Pollination

A Geoffroy's tailless bat (Anoura geoffroyi) is pollinating a Siphocampylus flower in southern Ecuador. This little known plant genus includes 200 species distributed in mountainous regions of Costa Rica and Panama and in the Andes from Venezuela to Bolivia. The plant S. giganteus is found only in Colombia and Ecuador. It appears to rely primarily on bats for pollination. Pollination

A Geoffroy's tailless bat (Anoura geoffroyi) is pollinating a Siphocampylus flower in southern Ecuador. This little known flower is named Siphocampylus giganteus (Campanulaceae). Its genus includes 200 species distributed in mountainous regions of Costa Rica and Panama and in the Andes from Venezuela to Bolivia. The plant S. giganteus is found only in Colombia and Ecuador. It appears to rely primarily on bats for pollination. Pollination

A Geoffroy's tailless bat (Anoura geoffroyi) pollinating Puya nitida in the Andean subparamo at about 9,000 feet elevation above Cuenca, Ecuador. This plant genus contains over 100 species, is found mostly at higher elevations of the Andes and is the oldest genus of bromeliads. Though most bromeliads are found in tropical rainforests growing as epiphytes on trees, Puya, are solely ground-dwelling and are very tolerant of low temperatures, surviving down to -20°C. Puya are long-lived plants and some of them need about 100 years from the seed until they flower. This species grows in dense colonies. Individual plants normally die once flowering is complete, though the colonies persist. Flowers are highly attractive to bats. Hummingbirds also visit them by day. As pollinators are scarce in this high mountain region where they normally grow Puya need to attract both birds and bats. However bats have been shown to be their most effective pollinators. Pollination

A Geoffroy's tailless bat (Anoura geoffroyi)pollinating Puya nitida in the Andean subparamo at about 9,000 feet elevation above Cuenca, Ecuador. This plant genus contains over 100 species, is found mostly at higher elevations of the Andes and is the oldest genus of bromeliads. Though most bromeliads are found in tropical rainforests growing as epiphytes on trees, Puya, are solely ground-dwelling and are very tolerant of low temperatures, surviving down to -20°C. Puya are long-lived plants and some of them need about 100 years from the seed until they flower. This species grows in dense colonies. Individual plants normally die once flowering is complete, though the colonies persist. Flowers are highly attractive to bats. Hummingbirds also visit them by day. As pollinators are scarce in this high mountain region where they normally grow Puya relies on both birds and bats. However bats have been shown to be their most effective pollinators. Pollination

A Geoffroy's tailless bat (Anoura geoffroyi) is pollinating a gaňal plant, Oreocalis grandiflora, inflorescence in southern Ecuador. Gaňal flowers have close relatives in New Guinea, eastern Australia, northern Peru and central Ecuador. The O. mucronata we encountered formed extremely dense thickets of montane cloud forest shrubs about five to six feet tall and were found at about 9,000 feet elevation. Each inflorescence consists of many flowers and is conspicuously located at the tip of a branch extending above the surrounding foliage, making them easier for bats to find at night. Flowers were cream-colored and appeared to remain active both day and night, visited by bats by night and hummingbirds by day. The originally red ancestral flowers of this genus have lost their red color in this species, implying a growing reliance on bats. Pollination

This cactus (Espostoa frutescens, Cactaceae) is endemic to a single river valley in Ecuador. Members of this genus, to varying degrees, produce woolly hairs on the flowering sides of their branches. These are most prominently seen in Espostoa frutescens. Locals referred to it as el viejito (the old man cactus). The woolly “fur” is an adaptation to help bats locate its flowers. A large proportion of columnar cacti rely on bats as primary pollinators (see National Geographic, June 1991). E. frutescens blooms only at night and produces copious pollen and nectar. My photographs provide the first documentation of its being pollinated by bats. Habitat, Pollination

