Journey North News



Lesser Long-nosed Bat Migration Update:
April 11, 1996

This migration story is produced as part of the Forgotten Pollinator's Campaign of the Arizona-Sonora Desert Museum. Accompanying today's report you'll find a classroom activity which challenges you to identify the mystery pollinator. Thanks to Dr. Steven Buchman, co-founder of the campaign, for providing this fascinating look at flowers and the animals that pollinate them. Click here for bee & pollination information .

To: Journey North
From: Ginny Dalton, Bat Biologist

For years, bats' mysterious lives have presented challenges to scientists and others trying to learn about them. The details of their lives are hidden under the cover of darkness and facts about them are not easy to discover. People studying the life cycle of the lesser long-nosed bat in the desert Southwest were puzzled by many things. Among the questions they asked were these:

* Why aren't these bats found in Arizona and New Mexico during the winter months?

* Where do they go---and why?

* Why do they return?

Over the next weeks, we'll share pieces of the puzzle with you. Throughout the spring, consider our original question: Challenge Question # 47: "Why do you think lesser long-nosed bats migrate?"

In today's report we'll tell you what we know about the plants lesser long- nosed bats eat. This new information should help you answer today's Challenge Question:.

Challenge Question # 78

"Does there seem to be a nectar pathway across the bats' range which they could follow to Arizona and New Mexico each spring?"

(To respond to this Challenge Question, please follow the directions at the end of this report.)

Leptos are "nectivorous" and "frugivorous" meaning they eat nectar and fruit. While they sometimes eat insects, like most of the bats you probably know, in the spring time they feed primarily on the nectar found in flowers. This means they must always find flowers that are in bloom. Since flowers bloom at different times of the year in different locations, the bats' food sources can change with the seasons.

Last week you were to make a range map for Leptos, based on bat sightings at various locations in Mexico and the U.S. However, your range map does not tell you WHEN the bats were seen at each place. Therefore, we've provided a blooming calendar below which shows some of the most important nectar sources available to bats at different locations. Using today's information see if you can answer Challenge Question # 78 above.

Food Sources for Lesser Long-nosed Bats
at Selected Portions of Their Range

(by Month)

November through January:
There is a frost-free zone south of Sinaloa and Durango, Mexico. Tree morning glories and wild tequila century plants bloom in the foothills of the Sierra Madres as well as from nearby fields where the plants are cultivated as a cash crop. Localities for these plants in bloom include Chapala, Jalisco and Infiernillo, Michoacan. Peak blooming of these plants at these locations is over by the end of April.

February through March:
In Sinaloa and in the "barrancas" of central and southern Sonoran, nectar is available from flowers of the northern-most tree morning glories and bacanora century plants. (The "barrancas" are similar to the Grand Canyon. The local people make bootleg mescal, a local form of tequila, from these century plants.) Localities for these plants in bloom include Pericos and Concordia, Sinaloa.

April:
Giant columnar cacti that Leptos are known to feed upon are in bloom in western Mexico from the northern part of Sinaloa (Pericos) southward through the southern part of Nayarit (Nayar). By early May, peak blooming in those areas for those cacti is over. Agaves do not begin to flower in those areas until late May/early June.

May:
The majority of the saguaro cacti are in bloom from southern Sonora, Mexico northward into southern Arizona. Early May to late June is during the peak of cactus flowering. Localities for these plants include Guaymas and Carbo in Sonora and Ajo in Arizona. These cacti are not located in Portal, Arizona.

June:
The fruit of the giant columnar cacti begin to ripen in the same locations as are mentioned in May. In addition, Palmer and Parry's agaves begin to bloom in southeastern Arizona (Portal and Sierra vista) and southern New Mexico (Animas). Each flowering stalk, or "panicle", of these agaves produces as much as a cup of nectar! (These wild century plants were historically a major food source for Mescalero Apaches.)

July and August:
In mid to late July, in the U.S., century plants are in bloom in the mountainous regions of southwest Arizona (e.g. Portal and Sierra Vista); namely the Chiricahua Mountains, Huachuca Mountains and the Santa Rita mountains. Near Ajo, Arizona, the peak flowering and fruiting is past, although some are still produced. Agaves are more scarce in this region. In Mexico, agaves that bats feed upon bloom from July through late September/early October in the state of Sonora.

September and October:
Agaves in Arizona, New Mexico and northern Sonora have passed the peak flowering. More agaves are now blooming in southern Sonora, western Chihuahua, Durango and Jalisco (e.g. Chapala).

How to Respond to Challenge Question # 78

1. Address an e-mail message to: jn-challenge@learner.org

2. In the Subject Line of your message write: Challenge Question #78.

3. In the Body of your message, answer this question:

"Does there seem to be a nectar pathway across the bats' range which they could follow to Arizona and New Mexico each spring?"

The Next Lesser Long-nosed Bat Migration Update Will be Posted on April 25, 1996.



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