579 Conclusions 580 581 Guadua bamboo forests are strikingly unique habitats because they occur as mono-dominant 582 forest islands surrounded by hyper-diverse rainforest-providing an uncommon, spatially and 583 biologically distinct habitat.…”