Blue-footed booby
The blue-footed booby is a specialized fish eater, feeding on small schooling fish such as sardines, anchovies, mackerel, and flying fish. It will also take squid and offal. The blue-footed booby hunts by diving into the ocean after prey, sometimes from a great height, and can also swim underwater in pursuit of its prey. It can hunt singly, in pairs, or in larger flocks. Boobies travel in parties of about 12 to areas of water with large schools of small fish. When the lead bird sees a fish shoal in the water, it will signal to the rest of the group and they will all dive in unison, pointing their bodies down like arrows.
Blue-footed booby
Males also assess their partner's reproductive value and adjust their own investment in the brood according to their partner's condition. Females that lay larger and brighter eggs are in better condition and have greater reproductive value. Therefore, males tend to display higher attentiveness and parental care to larger eggs, since those eggs were produced by a female with apparent good genetic quality. Smaller, duller eggs garnered less paternal care. Female foot color is also observed as an indication of perceived female condition. In one experiment, the color of eggs was muted by researchers, it was found that males were willing to exercise similar care for both large eggs and small eggs if his mate had brightly colored feet, whereas males paired with dull-footed females only incubated larger eggs. Researchers also found that males did not increase their care when females exhibited both bright feet and high-quality offspring.