Tiny and yolk-less egg

[lynchristine]

Found this egg in my nest box today. It was after one day of my five hens not having commercial laying feed (ran out and the feed store is not close). They are 22 months old and have been laying regularly for about 16 months.

The coop and chicken run are not super sealed up (no major predator issues where I live) so wild birds hang out often.

Could this be a irregular chicken egg (and if so what is up?) Or maybe another bird species?

 

[sumi]

See here for possible causes: https://www.backyardchickens.com/a/common-egg-quality-problems