Monday, May 29, 2017

How to Rehabilitate – Lesson 1


by Peter Gau
Wildlife Keeper


Ever wonder how we get the birds we rehabilitate back to flight ready status? Well the answer might surprise you, maybe you have even experienced it yourself. We put them through physical therapy! That’s right, we work their muscles for them! Now you are probably wondering how you work a bird’s muscles. We can’t ask them to extend their wing or to stretch their leg out. In order to get them back to flying condition we have to be innovative and crafty.

Picture a bird that got hit by a car. They come in to our rehab facility with a fractured right humerus. Radiographs show that the break is clean and the ends are perfectly lined up. We put the bird in a wing wrap and start them on an anti-inflammatory/pain medicine. After their wing has healed and they are done with medications, we start them on their first part of physical therapy. That includes grabbing the bird, and stretching the post-injured wing several times a day. The point of this is to create some flexibility in the wing as it starts to heal and, hopefully, prevent tough scar tissue from growing. After this is done we then move them outside to a flight enclosure.

Now, I want you to remember that this bird has been in a small enclosure for about 2-3 weeks to limit their wing movement in order to promote correct bone healing. They haven’t been able to exercise their pectoral or breast muscles (flight muscles), which account for 15-25% of their body weight, and are the main muscles that control their flight. During that 2-3 week process they go through a small amount of muscle atrophy, which is to be expected. Imagine that you laid in bed for 2-3 weeks, without getting up once, your legs would lose some amount of muscle and wouldn’t be as strong as they were. That is where physical therapy comes in handy.

When we place them outside we need to build on their flight muscles again. When a bird is left alone outside by itself, they will more than likely just sit in one spot and not move. That obviously won’t build any muscle. It is our job to go in the enclosure with them and convince them to fly. Whether that is just walking close to them, or standing behind them and clapping. We use the bird’s healthy fear of humans to encourage them to exercise and re-build their flight muscles. We keep track of flights completed and make sure that number steadily goes up. Once they complete a pre-determined number (species dependent) of completed flights and don’t show they are tired, they are ready to once again be part of the wildlife you see every day!

video

Wednesday, May 10, 2017

Part 2: Re-nesting Great Horned Owls in Rutland, VT

By Nathan Thoele
Environmental Educator

Two days after finding the colony of nests, the second Great Horned Owlet, and at least one parent, our team (Peter, Grae, and myself) returned to the nest site at the College of St. Joseph. With a ridiculously long and heavy ladder, a laundry basket, some paracord, scale, some nets, and the little owlet who’d been brought to VINS, we were ready to build and seek a new home.

After caching all of this, the first thing we did was search for the wild owlet. Amazingly, after 36 hours, it was still perched atop the ten-foot-tall snag. Only now, where he was standing at attention two days ago, he was lying on his belly like a duck. Nonetheless, he looked healthy and alert. The second thing we did was search for an appropriate tree to make a nest in. Just ten yards away, standing next to a stone wall, we found it: a wolf tree, or an old, huge, split-trunked pine with gnarly, but hefty branches. Just 20 feet off the ground, two of these branches radiated out from the trunk, side by side: perfect for cradling our new nest.

While Peter and I wrestled the ladder into place on top of the stone wall, Grae filled the laundry basket with leaves and a carefully woven network of sticks—much more work than any Great-horned Owl would put into its own nest. During this construction process, Dick and Ann, the two who found the owlet, showed up with a few friends and family members, ready to share the enthusiasm and even some of the labor. They were delighted to hear how we found the second owlet and took some photos of our work.

With basket-turned-nest in tow, Peter and I climbed the ladder and began lashing it into place. It is surprisingly difficult to stand in the crotch of a split-trunked pine and securely wrap paracord around a couple of branches to secure a laundry basket, but that is exactly what we did. Much to our relief, the gnarly branches of the pine held solid and we could comfortably maneuver everywhere we needed to. Our final task before calling it good was to drill holes into the bottom of the nest for drainage.

