On Saturday mornings I drive 15 miles to a sanctuary in rural Maryland where I join a small team of volunteers tending to farm animals rescued from neglect or abuse. Some of these animals will never fully trust a human. Others want to interact.
As a biologist with a special interest in animal happiness, I’ve figured out where they like to be scratched and rubbed. Goats, such as Trudy or Malcolm, walk over to me and lean gently against my leg. I scratch between their horns, caress their faces and vigorously swipe my hand down their backs and flanks. They become noticeably more relaxed. Their eyelids droop and they stand completely still. One of the older sheep, a ram named Adam, wags his tail in approval when he is petted. Another sheep, Clover, once scraped her hoof across my boot repeatedly when I briefly stopped massaging her back — a sheep’s way of asking for more. At the pig barn, 700-pound adults lying blissfully on soft hay will assist the effort to give them a belly-rub by shimmying further onto their sides and raising their legs. And when the chicken barn door opens, about 20 birds come surging out into the sunlit garden. They spend the next few hours foraging. They nibble at seeds and vegetation, and search for invertebrates by pawing backwards at the earth with their strong feet then stooping down to peer and peck at any moving morsel they’ve uncovered. They do this with devotion, taking breaks to sunbathe by reclining on their sides, fluffing out their feathers, and stretching a wing to maximize the surface area available to the sun’s warm rays.
Animals and sentience
Watching these animals pursue their wants and needs reminds me that they are individuals with intentions and preferences. Their lives matter to them. Their desire for rewards is part of sentience — the capacity to feel. Sentience encompasses a universe of positive and negative physical and emotional experiences.
Today, most scientists agree that all vertebrate animals — mammals, birds, reptiles, amphibians and fish — are, to varying degrees, sentient. A rich and varied collection of research has made the evidence impossible to dismiss.
But this perspective wasn’t always popular.
Historically, for example, sea-life rarely made it into humanity’s realm of concern when it came to the ability to suffer. But meticulous experiments performed on trout a decade ago essentially have laid to rest the common view that a fish cannot feel pain. There now is also scientific support for sentience in at least some invertebrates. In research by Canadian biologist Jennifer Mather and colleagues, octopuses show curiosity, play and personality. And in a study led by Robert Elwood at Queens University Belfast, prawns spent more time grooming and rubbing a pinched antenna, unless they received a follow-up application of local anesthetic.