The pelican is usually a sign of charity. The pelican is a symbol of the atonement and the Redeemer and is often found in Christian murals, frescos, paintings and stained glass.
The symbolism of the mother pelican feeding her baby pelicans seems to be rooted in a legend older than Christianity, which said that in times of famine, the mother pelican wounded herself, striking her breast with the beak in order to feed her young with her own blood to prevent starvation. There is another version of the legend that says that the mother fed her dying young with her blood to revive them from death, but in turn lost her own life.
In the hymn "Adoro Te," St. Thomas Aquinas addresses the Savior with, "Pelican of Mercy, cleanse me in Thy Precious Blood." Allusion is even made to this belief in "Hamlet" (act iv): "To his good friend thus wide I'll open my arms And, like the kind, life-rendering pelican, Repast them with my blood."