Tag: climate change

Bee populations expanded during global warming after the last Ice Age

The Australian small carpenter bee populations appear to have dramatically flourished in the period of global warming following the last Ice Age some 18,000 years ago.

The bee species is found in sub-tropical, coastal and desert areas from the north-east to the south of Australia. Researchers Rebecca Dew and Michael Schwarz from the Flinders University of South Australia teamed up with Sandra Rehan, the University of New Hampshire, USA, to model its past responses to climate change with the help of DNA sequences. Their findings are published in the open access Journal of Hymenoptera Research.

“You see a rapid increase in population size from about 18,000 years ago, just as the climate began warming up after the last Ice Age,” says lead author Rebecca Dew. “This matches the findings from two previous studies on bees from North America and Fiji.”

“It is really interesting that you see very similar patterns in bees around the world,” adds Rebecca. “Different climate, different environment, but the bees have responded in the same way at around the same time.”

In the face of future global warming these finding could be a good sign for some of our bees.

However, the news may not all be positive. There are other studies showing that some rare and ancient tropical bees require cool climate and, as a result, are already restricted to the highest mountain peaks of Fiji. For these species, climate warming could spell their eventual extinction.

“We now know that climate change impacts bees in major ways,” says Rebecca, “but the challenge will be to predict how those impacts play out. They are likely to be both positive and negative, and we need to know how this mix will unfold.”

Bees are major pollinators and are critical for many plants, ecosystems, and agricultural crops.

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Original source:

Dew RM, Rehan SM, Schwarz MP (2016) Biogeography and demography of an Australian native bee Ceratina australensis (Hymenoptera, Apidae) since the last glacial maximum. Journal of Hymenoptera Research 49: 25-41. doi: 10.3897/JHR.49.8066

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

A botanical survey to help understand change in our wild flora

Volunteers in the north-east of England have created a benchmark survey of common plants with which to identify change in the countryside, its result and causes. This survey will be used in future to monitor the effects of climate change on plants; assess the success of conservation measures and predict future change. Its findings are published in the open-access journal Biodiversity Data Journal, contributing an additional 35,000 observations to the 200,000 observations collected by local recorders since the turn of the millennium .

Many people remark on the changes that are occurring in the countryside, the disappearance of some species and the spread of others. Yet, these anecdotes cannot substitute for hard facts. There are also many suggested causes for all these changes such as warmer climate, different agricultural practices, eutrophication, or alien species. Botanical observations tend to be biased. For example, common species are often ignored in the interest of exceptional ones. Therefore, what was needed was a dedicated survey with a clear and repeatable methodology.

Common plant species are the mainstay of habitats, they create our woodlands, hedgerows and meadows. They also provide the food for herbivores and pollinators and create homes for birds and mammals. Changes in the abundance of rare species have little impact on other species, but change in the abundance of common species can have cascading effects on whole ecosystems of which we are a part.

For these reasons volunteer botanists in the north-east of England conducted a four-year survey to benchmark the abundance of common plants. Led by the Botanical Societies vice county recorders, John Durkin Ecology, Botanical Society of Britain and Ireland, and Botanic Garden Meise, the volunteers surveyed the plants in a randomly selected sample of 1km2 grid squares in the vice counties of Durham and South Northumberland.

They created a solid foundation that can be used to qualify the abundance of common species and compare against previous and future studies. The project was conducted over four years and required volunteers to go to various places. Some surveyed post-industrial brown-field sites, while others walked for miles across bleak moorland to reach sites high in the hills. Although these moors are arguably wilder and natural, the industrial wastelands turn out to be far more biodiverse.

Botanical surveying continues in the region despite the end of the project. Volunteers continue to monitor rare plants in the region and are currently working towards the next atlas of Britain and Ireland, coordinated by the Botanical Society of Britain and Ireland.

“Good biological conservation in the 21st century will have as much to do with sensitive adaption to change as it is about preserving what we have,” point out the authors. “Human memory is short and fickle and it is only with benchmark surveys, such as this that we can hope to understand and manage that change.”

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Original source:

Groom Q, Durkin J, O’Reilly J, Mclay A, Richards A, Angel J, Horsley A, Rogers M, Young G (2015) A benchmark survey of the common plants of South Northumberland and Durham, United Kingdom. Biodiversity Data Journal 3: e7318. doi: 10.3897/BDJ.3.e7318