Natural History

There’s an odd feeling waking up from a dream and not being able to recall any of its details. A color, a feeling, a flavor might stand out, but the context is elusive. Trying to define “natural history” gives me the same feeling. Rarely used in everyday life, I don’t have a good sense of context to give it meaning.

The term may be vague, in part, because it is a moving target. I understand natural history to refer to a species’ habits or a habitat’s history: everything that is known about that species or place. But life – from the species level to an entire ecosystem scale – is always changing and histories are constantly being rewritten. One recent example came out of Florida where American Kestrels were observed using an unusual nest site.

The natural history of kestrels tells us that they nest in ready-made cavities: natural tree hollows, old woodpecker holes, or rock crevices. They have also expanded in recent years into man-made nest boxes. But now kestrels have been observed using a nest built by a non-native species.

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Monk Parakeets and their colonial stick nest.  (đŸ“·: Eduardo Merille)

Monk Parakeets, native to South America, were brought to the United States in large numbers through the exotic pet trade. Some escaped and quickly established colonies in southern Florida. Unlike other parrots, these parakeets build large stick nests with separate chambers for 20 pairs or more. The nests are typically found in trees, but silos and utility poles are also used.

The nest cavities must be just the right size for kestrels, too. Two pairs of American Kestrels were observed re-purposing parakeet nests for their own families, and both successfully fledged young at the end of the season. As a species in decline, it is exciting to see kestrels taking advantages of new opportunities and re-writing their natural history.

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Theo

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We were sad to say goodbye to our resident Great Horned Owl, Theo, this week.

Theo came to the Museum in 2014 after being hit by a car near Drummond, Wisconsin. A broken radius and ulna in his left wing healed improperly and left him unable to fly. Unfortunately, this injury continued to cause problems as the misalignment started to cause arthritis and affect feather growth.

Quality of life, including physical and emotional health, is always the first priority for our live collections. Through evaluations and consultations with veterinarians and other raptor experts, we concluded that humane euthanasia was Theo’s best option. He will be fondly remembered by his trainers and the visitors that met him.

Digging

After Emory the rat snake explored the great outdoors last week, Digger was not about to be left out on the fun! Once in the grass, Digger lived up to her name and started tunneling right away:

Digger is a Western Hognose Snake, a species that features an upturned “nose” that acts like a shovel. They use this tool to burrow underground, often finding their favorite foods like toads and frogs. With their excellent sense of smell, western hognose snakes have also been known to follow turtle nest scent trails and dig up the eggs for a meal. This species is native farther west, but Wisconsin is home to the similar Eastern Hognose Snake.

 

Novel Basking

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Raptor enrichment is always on my mind as I plan interesting things to keep the birds occupied, but it is easy to forget about the snakes that rest quietly in their enclosures. I found Emory the Great Plains Rat Snake cruising around her habitat one morning and wondered what kind of contraption I could construct to change up her routine. Then I realized there was an easier, ready-made enrichment item: the great outdoors!

Both of our snakes hatched in captivity and are accustomed to living indoors. To create a novel experience for Emory, we went out to the backyard and I set her gently in the grass. She wiggled a bit, free from my grasp, but then lay still. Her tongue flicked out a few times before she rested completely motionless. A snake’s thoughts are impossible to read, but I wondered if she was overwhelmed by this new environment or just enjoying it. The texture of green grass, vibrations traveling through the ground, the bright glare and heat of the sun were new experiences that we will continue to explore through the summer and into fall.

Sitting in the Sun

It wasn’t a terribly hot day, highs in the upper 70’s, but the humidity was thick. I hurried across the short path between the office and the mews to avoid the sun’s heat. I checked on Theo the owl who was sitting on his favorite perch in the back of the mew, Carson the hawk perched on the edge of her water pan with wet feet, and I wondered how Aldo the kestrel was staying cool as I neared the last mew. The door swung open and I was surprised to find Aldo on his rope perch, a place I rarely see him use. He had chosen to sit right in the narrow column of sun peeking through the skylight. In the wild, he would probably be perched, hunting, in an open field, even on a muggy day like today. I was glad he had the option to sun himself, even though it seemed a little crazy to me.

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Spiders

The mew building was made to keep the birds in – and other critters out. Large animals are easy to exclude with 1/2-inch wire mesh. Each mew is also equipped with screens to keep most small pests out, but flies still find their way inside and buzz around any leftover pieces of food. I am always happy to see a busy little spider in the mew, hoping its web will catch a few flies and not me.

The sun hit the mew just right for a shimmering web to catch my eye. Instead of the flat, criss-crossed lines that make up a stereotypical web, this spider had formed a dome in the corner of the hallway. Above the inverted bowl was a tangled mess of fibers, ready to knock insects down to the main platform where the Filmy Dome Spider sits. She hangs upside down on spindly legs, waiting for her next meal. With all of the buzzing flies around, it looks like she found a good spot to stay well-fed.

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