It's listed as a variant
Also, please read the FAQ to see where you need to go to request changes to items. Jisho doesn't maintain the dictionary content themselves, they just display other resources.
I just submitted 鷗 on JMdictDB. Assuming they accept it, it should appear on jisho.org the next time the JMdict build is updated (search JMdict
to check the date)
@Thermospore Looks like your change was incorporated into JMdict. But Jisho was stuck on a late February version because the download location for JMdict changed. I've updated to the new location and your change should reflect on Jisho within the next 24 hours.
Ahh I was wondering why it hadn't updated for so long, thanks for the update
鴎 -> 鷗
鷗 is also very used today.
Add 鷗 to "others forms"