Current World Health Organisation (WHO) guidelines typically recommend 2–7 days of abstinence before taking semen samples or assisted reproduction. However, a new study led by Oxford University researchers suggests that regular ejaculation – whether through sexual activity or masturbation – results in higher quality sperm, with less DNA damage. 

Natural yeasts ferment anything sugary, including fruit, flower nectar and sugar water in a hummingbird feeder. In the first study to analyze the ethanol content of nectar in a range of species, UC Berkeley biologists fought off the birds and bees to collect samples. Nearly all contained ethanol. Hummingbirds can sip up to twice their weight in nectar daily, which could provide a dose equivalent to a standard alcoholic drink for a human.

A major new UN assessment finds that the world’s great freshwater fish migrations are rapidly collapsing, threatening ecosystems, fisheries, and the livelihoods of hundreds of millions of people. Being released by the Convention on the Conservation of Migratory Species (CMS) at its COP15 in Brazil, the Global Assessment of Migratory Freshwater Fishes identifies 325 species requiring coordinated international conservation action, their declines driven by dams, habitat fragmentation, pollution, overfishing, and climate change. Migratory freshwater fish populations have fallen by about 81% since 1970, making them among the most imperiled wildlife on Earth. Because many species migrate across national borders through shared river basins such as the Amazon, Mekong, Danube, Nile, and Ganges–Brahmaputra, the report stresses that effective protection depends on countries managing rivers as connected systems. At CMS COP15, governments will consider new basin-scale action plans, conservation listings, and other initiatives to protect iconic long-distance migrant species such as the massive Amazonian catfish.