Bird's nest Rhaphidophora

If you grow many aroids you may be familiar with the bird's nest Anthuriums, but have you ever heard of a bird's nest Rhaphidophora?

Rhaphidophora tetrasperma beginning to climb the bark pole

I set up this tall bark wall for my Rhaphidophora tetrasperma to climb last year. This spring, while my greenhouse door was open, a bird built a nest nestled at the base of the plant.

Bird nest in the pot

I'm not really up on my bird identifications, but I have seen two tiny birds in my greenhouse - presumably the parents.  I think they were both pretty plain brown except for their beaks, which were orange.  Can anyone identify the bird from the egg?

Unknown bird egg - any ideas?