Things that go ‘kwak’ in the Night

Alex and I had great looks at both night heron species on my patch last night. It was dusk and a good opportunity to enjoy the differences between the two.

Can you identify these herons? What differences stands out between them?

Both species differ in shape when seen on the ground – BCNH tend to be compact neckless birds with a large head and shortish legs, while YCNH are rangier with a longer neck, disproportionately small head and long legs. These features also hold up in flight and when seen in silhouette and with comparative experience, both species are pretty easy to identify.

Note amount of leg projection beyond wings - YCNH (left) and BCNH (right)

The right bird is thus a BCNH because:
– a compressed shape 
–  lacks obvious neck bulge
–  almost no leg projection beyond the tail make it a BCNH.

The left bird is thus a YCNH because:
– it has a longer torso
– an egret-like neck bulge (due to the longer neck)
– a noticeable amount of  leg projection

Also, on the YCNH, the pale earcovert patch is just discernible, a feature never shown by BCNH

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