Navegando por Assunto "Ecology"

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Artigo
ECOLOGIA DE PEIXES DE RIACHOS DE CAVERNAS E OUTROS HABITAT SUBTERRÂNEOS
(2021) Bichuette, Maria Elina
Brasil desponta como um país rico em cavidades naturais subterrâneas, com mais de 20.000 cavernas cadastradas oficialmente. Além das cavernas, as quais se desenvolvem em diferentes tipos de rocha, há outros habitat subterrâneos (hipógeos) com corpos d’água na forma de drenagens (riachos de nível de base), de afloramentos do freático (zona saturada) em cavernas inundadas ou na forma de poças e lagos dentro de cavidades, além de bolsões de aquíferos superiores formados por água de infiltração na rocha. Em alguns casos, as águas subterrâneas não afloram em cavidades, e sim em aluviões próximos a rios, representando uma zona hiporreica. A ictiofauna subterrânea brasileira é composta por peixes restritos às cavernas e outros habitat subterrâneos (geralmente categorizados como troglóbios/estigóbios) ou por espécies que possuem populações bem estabelecidas nestes habitat, mas que também ocorrem em riachos e corpos d’água da superfície (categorizados como troglófilos). Atualmente há mais de 80 espécies de peixes com populações troglóbias e troglófilas no Brasil. Alguns estudos populacionais para peixes troglóbios/freatóbios apresentam estimativas de tamanhos e densidades populacionais variáveis, geralmente caracterizadas por populações pequenas; uma tendência ao sedentarismo; baixos valores de fator de condição e estratégias de ciclos de vida tendendo ao K dentro do continuum r-K. Estas características são relacionadas às condições abióticas únicas destes habitat, tais como aporte de nutrientes baixo, infrequente e muitas vezes imprevisível, o que pode representar um filtro acentuado. Em relação à conservação, os peixes de riachos de cavernas e de outros habitat subterrâneos encontram-se ameaçados e a maioria das espécies descritas formalmente está inserida em listas de fauna ameaçada no Brasil, apenas quatro espécies foram incluídas e avaliadas globalmente (a piaba Stygichthys typhlops e os bagres Pimelodella kronei, Phreatobius cisternarum e Phreatobius sanguijuela).
Texto publicado em jornal
Ecology of Antricola ticks in a bat cave in north-eastern Brazil
(2020-09-12) Barbier, Eder; Bernard, Enrico; Dantas‑Torres, Filipe
Argasid ticks are a diverse group of acarines that parasitize numerous vertebrate hosts. Along with birds, bats serve as hosts for several argasid ticks, which are commonly found in bat caves. Argasid ticks have regained attention from tick taxonomists in recent dec-ades, with a number of new species described in various zoogeographical regions. None-theless, studies on their ecology are still scarce. We conducted a 1-year longitudinal study to assess the presence of argasid ticks in a bat cave in the drylands of north-eastern Brazil and evaluate their possible response to abiotic factors. From July 2014 to June 2015, 490 ticks were collected (272 nymphs, 169 males and 49 females) in a cave chamber hosting a large colony of Pteronotus spp. bats, being relatively more frequent from July to December 2014. Adults were identified as Antricola guglielmonei, whereas nymphs were assigned to the genus Antricola. Almost all ticks (98%) were collected on the cave walls. Only 2% were on the ceiling and, surprisingly, no specimens were found on the floor and/or guano. Adults were usually clustered in the crevices and little mobile, whereas nymphs were dispersed and more active, moving over the walls or ceiling of the cave. Although present in most of the studied period, there was a significantly negative correlation between tick abundance and relatively humidity, and A. guglielmonei was more frequent during the dry season. Moreover, there was no evident correlation between the abundance of ticks and bats. Fur-ther long-term studies will be able to verify whether this pattern is repeated over time, and even whether other variables can influence the population dynamics of A. guglielmonei.
Texto publicado em jornal
Epigean and hypogean drivers of Neotropical subterranean communities
(2020-10-29) Rabelo, Lucas Mendes; Souza-Silva, Marconi; Ferreira, Rodrigo Lopes
In addition to cave size and other subterranean habitat characteristics, cave entrances are important structurers of neotropical cave communities. However, little is known about the epigean ecosystems factors that might dictate the influence of entrances and the relationship among surface and cave communities, as entrance re-gions are ecotonal zones between the epigean and hypogean ecosystems. We aimed to assess the influence of epigean and hypogean factors as potential drivers of inver-tebrate species richness in Neotropical caves as well as the influence of the regional pool of invertebrate diversity on cave invertebrate diversity.
Artigo
The effect of urbanization on species composition and trophic guilds of bats (Mammalia, Chiroptera) in the Brazilian Savanna
(2023-10-26) Alencastre-Santos, Ana Beatriz ; Gonçalves, R; Correia, Letícia Lima ; Brito, D.; Oprea, Monik ; Vieira, Thiago Bernardi
Urban environments present less environmental heterogeneity in relation to the natural ones, affecting the biodiversity of bats and the ecological processes in which they participate. In this way, we will identify how urbanization influences the structure of bat communities in the municipality of Goiânia, Goiás, Brazil. We compared species composition, guilds and bat richness in a gradient that crossed urban, semi-urban and natural areas in the municipality of Goiânia, contained in the Cerrado biome. We captured a total of 775 bats of 16 species distributed in three families. Urban areas had a higher species abundance, while semi-urban areas had a higher species richness. The three types of environments have different compositions, the urban one being more homogeneous, the fauna in these areas is composed of generalist species, which benefit from this process. The diversity present in semi-urban areas is a consequence of the intersection between urban and natural fauna, which is why urban expansion needs to occur in a planned manner to minimize the impacts of this process and ensure the maintenance of biodiversity.
Artigo
USE OF A GLASS BOTTOM BOAT FOR SEA TURTLE RESEARCH AROUND FERNANDO DE NORONHA ARCHIPELAGO, BRAZIL
(2016) BORTOLON, L. F. W.; VERAS, L. B.; NASSAR, P.R.; SANTOS, A. J. B.; BELLINI, C.
Fernando de Noronha archipelago is located 346 kilometers from the Brazilian continental coast, which is a green turtle rookery and developmental site for green and hawksbill turtles. Loggerhead and olive ridley turtles seldom appear in the archipelago. This is the first research that has used a glass bottom boat to gather data on the behavior, frequency, and species composition of sea turtle populations within the archipelago. This research aimed to test the effectiveness of this new method of observation, for scientific purposes.