You can make these dollhouse or scale miniature white doves or white racing pigeons from a range of materials, two part epoxy putty, polymer clay, or air dry clay which I used for the photographs. The techniques are very similar for all the modelling materials. All the different materials have some advantages.
Lightweight Air Dry Clay - I used Delight Clay - which has the advantage of being very light weight but needs a protective painted coating. Birds made with air dry clay can nest in branches or hang on tiny trees without pulling the tree branch down. The Delight clay rolls very thin, and when pulled apart has the effect of tiny feathers on the edge. The best tips for light weight air dry clay are to work on a piece of glass to keep the clay clean, only remove very small amounts of clay from your carefully sealed stash for each stage of the build, and to use a soft paint brush to blend the joins between sections. You need very small amounts of this clay. Keep the open package in a resealable bag with the air removed and only take out tiny amounts for each step.
Two Part Epoxy Putty - Air dries or cures to a very hard finish, can be sanded and painted, can have sections added on as you build. This makes birds which are heavier than the ones made from air dry clay, but they are less prone to breakage. As with the air dry clay, only mix small amounts of putty for each step. Blend two part epoxy putty sections together with a bit of water on the surface using modelling tools or a dampened finger.
Polymer Clay - Easy to sculpt and blend, colors should be mixed and added for the various sections, rather than painting the finished model. Polymer clay is heavy enough to bend small branches, so you may need sturdy trees for polymer clay birds.