Interestingly, all the living things of any sex in that list produce and require estrogen and estrogen analogues, and if the chairs are wooden and well sealed, it may still have small traces of phytoestrogens in it (being mainly dead tree).
With respect to that list, because of the way the matrix of (flying!) avian bone is laid down, and the necessity of low skeletal mass, estrogens are probably most important to birds of both sexes as a way of controlling osteoclast (cells involved in bone turnover) activity, and if they don't have enough estrogens through a combination of self-production and diet then they develop aggressive osteoporosis and also serious problems with blood chemistry. (http://ps.fass.org/cgi/reprint/83/2/200.pdf is a cool overview, and there is lots more about the way estrogen interacts with the lysozyme genes in bird osteoclasts on the intarrweb).
Cars have negligible estrogen; they also have negligible testosterone.