Sticks

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Carson holding on to one of her sticks.

Even through the ice and snow last week, birds can sense that it’s spring. There seem to be more osprey than we’ve seen in recent years in the Cable area and they are busy nesting. Over the course of two or three days I watched one pair’s nest-building progress on my daily commute. What started as a few tree branches dangling precariously from a utility pole quickly became a sturdy mass of sticks. It is similar in structure to bald eagle and red-tailed hawk nests. In red-tailed hawks, the male and female work together to collect sticks and weave them together into a nest lined with strips of bark, fresh plants, or dried vegetation.

Our red-tailed hawk, Carson, has also sensed the springtime urge to build. Noticing an uptick in her activity this spring, I decided to test her interest in nest building. I placed 5 sticks around her mew one night and wondered if she would touch them. I was surprised to see each stick had moved the next morning. Since then, she moves the sticks around nearly every day, and occasionally she gathers them on top of her platform as if waiting for more sticks to appear so she can make a decent-sized nest.

Putting the “Tiger” in Tiger Salamander

Tiger Salamanders, one of seven salamander species found in Wisconsin, are named for their black and yellow markings that sometimes resemble tiger stripes. I think the name is still fitting for our salamander, “Scuba,” whose markings are more splotchy than striped. He lives up to his namesake by being a voracious predator.

Tiger salamanders are carnivores that eat pretty much anything that will fit in their mouth. As aquatic larvae, they might eat insect larvae, tadpoles, and small fish. Terrestrial adults eat worms, frogs, mice, or even other salamanders.

Scuba’s favorite snack is mealworms, but red worms are the bulk of his diet. When he senses a worm (and if he’s hungry), he strikes with surprising speed. A red worm is too long to swallow in a single gulp, so he vigorously shakes it to subdue his prey. Normally we see Scuba as a slow-moving and elusive creature, but he can become quite a tiger when food is around.

Vocal

Our Red-tailed Hawk, Carson, has been very vocal lately. When I enter the mew, she often grumbles and squawks. And every once in a while, we can hear her from the office when she gives her typical Red-tail “keeee-er” call.

I had never heard the high-pitched, repeated squawks before, so I posed a question to an international group of bird trainers online: “Does anyone speak Red-tailed Hawk?” It turns out these sounds are quite common in some birds. Some trainers said their Red-tails only do this in the spring during breeding season. Others said their birds make the repeated squawks when they see the trainer coming with breakfast. It was interesting to hear what other birds do and to try to piece together an explanation for Carson’s chatty habits. The vocalizations just started this spring so it is likely due, in part, to breeding season. She is also very food-motivated; she may be telling me to hurry up and deliver dinner!

 

Bath time

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Last Saturday was finally warm enough for the birds to take a bath outside. When I gave Carson a pan of water, she hopped in as soon as I left the mew. I watched from the door for a moment, but she just looked back at me. I went back to my office to give her some privacy. An hour later I returned to check on her, expecting to see a dripping hawk after splashing and playing in the water. Instead I found Carson still standing in her water, completely dry except for her feet.

I continued to check on her throughout the morning and nothing changed. She simply stood in the water pan for three hours straight. I guess she decided that all she needed was a nice foot soak!

Enrichment

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To maintain healthy birds in captivity, we encourage natural behaviors to keep their minds and bodies active. Most of a wild raptor’s day is spent simply sitting on a perch and watching their surroundings. That is easy to replicate in the mews: our birds sit and watch the Museum’s backyard daily.

For the rest of their time, we place new objects in the mew for them to look at or toys to play with. Carson recently received a phone book that Jayme (Living Collections Assistant) carefully folded like a fan. After a few weeks, Carson had ripped up nearly half of the book! Shredding is a natural behavior that wild raptors do when they catch a large meal, like a rabbit. This kind of enrichment keeps Carson busy and gives her an opportunity to rip and tear something for fun.

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.