A Pallas's long-tongued bat (Glossophaga soricina) is pollinating a San Francisco or old man cactus flower (Espostoa frutescens) in southern Ecuador. This cactus is endemic to Ecuador, known only from a narrow belt of aridity in one major river valley and its tributaries. Its flowers do not open until well after sundown and close long before sunrise. My photographs provide the first documentation of its being pollinated by bats. The furry material around its flowers absorbs bat echolocation signals, making the flowers more sonically visible to approaching bats. Pollination

A Leach's single leaf bat (Monophyllus redmani) is pollinating a relative of the organ pipe cactus in Cuba. This bat is an abundant cave-dwelling species found in Cuba, the Bahamas, Dominican Republic, Haiti, Jamaica and Puerto Rico. Pollination

Cuban flower bat (Phyllonycteris poeyi) pollinating Blue Mahoe Tree in Cuba. Pollination

Cuban flower bat (Phyllonycteris poeyi) pollinating Blue Mahoe Tree in Cuba. Pollination

A Leach's single leaf bat (Monophyllus redmani)pollinating a shingle vine in a Cuban forest. This bat is an abundant cave-dwelling species found in Cuba, the Bahamas, Dominican Republic, Haiti, Jamaica and Puerto Rico. Pollination

Cuban flower bat (Phyllonycteris poeyi), Phyllosomidae at Blue Mahoe Tree (Talipariti elatum; Malvaceae). Pollination

Leach's single leaf bat (Monophyllus redmani) about to pollinate a Marcgravia evenia flower in Cuba. The dish-shaped leaf is a reflector that guides echolocating bats as they approach. Pollination

A Leach's single leaf bat (Monophyllus redmani) pollinating a search-mi-heart flower (Rhytidophyllum tomentosum) in Cuba. This is a widely distributed shrub of the New World tropics. Like many other bat-pollinated flowers, it protrudes well above surrounding vegetation for easier recognition. Pollination

A Commissaris's long-tongued bat (Glossophaga commissarisi) with its tongue in a sea bean triggering slot, a split second prior to landing and having pollen fired onto its rump. The sea bean (Mucuna holtonii), is a legume that grows along streams, rivers and other rain forest edges from southern Mexico and Belize throughout Central America. It is a woody vine whose inflorescences open flowers only at night. Its flowers are highly specialized for exclusive bat pollination. Small bats, such as Glossophaga commissarisi (Brown long-tongued bat) and Hylonycteris underwoodi (Underwood’s long-tongued bat). It is apparently ignored by larger glossophagine species, such as Lonchophylla robusta (orange nectar bat). Its anthers and stamens are sized and shaped to effectively fire pollen onto the rumps of bats. Inflorescences hang below the surrounding foliage on 3-6-foot-long stems known as peduncles that facilitate approaches by flying bats. Each inflorescence is about 5-7 inches in diameter and contains many buds with up to 8 flowers opening each night for approximately 6 weeks. A flower that is ready to be pollinated signals its readiness by raising its dish-shaped banner (the vexillum), adapted to strongly reflect echoes from many different directions. Bats normally ignore this flower until its banner has risen to a nearly vertical position. The reflected echos guide an approaching bat to put its nose in an approximately 2-mm-wide space between 2 petals known as wings. When a nose pushes into this small opening, the flower is triggered to fire pollen onto the bat’s rump. Another pair of petals forms a “keel” which encloses the stamens and anthers. When the flower is triggered by a bat nose, the keel suddenly opens, releasing these male reproductive organs in a manner that fires pollen onto the bat’s butt. This process is described in detail by Helversen and Helversen (Nature 398, 759-760; 29 April 1999). The banner serves as “a small concave 'mirror' that works like an optical cat's eye, but in the acoustic domain, reflecting most of the energy of the bats' echolocation calls back into the direction of incidence. As flower firing is triggered, the bat is rewarded by receiving an average of 100 microliters of nectar (a relatively large quantity). Bats that subsequently visit already fired flowers get approximately 10-20 microliters of nectar. Each flower can fire only one time. Banners do not open all at once. Openings are staggered between sunset and about midnight, the first ones not reaching full readiness till an hour or more after sundown. This discourages nectar thievery by diurnal visitors, such as hummingbirds, who seldom achieve pollination, but attempt to feed on the nectar. Also, by staggering flower readiness, bats are encouraged to make multiple visits, ensuring improved pollination. At a bat’s first visit, a flower’s stigma (female reproductive organ) is not yet receptive, preventing self-pollination. It becomes receptive as subsequent pollen-bearing bats approach. The large, bean-like seeds of this plant are called sea beans, because they are extremely buoyant and adapted for sea dispersal. They are commonly found on beaches as far away as the southeastern United States and are a beautiful jet-black. When polished by natives, they are made into lovely necklaces, bracelets and other handcraft items. This plant is also a good nitrogen fixer and is fed upon by butterfly caterpillars, such as those of the blue morpho. Pollination

