The We s t e r n Pipistre l l e Bulgarian Bats C o n s e r vation in the Sea of Cort e z W W W . B A T C O N . O R G S U M M E R 2 0 0 1 BATS B A T C O N S E R V A T I O N I N T E R N A T I O N A L Bat Conservation Intern a t i o n a l P.O. Box 162603, Austin, Texas 78716 512-327-9721 • Fax 512-327-9724 www.batcon.org Publications Staff BATS Volume 19, No. 2, Summer 2001 Editor & Director of Publications: Elaine Acker Consulting Editor: David Baxter Publications Designer: Elysia Wright Davis Publications Coord i n a t o r : Sandra Forston Visual Resources Manager: Kristin Hay B AT S welcomes queries from writers. Send your article proposal with a brief outline and a description of any photos to the address above or via e-mail to: [email protected]. FEATURES M e m b e r s : Please send changes of address and all correspondence to the address above or via e-mail to [email protected]. Please 1 The Western Pipistrelle include your label, if possible, and allow six weeks for the change North America’s smallest bat of address. By Merlin D.Tuttle Founder & Executive Dire c t o r : Dr. Merlin D. Tuttle C h a i r m a n - E m e r i t u s : Verne R. Read B o a rd of Tru s t e e s : 3 Guyanese Villagers Discover Bats Wilhelmina R. Robertson, Chairperson John D. Mitchell, Vice-Chairman Surveying for bats in remote regions of Peggy Phillips, Secretary Guyana, South America Mark T. Ritter, Treasurer By Rebecca Shapely Jeff Acopian; Mark A. Adkins; Eugene L. Ames, Jr.; J. David Bamberger; Charles Chester; Eugenio Clariond Reyes; Michael L. Cook; Robert E. Gerrie; Joan Kelleher; Travis 4 Bats and Biodiversity Education Mathis; Scott McVay; Thomas Read; Verne R. Read; Lee Schmitt; Patsy Steves; Dr. Merlin D. Tuttle; Roy Vaughan; in Bulgaria Marc Weinberger European researchers promote conservation amid Associate Executive Dire c t o r : Steven M. Walker political unrest Membership Manager: Amy McCartney By Paul Elliot Development Dire c t o r : Arnold Phifer, CFRE Scientific Advisory Board : 7 Conserving Fishing Bats in the D r. Eduard Yavrouian, A r m e n i a ; D r. Leslie S. Hall, Sea of Cortez Greg Richards, Bruce Thomson, Australia; Dr. Irina K. R a k h m a t u l i n a , Azerbaijan; D r. Ivan Sazima, Brazil; By Luis Gerardo Herrera Montalvo and D r. Jiri Gaisler, Czech Republic; D r. Uwe Schmidt, Jose Juan Flores Martinez Germany; Dr. G. Marimuthu, Dr. Shahroukh Mistry, India; Dr. Rodrigo A. Medellín, Dr. Arnulfo Moreno, Mexico; Ir. Herman Limpens, Netherlands; Dr. Armando Rodriguez- Duran, Puerto Rico; Dr. Ya-Fu Lee, Taiwan; Dr. Paul A. Racey, United Kingdom; Dr. Denny G. Constantine, Robert DEPARTMENTS Currie, Dr. Theodore H. Fleming, Dr. Thomas H. K u n z, Dr. Gary F. McCracken, Dr. Don E. Wilson, United States; 12 Staff in Action Dr. José R. Ochoa G., Venezuela. B AT S (ISSN 1049-0043) is published quarterly by Bat BCI in the Classroom Conservation International, Inc., a nonprofit corporation By Kari Gaukler supported by tax-deductible contributions used for public education, research, and conservation of threatened and endangered bats. ©Bat Conservation International, 2001. 14 BCI Highlights All rights reserved. Bat Conservation International is dedicated to preserving and restoring bat populations and habitats around the world. Using a non- 16 News and Notes confrontational approach, we educate the public about the ecological and economic values of bats, advance scientific knowledge about bats and the ecosys- tems that rely on them, and preserve critical bat habitats COVER through win-win solutions that benefit both humans and bats. Brown big-eared bats (Plecotus auritus) are found in temperate regions of Europe, Asia, and A subscription to BATS is included with BCI membership: northern Africa. In summer, they frequently roost in tree cavities, which are becoming more and Senior, Student or Educator $25; Basic $30; Friends of BCI $40; Supporting $50; Contributing $100; Patron $250; Sustaining more scarce with intensive logging. European researchers are now conducting experiments with $500; Founder’s Circle $1,000. Third-class postage paid at artificial roosts to help this bat survive (see BCI Highlights, page 15). Austin, Texas. Send address changes to Bat Conservation COVER PHOTO BY ROLLIN VERLINDE, BCI / 916- 5308 International, P.O. Box 162603, Austin, TX 78716. BATS is printed on a 50/20 chlorine-free recycled paper with a water-based coating on the cover. The