Birds have a cone cell which is sensitive in the near-ultraviolet. So, yes, they can distinguish between wavelengths of light which humans would perceive as "black".
I'd be careful about saying they can distinguish *among* colors in the near-UV; with only one cone being triggered[1], they wouldn't be able to distinguish between a brighter, lower-wavelength stimulus and a dimmer, higher-wavelength stimulus.
For instance, given three surfaces, one of which reflects 370nm light, one reflects 330nm light, and one reflects, say, 80nm light[2], the human will perceive them all as black; the bird will perceive the first two as UV and the third as black; but the first two will be two intensities of the same color, because only the UV cone is operating at those short wavelengths.
Birds also use the UV cone in combination with others to perceive mixed colors, like humans do, but I'm not getting into that here.
[1] we know only one kind of cone's being triggered because birds' other cones overlap with human vision.
[2] the article I'm referring to as I make up these numbers actually cuts off the bottom of the chart for bird vision, so I picked 80nm out of the air as being way way low.
no subject
I'd be careful about saying they can distinguish *among* colors in the near-UV; with only one cone being triggered[1], they wouldn't be able to distinguish between a brighter, lower-wavelength stimulus and a dimmer, higher-wavelength stimulus.
For instance, given three surfaces, one of which reflects 370nm light, one reflects 330nm light, and one reflects, say, 80nm light[2], the human will perceive them all as black; the bird will perceive the first two as UV and the third as black; but the first two will be two intensities of the same color, because only the UV cone is operating at those short wavelengths.
Birds also use the UV cone in combination with others to perceive mixed colors, like humans do, but I'm not getting into that here.
[1] we know only one kind of cone's being triggered because birds' other cones overlap with human vision.
[2] the article I'm referring to as I make up these numbers actually cuts off the bottom of the chart for bird vision, so I picked 80nm out of the air as being way way low.