A Bat Man in the Tropics: Chasing El Duende

10. Along the Nectar Trail

Marcia came to visit me in the middle of our first field season at Kino Bay. Like me, she had never been to the Sonoran Desert before and wanted to see the new plants and bats I was studying. She froze with me in the desert at night while we slept between rounds of nectar sucking.One sunny morning we climbed past the Sierra Kino cave to the top of this 450-meter-tall basaltic massif. From its top, swaying in a stiff wind, we could see nearly forever—to the sparkling blue waters of the Gulf of California to the south, to the hazy mountain peaks of Isla Tiburón in the west, and to Tortilla Flats in the cactus-filled lowlands in the east. From this aerie we could see almost the entire daily home range of a typical lesser long-nosed bat—a vast area spanning kilometers of open ocean as well as many square kilometers of desert scrubland. Back at sea level, we swam in the still-cool waters of the gulf and walked barefoot along the water’s edge of the beautiful New Kino beach. On one of these walks I described to her my vision of what it was going to take to understand the population biology of this bat. I began this 217 10 Along the Nectar Trail Baja California scene with cacti and boojum trees. Drawing by Ted Fleming. soliloquy by reminiscing about the “good ole days” when I was studying the short-tailed fruit bat in western Costa Rica. “I could literally walk to three Carollia roosts in about two hours as well as traverse a typical bat’s feeding area in less than an hour. Many males lived within a few kilometers of their birthplace their entire lives,” I exclaimed in amazement. Not so with the lesser long-nosed bat. Our radio-tracking data would reveal that these bats typically fly over a hundred kilometers each night and have huge feeding areas. We didn’t yet know how far female bats migrate to get to their Sonoran Desert maternity roosts each spring, but this distance had to be orders of magnitude greater than the distances female Carollia migrate when they leave Santa Rosa for the uplands in the dry season. “To truly understand Lepto’s ecology and conservation needs,” I continued , “we’ll have to travel extensively in Mexico to find its winter roosts. Then we’ll have to figure out its migration routes and the plants that it uses to fuel its migration. Is it an obligate cactus and agave feeder throughout its geographic range, or does it have a broader diet away from the Sonoran Desert? “ Knowing the potential distances involved and the rugged terrain that lay between Kino Bay and south-central Mexico, I knew that answering these questions would be a daunting task. But then I had an even more audacious thought. I recalled that the lesser long-nosed bat had a southern subspecies that lived in arid parts of northernVenezuela and eastern Colombia as well as on the Netherlands Antilles islands of Aruba, Bonaire, and Curaçao. “Wouldn’t it be neat,” I asked, “if we could do parallel studies in Venezuela to determine Lepto’s role as a pollinator of tropical cacti? I wonder if it’s also a migratory bat down there?” As I rambled on, I’m sure Marcia must have thought I was crazy—that I had probably been out in the desert sun too long. However, she kept her thoughts to herself and just listened to my ideas that day. But as this grand scheme began to unfold over the next few years, she cheerfully joined me for long forays into southern Mexico and Baja California. As our desert research became more widely known, Mexican colleagues began to participate in these studies. My graduate students also became infected with my enthusiasm for the desert and joined our growing research team. By the tenth anniversary of our first field season in Kino, our studies had covered much of Mexico and the drylands of Venezuela and Curaçao. Much as I had hoped in 1989, we were well on our way to understanding what makes this nectar-feeding bat tick and its conservation needs. We had also gathered enough information to convince most bat biologists that this species was 218 / Chapter 10 not truly endangered in North America.Its addition...