This Shabbat is known as "Shabbat Shira - the Sabbath of Song."

During the Torah reading on this Shabbat we read the special song of praise to G-d which the Jews sang after crossing the Red Sea.
For Shabbat Shira there is a special custom of putting out food for the birds. The reason for this custom is quite interesting and originates in this week's Torah portion. We read this week about the manna, the bread from Heaven, with which the Jews were sustained during their 40-year sojourn in the desert. The Jews were commanded to gather each morning just enough manna to feed their families for the day. Miraculously, each person had precisely the amount he needed for his family, not more and not less.
Before Shabbat, the Jews were told to gather a double portion; no manna would fall on Shabbat since it is forbidden to gather on the holy day.
Some scoffers among the Jewish people saved some of their manna from that morning and scattered it on Friday evening. Their plan was to gather the manna Shabbat morning and bring it into the camp, thus discrediting Moses and proving their claim that Moses created his own mitzvot.
During the night, after the manna had been strewn, birds came and gathered it all up, thus vindicating Moses and sanctifying the Sabbath among the Jewish people.
In appreciation and gratitude of the birds' deed, we make sure to give them food on Shabbat Shira.
Might we not take a lesson from this Jewish tradition, passed on through the ages? If it is customary to show gratitude to birds for such a small act, might we not also learn to show gratitude to our brothers and sisters for each act of kindness or caring that they do for us?