(CNN) They walked slowly, their necks lowered and eyes barely open. One passed out, its legs splayed in the air.

The strange behavior caught the attention of neighbors in Huntington Beach, California, before the humans realized: These birds are intoxicated.

Residents don't seem to know how hundreds of pills got there.

It turns out, the goose and the gull had imbibed some of the hundreds of pills dumped this week at Carr Park, a city green space with a playground and a small fishing lake about three miles from the Pacific Coast.

The pills, which to the park's birds may have looked like grain, seemingly included heart medications, antidepressants, anti-anxiety and insomnia medications, experts with the nonprofit Wetlands & Wildlife Care Center posted at its Facebook page

No one seemed to know who dumped the pills or when, CNN affiliate KCAL/KCBS reported

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