SAN FRANCISCO (CBS SF) — Something is suddenly killing hundreds of birds in the South Bay and it might be related to the drought.

Native band-tailed pigeons stop eating and drinking before becoming so weak, they fall from the trees. They can no longer fly or see, their beaks are gaping open. And within a couple of days, they die.

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Many of the carcasses end up at the Wildlife Center of Silicon Valley where a closer look shows white lesions that have swelled up and blocked their throats.

Researchers think the culprit is avian trichomoniasis (trick-oh-mah-nye-ah-sis) and, despite all the dead birds, the good news is that it can’t spread to humans.

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Since the beginning of January, a minimum of 200 to 300 pigeons have died.

Due to the drought, the birds are forced to share dwindling water sources and feeding ground, making it easier to spread the highly contagious bacteria.

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Similar cases have also been reported in Lafayette and Orinda.