Northern Song Dynasty Cizhou Ware Green-glaze figurines with Bird Shaped

A figurine made in the Cizhou kiln during the Northern Song dynasty.
Cizhou Ware is famous for white iron painting and scraping, but there were also green-glazed ceramics, mainly during the Northern Song Dynasty.
It is famous as a kiln for daily necessities, but toys such as figurines and dolls are also one of the indispensable products of Cizhou Ware.
This product, which seems to resemble a bird floating in water, is made realistically, with a curved neck and a curled beak to show its belly.
The fur and wings are expressed in carved patterns, and the back is decorated with flowers.
The dry clay of the Cizhou Ware is hollow inside, so it is light and has a hole at the bottom to prevent it from exploding during firing.
The green glaze of the North Song Cizhou Ware is a low-temperature lead glaze, and copper is mainly used as a coloring agent.
The lead glaze is highly transparent and flows easily, and the surface is covered with a smooth dark green glaze.
The glaze that collects in the grooves of the wings emits an even darker green color, giving the work a three-dimensional effect.

Sold as a pair.There is aged deterioration on the entire surface, but there is some luster.It is hollow inside and makes a small rattling sound when shaken. I think part of the material inside has come off.