Ontogeny Recapitulates Ornithology

         Since I got the news that I'm going to be an aunt, I've found myself becoming interested in fetal development. This is not a subject I had previously given much any thought to. As I count down the weeks until I meet my future nephew, I've been keeping track of his size using the customary fruits and vegetables that websites suggest. This is problematic because vegetables are variable in size and also boring. My mind went instead to birds. I started looking up a bird that matched the mass* of the fetus each week, much to the possibly feigned delight of my pregnant sister. I now present a full list for the enjoyment of pregnant folks and the birders who love them.

* Note that most birds are less dense that a fetus, and therefore greater in size at the same mass.

PC: Gregory Smith

Week: 9
Mass: 2 g
Bird: Bumblebee Hummingbird





PC: Eric Carlson

Week: 10
Mass: 4 g
Bird: Anna's Hummingbird









PC: Francesco Veronesi

Week: 11
Mass: 7 g
Bird: Wilson's Warbler





PC: James Diedrick

Week: 12
Mass: 14 g
Bird: Vermillion Flycatcher








PC: Eric Carlson

Week: 13
Mass: 23 g
Bird: Tree Swallow







PC: Eric Carlson

Week: 14
Mass: 43 g
Bird: Snowy Plover









PC: Eric Carlson

Week: 15
Mass: 70 g
Bird: Northern Pygmy-Owl









PC: Andy Morffew

Week: 16
Mass: 100 g
Bird: Green Jay








PC: Eric Carlson

Week: 17
Mass: 140 g
Bird: Burrowing Owl









PC: USFWS

Week: 18
Mass: 190 g
Bird: Merlin







PC: Judy Gallagher

Week: 19
Mass: 240 g
Bird: Purple Gallinule






PC: Jerry Kirkhart

Week: 20
Mass: 300 g
Bird: Long-tailed Jaeger









PC: Ron Knight

Week: 21
Mass: 360 g
Bird: White-tailed Ptarmigan






PC: Andy Morffew

Week: 22
Mass: 430 g
Bird: Swallow-tailed Kite






PC: Bettina Arrigoni

Week: 23
Mass: 501 g
Bird: Bristle-thighed Curlew






PC: USFS

Week: 24
Mass: 600 g
Bird: Spotted Owl







PC: David Alvarez Lopez

Week: 25
Mass: 660 g
Bird: Fulvous Whistling-Duck






PC: Ingrid Taylar

Week: 26
Mass: 760 g
Bird: Tufted Puffin






PC: Great Sand Dunes NP

Week: 27
Mass: 875 g
Bird: Swainson's Hawk





PC: Stephen Lester

 Week: 28
Mass: 1005 g
Bird: Western Gull







PC: Eric Carlson

Week: 29
Mass: 1153 g
Bird: Common Raven









PC: Cuatrok77

Week: 30
Mass: 1319 g
Bird: Anhinga






PC: Eric Carlson

Week: 31
Mass: 1502 g
Bird: Roseate Spoonbill









PC: Ozzy Delaney

Week: 32
Mass: 1702 g
Bird: Barnacle Goose









PC: Bob Peterson

Week: 33
Mass: 1918 g
Bird: Turkey Vulture









PC: Silver Leapers

Week: 34
Mass: 2146 g
Bird: Common Eider






PC: Cuatrok77

Week: 35
Mass: 2383 g
Bird: Wood Stork





PC: Francesco Veronesi

Week: 36
Mass: 2622 g
Bird: Arctic Loon






PC: USFWS

Week: 37
Mass: 2859 g
Bird: Greater Sage-Grouse (male)






PC: Bettina Arrigoni

Week: 38
Mass: 3083 g
Bird: Laysan Albatross






PC: BLM

Week: 39
Mass: 3288 g
Bird: Lesser Sandhill Crane









PC: M. J. Taylor

Week: 40
Mass: 3462 g
Bird: Brown Pelican







Sources:
www.babycenter.com
The Sibley Guide to Birds, 2nd Ed., by David Sibley, 2014

Comments

  1. Oh holy crow. This is so clever and so illuminating!! As a two time mom, I was OK with the bee Hummingbird, but couldn't help wincing at the thought of bringing forth a brown pelican. Actually the Raven gave me pause. And I thought about the turkey vulture and was amazed that it outweighs a male snowy owl. Thank you Sarah! Sibley's weights and wingspans are two of my favorite features of his miraculous work. This is the bomb!

    ReplyDelete
    Replies
    1. I'm so glad you enjoyed it! Thanks for taking the time to write such a thoughtful comment!

      Delete
  2. Not only are you a crack birder person and stellar (Steller?) birdathon cap'n, and a great writer, but you're a complete goof. I like that in a person.

    ReplyDelete
    Replies
    1. Awww, thanks Murr. I also appreciate your dedication to goofiness.

      Delete
  3. I was rooting for the stork...

    ReplyDelete
  4. Gross.

    But also, mass-wise, 7.17 Burrowing Owls fit in one Western Gull? My mind can't handle this information.

    ReplyDelete
    Replies
    1. Bird mass is a very weird thing. Those feathers really make comparisons difficult. Apparently owls are mostly made of air.

      Delete

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