Caño Colorado: a Lowland Tropical Forest in North-East Venezuela
Total Page：16
File Type：pdf, Size：1020Kb
COTINGA 3 Caño Colorado Caño Colorado: a lowland tropical forest in north-east Venezuela Peter Boesman Resum en La selva tropical en el nor-este de Ven ezuela no ha sido estudida profundamente. El autor describe un sitio en el nor-este del estado Monagas, Caño Colorado, donde ha observadas unas 220 especies de aves, de las cuales unos 40 no habien sido observadas antes en el estado Monagas, y 16 especies son nuevos para el nor-este de Venezuela. Se puede considerar la selva de esta region como una extension en el norte de las selvas Guayanan al otro lado del Orinoco. Se puede esperar que esta isla de Map 1: Caño Colorado, north-east Venezuela selva en el norte tenga vida endémica, tal como por ejemplo el Telegrafista Punteado Picumnus nigropunctatus en el caso de las aves. El tipo de selva que se encuentra en Caño Colorado es principalmente várzea, y muchos especies observadas son típicos pro este habitat. El sitio en peligro por la expansion de las plantaciones de palmas para la extracción de aceite, y urge determinar el tamaño de estas selvas para poder tomar acciones para preservar una parte importante de las mismas en el nor este de Venezuela. Introduction Venezuela is widely known as an ornitho logical paradise. Many birders get their first Neotropical experience in north-west ern Venezuela, and yet remarkably few species. As access is relatively easy, it might be have made it to the north-east. Any visits worthwhile including the site in Venezuelan bird are generally brief and limited to the ing itineraries, especially as it lies on route from Oilbird Steatornis caripensis cave in Caripe or the Paria peninsula to the state of Caripe, or a search for the Paria endemics Bolivar in the south. in the coastal mountains. To many, it will come as a surprise that north-east Ven Description of the area ezuela contains tropical lowland forest. The area is known as Caño Colorado and is lo There is some evidence for the occurrence cated east of Maturín, the capital of Monagas of tropical forest species in the state of (Map 1). When taking the road to La Pica, which Sucre1, but Monagas state seems com passes the airport of Maturín, the road becomes pletely unexplored. unsurfaced after some 23 km. Caño Colorado The aim of this article is to introduce a proper begins at this point (Map 2). Around 20 tract of tropical forest in north-east years ago the area was mainly forested and was Monagas which harbours some interesting included within the “Reserva Forestal 31 COTINGA 3 Caño Colorado Guarapiche”. Unfortunately, when the culti birding a delight. From July 1993 to August vation of African oil-palms made the area eco 1994, I made some 20 visits to the area, mainly nomically valuable, deforestation began (a le in the dry season, and observed a total of 220 gitimate activity within a “reserva forestal”). species. Of these, no less than 40 (18%) are At present, the first 9 km of dirt road passes not mentioned by Meyer de Schauensee & through degraded habitat, primarily compris Phelps1 for Monagas state, and 16 species are ing oil-palm plantations. Further on, the for new for north-eastern Venezuela. The area est becomes increasingly intact. There are undoubtedly holds many more species as I many side roads along which other patches of averaged five new species for the local check good forest can presumably be reached. list on each of my last five visits. The whole area is below 20 m altitude and Birding is best from just before dawn un in the wet season (June–September) the last til 10h00, at which time it begins to get too 8 km of the main road is inaccessible by car. hot. Access is easy from January to April, but during the wet season the area is virtually im penetrable as grass grows to head-height, and water reaches a depth of 30–80 cm in the flooded forest. Typical birds Caño Colorado can be considered part of the northernmost extension of the Guayanan tropical forests. This forest in eastern Sucre, north-eastern Monagas and northern Delta Amacuro is somewhat isolated because of the Orinoco delta, and thus it is neither surpris ing that several Guayanan/Amazonian species reach their northernmost limit there, nor that the majority of Guayanan/Amazonian species Crimson-hooded Manakin Pipra aureolo (David D. Beadle) do not range as far north (due to the barrier effect of the Río Orinoco). At this time, large areas of forest are flooded As a consequence of the area’s partial iso (i.e. várzea), whilst terra firme is restricted lation, one might expect some degree of ende to raised areas. The várzea is characterised mism, which is indeed the case, though pri by a relatively open understorey, a low canopy marily at the subspecific level. An interesting and (especially from the caño