Water voles are declining , but brown hare and polecat populations are rising .
水鼠数量在下降，而棕色野兔和臭鼬的数量却在上升。
Oxytocin was found to affect the pleasure systems of the brain mainly in the monogamous voles .
研究发现荷尔蒙主要影响单配型鼹鼠脑袋里的的愉悦系统。
The researchers said that while the love lives of voles differ from those of humans , the same brain structures work in much the same ways across different species .
