A very large mouse can take a long time to go down, in which case Wesley would produce a lot of saliva and sometimes even paw at his beak, unable to get it down or push it back up. That would really scare me and I would pull the mouse out by the tail. I learned to give him mice small enough to avoid this problem.
Hawks and eagles will pull the fur and feathers off prey before eating, but barn owls need that roughage. Fish-eating birds such as pelicans and seagulls have the same anatomical setup, with the esophagus along the back of the throat and the glottis up near the tongue and well out of the way of incoming food. Barn owls do not have a crop to store food as do seed-and fruit-eating birds and some raptors.
The other way Wesley ate was to pick out his favorite mouse parts, in this order: the head, heart, liver, and rack of ribs, which he plucked out through the mouse’s neck hole after having eaten the head. If I gave him a large pile of mice he might go through and eat just the heads of every single mouse and leave the rest. A lot of the owls at Caltech and raptor rehab centers do this when there is an abundance of mice. Later, if they get hungry again, they’ll go back for the most blood-filled parts, like the heart and liver. After all those good parts are gone, they’ll eat the rest.
Wesley would toss whatever mouse parts he didn’t want to eat off the ledge of his perch. Of course, this mess o’ mice might land anywhere in my room, bed, or even on me. Wesley always hated eating the intestinal tract, and when he was a baby I’d disguise the guts by wrapping them in fur with some liver sticking out to fool him into swallowing them. He needed to eat the whole mouse in order to stay healthy, although I probably worried too much about it. Owl mothers don’t try to trick the babies into eating everything. But when Wesley was feeding himself and being finicky, he’d extract the entire digestive tract with the skill of a surgeon and fling it as far away from himself as possible. Sometimes he would toss aside an entire mouse, which I’d pick up and return to his perch for him to eat later when he was hungry. Occasionally, I wouldn’t see these food rejects and I’d end up stepping on mice—usually in bare feet—with guts popping out and exploding across the floor or over the top of my foot. I can’t count the number of times I left the house with mouse gore on the bottom of my shoe.
Given this state of my owl’s territory, I was nervous about our guests looking into my bedroom at Wesley and seeing mouse guts on the floor. Of course, I cleaned up regularly, laying towels below the perch and replacing them constantly. But sometimes I would miss something.
An enthusiastic eater, Wesley never tired of the same fare, day in and day out. When I brought him his daily serving of mice, he rejoiced every time and ate with gusto. If he was really hungry, he’d make intense begging sounds, pouncing on the mouse immediately, devouring it in an instant. If he was only mildly hungry, he’d take the time to sound off with a joyous exclamation, similar to his victory cry. Holding the mouse in his beak, he’d lift up his head, and celebrate loudly—“deDEE deDEE deDEE.” Sometimes he became so enthused that he’d drool his acidic saliva all over the mouse, which would then slip out of his beak and onto the floor. Then he’d start crying and I’d have to pick the slimy mouse up off the floor and offer it back to him. He’d then repeat the whole process with his song of rejoicing, eventually getting around to swallowing his meal.
I have never seen any creature enjoy his food as much as Wesley did. He even developed a special sound while eating that I have never heard any other owl make. Holding a favorite piece of food in his beak, he’d emit a long, soft, secretive sound, a low staccato, rising slightly in pitch then remaining on one note for a long time—“dododoDoDoDoDoDODODO”—until it slid back down to the original note, “DODODoDoDoDoDodododo,” so soft at the end that only the two of us could hear it. He did it so rarely that I could never catch it on tape.
American barn owls’ entire physiology is based on a mouse-only diet. Years before, at Caltech, when we had been using chopped rat patties, we had a tragic incident where an owl had choked to death on a rat skull. The rat head apparently got stuck in the esophagus for so long that the owl couldn’t get it to go down or up and may eventually have choked on his saliva or died of the stress during the night before we found him. Normally, barn owls eat only what they’ve killed, and don’t end up in this situation. American barn owls are unable to kill adult rats, which are too large and powerful for this fairly small owl to take on. Other bigger owls, that take much bigger prey like skunks, probably tear off pieces to eat rather than swallowing them whole. We realized that there were absolutely no shortcuts to feeding owls mice, food they would have killed for themselves in the wild, and from then on that’s all we fed them.
People often asked me, “Couldn’t you feed owls nuts or make them vegans?” No. Owls evolved to eat mice, just as cats evolved to eat meat and cannot tolerate a vegetarian diet. Dogs and cats evolved to eat meat plus the partially digested vegetable foods in the stomach of prey or scavenged carcasses; unlike owls, they need some vegetables as well for a balanced diet. It would be impossible for a true predator to live without meat. Wesley would not have even recognized anything other than meat as food. Putting a spear of broccoli on his perch would have been like putting a rock on my dinner plate. You cannot change the needs and physiology of a wild predator whose body evolved to eat a particular animal in a specific niche.
