Landscape and soil regionalization in southern Brazilian Amazon and contiguous areas: methodology and relevance for ecological studies

Abstract Accurate identification of predator species is a critical requirement to investigate their diet using faecal samples. We used non-invasive sampling and two methods of predator identification to investigate the diets of sympatric carnivores in a highly deforested region of the Brazilian Amazon. Of 108 scats, 81 could be identified at the species level using DNA sequencing and/or trichology. The former performed better than the latter (81.5% vs. 54.3% of the identified samples), and results were quite congruent (89.7% concordance in the 29 samples that could be assessed with both approaches). Nine species were identified, out of which four (crab-eating fox, ocelot, puma and jaguar) presented a sufficient number of samples to allow dietary analyses. The crab-eating fox was the most generalist (BA=0.92); ocelots focused on small- to medium-sized prey; pumas fed mostly on medium-sized items; and jaguars mostly targeted large-sized prey. A considerable overlap was observed between ocelots and pumas in all estimations (O=0.47–0.83). The presence of jaguars in the same region could be driving pumas to select medium- and small-sized prey. The results of this study highlight the importance of reliable predator identification and the need for in-depth ecological studies in areas where carnivore species are sympatric.

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Functional trophic composition of the ichthyofauna of forest streams in eastern Brazilian Amazon

Neotropical Ichthyology ◽

10.1590/s1679-62252013005000006 ◽

2013 ◽

Vol 11 (2) ◽

pp. 361-373 ◽

Cited By ~ 33

Author(s):

Gabriel Lourenco Brejao ◽

Pedro Gerhard ◽

Jansen Zuanon

Keyword(s):

Functional Organization ◽

Brazilian Amazon ◽

Behavioral Observation ◽

Main Channel ◽

Taxonomic Structure ◽

Trophic Groups ◽

Ecological Studies ◽

Alternative Approach ◽

Ad Libitum ◽

Forest Streams

This study aimed to describe the functional organization of the ichthyofauna of forest streams from northeastern Pará State, Brazil, based on behavioral observation of species' feeding tactics. Seven streams were sampled between June and November, 2010, during snorkeling sessions, totaling 91h 51min of visual censuses at day, dusk, and night periods. Seventy three species distributed in six orders, 26 families and 63 genera were observed, with dominance of Characiformes, followed by Siluriformes. From information gathered by ad libitum observations, each species was included in one of 18 functional trophic groups (FTGs), according to two main characteristics: (1) its most frequently observed feeding tactic; and (2) its spatial distribution in the stream environment, considering their horizontal (margins or main channel) and vertical (water column) dimensions. The most frequent FTGs observed were Nocturnal invertebrate pickers (9 species), Diurnal channel drift feeders (8 spp.), Diurnal surface pickers (7 spp.), and Ambush and stalking predators (6 spp.). The FTGs herein defined enable a comparative analysis of the structure and composition of ichthyofauna in different basins and environmental conditions, which presents an alternative approach to the use of taxonomic structure in ecological studies. The ichthyofauna classification based in FTGs proposed in this study is compared to three other classifications, proposed by Sazima (1986), Sabino & Zuanon (1998) and Casatti et al. (2001).

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Distribution extension of Ateles chamek (Humboldt 1812) in the southwestern Brazilian Amazon: identification by visual evidence and fecal DNA

Mammalia ◽

10.1515/mammalia-2016-0180 ◽

2018 ◽

Vol 82 (2) ◽

pp. 173-177

Author(s):

André Valle Nunes ◽

Ricardo Koroiva ◽

Gabrielle Nóbrega Gomes Vanessa ◽

Vinícius Santana Orsini

Keyword(s):

Species Identification ◽

Brazilian Amazon ◽

Hair Color ◽

Fecal Dna ◽

Ecological Studies ◽

Mato Grosso ◽

Facial Hair ◽

Visual Evidence ◽

Molecular Sequencing ◽

Threatened Status

Abstract One group of Ateles chamek (Humboldt 1812) was observed during 12 days in the Vila Bela da Santíssima Trindade municipality, in the state of Mato Grosso. During that time fecal samples (n=10) were collected and molecular sequencing was used to confirm species identification. The results suggest that the particular pattern of facial hair color observed in this group may be used for differentiation from other sub-populations; however, a deeper study is required for confirmation of these results. This record represents the most southwestern observation of this species, and increases the geographic distribution of A. chamek for about 16 km into the southern Brazilian Amazon. Taking into consideration the threatened status of this species of monkey, and that this region is under constant intensive deforestation, it is important to highlight that ecological studies and conservation activities require urgent development.

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