Following is a summary of current science news briefs.
Alien enthusiasts descend on Nevada desert near secretive U.S. base
Scores of UFO enthusiasts converged on rural Nevada on Thursday for a pilgrimage of sorts to the U.S. installation known as Area 51, long rumored to house government secrets about alien life, as law enforcement officials beefed up security around the military base. Visitors descended early in the day on the tiny desert town of Rachel, a short distance from the military site, in response to a recent, viral social-media invitation to "storm" Area 51 on Friday, raising concerns by local authorities of unruly crowds overwhelming the community.
Bird numbers plunge in U.S. and Canada with people to blame
From grasslands to seashores to forests and backyards, birds are disappearing at an alarming rate in the United States and Canada, with a 29% population drop since 1970 and a net loss of about 2.9 billion birds, scientists said on Thursday. People are to blame, the researchers said, citing factors including widespread habitat loss and degradation, broad use of agricultural chemicals that eradicate insects vital to the diet of many birds, and even outdoor hunting by pet cats.
Arctic expedition to investigate 'epicentre of climate change'
Scientists from 19 countries are preparing to embark on a year-long expedition to the Arctic, the longest project of its kind, to better understand global climate change. The icebreaker Polarstern is preparing to set sail from Tromsoe in northern Norway, allowing hundreds of rotating researchers to spend the next year close to the north pole.
Scientists reconstruct skeleton of elusive, pre-historic human
Researchers in Israel say they have reconstructed the skeleton of a pre-historic human from a long-extinct and elusive species using DNA found in the pinky bone of a 13-year-old girl who died 70,000 years ago. Little is known about the Denisovans, who were ancient relatives of the more familiar Neanderthals and our own species. Their existence was only recently discovered and has fascinated scientists worldwide.