It doesn't matter how cute they are: if you see some fuzzy little baby birds along the shore, keep your distance.
Advocates for seabirds have issued a warning to beachgoers about the dangers of disturbing juvenile animals. A little human intervention can wreak havoc on fragile colonies, so biologists have emphasized the importance of leaving wild animals alone.
Although San Franciscans might be relatively accustomed to avoiding threatened species, tourists might want to get a closer look without realizing the extent of the harm they might cause.
If humans bother nesting areas, adult birds may abandon their offspring, according to the SF Appeal.
Alcatraz is a particularly fertile area for nests, and also relatively safe: because large areas of the island are fenced-off, gulls and cormorants are able to reproduce without human intervention. Of course, they still face challenges from other predatory birds.
Urban birds aren't the only ones facing risks from human contamination. Environmental advocates have also pointed to pollution along waterways as a major source of damage to local species. Along the Petaluma River, for example, sunken boats have been identified as leaking poisons into the water.