| Popis: |
Ortalis remota Pinto, 1960 stat. nov. Ortalis guttata remota: Pinto, 1960: 11. Ortalis guttata remota: Pinto, 1964: 109. Ortalis guttata squamata [in part]: Vaurie, 1965: 6. Ortalis guttata squamata [in part]: Vaurie, 1968: 243. Ortalis motmot squamata [in part]: Delacour & Amadon, 1973: 116. Ortalis guttata squamata [in part]: Blake, 1977: 395. Ortalis guttata remota: Pinto, 1978: 79. Ortalis guttata squamata [in part]: Grantsau, 2010: 426. Ortalis guttata remota: Piacentini et al., 2015: 101. Type material. MZUSP 11359, holotype (João Leonardo de Lima col., VII/1927). Type locality. Brazil, Mato Grosso do Sul state, Porto do Sapé (formerly “ Pôrto do Sapé ”), at the mouth of Pardo RiVer (right-bank tributary of Paraná RiVer). Description. Crown dark reddish brown. Bill gray. Bare facial skin, forehead, nape, throat and chest brown. Ventral and lateral portions of neck and whole chest edged with Very pale-brown clouded colour, forming a speckled pattern in the neck region and a poorly defined scaled-like pattern in the chest region. In the chest, this white margin runs across the whole feather. The pattern fades towards the abdomen as the colour of the margins become more similar to the background colour of the feathers. Abdomen light yellowish- brown. Flanks brownish yellow. Crissum and tail coVerts yellowish-red. Wing coVerts and flight feathers dark reddish brown. External rectrices chestnut-brown, central rectrices dark oliVe brown with metallic dark grayish-green tone. Diagnosis. Ortalis remota differs from other members of genus by haVing a distinctiVe colour pattern to its chest, with uniform brown feathers with clouded pale brown edges forming poorly defined scales that fade towards the abdomen. The chest feathers of O. guttata sspp. haVe white or whitish edges with a distinctiVe white dot in the middle forming a speckled pattern (Figs. 2–5). In turn, O. squamata has well-defined white feather margins forming a defined scaled or scalloped pattern. Each chest feather of O. squamata has three colours: dark oliVe brown on the base, dark brown in the middle and white on the edge, making the scaled or scalloped pattern eVen more eVident; this pattern is present in the abdomen feathers, but with a light grayish colour instead of white. Ortalis remota also differs from O. guttata sspp. and O. squamata by an oVerall lighter coloration across the whole body, mainly composed of clearer brown tones. Ortalis guttata is darker in the crown (despite the whitish marks of some specimens), neck and chest (eVen the paler O. g. subaffinis has a darker neck than O. remota; Fig. 5) and O. squamata is the darkest one, but also with an oVerall grayer coloration in the abdomen and flanks, as well as black bare facial skin. Ortalis remota and O. guttata sspp. present completely chestnut brown external rectrices, while those of O. squamata and O. araucuan haVe a dark oliVe brown base and chestnut red in the tip (Figs. 2-5). Ortalis remota neck feathers haVe white margins forming a speckled pattern that does not extend to the head, while in O. guttata this pattern is also present in the head and remarkably in the forehead and crown in some specimens. The grayish tarsi seen in the pictures of O. remota is distinct from the pinkish gray to reddish pink tarsi seen in O. guttata sspp. and browner, less bluish than the gray tarsi of O. squamata. Remarks. The distribution of Ortalis remota occupies a geographically intermediate position between its related taxa, i.e. the Amazonian O. guttata, the Atlantic O. squamata and O. araucuan, and perhaps another one, the peripheral Chaco representatiVe O. canicollis. It is probably an endemic of the central region of the “Bosque Paranaense” ProVince (Morrone 2001), an area seVerely modified eVen before adequate biological inVentories could be taken. These regions include riparian habitats of the Parana RiVer, ranging from its major tributaries (Grande, Paranaíba and Aporé RiVers), along the western border of São Paulo, and ending at the extreme west of the state of Paraná, near 24°S. Unfortunately, the lack of information on its distribution makes unfeasible any hypothesis of former and actual distributions. EVen skilful naturalists (e.g. Johann Natterer), who worked near confirmed localities within the species’ range, did not obtain specimens of Ortalis there, suggesting that it was probably already rare eVen in the early 19th century. The explorers Telêmaco and Nestor Borba, when traVeling to northwest of the state of Paraná, mention the presence of "aracuans" (i.e., “chachalacas ”) with "johós" (Crypturellus undulatus, a species locally extinct since the 1950s) perhaps near the mouth of the Paranapanema RiVer (Borba 1908; Straube 2013), but without further details. Kozák et al. (1979) reported that the extinct Xetá ethnic group from Serra dos Dourados (northwest of Paraná) hunted regularly aracuans (" Ortalis sp."), but they did not record this actiVity in their field journals, photographs, and films, nor is it eVidenced in the plumary art collected by him during his work in the 1950s. In addition, a specimen (MHNCI 1574) from the "Passeio Público - ParanaVaí" (northwest of Paraná) is, in fact, an indiVidual Ortalis squamata that died in captiVity at a local zoo. There are seVeral conserVation implications for O. remota. The recent recordings in the northwest of São Paulo indicate that this species occurs in the remaining woodlands of secondary Vegetation and the border of gallery forests of the Grande, Paraná and Tietê riVers basins in southeastern Brazil. Unfortunately, the habitats that still sustain this species were drastically reduced to small fragments or are disappearing along riVers due to human impacts (Fig. 6). Much is known about the destructiVe process caused by humans in the remaining semideciduous Atlantic forest and Cerrado in countryside São Paulo State (Durigan et al. 2007; Ribeiro et al. 2009). An old history of disturbance caused by the expansion of pastures and liVestock, monoculture plantations (currently, sugarcane and soybeans), and urbanization associated with a ‘hoodwinking’ attitude towards Brazilian enVironmental laws are current threats to the biodiVersity of the region. A major threat to the species’ surViVal has been the construction of dams in the main riVers of the Paraná basin. Most of the riVerine forests of the upper Paraná RiVer, including those at the type locality, as well as the lower stretches of the Tietê and Grande RiVers, haVe been flooded by many large reserVoirs for hydroelectric power. A quick measurement with Google Earth images shows that, from the type locality up riVer to about 500 m a.s.l. (the known upper limit of the species) on the main channels of the Tietê, Grande and Paranaíba RiVers, about 1070 km of riVerine forests out of 1360 km (78%) are now flooded (Fig. 3). Not surprisingly, most of the recent records of O. remota come from the TurVo RiVer basin in São Paulo, which is one of the few main riVers of the upper Paraná basin not transformed by dams, and which may be a stronghold for the species. In this sense, a few of the rare, unflooded tributaries of the upper Paraná RiVer, such as the Aguapeí and do Peixe RiVers in western São Paulo, are potential candidates to hold unknown populations and should be urgently surVeyed in their lower portions. Furthermore, the Vulnerability of O. remota to extinction increases substantially giVen that cracid species are culturally (though illegally) considered game birds in Brazil. The larger body size and greater source of proteins in relation to other smaller birds are prominent characteristics sought by rural people (Peres & Palacios 2007). Since the 19th century, hunters’ reports reVealed the presence of chachalacas in São Paulo state (Ihering 1898). HoweVer, these birds may be negatiVely affected by hunting in concert with unsustainable forest destruction, due to loss of sites for feeding, nesting, and roosting (Schmitz-Ornés 1999). Regarding ecological functions, the disappearance of O. remota, will potentially lead to losses in terms of seed dispersal and plant recruitment, since part of the diet of chachalaca species is composed of a Variety of fruits (in addition to seeds, green shoots, flowers, leaVes, and small inVertebrates; Caziani & Protomastro 1994; del Hoyo et al. 1994; Sick 1997). GiVen the preliminary few records of O. remota presented in this study, a proper estimation of the species’ geographic distribution and abundance is urgently needed to classify its degree of threat. Despite any controVersy on its taxonomic status, O. remota was recently declared as a Critically Endangered taxon in the Red Lists of Brazil (MMA 2014) and São Paulo State (SilVeira et al. 2009). For these reasons, and in a second step, conserVation measures such as restoration of natiVe habitats and connection of Vegetation fragments using ecological corridors are needed. If seVere risk of species extinction is detected by population estimates, the use of captiVe breeding focusing on increasing population and posterior releases of indiViduals in restored natiVe habitats will be the most appropriated measures to conserVe the species. |