Western Pipistrelle North America’s smallest bat... by Merlin D. Tuttle ext time you are enjoying a beautiful sunset in an arid western canyon, anywhere from Canada to Mexico, take a closer look at the sky a Nhundred feet or so overhead. Chances are, you will see one or more western pipistrelles getting a head start on dinner. Sometimes they are seen as much as two hours before sundown. Western pipistrelles are among the first bats to emerge in the evening. They feed on a wide variety of insects including These tiny bats, with their silky must be extraordinarily selective, often find- moths, beetles, and mosquitoes. straw-gold fur, striking black face masks, and ing just one in thousands of crevices suit- unusually large eyes, rank among the west’s able to meet their needs. most attractive animals. On average, they Most western pipistrelles mate in late weigh only slightly more than a penny, and September or early October, prior to enter- even with their wings spread, they are only ing winter hibernation. In that season, pairs about the width of a human hand. have been observed alternately chasing each A m a z i n g l y, despite their small size, other and landing toge t h e r, a p p a re n t ly western pipistrelles rank among America’s courting on cliff-faces. Sperm are stored in hardiest animals. Year-round, they typically female reproductive tracts until spring, with On average, western pipistrelles weigh live in rock crevices, mostly in cliff faces, mothers becoming pregnant in April or May slightly more than a penny. With their though given their almost magical evening and giving birth to twins in June or July, wings spread, they are about the width of appearances in even the remotest desert depending on latitude. In sharp contrast to a human hand. flat-lands, it has been speculated that they probably also occupy rodent burrows in the ground.With tiny bodies and large areas of wing surface, such bats are exceptionally vulnerable to dehydration and temperature stress. To minimize water loss and maintain appropriate body temperatures, pipistrelles we d ge themselves into narrow ro ck crevices, relying on just the right combina- tion of sun exposure and crevice depth to keep their bodies at required temperatures with minimal ex p e n d i t u r e of metab o l i c energy. In summer, they move closer to entrances for greater warmth, doing the opposite to avoid extreme cold in winter. This approach is very energy-efficient, but to find appro p riate crev i c e s , p i p i s t r e l l e s S U M M E R 2 0 0 1 1 B A T S © MERLIN D. TUTTLE, BCI / 849- 6104 © MERLIN D. TUTTLE, BCI / 854- 6101 Found in arid regions, western pipistrelles other tiny animals, such as shrews, young kinds of moths, b u g s , and beetles. M a ny often reside in the very few cliff face pipistrelles do not reach maturity until they insects are caught high above the ground, crevices that provide suitable temperatures. are two years old, and banding records indi- though aquatic kinds are often skimmed cate survival to ages of at least six years. directly from the surface of ponds or rivers as These bats do not form large nursery or they hatch. If you would like to eavesdrop on b a chelor colonies like many others . these bats while they hunt, you will need to However, several mothers and their young tune your bat detector a bit higher than occasionally share an extra-attractive crevice usual, probably to at least 60-70 kHz. while re a rin g yo u n g . Males are typically Like many other bats, despite their unusu- found roosting alone, often at higher ally small size, western pipistrelles appear to elevations or in deep, cool valleys. Mothers be highly social and intelligent. They have normally rear young in warmer locations. been known to land on researchers and run Females seldom become active in winter down an arm to join others that have already and are never active when temperatures are been captured and placed in a cage, and they b e l ow fre e z i n g . H oweve r, males are q u i ck ly learn from observing other bats. amazingly capable of flying in sub-freezing While photographing bats in the Big Bend temperatures, and have been seen traveling region of Southwest Texas, I once trained a The western pipistrelle is strikingly over snow - c ove red ground when air pallid bat to come to my hand on call in the marked with a black face mask that temperatures were just 18ºF (-7.78º C).