1 Normally flickers lay 6 or 7 eggs.  Cowbirds (which parasitize the nests of other birds) usually lay about six eggs (one each day) in different nests, wait a few days, and then start again. They may lay more than 11-20 eggs per season. A captive female was recording laying 77 eggs, 67 of those in a continuous sequence.
What is nystagmus? Nystagmus is an involuntary condition in which the eyes make rapid, repeated, uncontrolled movements. These eye movements may be in any direction including horizontally, vertically, or rotationally (in a circle). Many people with nystagmus do not experience visual symptoms.
Although the exact cause of nystagmus is not known, it is thought to be related to a disorder in the part of the brain that controls eye movement. Nystagmus may be present at birth (congenital nystagmus) and is often inherited or caused by development problems in the visual system. Another variation of nystagmus, called spasmus nutans, usually appears by the age of six months and goes away by itself in early childhood.