# Which animals have the biggest babies relative to their mother's size? **URL:** \ **Category:** Factual Questions\ **Created:** [May 13, 2018, 4:06pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090 "2018-05-13T16:06:35Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [May 13, 2018, 4:06pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/1 "2018-05-13T16:06:35Z")
My question is not which animals have the largest baby. That’s a blue whale. Instead, I’d like to know which baby animals are the largest at birth **compared to the size of their mother**. If we include birds, that’d be baby minus the shell. Some very large animals like polar and panda bears and red kangaroos have really small newborns, so Mom’s size doesn’t seem to strictly determine the infant’s. So it’d be interesting if the largest baby compared to mother is a big animal or a small one. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 13, 2018, 4:11pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/2 "2018-05-13T16:11:37Z")
I’m going to go with the [kiwi](http://www.google.com/search?q=kiwi+egg+x+ray&oq=kiwi+egg+x+ray&gs_l=mobile-heirloom-serp.12...0.0.1.1588.0.0.0.0.0.0.0.0..0.0....0...1c..34.mobile-heirloom-serp..3.6.1334.Gkgad0P9QR8), and say that “egg minus shell” is a meaningless distinction because the baby birds grow to completely full the shell before hatching anyway. ---
**Author:** ![Jophiel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jophiel/32/66_2.png) [@Jophiel](https://boards.straightdope.com/u/Jophiel)\ **Post date:** [May 13, 2018, 4:15pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/3 "2018-05-13T16:15:37Z")
On the mammalian side, baby giraffes are [1/10th the size](https://news.nationalgeographic.com/2015/08/150828-baby-mammal-size-differences-panda-kangaroo-science/) of their mothers. By way of comparison, human babies are 1/22. ---
**Author:** ![Kamino\_Neko](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kamino_neko/32/34_2.png) [@Kamino\_Neko](https://boards.straightdope.com/u/Kamino_Neko)\ **Post date:** [May 13, 2018, 4:23pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/4 "2018-05-13T16:23:05Z")
> [@Darren\_Garrison](#): > > I’m going to go with the [kiwi](http://www.google.com/search?q=kiwi+egg+x+ray&oq=kiwi+egg+x+ray&gs_l=mobile-heirloom-serp.12...0.0.1.1588.0.0.0.0.0.0.0.0..0.0....0...1c..34.mobile-heirloom-serp..3.6.1334.Gkgad0P9QR8), and say that “egg minus shell” is a meaningless distinction because the baby birds grow to completely full the shell before hatching anyway. Concur - in fact, this is what I was coming in to say. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [May 13, 2018, 4:30pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/5 "2018-05-13T16:30:04Z")
My friend Christa is a petite little hundred pound lady who bore twin boys (vaginally) last year. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [May 13, 2018, 5:07pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/6 "2018-05-13T17:07:22Z")
> [@kayaker](#): > > My friend Christa is a petite little hundred pound lady who bore twin boys (vaginally) last year. What was their combined weight? Otherwise that doesn’t tell us much. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [May 13, 2018, 5:13pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/7 "2018-05-13T17:13:41Z")
> [@Qadgop\_the\_Mercotan](#): > > What was their combined weight? Otherwise that doesn’t tell us much. Unless they came out simultaneously. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [May 13, 2018, 6:18pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/8 "2018-05-13T18:18:08Z")
> [@Qadgop\_the\_Mercotan](#): > > What was their combined weight? Otherwise that doesn’t tell us much. They was fucking huge! Yeah, I don’t know things like baby’s weights. But their size shocked everyone. Little Christa was telling everyone that she was pregnant, but she was a wisp of a gal. A month later she told everyone that ultrasound showed she was carrying twins. We all assumed she was psycho. Months later she was barely showing. Then outa nowhere she got a belly. She worked (Bartending) until her water broke and returned to work shortly after delivering twins. I ordered a beer and she told me, “just a sec, gotta go pump”. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [May 13, 2018, 6:19pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/9 "2018-05-13T18:19:10Z")
> [@running\_coach](#): > > Unless they came out simultaneously. I’m telling you, the _afterbirth_ was nine and a half pounds! ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [May 13, 2018, 6:39pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/10 "2018-05-13T18:39:00Z")
> [@running\_coach](#): > > Unless they came out simultaneously. I used to practice OB, and was involved in a few twin deliveries. This does NOT happen. Otherwise there’d be no way for one twin to determine superiority over the other. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [May 13, 2018, 6:44pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/11 "2018-05-13T18:44:04Z")
> [@Qadgop\_the\_Mercotan](#): > > I used to practice OB, and was involved in a few twin deliveries. This does NOT happen. Otherwise there’d be no way for one twin to determine superiority over the other. I should have added a smiley. :smack: How about [sideways?](https://www.youtube.com/watch?v=LIRHB0mNeqM) 😃 ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [May 13, 2018, 6:55pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/12 "2018-05-13T18:55:51Z")
The paradoxical frog beats anything you could think of (unless, of course, you regularly imagine animals violating the laws of hysics) > **[Pseudis paradoxa](https://en.wikipedia.org/wiki/Pseudis_paradoxa)** > > above — Mana, French Guiana > below — Apure, Venezuela > Pseudis paradoxa, known as the paradoxical frog or shrinking frog, is a species of hylid frog from South America. Its name refers to the very large—up to 27 cm (11 in) long—tadpole (the world's longest), which in turn "shrinks" during metamorphosis into an ordinary-sized frog, only about a quarter or third of its former length. Although the recordholder was a tadpole in Amapá that belonged to this species, others in the genus Pseudis also ... ---
**Author:** ![Filbert](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/filbert/32/3433_2.png) [@Filbert](https://boards.straightdope.com/u/Filbert)\ **Post date:** [May 13, 2018, 8:27pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/13 "2018-05-13T20:27:22Z")
For mammals, possibly some species of sengi (aka. elephant shrew, aka. macroscelididae)? I used to work with one species, and their baby was comparatively huge at birth, and very precocious. [This](http://journals.sagepub.com/doi/pdf/10.1258/002367772781006301) depressing '70s study gives an average adult weight of 49.2g for adults and 10g for newborns for _Elephantulus intufi_, which is about 20% per baby (and they often have twins!) They’re ridiculously cute as well. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [May 13, 2018, 11:01pm UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/14 "2018-05-13T23:01:06Z")
If you go all the way to the smallest animal, amoebas reproduce via binary fission so after ‘birth’ the mother and child are of equal size… ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [May 14, 2018, 12:30am UTC](https://boards.straightdope.com/t/which-animals-have-the-biggest-babies-relative-to-their-mothers-size/814090/15 "2018-05-14T00:30:40Z")
> [@jasg](#): > > If you go all the way to the smallest animal, amoebas reproduce via binary fission so after ‘birth’ the mother and child are of equal size… Amoebae are not animals.