This is the Wiersema family coat of arms. (Picture provided courtesy of Jos Wiersema)
It shows a pelican feeding or spraying its chicks with blood.
A pelican was thought (in the 13th-15th century) to be able to revive its chicks with its own blood.
The use of this symbol within christian communities to depict the sacrifice of Jezus was started by the work "Adore te Devote" of Thomas of Aquino 1225-1274 A.D.
The pelican has stood through the ages for compassion and altruism.
Even today the Pelican (albeit a bit modernized) is still used by the Dutch bloodbank
to depict giving of blood for the benefit of others.