Fly Eggs

It was 9pm. The baby birds were fed and covered, and evening medications had been administered.  I knew that all I had to do was to get comfortable for Beth to arrive with the owl.   I turned on one of our large incubators and jacked the temperature up to 105°.  I placed a thick towel on the stainless steel examination table.  I filled a mug with hot water, placed a syringe with 20cc lactated ringers solution into it, scooped some ice cream into bowl, and sat down to read a book about harriers.  Five minutes later, the car pulled in.

When she had called earlier, Beth identified the large owl she’d found that day as a Great horned owl.  Horned owls are the largest, most powerful owl in the area. They range from 18 to 25 inches tall, the female tending to be larger than the male, and can weigh two, three, even four pounds.  Great horned owls are called “Cat Owls,” probably because of their size, large, yellow eyes, black pupils and ear-like feather tufts at the tops of big, round heads. For the most part, any encounter with one is from a prey’s perspective, below the owl, as they tend to perch high in trees. Like a cat, a Great horned owl can remind you of your insignificance with just a glance.

We have enhanced the world for Great horned owls; they eat what we consider “vermin,” and in our fumbling with local ecosystems, vermin have more or less followed us through history. The resulting food sources (mice, rats, squirrels) provide a rich and varied diet for this not-very-picky, opportunistic predator. For this reason, and for their ferocity, Great horned owls are also called “Tigers of the Forest.”

At our busy wild bird hospital we are always a little dubious when people identify raptors. I have personally traveled to get a “baby eagle” or a “young hawk” from well-meaning homeowner’s back yards – birds that ended up being pigeons or woodpeckers.  Once I went to a home in rural New Jersey to get a “huge” owl out of a wood-burning stove.  “How big is it?” I asked the woman who frantically summoned our center with her plight.  I needed to know because if I am going to open a stove door and meet a cornered, four-pound Tiger of the Forest, well, I’d like to prepare myself.  To answer me, her eyes opened wider and she held her hands one over the other, 24 inches apart.  I put on elbow long, thick welder’s gloves, opened the stove door and found an eight inch Eastern screech owl staring sleepily at me.

People have entered our center carrying refrigerator boxes with tiny nestling robins gaping frantically within.  Or a small dog carrier stuffed with a Great blue heron.  When Beth and her husband carried the plywood board with the garbage container sitting over it into the infirmary, I tilted it up and saw the huge, golden- feathered feet tipped with long black talons.

This was a Great horned owl.  She was huge, but pathetically thin and blind.  One eye was ruined; the black of the pupil was torn and misshapen. The other eye was filled internally with blood, as if it had been struck.  Her keel – the breast bone, named for the boat-underside that it resembles – was blade-sharp, almost concave on either side, lacking any fat or muscle.  On the owl’s rump, under and over the tail, in the downy feathers and in the vent and preen gland, were fly eggs, more fly eggs than I had personally ever encountered.

If you did not know fly eggs, you’d probably not recognize them as the preface to the voracious grubs which they become: maggots.  Fly eggs appear innocuous: pale yellow, powdery-looking, they look like you could just brush them off, like snow. But the eggs are not powdery; they are sticky, like cotton candy, and to pry them off feathers is no small task.   In fact, I had stayed late because Beth had mentioned that there were flies around the owl, so I was prepared for eggs or for maggots.

I was relieved to see eggs.  Anyone who has dealt with injured animals in the summer knows why.  It takes about 24 hours for maggots to hatch from the eggs. Besides not eating, squirming and swimming through open and closed flesh, fly eggs suggested that the bird wasn't down long.

I placed the owl into the warm incubator to stabilize her and began to gather anything I might need to pick off fly eggs.  I had never done this alone – usually one of us holds the raptor while the other person treats it - and I didn't want to make the mistake of shorting myself on what I needed for cleaning her.  I searched for the long, slant-ended, fly-egg-maggot-picking tweezers. I'm sure they must be called something else and created for other purposes, these instruments, but they perfect for picking a number of eggs or maggots at once with their half-inch slanted tips, as opposed to picking one at a time with regular tweezers. Even with them, I saw myself picking fly eggs by the millions into the morning.

I put thick leather gloves, and after about 30 minutes - long enough to be sure the she was warmed - I carefully slid the owl out of the incubator.  She was weak, but still strong enough to grab and hold the towel on which she lay.  She wouldn't let go, even as I tried to work it out of her feet, each of which were, by the way, about half the size of my hand.  Okay, I thought, I'm not going to make an issue out of this.  I could always use an extra towel around her feet.

At the examination table, holding both her legs under her belly with my left hand, I lay the big owl on her side on a clean towel, her feet away from me, covering her head with part of that towel and wrapping her feet with the one she was holding.  This way if I got too absorbed in my egg-picking I couldn't inadvertently tilt my head into those taloned feet and find myself attached to a very pissed-off owl.

She lay still, as most birds do when you cover their heads and don’t hurt them.  Debilitated as she was, her big feet yet held tight to her towel.  Her sharp keel was testimony to her hunger. A healthy female Great-horned owl can weigh over four pounds and make meals of skunks and Canada geese. This owl weighed maybe 20 ounces and had probably eaten nothing for days.  I carefully examined her mouth, beak and ears. Flies infest any openings as well as wounds.  Her mouth was very pale and pasty, indicating shock and dehydration.  I would give her fluids later. In the meantime, I applied ophthalmic antibiotic ointment to her eyes.

I had prepared gauze pads and two small bowls of warm water and betadine: one for cleaning and swabbing the owl’s skin, the other for dunking the tweezers of the eggs. I sprayed the owl’s rump with an oily medicine that kills maggots, and began picking eggs, methodically, dunking and swabbing.  There were so many eggs that I put down the slanted-edged tweezers and used my gloved fingers, to get more mileage, as it were.   But fly eggs are tenacious, and after about five minutes of finger-picking, I resorted again to the tweezers.

I lost track of time.  My world became confined to the soft rear of a Great-horned owl’s rump and my objective in life was limited to the picking and picking of the fly eggs on it.  From big masses of eggs I had reduced the load to small clumps, close to the base of her downy feathers. They were hard to remove without tearing out feathers.  I wasn’t sure of the priorities.  I decided to sacrifice some feathers for the cleaning of eggs.

By midnight, the owl’s rump was clean of fly eggs. She lay still, but I could see the soft rise of her breath.  I wrapped her in the towel, lifted her gently, tilted up her head and tubed her the lactated ringers solution. The fluids – which I had to warm again - would help rehydrate her.

I’d done as much as possible. Tomorrow, we’ll see if she’s up for a more comprehensive examination. Maybe we can then make sense of her injuries.

I put her back into the incubator, propping her on a towel to support her breast so her poor eyes were safe from the walls if the incubator. She had objected to nothing of the indignities of the evening.

She still had the towel with her feet.