Nature Bytes

Birds are under threat

One in eight bird species is threatened with global extinction, but at least 25 bird species have been brought back from the brink of extinction so far this century, finds a new study of global bird populations by Birdlife International. Iconic birds such as the snowy owl, turtle dove and the puffin are all struggling to survive and humans are to blame for the shrinking numbers, say the scientists.

The State of the World’s Birds, a five-year compendium of population data from the best-studied group of animals on the planet, reveals a biodiversity crisis driven by the expansion and intensification of agriculture. In all, 74% of 1,469 globally threatened birds are affected primarily by farming. After farming, logging is a key factor in declines of 50% of the most globally endangered species, followed by invasive species (39%), hunting and trapping (35%), climate change (33%) and residential and commercial development (28%).

Network analysis & natural history

A team of researchers is using network analysis techniques to find patterns in earth’s natural history, as detailed in a paper published in the Proceedings of the National Academy of Sciences. By using network analysis to search for communities of marine life in the fossil records of the Paleobiology Database, the team was able to quantify the ecological impacts of major events like mass extinctions. The team’s approach offers a new perspective on the ecological impacts of present-day species extinctions, said Drew Muscente, a postdoctoral research fellow at Harvard University, USA and lead author of the paper.

Given the rate of species disappearances over the past few centuries, many scientists suspect that earth is in the midst of the sixth mass extinction. “The fossil record contains evidence of repeated mass extinctions. Data on how ancient communities of organisms changed during these events can help us understand the potential consequences of the present-day biodiversity crisis,” said Drew. “Our work shows that this crisis, regardless of what you call it, may irreparably alter communities of organisms and their ecosystems in some surprising ways, which can’t be predicted with other methods.”

Oceans filled with microplastic

Experts at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have recently found higher amounts of microplastic in Arctic sea ice than ever before. However, the majority of particles were microscopically small. The ice samples from five regions throughout the Arctic Ocean contained up to 12,000 microplastic particles per litre of sea ice.

Further, the different types of plastic showed a unique footprint in the ice allowing the researchers to trace them back to possible sources. This involves the massive garbage patch in the Pacific Ocean, while in turn, the high percentage of paint and nylon particles pointed to the intensified shipping and fishing activities in some parts of the Arctic Ocean.

The study has been published in Nature Communications. “During our work, we realised that more than half of the microplastic particles trapped in the ice were less than a twentieth of a millimetre wide, which means they could easily be ingested by Arctic microorganisms like ciliates, but also by copepods,” says AWI biologist and first author Dr Ilka Peeken.

Human Planet

Human Planet is an eight-part documentary series that focuses on humans and their interactions with their environment, natural resources and other creatures. Directed by Dale Templar, this series travels the globe to explore the connection between humans and the natural world, in myriad climates and environments. Each episode focuses on a different natural environment like oceans, deserts and rivers.

It examines how humans have penetrated and now live in all the most diverse environments of the earth, from deserts to the icy wastes of the Arctic, from the mountains to the coastal plains and from the grasslands to the rainforests. In its exploration, Human Planet captures much of what is most breathtaking about the world in which we live. To watch the documentary, visit www.bit.ly/2HzAWOp.