Talons

The tiniest detail can tell quite a story. If I were to take a magnifying glass to a raptor, I might look at the shape of the beak, its eye color, or the texture of the feathers. Zooming in on the talons, though, will give me a clear picture of how this bird hunts.

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Take a look at the Peregrine Falcon’s talons. Their slender toes end with equally slender talons. These relatively small talons tell me that they don’t have a difficult job to do when catching prey. Falcons often stun their prey by striking it in the air at high speed. Once caught, they will kill the animal with their beak, using a special notch to sever the neck quickly. That means the talons really don’t have to work very hard; small talons are sufficient when their primary job is holding onto subdued prey.

 

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Compare that to the talons of the Red-tailed Hawk.¬†Check out those beefy talons, especially the enlarged talons on the toes labeled “I” and “II” in the photo. These talons have some serious work to do. Red-tailed hawks often catch prey on the ground that are larger than their feet. Imagine a hawk pouncing down on a rabbit. That rabbit will surely be fighting for freedom (and sometimes it succeeds), so the hawk needs a strong, deep grip. Those enlarged talons restrain its dinner until the hawk gets a chance to start eating.

 

GGOW talons.jpgAnd the Great Gray Owl presents a new set of talons and a new hunting strategy. These medium talons are relatively long on short toes and are less curved than other raptor talons. These weapons are ideal for catching small prey, like mice or voles, that fit in the bird’s foot. By maximizing grip strength, the talons can wrap around and constrict their prey. Unlike hawks, owl talons are just about equal in size. This ensures a uniform grip as they clench their bite-size meal.

 

You could probably tell the difference between a carpenter and a dentist just by looking at their fingernails. Whatever type of work we choose to do is imprinted on our hands. For birds, the correlation is flipped. The physical tools that raptors have dictate the lifestyle they need to survive.

 

Photos adapted from the scientific paper, Predatory Functional Morphology in Raptors: Interdigital Variation in Talon Size Is Related to Prey Restraint and Immobilisation Technique,” by Fowler, Freeman, and Scannella. (2009)

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Window Strikes

During raptor mew renovations a few weeks ago, maybe I shouldn’t have been surprised that the plexiglass windows were clear – really clear. They were so fresh and clean that I couldn’t see them from inside the mew. I worried that the birds wouldn’t see them either, and might hurt themselves flying into them.

Windows are some of the most dangerous obstacles a wild bird will face. Millions of birds die each year from window strikes as they mistake the reflections for open space. Luckily there are many solutions to prevent these collisions.

New buildings can install windows angled downward to reflect the ground or choose window panes infused with UV reflective properties that birds can see but are invisible to us. For existing windows, homeowners can add UV decals or bird-friendly tape to make the windows more visible to birds.

There are also low-tech solutions that can be just as effective. I recently found the “Acopian BirdSavers” method, named after the Acopian family. Wanting to reduce bird collisions with their windows in the 1980’s, the family began hanging decorative beaded curtains outside their windows. This design was simplified over the years to a more classic, rather than groovy, vibe. Modern Acopian BirdSavers are simply made by hanging lengths of parachute cord from the window frame, spaced 4 inches apart. This curtain alerts birds to the window’s presence while having a minimal impact on a human’s view.

I happened to have a roll of parachute cord on hand and crafted a “BirdSaver” on each raptor mew window. The thin cords remind the birds that there is a barrier while not disrupting their views of the backyard.

 

 

 

Fall Fest

The town of Cable was hopping last weekend during our 16th annual Fall Festival. Not one to miss out on the fun, Aldo made a few appearances in front of the Museum to meet festivalgoers and appreciate the classics in the car show.

Aldo was raised at a rehabilitation center and imprinted on his human caretakers. He learned to associate with people rather than other kestrels, so he cannot be released back into the wild. It also makes him the perfect ambassador at a crowded festival. He can handle noise and activity better than the other birds, but he still has his limits. After about 15 minutes of watching the crowds, he started to spread his wings to tell me he was ready to leave. I brought him back to his mew to rest and watch activity from his new window.

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Remodel!

Last week was very exciting for the birds: their mews were remodeled!¬† Each bird’s enclosure received a plexiglass window in front and and open skylight. In addition to more natural light in the mews, the birds now have access to rain and snow, breezes, and even entertainment watching chickadees and cedar waxwings flutter in the trees above them.

You can see photos of construction and the birds’ reactions here!

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Enriching

Every once in a while, I give homemade “toys” to the birds as enrichment. They might decide to play with the object, manipulate it in some way, or ignore it. Each bird has unique preferences. Aldo only interacts with his enrichment if it is tied to his favorite perch, and even then he might ignore it for a few days. Carson is easier to please: she’ll shred anything anywhere in her mew.

This time the birds received egg cartons of varying sizes stuffed with newspaper strips. As expected, Carson hopped down to grab the carton right away, but surprisingly dropped it and ignored it for the rest of the day. Even though she didn’t use the toy very much, I still consider it a successful enrichment because it was something out of the ordinary that occupied her mind – and her talons – for a little while.

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Aldo, however, jumped right in and his newspaper was destroyed in a matter of minutes. Theo the nocturnal owl is rather reluctant to move about during the day so he saved his toy for later. The next morning, it was shredded and scattered around the mew. Their reactions are equally enriching for me as I try to figure out new ways to keep them active and engaged.

Jess Grease

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This week I noticed Aldo’s jesses, the leather straps that hang from his legs, becoming more and more stiff. He seemed to notice, too, when he stamped his feet to move the leather to a more comfortable position. It was time to apply an oil to condition the leather. Luckily falconry suppliers make a conditioner specifically for this purpose: jess grease.

To condition the whole length of each jess, I need to remove the leash that binds the pieces of leather together and secures him to my glove when he is out of the mew. That means that if he tries to fly away during this process, he is more likely to escape. In case he gets away from me, I choose the smallest room with the lowest ceiling and fewest perches: the staff bathroom. Applying the jess grease is easy and I simply rub it in with my fingers. The grease will sink into the leather to keep it supple and waterproof for a few more weeks.

 

The Fair

I was excited to go home to the Twin Cities last weekend to join my family at the Minnesota State Fair. Starting out early in the morning, we found breakfast at the mini doughnut stand and wondered what to do next. My eye was soon caught by a tortoise outside of “Monty’s Traveling Reptile Show.” I always thought this building was a little tacky, with signs worthy of a peculiar circus, and had never been inside. I was surprised when my mom said, “Let’s go in, you’ll love it!”

The atmosphere inside was not the circus I was expecting. Instead, a variety of reptiles lay in individual terrariums with educational signs about each. The number of reptiles represented from around the world was stunning. As I stepped away from the diamondback rattlesnake display (grateful that I live in a place with so few deadly animals), I saw a peaceful Black-throated Monitor lizard snoozing against the glass. There was a clear view of a gaping hole in the side of his head.

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I knew that snakes don’t have external ears, so what could that hole be? It turns out that most reptiles like lizards, crocodiles, and turtles, do have external ears. This lizard’s tympanic membrane, or eardrum, was clearly visible and capable of picking up sound waves through the air.

After a full day at the Fair, I was relieved to return to the quiet town of Cable and to care for my own reptiles. I had to admire Digger’s smooth head which lacked a hole for his ear. His ear structure (hidden behind a layer of scales) is capable of hearing sound waves through the air but is better equipped to sense vibrations transmitted through the ground into his jawbone. Even though he didn’t respond, I’m sure he heard my excited, “Hello, Digger!” when I returned.

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