It has recently been brought to my attention that the following story actually falls into the category of "urban legend". Pity - its a great motivational piece. I'll leave it up, and you decide. For more details, see http://www.snopes2.com/glurge/birdwing.htm.
An article in National Geographic several years ago provided a penetrating picture of God's wings. After a forest fire in Yellowstone National Park, forest rangers began their trek up a mountain to assess the inferno's damage. One ranger found a bird literally petrified in ashes, perched statuesquely on the ground at the base of a tree.
Somewhat sickened by the eerie sight, he knocked over the bird with a stick.
When he struck it, three tiny chicks scurried from under their dead mother's
wings. The loving mother, keenly aware of impending disaster, had carried her
offspring to the base of the tree and had gathered them under her wings,
instinctively knowing that the toxic smoke would rise. She could have flown
to safety but had refused to abandon her babies. When the blaze
had arrived and the heat had singed her small body, the mother had remained
steadfast. Because she had been willing to die, those under the cover of her
wings would live.
The Bible often refers to God protecting us, and sometimes uses this illustration of a bird protecting her young.
Ruth 2:12
May the LORD repay you for what you have done. May you be richly rewarded by the LORD, the God of Israel, under whose wings you have come to take refuge.
Psalm 91:4
He will cover you with his feathers, and under his wings you will find refuge; his faithfulness will be your shield and rampart.
Matthew 23:37 & Luke 13:34
"O Jerusalem, Jerusalem, you who kill the prophets and stone those sent to you, how often I have longed to gather your children together, as a hen gathers her chicks under her wings, but you were not willing..." (JESUS)
For a more Christian group (i.e. not focussing on evangelism), rather use this story to illustrate God's absolute faithfulness and willingness to sacrifice all for our protection and safety.