A Commissaris's long-tongued bat (Glossophaga commissarisi) with its tongue in a sea bean triggering slot, a split second prior to landing and having pollen fired onto its rump. The sea bean (Mucuna holtonii), is a legume that grows along streams, rivers and other rain forest edges from southern Mexico and Belize throughout Central America. It is a woody vine whose inflorescences open flowers only at night. Its flowers are highly specialized for exclusive bat pollination. Small bats, such as Glossophaga commissarisi (Brown long-tongued bat) and Hylonycteris underwoodi (Underwood’s long-tongued bat). It is apparently ignored by larger glossophagine species, such as Lonchophylla robusta (orange nectar bat). Its anthers and stamens are sized and shaped to effectively fire pollen onto the rumps of bats. Inflorescences hang below the surrounding foliage on 3-6-foot-long stems known as peduncles that facilitate approaches by flying bats. Each inflorescence is about 5-7 inches in diameter and contains many buds with up to 8 flowers opening each night for approximately 6 weeks. A flower that is ready to be pollinated signals its readiness by raising its dish-shaped banner (the vexillum), adapted to strongly reflect echoes from many different directions. Bats normally ignore this flower until its banner has risen to a nearly vertical position. The reflected echos guide an approaching bat to put its nose in an approximately 2-mm-wide space between 2 petals known as wings. When a nose pushes into this small opening, the flower is triggered to fire pollen onto the bat’s rump. Another pair of petals forms a “keel” which encloses the stamens and anthers. When the flower is triggered by a bat nose, the keel suddenly opens, releasing these male reproductive organs in a manner that fires pollen onto the bat’s butt. This process is described in detail by Helversen and Helversen (Nature 398, 759-760; 29 April 1999). The banner serves as “a small concave 'mirror' that works like an optical cat's eye, but in the acoustic domain, reflecting most of the energy of the bats' echolocation calls back into the direction of incidence. As flower firing is triggered, the bat is rewarded by receiving an average of 100 microliters of nectar (a relatively large quantity). Bats that subsequently visit already fired flowers get approximately 10-20 microliters of nectar. Each flower can fire only one time. Banners do not open all at once. Openings are staggered between sunset and about midnight, the first ones not reaching full readiness till an hour or more after sundown. This discourages nectar thievery by diurnal visitors, such as hummingbirds, who seldom achieve pollination, but attempt to feed on the nectar. Also, by staggering flower readiness, bats are encouraged to make multiple visits, ensuring improved pollination. At a bat’s first visit, a flower’s stigma (female reproductive organ) is not yet receptive, preventing self-pollination. It becomes receptive as subsequent pollen-bearing bats approach. The large, bean-like seeds of this plant are called sea beans, because they are extremely buoyant and adapted for sea dispersal. They are commonly found on beaches as far away as the southeastern United States and are a beautiful jet-black. When polished by natives, they are made into lovely necklaces, bracelets and other handcraft items. This plant is also a good nitrogen fixer and is fed upon by butterfly caterpillars, such as those of the blue morpho. Pollination

