Berkeley's Aquatic Park. CA

3/8/14
I found a 'helmeted' warbler, only it appeared to be a season's worth of gum from the eucalyptus. This accretion of material appears to block some forward vision but luckily does not block the nares. It does look like it has been shaped by the bird swiping it's beak across a stick and I suppose it will eventually molt off. The warbler otherwise acted healthy.