My world is very earthlike and I am looking to create a bird that primarily eats bone marrow. I wanted my bird to crack the bones of the carcasses to eat the marrow inside. What would the ideal beak shape for breaking bones and removing marrow be? I was thinking something like a parrot would be best, but I'm not sure if it would work.

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  • $\begingroup$ What evolutionary pressures would move the bird towards eating bone marrow? Wouldn't the bird benefit from eating any available portion of the animal? $\endgroup$ – Richard Smith Oct 2 '19 at 2:32
  • $\begingroup$ Terror Birds they are quite formidable and have some extreme bite forces. While bone marrow probably was not their main diet, no carnivore that can gain access is going to say no to it. As a bonus they likely optimised toward such a diet as other mammalian predators cornered the prey market. The remaining resource bone marrow. $\endgroup$ – Kain0_0 Oct 24 '19 at 3:07


green woodpecker tongue https://www.earthtouchnews.com/wtf/wtf/green-woodpecker-tongues-are-so-long-they-wrap-around-their-skulls/

Woodpeckers are perfect for eating marrow. They love fat and are always at suet feeders in winter. They already drill their way into trees. Then they extend their long tongues to lap up the morsels within. A giant woodpecker could hold a bone, peck through its cortex and use its tongue to get at the marrow inside.

This seemed so plausible that I wondered if it had ever been observed. It turns out woodpeckers do use their bills to drill through bone and do use their tongues to eat what is inside - in this case, brains.


What happens next may upset you (and in fact, if you’re sensitive to bird-on-bird violence, you may want to stop reading here). Before the chicks even realize there’s an enemy at the gates, the woodpecker cocks its head back and starts to peck … their skulls. The Gila’s head moves like a pneumatic hammer, up and down, up and down, drilling into flesh and bone with the force of 1,000 G’s. Soon both chicks’ skulls have been opened up like coconuts. At this point, the woodpecker begins extracting brain and blood with its long, sticky tongue.

I bet woodpeckers eat marrow bones now. I will keep searching...

almost there... woodpecker and marrow bone https://www.dailymotion.com/video/xoxpvs

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    $\begingroup$ An excellent answer! I hope you find something on woodpeckers eating marrow. +1 $\endgroup$ – Gryphon Jul 29 '18 at 1:22
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    $\begingroup$ Woodpeckers eat... Brain?! $\endgroup$ – Nelson Jul 30 '18 at 7:09
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    $\begingroup$ That would explain the insane ha-ha-ha-HAA-ha, mad woodpecker disease. $\endgroup$ – BentNielsen Jul 30 '18 at 14:36

Just like so many of our questions, the answer to this one is: "nature beat you to it."

Presenting the Lämmergeier, or Bearded Vulture, a species of vulture that specializes in consuming bone marrow, just like your fictional bird!

A Lammergeier in action

These vultures leave the hard work of breaking open the bones to our old friend, gravity. By simply carrying bones to great heights and dropping them onto rocks, the Lämmergeier breaks open the bones without even using its beak!

A Lämmergeier's beak

As you can see from the above image, the Lämmergeier's beak is curved, with the top segment extending past the bottom part in a downward-curving hook, designed to scoop and scrape marrow from cracked and broken bones as efficiently as possible. Your fictitious bird could employ the same strategy of dropping bones from a height and have a near-identical beak shape, or, instead of inventing a bird, you could simply co-opt this one if it suits your purposes.

