Discovered: Dolphins use unique whistles to call for each other; smoking gives mice Alzheimer's; 80 percent of all farm fertilizer goes toward meat production; golden moles are size queens.

Dolphins have something like names for each other. Those giddy dolpin whistling noises may be the names of specific dolphins. University of St. Andrews marine biologist Stephanie King and her colleagues studied recordings of these "signature whistles," finding patterns that suggest the dolphins can recognize each other's distinct squeals and even utter them back in order to call out to other dolphins. "It means they were calling a specific individual," King says, saying their findings show "that they want to reunite with a particular individual ... You don't call out your name; you call the name of your friend. That's how you get back together." [ScienceNow]

Smoking harms mouse brains. Inhaling cigarette smoke gave a group of lab mice Alzheimer's disease in an experiment led by Claudio Soto of the University of Texas Medical School. Compared with control group mice, rodents that were exposed to tobacco fumes developed sever brain inflammation, more amyloid beta plaques, and heightened abnormal tau protein loads. The scientific literature is pretty clear about smoking's damage to the lungs, and emerging evidence suggests it can also lead to brain disease. [Science News]

Most of the world's fertilizer is being used to produce meat. The United Nations Environment Programme has released a report that finds 80 percent of the world's farm fertilizer going towards meat production. And since most of it isn't absorbed by crops, pollution from over-fertilization is harming rivers, contributing to the rise of invasive species, and spurring more acid rain. So what does lead researcher Mark Sutton suggest we do to fix this problem? He has some guidelines for making fertilizer use 20 percent more efficient by 2020, but his most commonsense suggestion is for everyone to eat less meat. [New Scientist]

For female golden moles, size matters. Female Hottentot golden moles judge their mates by how well — ahem — endowed they are. Nigel Bennett and his colleagues at South Africa's University of Pretoria found that mating rituals hinge largely on penis size amongst this blind, underground-dwelling species. Even the males with the largest penises are still quite lacking, relatively speaking. "They probably have one of the smaller penises per length of body in the animal kingdom," says Bennett about their 1.2 to 2.5mm members, compared with a 74 and 97mm average body length. [BBC News]