Alina and Silas Gihl box
This yellow-eyed penguin breeding pair has returned to their sponsored nest box they used last year and here the male is proudly sitting on their first egg. Neither parent will sit tightly on the first egg effectively delaying the start of incubation until the second egg arrives about 3 days after the first. Then the incubation starts properly and the chicks will hatch on the same day. That makes them the same size and the first-laid egg/chick doesn't have a size and age advantage over its sibling.