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    $\begingroup$ The cool thing about these birds is that their feathers are naturally a white-gray. They actively seek out iron rich clay to stain their plumage. Science still isn't sure why, but it's looking increasingly likely that is cosmetic (with the other possible benefits as a bonus). $\endgroup$ – Draco18s no longer trusts SE Jul 29 '18 at 5:05
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    $\begingroup$ @Draco18s, I think the whole "drop bones onto massive rocks, and then swoop down to dig the marrow out of the shattered remains" thing is fairly cool as well. However, the plumage staining is also extremely interesting. Is it likely for sex selection purposes? $\endgroup$ – Gryphon Jul 29 '18 at 11:10
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    $\begingroup$ We don't fully know. There's a possible anti-bacterial effect, but scientists are pretty sure that that is just a side effect (and there is little evidence that iron oxide works, as some bacteria fights for iron). No evidence has been found to support (or refute) sexual selection either. For example, parents will rub the iron oxide into the feathers of their offspring. $\endgroup$ – Draco18s no longer trusts SE Jul 29 '18 at 15:09
  • $\begingroup$ @Draco18s Hmm, sounds like something that someone should start doing some research on. I certainly wouldn't be surprised if it had something to do with sexual selection, though. $\endgroup$ – Gryphon Jul 29 '18 at 17:16
  • $\begingroup$ The red soil is rare where the vultures live, and being able to secure and maintain a cache is a good demonstration of the bird's strength and/or intelligence. It's also eye-catching on its own. So most likely it is for both sexual attraction as well as social signaling - the bird equivalent of wearing fancy clothes. (Painted males do tend to mate more frequently than uncolored ones, but both males and females do it.) $\endgroup$ – IndigoFenix Oct 24 '19 at 8:47

Think about what this bird needs to do to get to and eat the marrow. It first has to break through bone, so the beak needs to be thick or tough. Next, after a hole in the bone is made it needs to gather enough food from what it can reach through the hole, so a long, narrow beak would be beneficial. If it is a bigger bird, it may be strong enough to simply snap the bones in half, but the second problem still remains, it must be narrow enough to fit its open beak into the bone and long enough to eat more.

Like a woodpecker crossed with a hummingbird.

I recommend looking at the various types of Galapagos finch, discovered by Charles Darwin.

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    $\begingroup$ A hummingbird's beak is very specially adapted to extracting nectar from flowers, which have co-evolved with the hummingbirds to make it difficult for other species to extract the nectar. It's a very specialised situation and nothing at all like eating marrow from a bone - a beak like that could not be strong enough to break bone and would be ineffective at extracting marrow. (The woodpecker part of the idea is reasonable though. Woodpeckers have long tongues as well as tough, pointed beaks, so a bird like that could extract the marrow with its tongue without needing a very long beak.) $\endgroup$ – Nathaniel Jul 29 '18 at 4:56
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    $\begingroup$ (And in fact, from Willk's answer below, it seems quite likely that woodpeckers do indeed eat bone marrow.) $\endgroup$ – Nathaniel Jul 29 '18 at 5:00
  • $\begingroup$ @Nathaniel it would be similar to a hummingbirds in that it would be beneficial to the bird to have a long narrow beak (like a hummingbird) to reach further into a narrow hole in the bone $\endgroup$ – ZoneWolf Jul 29 '18 at 6:28
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    $\begingroup$ Ehh... beak design as optimized for what kind of bone is being broken will vary based on predominant dead food source. Big open spaces with lots of large animals like the american mid-west w/ buffalo, the plains of africa, etc. means big heavy bones to break through. Marshes, wetlands, etc. means lots of birds which means hollow bones, much easier to crush through. The issue I'm seeing with beak design is that something good at crushing a heavy bone (think parrot opening a brazil nut) might not support a tongue structure suitable for retrieving all that nice gooey marrow.... $\endgroup$ – ivanivan Jul 29 '18 at 20:19
  • $\begingroup$ @ivanivan chameleon like tongue rolled up in the back of the mouth (like both chameleons and woodpeckers use) could work with a beak strong enough to crack bone. $\endgroup$ – jwenting Nov 27 '19 at 5:08

They would need to have a very thin and flexible beak or tongue specifically evolved to eat bone marrow since it is inside the bones. The new organ would have to produce specific enzymes that would dissolve the hard bone to reach the bone marrow inside it.


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