onwards) many example is Black-dotted Piculet Picumnus natural palms. Caño Colorado is probably rep (spilogaster) nigropunctatus which is only resentative of the large area of intact habitat known from this general area. As this forest that still exists behind the mangroves and is essentially unvisited by collectors, it poten swamps lining the coast of Sucre and Delta tially holds a number of undescribed taxa. Amacuro (Fig. 1). A list of typical Guayanan/Amazonian spe cies which have been observed at Caño Colo Birding the Caño Colorado rado, at the northern limit of their distribu A wide variety of species can be seen in the tion, is presented in Table 1. It is clear from deforested area and along forest borders where this list that the occurrence of many of these observation is easier, but many of the more species so far north was not previously real interesting species occur only in continuous ised. As many Guayanan/Amazonian birds are forest. A morning walk down the main track not present, however, it appears that other normally produces 90–100 bird species, which birds not usually associated with this type of is remarkable for a forested area north of the habitat have colonised or remained in the area Orinoco with one basic habitat at one altitude. because of the lack of competition. As exam Several larger forest species are still ples, it is surprising to find Red-legged present despite hunting pressure from the Tinamou Crypturellus erythropus in várzea “campesinos”. One can walk for hours, how forest substituting for Undulated Tinamou C. ever, without seeing anybody, which makes undulatus and Variegated Tinamou C. 32 COTINGA 3 Caño Colorado variegatus. The same is true for Russet- recently this (sub)species was known from throated Puffbird Hypnelus ruficollis (replac only two sites in Delta Amacuro, and the fe ing Buceo puffbirds), Rufous-and-white Wren male plumage was undescribed. It has now Thryothorus rufalba (replacing Coraya Wren also been found in north-eastern Sucre and T. coraya) and Golden-fronted Greenlet around Tucupita, Delta Amacuro (S. Hilty Hylophilus aurantiifrons (for Buff-cheeked pers. comm.), although Caño Colorado is one Greenlet H. muscicapinus). The replacement of the easiest places to see this (sub)species, species are normally confined to much drier the range of which is from central Delta habitats. Additionally, because of recent de Amacuro to north-eastern Monagas and east forestation, several species typical of savanna ern Sucre. Although recently lumped with or llanos-type habitat have colonised the more White-bellied Piculet P. spilogaster, it probably open areas. deserves full species status. Ringed Woodpecker Celeus torquatus The following annotated list comprises spe Uncommon and far outnumbered by Cream- cies that are difficult to observe in other parts coloured Woodpecker C. flavus and Chestnut of Venezuela, or whose presence at Caño Colo Woodpecker C. elegans, which are both excep rado constitutes a notable range-extension. It tionally common. C. torquatus is uncommon also reveals that the typical birds of Caño everywhere and Caño Colorado is the most Colorado are characteristic of várzea forest, northerly site in its known range. humid forest and woodland edge, i.e. the habi Striped Woodcreeper Xiphorhynchus tats prevalent at this site. obsoletus This is another interesting north Blue-throated Piping-guan P ip ile ward range extension. This species is rela cumanensis A single record along the forest tively common, especially along the furthest edge constitutes an important range-exten part of the track because of its preference for sion. Preferring river-edge, this species prob várzea forest and swamps. ably occurs east of Caño Colorado up to Jet Antbird Cercomacra nigricans One Pedernales, only 15 km from Trinidad. The of the typical, common antbirds of Caño Colo distributional proximity of this species to rado, being much commoner than at most Trinidad Piping-guan P. pipile is a new and other Venezuelan sites. intriguing discovery. Black-chinned Antbird Hypocnemoides Blue-and-yellow Macaw Ara ararauna melanopogon and Silvered Antbird This beautiful macaw is still present in good Sclateria naevia Interestingly, this numbers, and several small groups (normally Guayanan/Amazonian species pair both occur of 2–3 birds, but up to 20) can be seen daily. at Caño Colorado. Their affinity for várzea They are mainly observed in early morning forest and swampy habitats presumably fa and late afternoon in the dry season, when fly cilitated the crossing of the Orinoco delta. ing to and from their roosts. Along the fur thest part of the main track they are fre quently encountered feeding in the canopy. Scarlet-shouldered Parrotlet Touit huetti This small parrot is relatively common, though mainly in the wet season, when Lilac tailed Parrotlet T.