The nest of the ovenbird is a protective home because it is a dome made of mud pellets.


“In about two weeks these diminutive birds manage to work two thousand pellets of mud, weighing about ten pounds in all, into an impressive dome…The oven’s construction involves building a rather ordinary but oversized adobe cup on the branch. This is then built up to make a sphere with a circular opening on one side, close to but not directly over the branch. Adding the mud pellets and smoothing them out without risking a collapse of the domed roof as it curves inward must require considerable care; the procedure employs behavior highly modified from that used for the cup…The birds construct a curved internal wall about three-quarters of the way toward the roof, creating an entrance chamber between the door and the nest cavity. The indirect entryway becomes a severe obstacle for predators, and the smooth concrete-like dried mud itself repels attacks.” (Gould and Gould 2007:185)

Animal Architects: Building and the Evolution of IntelligenceJune 3, 2012
James L. Gould

Rufous HorneroFurnariusSpecies