The sea bean (Mucuna holtonii), is a legume that grows along streams, rivers and other rain forest edges from southern Mexico and Belize throughout Central America. It is a woody vine whose inflorescences open flowers only at night. Its flowers are highly specialized for exclusive bat pollination. Small bats, such as Glossophaga commissarisi (Commissaris's long-tongued bat) and Hylonycteris underwoodi (Underwood’s long-tongued bat). It is apparently ignored by larger glossophagine species, such as Lonchophylla robusta (orange nectar bat). Its anthers and stamens are sized and shaped to effectively fire pollen onto the rumps of bats. Inflorescences hang below the surrounding foliage on 3-6-foot-long stems known as peduncles that facilitate approaches by flying bats. Each inflorescence is about 5-7 inches in diameter and contains many buds with up to 8 flowers opening each night for approximately 6 weeks. A flower that is ready to be pollinated signals its readiness by raising its dish-shaped banner (the vexillum), adapted to strongly reflect echoes from many different directions. Bats normally ignore this flower until its banner has risen to a nearly vertical position. The reflected echos guide an approaching bat to put its nose in an approximately 2-mm-wide space between 2 petals known as wings. When a nose pushes into this small opening, the flower is triggered to fire pollen onto the bat’s rump. Another pair of petals forms a “keel” which encloses the stamens and anthers. When the flower is triggered by a bat nose, the keel suddenly opens, releasing these male reproductive organs in a manner that fires pollen onto the bat’s butt. This process is described in detail by Helversen and Helversen (Nature 398, 759-760; 29 April 1999). The banner serves as “a small concave 'mirror' that works like an optical cat's eye, but in the acoustic domain, reflecting most of the energy of the bats' echolocation calls back into the direction of incidence. Pollination

The Commissaris's long-tongued bat (Glossophaga commissarisi) is a primary pollinator of the sea bean (Mucuna holtonii). Here it approaaches a "ripe" flower with its nose leaf aimed into the reflecrive "banner." Only flowers that present an echo-reflective, concave banner in an upright position, indicating a "ripe" (ready for pollination) flower, are approached. It typically makes at least one investigative approach prior to landing on a ready flower. Then it orients directly to the banner to land and locate the triggering slot that is between two petals called "wings" just below the banner. When the tongue enters the slot, two more paired petals that form the "keel" split apart, freeing the spring-loaded, curved stamens that fire pollen from anthers at the tips onto the triggering bat's rump. By putting the pollen onto the bat's rump, the flower avoids contaminating its pollen with any from other plant species the bat may have visited. Other species we observed applied their pollen to the bats' throat, forehead or wings. Each Mucuna flower fires only once, rewarding the bat with a generous amount of nectar. A typical bat lands, triggers the flower and leaves in a small fraction of a second, though some flowers fire slower than others. Bats also visit already fired flowers later in the evening after lessor amounts of necter have been replenished. Stages photographed include the initial inspection, the actual approach, a brief landing and triggering and departure, often with the tongue still extended and loose pollen flying. Occasionally, bats fight over inflorescences similar to hummingbirds. Pollination

A Commissaris's long-tongued bat (Glossophaga commissarisi) is about to eat a tiny male flower of the caligallo palm. This is a stemless, understory, rainforest plant. It is highly specialized for bat pollination. A plant can produce both male and female flowers, but only one sex at a time. Tiny flowers are produced on inflorescent spikes that protrude vertically from the plant center for about 3 feet. A spike produces only male flowers for 5 nights, then produces no flowers for 3 nights, followed by female flowers for 2 nights. Early in the evening male flowers are firmly attached to the inflorescent spike, but they become progressively easier to remove. By the time bats arrive, they are easily pulled loose and eaten. In the process, pollen becomes attached to bat fur. Pollination

