Shed!

I normally write about our mew residents in “News from the Mews,” but this non-feathered member of our Living Collections is just too cool not to share. Emory, the Great Plains Rat Snake, has lived at the museum since 2013 and can be found basking in the Curiosity Center.

Whether you find snakes creepy or irresistible, it’s often for the exact same reason: snakes are weird. They are so different from the furry mammals or cute birds we find immediately appealing. It is difficult for us to relate to their strange scaly, legless bodies. Those differences, though, mean they have some unique adaptations that make them endlessly fascinating.

One example is their skin. Unlike mammals, snake skin does not grow with the animal; the snake has to shed the outer layer in order to grow. Last week, Emory had cloudy, opaque eyes that meant she was preparing to shed. A few days later, I noticed her rubbing her head on rocks and logs in her enclosure. The skin on her head broke free and she worked the rest off in once piece. The final shed is actually inside-out because it peels off the snake like you peel a sock off your foot. I was mesmerized by the whole process and I’m sure she feels good with her fresh, shiny scales.

Weights

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Animals are amazing actors with the ability to mask injuries and illness. They want to hide any weakness from potential predators or competitors, while still finding their basic needs to survive. Raptors will keep hunting for food even with extreme injuries. When our Great Horned Owl, Theo, was rescued, he appeared to be well fed. The rehabilitators believed he was actually running down mice despite having a broken wing. Since their behaviors rarely show signs of illness, their weight is often the first sign of a problem. We take daily or weekly weights to track our birds’ health. The key is knowing what is normal for each bird.

I chart each bird’s weight to keep an eye on patterns. Aldo’s chart, for example, shows daily fluctuations and seasonal changes. His weight last summer hovered around 108 grams (3.8 oz) and increased in November. The higher weight gives him a little extra buffer against cold temperatures through the winter. As spring approaches, he has begun shedding weight in preparation for breeding season and warmer weather. With a baseline of these normal weight patterns, I can identify abnormalities and keep him at healthy weight.

Basking

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Animal training is never a linear line; there are always ups and downs. One day Carson runs to greet me, ready to train. The next day she might ignore me completely and tuck her foot into her belly feathers, telling me she’s not going anywhere. Despite the occasional setback, I was reminded last week that our overall progress is overwhelmingly positive.

When I started working with Carson last July, she ran away from me multiple times before stepping on my glove. She remained uncomfortable when we came outside, often trying to fly away after any noise or sudden movement. I decided to “go back to kindergarten” with her training. We started with basic trust building and slowly reintroduced the glove, this time letting her tell me when she was ready to move to the next step.

We reached a huge breakthrough last week: we finally made it outside. She ran to me when I entered the mew and stepped on my glove right away. She stayed with me as I attached her leash and we stepped out the door. We basked in the sun for a few minutes as Carson calmly looked around the backyard and ate some rat tidbits. Not only was she calm that day, but she decided to do it all over again the next day. I couldn’t be happier or more proud of how far she has come. (I tried to be professional writing this article, but rest assured the original entry in my training log contained a plethora of incoherent exclamation points and smiley faces. 🙂 )

Beak Styles

It had been three months since Aldo’s beak was last trimmed and it was clear he needed another touch-up. The tip of the beak had grown long and his tomial tooth extended far below his bottom bill.

Birds don’t have teeth, so this unique feature of falcon beaks is poorly named. The tomial tooth is not a tooth at all; it is simply a notch in the corner of the hook. Compare that shape to the smooth line on the inside edge of the hawk beak. While this small notch gives me a challenge to shape when trimming Aldo’s beak, it helps falcons quickly dispatch their prey. The notch fits into the vertebrae of their bird or mouse meal and snaps the neck quickly, allowing the falcon to fly off without struggling with its prey. It must be a useful tool, especially considering falcons’ long, slender toes that might not have the power needed to kill prey with their feet alone. Another small meat-eater (one that has no talons at all) takes advantage of having tomial teeth: northern shrikes!

I carefully studied photos of the shape and position of the tomial tooth before trimming Aldo’s beak. I was reassured by knowing that the notches will grow back on their own if I don’t shape them properly, but I wanted to give him a proper falcon beak. Since I had worked on his beak two times before, I felt more confident as I dremeled away the excess keratin. This time he ended up with two intact, correctly-positioned tomial teeth, ready to slice through his mouse reward.

Plumage

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Last time Aldo was inside due to cold temperatures, he spent some quality time in my office. He kept busy by watching visitors pass by in the hallway, listening to the strange noises emanating from my computer, and, apparently, mimicking the artwork on the wall. The watercolor prints were done by a naturalist that I worked with a few years ago. She painted a variety of animals, but my favorite piece is the male kestrel, shown at the perfect angle to highlight his handsome plumage. The solid block of rusty-brown on the tail and slate-blue wings contrast with the female’s rather plain brown wings and tail.

Such a striking difference is rare in raptors. In most species, there is no difference in plumage. The only way to tell male from female is by size: if you see them sitting right next to each other, the female is the larger one of the pair. With individual birds, it’s a bit of a guessing game. Our Red-Tailed Hawk, Carson, weighs just over 3 pounds. That falls in the upper range of Red-Tailed Hawk weights, so she is likely a female. With Aldo we don’t have to guess: his colors tell us without a doubt that he is male.