The choice of surrogates of biodiversity is an important aspect in conservation biology. The quantification of the coincidence in the spatial patterns of species richness and rarity between different groups and the vulnerability of groups are different approaches frequently considered to accomplish this task. However, a more appropriate approach is to verify the efficiency of priority networks selected using information from one group of organisms to capture the biodiversity of other groups. Using a deconstructive approach, the main purposes of this study were to evaluate the performance of some orders and families of birds in the Cerrado biome (a savanna‐like biome) as surrogates of other bird groups, in a pairwise analysis, and to investigate the characteristics of these groups that predict the efficiency in representation of other groups. We used biogeographical data on bird orders or families with more than 10 species that occur in the Brazilian Cerrado. The best surrogate group was the Thamnophilidae. Moreover, this group is not the most specious, favouring further survey efforts that are necessary to verify the conservation value of areas at suitable scales. The majority of the species from this family are dependent on forest habitats, one of the characteristics that most influenced representativeness level, probably due to the spatial distribution of these habitats throughout the Brazilian Cerrado. Beta diversity patterns of the different groups also affected representativeness, and our analyses showed that the networks selected by a surrogate group will be more effective in the representation of other groups of species if their patterns of beta diversity (not richness) are correlated.
TÔ rres and R o g É r i o P e r e i r a B a s t o s Abstract Increasing rates of habitat loss and human occupation are creating demands for optimum strategies that maximize conservation efforts, despite the lack of detailed data required for implementation. Broad scale biogeographical data may furnish initial guidelines for conservation planning in a hierarchical framework for establishing conservation priorities and helping guide future research programmes. This approach may be critical in regions for which few detailed data on diversity, abundance and distribution are available, such as in the Cerrado biome of central Brazil. We used a macroecological approach, based on the extent of occurrence of 127 species of terrestrial vertebrates endemic to the Cerrado, to design a regional network of potential areas that represent all species at least once. The final network has a total of 24 regions widely distributed throughout the biome. We also evaluated these regions in terms of their human occupation by adding a cost for each cell based on 23 variables expressing variation in agricultural, demographic and cattle-ranching patterns on the Cerrado. Our analyses showed that conservation efforts should be concentrated in the south and south-east of the biome. This macroecological approach can provide broad guidelines for conservation and define the focus for more local and realistic conservation efforts.
Spatial autocorrelation is the lack of independence between pairs of observations at given distances within a geographical space, a phenomenon commonly found in ecological data. Taking into account spatial autocorrelation when evaluating problems in geographical ecology, including gradients in species richness, is important to describe both the spatial structure in data and to correct the bias in Type I errors of standard statistical analyses. However, to effectively solve these problems it is necessary to establish the best way to incorporate the spatial structure to be used in the models. In this paper, we applied autoregressive models based on different types of connections and distances between 181 cells covering the Cerrado region of Central Brazil to study the spatial variation in mammal and bird species richness across the biome. Spatial structure was stronger for birds than for mammals, with R(2) values ranging from 0.77 to 0.94 for mammals and from 0.77 to 0.97 for birds, for models based on different definitions of spatial structures. According to the Akaike Information Criterion (AIC), the best autoregressive model was obtained by using the rook connection. In general, these results furnish guidelines for future modelling of species richness patterns in relation to environmental predictors and other variables expressing human occupation in the biome.
grupos indicadores pode ser importante para minimizar problemas gerados pela falta de conhecimento. Assim, essa abordagem é interessante em um cenário de grandes incertezas (ausência de dados detalhados) e de rápida transformação da paisagem, possibilitando a otimização de estudos em grandes escalas e depois transferir os resultados para escalas espaciais mais locais e realmente relevantes para a conservação. nessas regiões, podem ser realizados, em um segundo momento, estudos mais detalhados a fim de avaliar padrões de viabilidade populacional, fragmentação de habitat e regiões potenciais de manutenção da diversidade genética.
SummaryThe rapid destruction of habitat in biodiversity hotspots calls for the urgent formulation of conservation strategies. In this study, macro-scale biogeographical data for 33 species of Psittacines were used to select networks of priority areas, using an algorithm based on the complementarity concept. Human population size was also incorporated as a cost in the selection process, and the two networks of priority areas (with and without cost) were compared. In the comparison the number of cells selected to represent all species did not differ, but a rearrangement occurred between them. Two of the four cells were located in the same place, and the others changed location but stayed aggregated within the same regions. The study shows that it is possible to minimize human population size and represent all species in a network of priority areas.
This is a report on two nesting attempts by the Common Potoo (Nyctibius griseus) in an urban environment at Palmeiras de Goiás, Goias state, central Brazil. In December 12, 2006, a nest was found on a tree (Caesalpinia pothoroides), 2.8 m above the ground. This nest contained a white egg with dark red and brown patches. A few days later, no eggs were found in this nest. Other nesting attempt was recorded on October 9, 2007, when a chick was found in the same place used as nesting site in 2006. The young was not found in the next days. Our study is the first to document the nesting of N. griseus in the Cerrado core area.
Key words: Caprimulgiformes, nest site, Cerrado, urban ecology.
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