Now it was Grae’s turn to climb the ladder: this time up the snag to catch the wild owlet who had been watching the whole thing unfold. Up until now, the owlet had been watching with interest and without concern. When Grae ascended with a net in hand, though, he took to his feet and started beak clacking and hissing, two behaviors that we interpret as “stay away or I’ll attack!” For good reason, he was afraid of us. To the owlet, we were just a bunch of predators ready to pluck him out of his roosting spot and eat him. That, however, was far from our intention! By the advice of a professional raptor re-nester, our goal was to examine the owlet’s health, as we did with its sibling, and to re-nest them together.

Without even using the net, Grae managed to safely grab the owlet and ferry him down the ladder, all the while being gentle with his newly growing feathers and covering his big yellow eyes to keep him calm. Now it was time for the exams.

The only flat surface happened to be a stone alter-like table in front of the statue of St. Joseph. Thus, we carried both owls, some protective gloves, and a scale up to it and proceeded to examine the owlets. After checking their bodies for any signs of injury or malnourishment, we weighed the owlets and found them to be healthy, and very nearly full-grown.

With Dick’s help (it turns out he used to be a roofer!) we easily finagled the ladder back into place atop the stone wall and against the big pine tree. Peter climbed up to the nest, and we ferried the owlets up to him so he could place them gently into their new home.

At first, when both owls were back together, they looked at each other with shock and spread their wings defensively, not sure where the other had come from or what its intentions were. Then they quickly realized the bigger threat was the giant two-legged, ladder-climbing creature just feet away. Confident that they were not going to attack each other, Peter descended the ladder.

***

The next morning, Peter, Grae, and Anna went back to weigh them after their first night in the new nest only to discover that they had already left it! Both owlets now sat inaccessible at the far end of one of the anchoring branches. Probably, their parents had come back during the night with a tasty meal, alighted on the branch, and the young, already confident from recent adventures, scurried up and out after her, then found themselves in this spot until morning.

Our intention had been to weigh the birds twice to ensure that their parents had fed them overnight. Without this second weight, it was hard to be sure what had happened. However, since it would have been dangerous to try to get to them, the team went back to searching for signs. Sure enough, another few owl pellets turned up, as well as some discarded prey—the foot of a large songbird, most likely a crow, among those remains. This was a very good sign, showing the owlets had indeed eaten since we put them in this new spot.

After taking some pictures, videos, and time to admire these wild creatures, everyone headed back home. Over the next few days, Dick and his family drove out to check on the owls, and to make sure they were both safe. They were rewarded by seeing both young and the adult at various times this last week. With confidence, we hope that these two young owls will grow into capable hunters and beautiful birds of prey, and will be a vital part of this ecosystem for many years to come.


Tuesday, May 2, 2017

Part 1: Re-nesting Great Horned Owls in Rutland, VT

By Anna Autilio
Environmental Educator


Spring means many things in Vermont, and for the Center for Wild Bird Rehabilitation (CWBR) at VINS, it means the beginning of baby bird season. As early as the second week of April, some local species already have new families well underway.

Dick and Ann showed up at CWBR on April 14th with a cardboard box containing the bird they’d found while hiking in Rutland, VT. Bringing the container in to the exam room, Grae didn’t have to open the box all the way to know it contained a very young bird: puffs of down coated the football-sized lump, out of which peeked two wide, yellow eyes. So it was that CWBR received their first baby bird of the 2017 season: a fledgling Great Horned Owl.

Being a fledgling means the owl was already making short explorations out of the nest to feel new perches under its growing feet. Many baby birds make such excursions even weeks before they can fly. This can be dangerous if the bird strays too far from its nest, or into an area containing cats, dogs, and cars. But for most wild animals, this is a time for the young to learn about the world while still being cared for by their protective and watchful parents.

A quick examination determined the baby owl was uninjured, and therefore should be reunited with its parents. Dick and Ann were concerned about this—after all, they had found the bird in the middle of a walking trail on a college campus. Wouldn’t it be dangerous to put the bird back in the same spot? Grae explained that a reunion would be much more involved than simply returning the bird. It would be a re-nesting: finding the old nest or creating a safe, artificial nest to place the bird in where it would be out of reach of predators. It seemed unlikely there would be no nest near where the baby was found. If he had fallen, he could not have traveled far. We determined to go see the place ourselves.

