Tool Use in Birds

Summary: Did you know that birds use tools? They do! Join Cheryl and Kiersten as they discuss all the ways bird use tools.

 

For our hearing impaired listeners, a transcript of this podcast follows the show notes on Podbean.

 

Show Notes:

https://pigeon.psy.tufts.edu/

https://www.birdwatchingdaily.com/news/science/various-ways-that-birds-around-the-world-use-tools/

“Bait-fishing by Birds: A Fascinating Example of Tool Use” by William E. Davis and Julie Zickefoose -  https://sora.unm.edu/

https://web.stanford.edu/group/stanfordbirds/text/essays/Tool_Using.html

“Tool Use in Birds: An Overview of Reported Cases, Ontogeny, and Underlying Cognitive Abilities” Thesis by Yvonne Christina Roelofs, University of Groningen

 

Background bird song:  Naturescapes Backyard Birds www.naturescapes.com

Our email address, please reach out with comments, questions, or suggestions: thefeathereddesert@gmail.com

 

Transcript

 

Host Voice: Welcome to The Feathered Desert a podcast all about desert bird feeding in the Southwest region of the United States. (Various bird calls play)

Tool Use in Birds

Kiersten: Welcome to the Feathered Desert this episode will open your mind to the amazing abilities of birds. Cheryl and I are going to talk about tool use in birds! As humans one of the abilities that we thought separated us from the rest of the animal kingdom was our use of tools, but as researchers continue to study the natural world, we have discovered that we are not the only ones capable of using tools.

            To research this controversial topic, scientists first started off with an accepted definition of true tool use. The definition states that true tool use is “the exertion of control over a freely manipulable external object (the tool) with the goal of (1) altering the physical properties of another object, substance, surface, or medium (the target) via a dynamic mechanical interaction, or (2) mediating the flow of information between the tool user and the environment or other organisms in the environment.”

 

Cheryl: We’re going to start this conversation off with baiting. Baiting is the deliberate use of an item to lure prey to a predator, like when humans go fishing. We use a lure to attract fish to our hook and catch them. This is a pretty advanced form of fore-thought that many scientists didn’t think birds were capable of performing, but we have two examples of baiting in birds.

1. The first example is herons using various items to attract fish to their fishing spot. The Striated heron uses bits of bread, insects, twigs, or other vegetation to lure fish close to the branches that hang over the water that they use as hunting spots. Green herons have been seen using bread crumbs to lure fish close enough to easily catch them and chasing away coots that tried to eat their bread lure indicating the heron’s understanding that the bread was helping lure fish. Use of luring has also been reported In the Great Egret, Black-crowned Night-heron, Great Blue Heron, Black Kite, Sun Bittern, and the Pied Kingfisher.
2. Another bird that is one of our favorite Valley birds is also on our tool use list. The Burrowing Owl will line the entrance of its burrow with dung to attract one of its favorite insects to eat, the Dung Beetle. Scientists did a few experiments and discovered that owls using the dung as a lure ate 10 times more dung beetles as owls not using the lure. It’s cheaper than using UberEats!

 

Kiersten: Anting is another example of true tool use but it involves other live animals such as insects. Anting is when a bird rubs an ant, caterpillar, centipede, snail, or other insect all over its body. It happens most often in passerines, aka songbirds, but no one really knows why they do it. One guess is that they use the chemicals in the insect as bug repellent. Another guess is that it could be a way to prepare the insect before eating, since most often the bird eats the insect after the rubbing activity.

 

Cheryl: Egyptian vultures love to eat ostrich eggs, but the shell is so thick they cannot crack it open with their own beaks. So, they fly up to 50 yards away to find the perfect rock to help them crack open the ostrich egg. When they find just the right rock, they hold it in their beak, stand next to the egg, and throw the stone at the egg. They only hit the target 40-60% of the time but they persist until they crack it open. The perfect rock is often an egg-shaped rock and this leads scientists to hypothesis that this behavior evolved from a time when the vultures threw eggs to crack them open instead of the other way around.

 

Kiersten:  An example closer to home is the Brown-headed Nuthatch. And this is a regional example of tool use. The Brown-headed nuthatches from a specific longleaf pine forest of Louisiana use bits of bark to pry off other pieces of bark in search of hidden treasures. They are looking for insects and cached pine nuts. They do this most often when the hunger quotient is high and resources are low.

 

Cheryl: Our next example for true tool use is drumming. Palm cockatoo males will remove twigs from trees to drum on tree trunks. They chose specific twigs that must be between 10-12 cm and they will remove any leaves or offshoots on those twigs until it’s just the way they want it. Then they will beat it against the tree truck and each male has a different rhythm. We’re not one hundred percent sure why they do it but it seems likely that they do it to advertise their territory and to attract a mate. The twig is often added to the nest after a successful pairing. I guess it really is true that the drummer always gets the girl!

 

Kiersten: Drumming actually takes us up a notch to creating tools out of available items. This is one of the most remarkable behaviors we’ve discovered in the bird world. The Woodpecker finch of the Galapagos Islands is an insect eating bird that loves to eat grubs. These grubs burrow into the bark of trees to protect themselves from predators, but the woodpecker finch has designed a way to outsmart them. They use a cactus spine to dig the grubs out of their hiding space and they are particular about which spine they use. They will look for just the right spine or twig and if that fails, they will snap one down to the right size. Once they have fashioned the perfect tool they will keep it with them, flying from place to place holding it in their beak.

 

Cheryl: One of the most amazing examples of tool making is the New Caledonia crow. This crow can make a tool out of almost anything! They break down twigs to the right size and even fashion wire into the perfect tool by bending the ends into the perfect curve. The leaf tools they develop have diversified over time on the island of New Caledonia, which is an unexpected accomplishment. A quote from Ornithology by Frank B. Gill states “The crow has developed the cultural capacity to evolve its tools in ways that resemble the feats of the early ancestors of modern humans.”

 

These birds are also sequential tool users which means they use multiple tools in a row to reach their objective. This is seen in captive experiments where the crow is presented with a puzzle with the reward being food. To solve the puzzle the birds must use different tools to solve each step to finally open the portion with the food. It’s a behavior rarely seen in animals outside of primates.

 

Kiersten: I saved my favorite for last. It’s not as complicated at the New Caledonia crow but it is pretty mind-blowing. The Black Kite of Australia, a type of raptor, has been seen by Aborigines for generations picking up burning sticks on the edges of wild fires and then dropping them further afield to make small prey items, such a mice, run in the direction they want them to go to catch them. This is an amazing example of tool use, but even more incredible it’s the only other example of an animal using fire besides humans!

 

We both hope that this episode of the Feathered Desert stays with you and next time you are watching your favorite birds at your feeder you remember these examples of bird intelligence and how similar birds really are to us.