Males tend to incubate the eggs diurnally and females, mostly nocturnally. Nesting occurs from May to August, and occurs nocturnally on a sandbank. They live in shallow water, which can also be slightly brackish, and feed nocturnally. They are typically active diurnally in cooler weather and nocturnally during hot weather "C. viridis". They feed almost exclusively on neritic and oceanic squid, mostly nocturnally. It feeds nocturnally on fish and frogs snatched from the surface of lakes and rivers. There are many birds that are active nocturnally. In 2011, "Bulbophyllum nocturnum" was discovered to flower nocturnally. The great horned owl occupies a similar ecological niche nocturnally to the red-tailed hawk. It has year-long, circadian activity and is most vocal nocturnally and crepuscularly. It is a vector of nocturnally subperiodic "Brugia malayi". For instance, it is a long held belief that the species is not nocturnally active. For this reason, the blood has to be collected nocturnally. However, in Alaska, they have been observed nocturnally.