Participants in the winter bird walks at the city's botanical gardens, El Charco del Ingenio, have witnessed another fascinating phenomenon: the emergence of hundreds, perhaps thousands, of white-throated swifts from narrow cracks in the wall of the canyon. This usually takes place sometime after ten in the morning when, apparently, the rock face gets warm enough to trigger their exodus. One can hear the birds cheeping within their caves, and then wave after wave of them flies out, until no more cheeping is audible. The reverse, the swifts returning to their rock face, takes place a little before sunset.

So, to catch a glimpse (and more) of some spectacular birds and join this month's Audubon walk, meet the Audubon triumvurate at the entrance to the Instituto Allende on the Ancha San Antonio at 7:45 am on Sunday morning. If there's sun (which has been happening more often of late) it will rise higher and higher during the walk and you'll be a happier person if you've brought a hat and water. Cars will be available, but if you come by one that can be shared, it will be very much welcomed, and it's an easy drive to the starting point.

If you have binoculars to bring, they too would be helpful, but not necessary. There'll be at least one scope along for the walk. And our leaders will have the Audubon bird guides with them for purchase. (Also, the new Audubon butterfly guides, spectacular in themselves.) The walk is free for Audubon members and 100 pesos for others. And that's all there is to it. You'll be back by about noon, with new entries for your life list and new friends in the world of birding. People with questions may call Linda Whynman at 152-2139.