1. National Audubon Society: The National Audubon Society is a nonprofit organization dedicated to the conservation of birds and their habitats. Their website has extensive information on seagulls, including their biology, behavior, and conservation status.
2. Cornell Lab of Ornithology: The Cornell Lab of Ornithology is a nonprofit organization dedicated to advancing the understanding and appreciation of birds. Their website has a comprehensive database of bird species, including seagulls, with information on their identification, vocalizations, and distribution.
3. The RSPB (Royal Society for the Protection of Birds): The RSPB is a UK-based charity that works to protect birds and their habitats. Their website has information on seagulls, including their conservation status, threats they face, and how to help protect them.
4. Wikipedia: Wikipedia has an article on seagulls that provides general information about the species, including their taxonomy, evolution, and behavior.
5. Books and scientific journals: There are many books and scientific journals that provide detailed information about seagulls, including their biology, ecology, and behavior. Some of these resources may require access through a library or subscription.
You can also find information about seagulls by searching online for reliable sources such as government agencies, universities, and scientific institutions.