Avifauna of the Upper Guaporé River Valley in Mato Grosso state, Southern Brazilian Amazon Forest

Ribeiro da Silva Nunes J*, Wagner Zago B, Joana da Silva C, Aparecida Lima da Cruz E and Aparecida dos Santos Galvanin E

Keywords: Birds and Environment; Conservation; Endangered Species

Introduction

The Upper Guaporé Valley, located in the southwest of the state of Mato Grosso-Brazil, is formed by a complex ecotone, made up of the confluence of three important Brazilian biomes, the Amazon Rainforest and the Cerrado [1]. Drained by the Guaporé River, the valley is made up of a mosaic of unique ecosystems, reflecting its rich biodiversity. This makes the region of fundamental importance for studies aimed at understanding the composition of the fauna and flora of these unique environments.

The Ornithological Records Committee has registered 1,832 species of birds in Brazil. Of these, 1,300 species are registered in the Amazon rainforest, with 20% endemic species. The Cerrado has recorded 837 species, of which 4.3% are endemic.

Although it has enormous potential for bird species richness, the Upper Guaporé Valley region has few studies Natterers-Pelzeln, et al. [2, 3, 4] which aim to carry out systematized surveys in order to gain knowledge of all its rich avifauna. In this way, we present the first systematized survey of avifauna carried out in the Alto Guaporé Valley region, in the municipality of Vila Bela da Santíssima Trindade - MT.

Results and Discussion

In this study we recorded 173 species of birds belonging to 48 families and 23 orders in the Upper Guaporé Valley, southwestern Mato Grosso State, Brazil (Table 1). The families with the highest number of species were Tyrannidae with 19 species, followed by the Accipitridae, Ardeidae and Icteridae families, all with 10 species, and the Psittacidae family with 9 species recorded. All the species recorded in this study are considered to be of low concern in terms of threat of extinction on a global scale [18] and are not on the Ministry of the Environment’s list of endangered species at a national or local level [19].

The frequency of occurrences showed that more than half (55%) of the species recorded in this study for the region were considered rare, 16% were very abundant, 13% were occasional, 8% were abundant and 7% were frequent species (Table 1).

In previous bird surveys carried out in the Upper Guaporé Valley by Natterers-Pelzeln [2]; Willis, et al. [3], Silveira, et al. [4], a total of 472 species were recorded for the region. In our surveys, we recorded 30 species that were not recorded in the aforementioned surveys: Dendrocygna autumnalis (Linnaeus 1758), Circus buffoni (Gmelin 1788), Porphyrio flavirostris (Gmelin 1789), Phaetusa simplex (Gmelin 1789), Brotogeris chiriri (Vieillot 1818), Pionus maximiliani (Kuhl1820), Phaethorni spretrei (Lessone Delattre 1839), Chloroceryle inda (Linnaeus 1766), Campylorhamphus trochilirostris (Lichtenstein 1820), Certhiaxis cinnamomeus (Gmelin 1788), Schiffornis virescens (Lafresnaye 1838), Elaenia flavogaster (Thunberg 1822), Elaenia chiriquensis (Lawrence 1865), Myiarchus swainsoni (Cabanise Heine 1859), Tyrannopsis sulphurea (Spix 1825), Griseotyrannus aurantioatrocristatus (d’Orbigny eLafresnaye 1837), Arundinicola leucocephala (Linnaeus 1764), Lathrotriccus euleri (Cabanis 1868), Riparia riparia (Linnaeus 1758), Troglodytes musculus (Naumann 1823), Cantorchilus guarayanus (d’Orbignye Lafresnaye 1837), Paroaria capitata (d’Orbignye Lafresnaye 1837), Sicalis flaveola (Linnaeus 1766), Sporophila nigricollis (Vieillot 1823), Sporophila bouvreuil (Statius Muller 1776), Piranga flava (Vieillot 1822), Icterus pyrrhopterus (Vieillot 1819), Icterus croconotus (Wagler1829), Amblyramphus holosericeus (Scopoli 1786), Molothrus oryzivorus (Gmelin 1788).

We recorded 5 known migratory species in this study [20]. The Osprey (Pandion haliaetus, Linnaeus 1758) (Figure 2), the only member of the Pandionidae family, was recorded from September onwards. P. haliaetus is native to North America, where it breeds, migrating to South America during the winter. This species can be seen in almost all Brazilian states. Its migration route usually follows bodies of water, due to its preference for feeding on fish.