Predators play an important role in the balance of nature, keeping the larger numbers of prey animals in check. Because predators tend to eat the weakest of a species, they keep the remaining population strong. Without predators, herds become weak and disabled. In contrast, when humans hunt animals for trophies, they kill the strongest of the species, thereby weakening the herd. The famed Canadian naturalist Farley Mowat proved this in his brilliant study of wolves and caribou herds, which became the basis of the book and movie Never Cry Wolf. His study, in the 1940s, was so famous that it helped to bring an end to the inhumane practice of chasing down wolves by airplane and shooting them when they were too exhausted to continue. The Canadian government had hoped to justify this by saying that the wolves were decimating the herds, which they were not. Unbelievably, as I write this, the same practice has been made legal again in the U.S.A., and history is repeating itself in spite of everything we’ve come to understand about predators and prey. “Hunters” are shooting wolves from airplanes again—the very same wolves that biologists have been painstakingly restoring to their natural habitats over the last few decades, at great expense and sacrifice.
I do not condone cruelty or the wholesale slaughter of animals, but a wild predator’s nutritional needs cannot be changed. Some people feed their cats a vegetarian diet, but then let the cat outdoors (which they shouldn’t, since cats are a leading cause of the decline in songbirds, after habitat loss and the continual poisoning of the environment), so that the cat hunts mice, rabbits, birds, and lizards to compensate for its dietary deficiency. If the “vegetarian” cat is kept indoors, he first goes blind, then dies of complications due to malnutrition. I never got used to having to kill mice and was just as horrified by it after many years as I was the first time. I had thought I would become desensitized to it, but it remained painful to do. Eventually, I found a pet store that would kill the mice for me before bagging them up, which helped somewhat.
I tried feeding Wesley chicken when mice were scarce, since at least chickens are related to the small birds that owls will sometimes eat. But he usually stared at it for a long time and then cried, begged, and pointedly stepped all over it until I took it away. I persisted because I needed some kind of mouse substitute to which I could resort if I just couldn’t find any mice to feed him. Through trial and error I found that he would reluctantly eat chicken livers, gizzards, and kidneys cut into small pieces, with dark muscle meat mixed in. However, I could not feed Wesley chicken parts for more than a day or two before he’d become listless. For him it would always be an unnatural diet.
I could tell just by picking Wesley up that he had eaten a mouse, since
he was so incredibly light that even the weight of one mouse made a noticeable difference. Also, his stomach pooched out in a perfectly round lump while the mouse was being digested. An hour or so later, when he was ready to cast a pellet, Wesley would lean to one side, looking more and more nauseated, then dramatically gag up the pellet, sometimes shaking his head to dislodge it from his throat. He seemed so miserable, but afterward, he’d give his head one last shake and smack his beak, seemingly glad to get that over with. For each mouse eaten, he produced one pellet. Rarely, he might eat two mice and produce a huge—21/2 inches long by 1 inch wide—double pellet. As a baby, when he was eating six mice per day, he produced impossibly large pellets that must have contained, at times, up to three mice. I wish I’d kept them.
AFTER I FINISHED helping Wendy in the kitchen, I raced back to my bathroom to finish off the mice. But when I got there, the paper bag was open. My stomach tightened. No, it couldn’t be. I counted the mice crawling in the bag, over and over. There should have been twelve, but two were missing.
I had to find them. And I couldn’t tell anyone, not even Wendy, because this visit was too important and she was already anxious. Her husband would have been particularly upset to know that mice were loose. He barely tolerated Wesley, but was on the road so often that he didn’t have to deal with Wesley’s presence very much. I quickly killed the remaining mice, flicking them against the floor, and sneaked into the kitchen to hide them in the back of the freezer. As I headed back to the bathroom to search for the escapees, our guests arrived.
While introductions were being made they probably thought I was a nervous sort since I couldn’t stop my eyes from darting around the room. It was such a large house that I knew that the longer I delayed, the less chance I had of finding the two mice.
Throughout dinner, the guests told us stories of their worldwide travels. My mind wandered, imagining mice appearing from just about anywhere: running across the table, scampering over our shoes, darting across the kitchen floor, dropping from the chandelier into our salad.
“Are you okay?” Wendy asked as I helped her serve the dessert course. “You’re so quiet tonight.”
“Oh, I’m just enjoying listening to all the stories,” I replied.
After dessert, I politely excused myself from the table and hurried off to my end of the house. Almost immediately I heard one of the mice moving around deep inside the clothes dryer, which was located in the hallway between my room and the bathroom. Okay, I knew where he was. Now I just had to locate the other one. I was feeling quite hopeful that it would be close by.
I hunted for it most of the night, long after everyone else went to bed. I didn’t want to sound like an intruder, so I tiptoed around the house with a flashlight, peering in every nook and cranny. I still couldn’t find him.
Finally, before dawn, I quietly disassembled the dryer and extricated the first mouse, putting him in a box. Then I reassembled the dryer and slipped back into my room as the sun came up.
That morning we all gathered at the breakfast table, and everything seemed normal. After finishing their meal the English couple returned to their room and I started hunting once again for the second mouse. It didn’t take long before I found a tiny, black poop in the hall outside the guest bedroom. Gulp. I had probably missed this telltale clue the night before. As I crept down the hall searching for another mouse dropping, the door to the guest bedroom opened.