In Rutland, Dick and Ann led us to the place where their dog found the owlet. It was just off a trail, in a patch of large, old pines overlooking a garden at the College of St. Joseph. One look skyward revealed the nest; a collection of thin twigs, molded around larger sticks, bark, and dirt. It was conspicuous, about 60 feet up in one of these pines, but the occupants were not. We stared for a while, passing around binoculars, when Nathan spotted another nest.

We switched to examining this one, wrapped around the trunk of another pine. Birds do build back-up nests, in case one is started in a less-than-ideal spot, and another area opens up later. Great Horned Owls, though, do not build their own nets, rather taking over the stick nest constructed by Red-tailed Hawks or Common Ravens. Because the owls nest so early in the year, it is possible for them to select the best of last year’s construction before the builders themselves return from their wintering grounds. One of these had to have been used by the Great Horned Owls—they were the right size and material, and the owlet had to have come from somewhere not too far away.

But... “Guys there’s another one.” Grae pointed to a 3rd nest.

“That’s…not the same one I was looking at,” I replied, pointing out a 4th.

In all, there were 6 or 7 large stick nests in as many of the pines growing in this stand. Many birds species do nest in colonies (think of penguins, or Purple Martins), and the density of nest sites is often related to how much food is available for all. Hawks and owls, however, rarely tolerate another nest within a certain distance of their own, no matter how much food there is to be found.

What we had found was not a huge colony of owls, but likely a group of American Crow nests. Crows are early nesters by songbird standards, but way behind owls. Whereas crows can be incubating eggs in early April, these Great Horned Owls had to have laid their eggs in mid-February at the latest, assuming the young one in our care was about a month old. The crows had been thinking of spring yet when these owls decided to nest.

The task was now to find which of the crow nests had been occupied by owls this spring, and that involved looking for signs. Nathan took off looking for casts, or owl “pellets”, under each nest tree. Because owls cannot digest the fur and bones in the prey they consume, their stomach compacts all of it into a neat pellet, which they then cough or “cast” up once or twice a day.

I noticed that one of the nest trees had whitewash, or projectile raptor poop, streaking down its trunk. Nathan scrambled over to this tree, and called back over his shoulder. “It is this one!”

Two owl pellets sat on the ground—one round and intact, with clean white bones poking out of dusty gray fur. The other had melted in the rain and fallen apart against a twig, but revealed the same kind of prey remains. There was no doubt that a Great Horned Owl had been here recently. And there was no doubt as to what had happened to evict the owlet—the nest was also “melting”, its twigs and branches spilled over the sides of the branch it sat on, with no neat cup to keep the young one contained.

The question remained, where is the adult?

The next step was to find a comfortable spot and sit silently in the woods, watching and listening for the adult owls. Having been trampling the dead leaves and calling back and forth to one another, it was unlikely we were going to just look up and see a wild owl. So we doubled back a bit, and were getting settled when Grae said, “Wait. Is—is that?—it is! An owlet?”

Right in front of us, staring back in our direction, was another fluffy, baby Great Horned Owl perched about 10 feet up on a tall snag. His body was facing away but his long, flexible owl neck was curved toward us, and his tiny ear tufts stood tall.

After taking a few moments to contain our surprise and excitement, we settled into quietly watching and listening into the darkening forest around us. The wild owlet never moved, but after a while did decide it was okay to ignore us. The Spring Peepers took up a few waves of calling, and the Northern Flickers hammered and squeaked at us from the trees. When half an hour of patient silence had gone with no sightings of an adult owl, Nathan gave a few Great Horned Owl calls into the woods, and Grae found a recording of a begging juvenile on her phone. When neither of these produced the adult after another 20 quiet minutes, we decided to leave and form a plan.

But before we could go, Grae froze, staring off into the woods. “There’s an owl… looking… right… at me…”

The rest of us turned to follow her gaze, and caught only a glimpse of the silhouette of an adult Great Horned Owl flying away into the forest. It made no sound as it went.

This is exactly what we had come to see—evidence that the young owls were still being watched over by their parents, even outside of their dilapidated nest. We had only now to construct a safe place to reintroduce our little fledgling to its sibling, and let the adult care for them both once again.

Check back in a few days for the conclusion of this re-nesting adventure!