The Cayman Crab Fly Revisited — Phylogeny and Biology of Drosophila endobranchia

BACKGROUND: The majority of all known drosophilid flies feed on microbes. The wide spread of microorganisms consequently mean that drosophilids also can be found on a broad range of substrates. One of the more peculiar types of habitat is shown by three species of flies that have colonized land crabs. In spite of their intriguing lifestyle, the crab flies have remained poorly studied. Perhaps the least investigated of the three crab flies is the Cayman Island endemic Drosophila endobranchia. Apart from its life cycle very little is known about this species, including its phylogenetic position, which has remained unresolved due to a cryptic set of characteristics. PRINCIPAL FINDINGS: Based on molecular data, corroborated by a re-analysis of the morphological make up, we have resolved the phylogenetic position of D. endobranchia and show that it somewhat surprisingly belongs to the large Neotropical repleta radiation, and should be considered as an aberrant member of the canalinea species group. Furthermore we also provide additional data on the behavior of these remarkable flies. CONCLUSION: Our findings reveal that the two Caribbean crab flies are not as distantly related as first thought, as both species are members of the derived repleta radiation. That this lineage has given rise to two species with the same odd type of breeding substrate is curious and prompts the question of what aspects of their shared ancestry has made these flies suitable for a life on (and inside) land crabs. Knowledge of the phylogenetic position of D. endobranchia will allow for comparative explorations and will aid in efforts aimed at understanding processes involved in drastic host shifts and extreme specialization

Para que servem os inventários de fauna?

Inventários de fauna acessam diretamente a diversidade de uma localidade, em um determinado espaço e tempo. Os dados primários gerados pelos inventários compõem uma das ferramentas mais importantes na tomada de decisões a respeito do manejo de áreas naturais. Entretanto, vários problemas têm sido observados em diversos níveis relacionados aos inventários de fauna no Brasil e vão desde a formação de recursos humanos até a ausência de padronização, de desenho experimental e de seleção de métodos inadequados. São apresentados estudos de caso com mamíferos, répteis, anfíbios e peixes, nos quais são discutidos problemas como variabilidade temporal e métodos para detecção de fauna terrestre, sugerindo que tanto os inventários quanto os programas de monitoramento devam se estender por prazos maiores e que os inventários devem incluir diferentes metodologias para que os seus objetivos sejam plenamente alcançados.Inventories of fauna directly access the diversity of a locality in a certain period of time. The primary data generated by these inventories comprise one of the most important steps in decisions making regarding the management of natural areas. However, several problems have been observed at different levels related to inventories of fauna in Brazil, and range from the training of humans to the lack of standardization of experimental design and selection of inappropriate methods. We present case studies of mammals, reptiles, amphibians and fishes, where they discussed issues such temporal variability and methods for detection of terrestrial fauna, suggesting that both inventories and monitoring programs should be extended for longer terms and that inventories should include different methodologies to ensure that their goals are fully achieved

Understory Bird Communities in Amazonian Rainforest Fragments: Species Turnover through 25 Years Post-Isolation in Recovering Landscapes

Inferences about species loss following habitat conversion are typically drawn from short-term surveys, which cannot reconstruct long-term temporal dynamics of extinction and colonization. A long-term view can be critical, however, to determine the stability of communities within fragments. Likewise, landscape dynamics must be considered, as second growth structure and overall forest cover contribute to processes in fragments. Here we examine bird communities in 11 Amazonian rainforest fragments of 1–100 ha, beginning before the fragments were isolated in the 1980s, and continuing through 2007. Using a method that accounts for imperfect detection, we estimated extinction and colonization based on standardized mist-net surveys within discreet time intervals (1–2 preisolation samples and 4–5 post-isolation samples). Between preisolation and 2007, all fragments lost species in an area-dependent fashion, with loss of as few as <10% of preisolation species from 100-ha fragments, but up to 70% in 1-ha fragments. Analysis of individual time intervals revealed that the 2007 result was not due to gradual species loss beginning at isolation; both extinction and colonization occurred in every time interval. In the last two samples, 2000 and 2007, extinction and colonization were approximately balanced. Further, 97 of 101 species netted before isolation were detected in at least one fragment in 2007. Although a small subset of species is extremely vulnerable to fragmentation, and predictably goes extinct in fragments, developing second growth in the matrix around fragments encourages recolonization in our landscapes. Species richness in these fragments now reflects local turnover, not long-term attrition of species. We expect that similar processes could be operating in other fragmented systems that show unexpectedly low extinction