Post #2066027

2026-05-05 18:45 UTC

I love it when you find a paper that precisely answers a question we were thinking about today - how much like a natural egg does a dummy egg have to look like so the gull will accept it? Answer - they'll even accept a bright red cube if it's approximately egg size, which I can vouch for, having seen Herring gulls incubating vaguely spherical rocks, golf balls, and on one occasion, a head from a Barbie doll https://pmc.ncbi.nlm.nih.gov/articles/PMC8599063/ #Gulls #Ornithology

Replies (8)

@sarahdalgulls@ecoevo.social 2026-05-05 19:24

I have just had a look at the original research on gulls and their eggs, Niko Tinbergen's 1953 study The Herring Gull's World. He found that giving the gulls a choice between Yellow and natural, Blue and natural or Red and natural coloured eggs, they didn't show preference except for Red or Natural - then they favoured the natural coloured eggs

Open ##2104441
@ProcessParsnip@mastodon.ie 2026-05-05 19:16

@sarahdalgulls that... that's real cute. What are these gulls even doing. 😂

Open ##2104444
@nev@flipping.rocks 2026-05-05 19:17

@sarahdalgulls related: https://www.researchgate.net/publication/326574850_Roly-Uoly_Egg_Sacs_Isopods_Used_as_Replacement_Egg_Sacs_by_the_Wolf_Spider_Pardosa_valens_Araneae_Lycosidae

Open ##2104447
@cccpresser@chaos.social 2026-05-05 19:19

@sarahdalgulls thank you for this post. This is the content that makes fediverse fun and interesting ♥️

Open ##2104449
@neckspike@indiepocalypse.social 2026-05-05 19:26

@sarahdalgulls a lot of birds are not good at identifying things that are not their eggs. Is it vaguely the right size? is it in my nest? must be my egg, lemme sit. Ratsnakes are also bad at identifying eggs. If it's kinda round and warm and possibly smells like bird butt it's delicious egg and they will swallow it.

Open ##2104452
@pmcneil@aus.social 2026-05-05 22:29

@sarahdalgulls they're quite gullible

Open ##2104453
@Steve@social.coop 2026-05-05 22:36

@sarahdalgulls Instinct is powerful, but not very specific.

Open ##2104455
@deborahh@cosocial.ca 2026-05-07 14:15

@sarahdalgulls@ecoevo.social @gnomon@mastodon.social so that's where my Barbie soll head went? 😠🕊️

Open ##2251229