Tarantulas: How They Hunt

Summary: Tarantulas are predators! They have a unique way of hunting their prey. Join Kiersten as she walks you through how these eight-legged wonders catch food.

 

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

 

Show Notes: 

The Tarantula Scientist by Sy Montgomery

Remarkable Animals: The Tarantula by Gail LaBonte

 

Transcript

(Piano music plays)

Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

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Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

This episode continues tarantulas and the fourth thing I like about these eight-legged wonders is how they hunt!

 

Most of the tarantulas that we currently know about are carnivores. That means they eat meat. We have yet to discover a tarantula that eats vegetables but you never know. Most tarantulas are ambush predators which means they lay in wait until the right prey comes along. They hide under cover and wait patiently until food comes to them. Some species will stay in or near their burrows to hunt while others will travel a short distance from their homes. If you’ve ever encountered a tarantula in your house at night, it was probably searching for a nice midnight meal!

 

What is the correct prey item for a tarantula? That can depend on the species of tarantula and how big they are, but the majority of them hunt other invertebrates. Tarantulas are opportunistic eaters which means they will consume almost anything that they can catch. Examples of common prey items are grasshoppers, crickets, beetles, wasps, cicadas, worms, caterpillars, and even other spider species. 

 

Sam Marshall, a scientist studying tarantulas in the wild, has been able to lure them our of burrows by dangling earthworms in front the entrance. I could go on but the list is long when it comes to invertebrates. Almost any kind of insect you can think of could be consumed by a tarantula. Hmmm. Maybe not ants, I haven’t seen any references to tarantulas eating ants.

 

Some of you may be asking if they eat things other than invertebrates. You may even be thinking about the bird-eating tarantulas of South America. They must eat birds if it’s in their name, right? That is a reasonable thought but…Not so much. These tarantulas are large enough to eat birds, but there is not a lot of evidence proving that they do eat birds. These large tarantulas eat bigger invertebrates, mice, lizards, and will even occasionally catch a toad. The reason they have this name is because of an illustration depicting an arboreal tarantula eating a hummingbird, but as of yet no one has seen this behavior in the wild. I’ll have more on this in a future episode.

 

Now that we know what they eat, let’s find out how they catch their prey. For those of you who have already listened to the episode on senses, you know that tarantulas have fairly poor eyesight. They cannot see in detail. So if they cannot see clearly, they must rely on another sense to detect prey, right? That is an excellent thought, Listeners. And that is exactly what they do! The sensitive hairs, or setae, covering their body help them feel prey items when they are close enough to successfully catch them. These hairs are extremely sensitive and as the tarantula gains experience it learns which movements indicate potential prey. They can tell the difference between a grasshopper, a moth, or a mouse. 

 

Tarantulas that hunt from home have another trick they use to successfully  catch a meal. All spiders spin silk and tarantulas are no exception. Other species of spiders spin large webs in open spaces to catch prey items that happen to get caught in the sticky silk. It’s an excellent way to catch prey unawares, but tarantulas do not use their silk webs in this way. However, they do set trip wires along the ground that attach to webbing laid down on the floor of their burrows. These trip wires will vibrate when something walks by it. The tarantula will sit patiently in the entrance of the burrow with one of its legs touching the silk attached to the trip wire. As soon as the silk vibrates at just the right frequency, they pounce!

 

Tarantulas cannot jump but they have strong chelicerae and pedipalps that aide in catching, as well as eating, food. Once they have determined that an appropriate food item is nearby they can move quickly to snatch it. They grab it with the two fangs that are attached to the end of the chelicerae and stabilize it with the pedipalps. Tarantula fangs can only move up and down, so they must rear back to expose their fangs when they are grabbing their prey. 

 

The fangs are connected to venom sacs that sit inside the chelicerae. The tarantula will inject their prey with venom to kill it. The venom also helps breakdown the insides of the prey into a soup-like liquid. Don’t worry, it’s likely that their prey is dead before their insides begin to dissolve. This can take a little time so the tarantula will hold their food patiently as they wait. 

 

After the venom has had time to work, the tarantula will crush its food with its chelicerae. The juices will squeeze out and the tarantula’s strong stomach muscles will suck the juices into its mouth, like a vacuum cleaner! I have to admit it sounds kind of gruesome, but it’s also terribly fascinating. 

 

Like most spiders, the tarantula can only digest liquids, but unlike most spiders they do chew their food to get all the liquid out. To make sure no large pieces of exoskeleton get into their digestive system, they have small hairs around their mouth that act like a filter keeping out those large pieces. The whole process can take up to twenty minutes, so the tarantula will pull back into their burrow or hiding spot while they eat to protect themselves from predators that might be hunting them! Once they’re done the only thing that is left is a little bit of exoskeleton.

 

After the tarantula has finished its meal, they take a moment to clean their mouth parts. They are very fastidious about cleanliness because the hairs around their mouths are so important in keeping them healthy.

 

The last question we need to answer about how tarantulas hunt is how often do they need to eat. The answer is quite mind-blowing. Are you ready? One grasshopper can be enough food for the tarantula for two months! That’s 60 days! Could you imagine if we could live off of one hamburger for two months? That is some slow digestion! 

 

I know this to be true, through personal experience. I had a rose-haired tarantula as a pet for 12 years and I gave her about five crickets a month. Sometimes the crickets died of old age before she even ate them! 

 

The way tarantulas hunt is fascinating and I know you loved hearing about it because it is my fourth favorite thing about tarantulas. 

 

If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 

 

Join me next week for another thing I like about tarantulas!

 

(Piano Music plays) 

This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.