The lady looked at me and then at the box in my hand.
“Excuse me,” she said softly. “Have you lost a mouse?”
“Well, yes,” I muttered in agony. “It’s for my owl.”
“I believe you’ll find him in here. He seems to have made himself quite at home.” The mouse was sitting quite contentedly in the middle of her bed, washing his face. I scooped him into the box.
“You know,” she said, “many people keep owls in England.”
“Really?” I said, feeling profoundly relieved. “So you’re not upset?”
Her husband chuckled, “Not at all.”
She winked at me and closed the door.
I never fed Wesley mice that had been on the loose because of the chance that they may have gotten into something that could make him sick. Besides, it just seemed like these two had earned their freedom as a matter of principle. I took the mice on a short hike to a field near a stream and let them go.
8
Understanding Each Other: Sound and Body Language
IN SPRING OF 1986 I became very ill and had to be rushed into emergency surgery. While I was in the hospital, Wendy took care of Wesley and, despite my misgivings about leaving him with a babysitter, I realized that by this time in the wild, at a year and three months, he would have become a lone owl, no longer dependent on a parent. Happily, in spite of his shyness toward other people, Wesley allowed Wendy to feed him without incident. Somehow he understood that he was in her care.
The surgery went well and I came home, but the doctor’s orders were “two months of rest and relaxation.” At first this sentence was an irritating interruption of my life and work at Caltech.
“What am I going to do now, Wesley?” I said, stroking his neck.
He gazed back at me and then I realized: nothing. I couldn’t go anywhere and I had no obligations at all. For the first time in my busy life, I could rest and, better yet, I had this lovely creature right here in front of me, and all the time in the world to spend with him. So I sat in bed or on the couch by the window with him standing on my head or shoulder and we just watched the world go by. At night I tethered Wesley to his perch next to my bed. Though he was older now, he still spent hours playing “helicopter” and doing mock perch attacks, always accompanied by rowdy screeches of joy. I found myself turning to Wesley and saying, “I’m going to go to sleep now, okay, Wesley? Go to sleep. Mommy goes to sleep.” While it may not have been very scientific to refer to myself as “Mommy,” I had had to choose one word to call myself, a consistent name that he could learn. Mommy seemed the obvious choice when he was little, and it stuck. Wesley would watch me turn over in bed and promptly go to sleep night after night. It wasn’t long before I could say, “Go to sleep,” and he’d slowly close his eyes, draw up one foot, and fluff his feathers as if he, too, were going to sleep. I say “as if” because I often caught Wesley peeking with one eye opened after a few minutes, only pretending. It was remarkable that he would try to emulate me because he was nocturnal. Even though he tried to be like me and sleep when I did, his natural instincts took over and he often woke me up at night. Eventually I could say “Go to sleep, Wesley” in the middle of the day and most of the time he would, which was handy when I needed a nap—and I often did.
By a few months old, Wesley had started to respond to many of the specific words and phrases I commonly used. I was not training him; he was learning naturally, the way a child would absorb the meaning of words as they are repeated over and over in the same circumstances or to describe the same behaviors. “Wesley you are sooo handsome. Mommy thinks you are sooo handsome,” I would croon, always stroking his cheek feathers and kissing his nose as I did so. At some point along the way, he learned to associate these words with physical affection. Now I could say “You are sooo handsome” from across the room and he immediately lowered his nictitating eyelids, turned his face coyly to the side, and preened a feather or two, acting shy, until I came over and stroked his face.
Wesley loved to be told he was handsome. So for the rare occasions when I asked Wendy or my mother to watch him, I taught them to say, “You’re so handsome” or “Go to sleep” to reassure him if he started acting up, and to say, “Here’s your mice” when they fed him. It always calmed him down when other people knew his special words. He got it. He understood them, and it worked.
Ever since he was an owlet, I’d been giving Wesley verbal explanations of everything I did. Now I could walk up to his perch say, “Wesley, do you want some mice?” If he was full and didn’t want any, he’d turn his head away.
If he was mildly hungry, he would stare at me and slowly lower his nictitating eyelids. If he was very hungry, he would lunge toward me and holler about it, sometimes making begging sounds, which sounded like a handsaw being pulled across metal.
Eventually, Wesley’s responses became more complex. He could answer a whole series of questions with his version of yes: lowering of the eyelids, direct eye contact, and sometimes excited audible responses; or no: turning his head away and not looking at me. We eventually developed a system much like twenty questions. “Wesley, do you want a mice?” (Whether there was one mouse or two mice, to be consistent, I always used the same word: “mice.” I didn’t expect him to learn plural versus singular.) Wesley would turn his head away if not hungry. “Okay, Wesley, do you want to go outside the room?” He would turn his head away in a no. “Wesley, do you want to play with water?” Head would turn away again; also a no. “Wesley, do you want a cuddle?” Instantly his head would whip around to make intense eye contact with me and he’d screech softly. Ah. That’s it. He wants to cuddle.
Wesley the Owl Page 8