Is a spotted seagull young seagull?

No, a spotted seagull is not a young seagull. While some seagull species do have spots or markings when they are young, these spots or markings usually disappear as the seagulls mature. For example, the common black-headed gull (Chroicocephalus ridibundus) has brown spots on its head and body when it is young, but these spots disappear by the time it reaches adulthood. Therefore, a spotted seagull is more likely to be an adult seagull that still retains its juvenile markings, rather than a young seagull.