Looking at the birds after reading Aldo Leopold

Matthew tells us that Jesus said, "Look at the birds of the air...."

I'm almost at the end of A Spiritual Field Guide, edited by Bernard Bray and mark Neuzil. This morning's reading included an excerpt from Aldo Leopold's Sand County Almanac. He cites these benefits from watching flocks of geese fly over: Perhaps one flock thrilled a score of schoolboys, awakening in them a sense of adventure. Another flock on a dark night may have awakened sleepers into memories and hopes. A third flock may have interrupted the drudgery of a plowman, bringing to him new thoughts of far lands and journeys.

I have always read Matthew's passage as warning us against obsessing about our futures. But, now I'm thinking that the command, "Do not worry about tomorrow," doesn't necessarily mean to be totally closed to thoughts of tomorrow.