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Swallow-tailed Kite (Elanoides forficatus, Linnaeus 1758) (Figure 3), recorded in March and then only from September onwards, with the number of individuals gradually increasing over the months, reaching 317 individuals in December flying over the study area in search of food, clearly demonstrating a migratory movement. E. forficatus has a subspecies resident in Brazil and a subspecies from North America, migrating to the south and southeast of Brazil from August/September and remaining until February/March, corroborating what was recorded in this study Nunes, et al. [21]. This pattern of occurrence was also recorded by Vitorino, et al. [22]; Nunes, et al. [23] Nunes, et al. [24] in different regions of the Pantanal in Mato Grosso.

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Vermilion flycatcher (Pyrocephalus rubinus, Boddaert 1783), a bird from the Tirannydae family, notable for the strong red coloration of the male during the breeding season. It was sighted from July to August, with the males wearing breeding plumage. P. rubinus are southern migrants, coming from southern Brazil and Argentina to the Amazon in winter. They return to the south in spring-summer to begin breeding.

Another noteworthy fact is the formation of a nesting area for wood stork (Mycteria americana, Linnaeus 1758) (Figura 4) at one of the sampling points. The area has dominant Buriti vegetation (Mauritia flexuosa, Linnaeus1782). The individuals of M. americana were seen sporadically from April onwards. Later, in July, around 120 individuals of M.americana (in a mixed flock with Platalea ajaja, Linnaeus 1758) established themselves in the area, building nests and starting to reproduce. Young individuals of M. americana began to appear in September and remained in the area until October. This makes the area extremely important for maintaining the species in the state’s Pantanal plains.

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It is important to note that the Upper Guaporé Valley is located in a region that is extremely rich in biodiversity and is still little known. It also has a unique composition of species as it is a transition area between two important Brazilian biomes (the Amazon and the Cerrado). This raises the need for the creation of Conservation Unit areas, in view of the advance of agricultural and pastoral activities in the region.

Table 1: Systematic list of birds recorded in the Upper Guaporé Valley - Mato Grosso, Brazil. (FO) Frequency of Occurrence: (Ma) very abundant, species recorded between 81-100%; (A) abundant, between 61-80%; (Fr) frequent, 41-60%; (O) occasional, 21-40%; (Ra) rare, 1-20%; (-) birds not considered for classification. The categories and abundance classes were based on Bugalho (1974). Status: (R) resident, (VS) seasonal visitor from the south of the continent, (VN) seasonal visitor from the north of the continent (VA (O)) vagrant, species of apparently irregular occurrence in Brazil; may be a regular migrant in neighboring countries to the west. Status classes were based on CBRO.

Bank Swallow (Riparia riparia) belonging to the Hirundinidae family, was only seen in December. R. riparia appears as a northern visitor in Brazil from September to April. Commonly found in mixed flocks with Barn Swallow (Hirundo rustica).

Black-backed Grosbeak (Pheucticus aureoventris, d’Orbigny eLafresnaye 1837), belonging to the Cardinalidae family, only one individual was seen in November. P. aureoventris has a scarce and irregular occurrence in Brazil, having so far only been recorded in the far west of the state of Mato Grosso. It can be considered a southern migrant, as it has a wide distribution in the Andes.

Conclusions

The Upper Guaporé Valley has great potential for richness of fauna and flora, its location in a transition area between the Amazon and the Cerrado, and with the Pantanal as a neighboring biome, the species composition in this environment becomes unique as species from all three biomes can be found in the area.

The species richness recorded in this study is considered to be high when compared to other environments in Brazil and even abroad, even more so when taking into account that we are only dealing with species that can be found along the river.

Conflicts of Interest

The authors declare that there are no conflicts of interest involving this publication.

Acknowledgements

We would like to thank the Research Support Foundation of the State of Mato Grosso (FAPEMAT), the National Council for Scientific and Technological Development (CNPQ), the Ministry of Science and Technology and the Bionorte Network for funding and maintaining the project, and the Coordination for the Improvement of Higher Education Personnel (CAPES) for granting the scholarship. We would also like to thank the State University of Mato Grosso (UNEMAT) and the Graduate Program in Environment and Agricultural Production Systems (PPGASP) for their support.