Disappearing Females

Bk/wh, gn/al's first attempt at polygyny was short-lived.  This morning all the eggs in his second nest were gone (perhaps illustrating the disadvantage of sharing a mate)!  You can see a picture of this nest below.  This is one of the frustrating cases where we're not sure exactly what happened.  Usually when a predator get's the eggs, they disturb the nest in some way.  This nest had some new sticks near the front and no evidence of the eggs either in the box or on the ground.  New sticks are usually a sign that either a new male has moved in or the male lost his female and resumed building.  I spotted bk/wh, gn/al on this territory today, but there was no sign of a female.  The next couple days could reveal what happened.  If there's a new egg or evidence of substantial female building tomorrow, this was likely a female replacement.  If there are no female signs tomorrow, it will remain a mystery.

Nest at A3.  Empty nest cup is at the back, new sticks are near the front.