The center of mass highlights the mass distribution of the system, which depends on the mass of individual particle making it, and its separation from the origin in the corresponding reference frame.
Assume that the origin in this case lies at point 4, and one checks the mass distribution of the sculpture about that point. Divide the sculpture into three blocks: one consisting of the head (Area A), the other consisting of the tail (Area B) and the rest as a body (Area C), as shown in figure below,


It is important to note that the center of mass of the first block lays near point 6, of second block near point 1, and of third block near point 2. The center of mass of the system can now be reduced to about three points, which are 6, 2 and 1 respectively, each containing the total mass of their corresponding blocks.
It can be seen from the figure that the mass of the third block is much larger than that of first and second. Therefore, the center of mass of the sculpture can be expected to be closest to the origin itself, that is, point 4.

The centre of mass is the point about which the total mass of the system is equally distributed.The centre of mass of the object depends on the mass of each particle of the system.The centre of mass of an irregular shape object is nearer to the part of the object whose mass is large.In the given figure,If point 4 is assumed to be origin.Then mass distribution tells us that the mass of the part containing points 3 and 2 is nearer to point 4.Thus point 4 is most likely to be the centre of mass of the bird