Tag: forest fragmentation

A decade of monitoring shows the dynamics of a conserved Atlantic tropical forest

Characterised with its immense biodiversity and high levels of endemism, the Atlantic Tropical Forest has been facing serious anthropogenic threats over the last several decades, demanding for such activities and their effects to be closely studied and monitored as part of the forest dynamics.

Cattle farming, expanding agricultural land areas and mining have reduced the Atlantic Forest to many small patches of vegetation. As a result, important ecosystem services, such as carbon stock, are steadily diminishing as the biomass decreases.

Brazilian researchers, led by Dr. Écio Souza Diniz, Federal University of Viçosa, spent a decade monitoring a semi-deciduous forest located in an ecological park in Southeast Brazil. Their observations are published in the open access Biodiversity Data Journal.

The team surveyed two stands within the forest to present variations in the structure and diversity of the plants over time, along with their dynamics, including mortality and establishment rates. They based their findings on the most abundant tree species occurring within each stand.

At the forest stands, the most abundant and important species for biomass accumulation are concluded to be trees larger than 20 cm in diameter, which characterise advanced successional stage within the forest.

“It is fundamental that opportunities to monitor conserved sites of the Atlantic Forest are taken, so that studies about their dynamics are conducted in order to better understand how they work,” note the scientists.

“The information from such surveys could improve the knowledge about the dynamics at anthropised and fragmented sites compared with protected areas.”

In order to encourage further research into the composition, diversity and structure of the Atlantic Forest over time and the subsequent contributions to the preservation of this threatened ecosystem, the authors made their data publicly available. The datasets, including species occurrences, are now openly accessible via the Global Biodiversity Information Facility(GBIF) and the biodiversity informatics data standard Darwin Core.

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Original source:

Diniz ES, Carvalho W, Santos R, Gastauer M, Garcia P, Fontes M, Coelho P, Moreira A, Menino G, Oliveira-Filho A (2017) Long-term monitoring of diversity and structure of two stands of an Atlantic Tropical Forest. Biodiversity Data Journal 5: e13564. https://doi.org/10.3897/BDJ.5.e13564

New immigrant: Shiny Cowbirds noted from a recording altitude of 2,800 m in Ecuador

Two juveniles of Shiny Cowbird, a parasitic bird that lays its eggs in the nests of other birds, were spotted in the Andean city of Quito, Ecuador, for the first time. This finding represents an altitudinal expansion of approximately 500 m.

Breeding populations might have been prompted by forest fragmentation and/or climate change, suggest the research team, led by Dr Verónica Crespo-Pérez, professor at Pontificia Universidad Católica del Ecuador (PUCE). Resultingly, the ‘immigrants’ could be threatening native birds. The study is published in the open access Biodiversity Data Journal.

“The Shiny Cowbird is native to the lowlands of South America but within the last 100 years, it has been expanding its distribution to higher altitudes and latitudes” says the lead author.

The bird had already been noted from high altitudes in Bolivia and Perú, and in some localities in the Ecuadorian Andes. Since 2000, Juan Manuel Carrión, co-author and director of the Zoo in Quito, recalls observing Shiny cowbirds near his home in a valley near Quito at 2,300 m above sea level (asl). However, one has never before been reported from an altitude as high as 2,800 m asl.

Moreover, the fact that the observed individuals were juveniles means that the species is already breeding in the city.

“Such a significant expansion of reproductive birds, of approximately 500 m, could be related to human disturbances, like forest fragmentation or climate change,” adds Crespo-Pérez.

The observations took place at the PUCE campus about a year ago. Two juvenile Shiny cowbirds were seen parasitizing two different pairs of Rufous-collared Sparrow, one of the most common birds in Quito. The cowbirds displayed food-begging behaviors to adult sparrows, including chasing the sparrows on the ground and chanting intensely on bushes and tree branches.

“These observations mean that the birth mother of the cowbird laid her eggs in the nests of the sparrows, who inadvertently, became the cowbird’s foster parents and incubated, fed and cared for the it as if it were its own, even though the cowbird is almost twice as big,” says Miguel Pinto, co-author and professor at Escuela Politécnica Nacional, and former postdoctoral fellow at the Smithsonian Institution.

“The sparrows were not feeding fledglings of their own species, which suggests that the Cowbird could be having some negative effect on the Sparrow, at least on their ability to reproduce,” points out Tjitte de Vries, co-author and professor at PUCE.

There are several published reports of negative effects of Cowbirds on other birds, especially on species that are already endangered or have restricted distribution ranges. Therefore, this report of an expansion of the Shiny Cowbird towards higher altitudes may be of concern, mainly for native, endemic or endangered bird species.

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Original source:

Crespo-Pérez V, Pinto C, Carrión J, Jarrín E R, Poveda C, de Vries T (2016) The Shiny Cowbird, Molothrus bonariensis (Gmelin, 1789) (Aves: Icteridae), at 2,800 m asl in Quito, Ecuador.Biodiversity Data Journal 4: e8184. doi: 10.3897/BDJ.4.e8184