A Commissaris's long-tongued bat (Glossophaga commissarisi) is just arriving at a sea bean flower. The sea bean (Mucuna holtonii), is a legume that grows along streams, rivers and other rain forest edges from southern Mexico and Belize throughout Central America. It is highly specialized for exclusive bat pollination. , ensuring improved pollination. Pollination

This tank plant (Werauhia gladioliflora) is one of the most abundant, widely distributed, epiphytic bromeliads of the Neotropics. These are called tank bromeliads due to their long-term retention of rain water. As water reservoirs of the forest canopy, these plants provide essential breeding habitat for a wide variety of microbes, insects and frogs. At least 6 genera and 21 species of bromeliads are reported to be pollinated by bats, though little attention has been paid to bat pollinated bromeliads. Pollination, Habitat

Merinthopodium neuranthum (Solanaceae) is an epiphytic shrub, this one pollinated by an Underwood's long-tongued bat (Hylonycteris underwoodi) in Costa Rica. Inflorescences include several flowers each that hang at the tips of approximately 1-meter-long stems known as peduncles. Pollinating bats have to approach from almost directly below, requiring an unusual maneuver. A heavy pollen load is applied to the bat’s throat. Pollination

Merinthopodium neuranthum (Solanaceae) is an epiphytic shrub, this one pollinated by an Underwood's long-tongued bat (Hylonycteris underwoodi) in Costa Rica. Inflorescences include several flowers each that hang at the tips of approximately 1-meter-long stems known as peduncles. Pollinating bats have to approach from almost directly below, requiring an unusual maneuver. A heavy pollen load is applied to the bat’s throat. Pollination

A Commissaris's long-tongued bat (Glossophaga commissarisi) pollinating an orchid tree flower in Costa Rica. This tree is found in tropical forests worldwide, often referred to as an orchid tree. It is frequently used as an ornamental. Its flowers open and become receptive after sundown. Visiting bats are rewarded with large quantities of nectar, and in turn the long spider-like stamens, with anthers at the tips, ensure that pollen is deposited on bat wings while most other plants deposit it at various locations on their bodies. Bat pollinated plants minimize cross-species mixing of pollen to avoid: 1) clogging of stigmas with unrelated pollen, 2) reducing seed set, 3) producing inviable or unfit hybrids. Pollination

An orange nectar bat (Lonchophylla robusta) pollinating a large tank plant (Werauhia kupperiana). This is one of at least 6 genera and 21 species of Neotropical bromiliads that rely on bats as their primary pollinators. It is the largest and one of the most abundant epiphytic bromeliads of the upper forest canopy, measuring up to 40 inches across. Its branching inflorescence is over a meter tall and produces multiple flowers per night (one per branch). Small glossophagine bats are the exclusive pollinators. It has been referred to as a tank plant, because it catches rain water, providing essential reservoirs for rainforest canopy life, from microorganisms and insects to frogs. Pollination

The sea bean (Mucuna holtonii), is a legume that grows along streams, rivers and other rain forest edges from southern Mexico and Belize throughout Central America. It is a woody vine whose inflorescences open flowers only at night. Its flowers are highly specialized for exclusive bat pollination. This plant is a good nitrogen fixer and is fed upon by butterfly caterpillars, such as those of the blue morpho. Habitat, Pollination

An orange nectar bat (Lonchophylla robusta) sipping nectar, head in contact with anthers at a Marcgravia nepenthoides flower (Marcgraviaceae) in Costa Rica. This is a woody vine that ascends high into the forest canopy. This is a rare and widely dispersed plant, making it an unlikely candidate for cross-pollination by non-flying animals. Pollination

A Commissaris's long-tongued bat (Glossophaga commissarisi) has just pollinated a calabash flower. The calibash tree is native to Central and South America. Its night-blooming flowers rely on bats for pollination. Its wood is used in a wide variety of human implements. Its large gourd-like fruits are used for water containers, cups and bowls and for musical rattles, and the fruit is used in traditional medicines. Pollination