As someone who has recently welcomed a new dog to the family (see my Twitter account for occasional photos), canines are on my mind. Our newest addition is going to be big, much bigger than any non-human I’ve lived with, and the video below helps raise a question I’d never considered: we have big cats (lions, tigers, etc.) in the wild, but why don’t we have any equivalent big dogs? We breed large dogs like Great Danes, but these are all variants of the same species as Toy Poodles, and are driven through human breeding efforts. Although large dog species can be found in the fossil record, the Northwestern Wolf is the biggest extant wild dog species, but their size doesn’t come close to that of the bigger cats.

The answer lies in the optimal hunting techniques and the environments in which they’ve evolved. Big cats (with a few exceptions) generally take a “solitary ambush predation” approach, sneaking up on their prey and pouncing. Wild dogs tend to live in more open areas with less cover, so their optimal strategy is endurance hunting, working in packs to exhaust their prey before attacking it. Size is not an asset for endurance hunting, so this has balanced out the optimal size for wild dogs to be smaller than cats. It also has impacted the size and shape of their teeth and claws. Interestingly enough, cats have bigger canines than canines.

So consider this your evolutionary factoid for the day.


David Crotty

David Crotty

David Crotty is a Senior Consultant at Clarke & Esposito, a boutique management consulting firm focused on strategic issues related to professional and academic publishing and information services. Previously, David was the Editorial Director, Journals Policy for Oxford University Press. He oversaw journal policy across OUP’s journals program, drove technological innovation, and served as an information officer. David acquired and managed a suite of research society-owned journals with OUP, and before that was the Executive Editor for Cold Spring Harbor Laboratory Press, where he created and edited new science books and journals, along with serving as a journal Editor-in-Chief. He has served on the Board of Directors for the STM Association, the Society for Scholarly Publishing and CHOR, Inc., as well as The AAP-PSP Executive Council. David received his PhD in Genetics from Columbia University and did developmental neuroscience research at Caltech before moving from the bench to publishing.


4 Thoughts on "Why Are There No Big Dogs?"

Interesting, but one would think that dogs would evolve to have greater speed than cats, yet cheetahs can outrun any dog.

Endurance is more important than speed for the hunting style. The point is to wear the prey out, rather than to just catch it and kill it, which is closer to the ambush style (hence the cheetah’s speed being essentially a pounce).

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