National Pollinator Week, June 20-26, is a time to celebrate and BEE excited about the amazing work of pollinators! Join the festivities at our annual Party with Pollinators (Cool Summer Nights) evening this Saturday, June 25. We will have special pollinator themed activities and learning opportunities.
Pollinator Week was developed to support pollinator health and raise awareness about the importance of pollinators and what we can do to protect them. So what is it pollination? Pollination is an essential stage in the life cycle of all flowering plants, and occurs when grains of pollen containing male genetic material move from the anther (male part) to the stigma (female part). Pollen could be moved within a single plant (self-pollination) or carried from one plant to another of the same species (cross-pollination). The transfer of pollen leads to the production of seeds, and a new generation of plants!
There are a few different ways that pollination can happen, including self-pollination, wind and water pollination, or via pollinators, which are animals that do the work of pollen transfer. While most people know bees are the world’s primary pollinators, many animals serve this vital role. About 200,000 invertebrates and 1,000 vertebrates attend this marvelous pollinator party. Bees, wasps, moths, butterflies, beetles, flies, birds, bats, lizards, and other small mammals all serve as pollinators.
Pollinators visit flowers to drink nectar, feed on pollen, or to collect plant resins. As they move from bloom to bloom, their bodies get covered in tiny pollen grains, which are then transferred between different flowers. This is known as passive pollination—you might say they arrived at the party unawares! Pollination is foundational to native ecosystems as well as human food systems—approximately 1 in 3 bites of food or drink are thanks to the work of pollinators.
Though not native to this part of the world, a striking example of mammal pollination is the black and white ruffed lemur, the world’s largest pollinator! Any animal that transfers pollen between flowers could be considered a pollinator. Here in the Sonoran Desert, birds and bats are the major vertebrate pollinators, collecting pollen on their bills or noses as they flit between plants feeding on nectar. Rodents, rabbits, monkeys, lemurs, lizards, and more can all be pollinators.
The VIP Guest List: Primary Pollinators
Though most flowering plants benefit from the activity of many pollinators, the bulk of pollination may come from a primary pollinator (or several). Let’s look at just a few of the pollinator partners of the Sonoran Desert.
SAGUARO. While visited by numerous species, this charismatic cactus is primarily pollinated by white-winged doves and bees, which take the day shift, and two migratory nectar-feeding bats, the lesser long-nosed bat and Mexican long-tongued bat, which take the night shift. After the flowers are pollinated and fruit develops, the bats and doves (and many other animals) eat the fruits and disperse saguaro seeds, which pass through their digestive systems. As a keystone species, many animals benefit from every part of the saguaro!
AGAVE. The lesser long-nosed bat and Mexican long-tongued bat also attend the agave pollination party as the primary pollinators of some agave species, including Agave tequiliana, native to central Mexico, and Agave palmeri in the Sonoran Desert. The next time you sip a tasty tequila, give thanks to the amazing bat! Sadly, both of these important bat species are endangered. Bats and other nectar feeding pollinators like monarchs and hummingbirds are threatened by habitat loss and fragmentation, human activity (such as mining, which can disturb bat colonies containing hundreds of thousands of bat babies), invasive grasses, changing fire regimes, and more. To ensure the continued survival of migratory pollinators, nectar corridors along their journey must be protected. Some tequila producers help bats by allowing some of their plants to flower (which ruins their tequila potential). Look for or ask for bat-friendly tequila brands!
CACTUS BEE. The cactus bee, Diadasia, prefers—you guessed it—cacti! These native bees are the chief pollinators of prickly pear and cholla cactus plants.
SACRED DATURA. A native perennial with large, funnel-shaped flowers that grows across Arizona, Datura wrightii flowers can be found in well-drained sandy soils such as arroyos, washes, and on roadsides. Their fragrant white flowers open at night, attracting hawkmoths and sphinx moths, their primary pollinators. Be warned—all parts of this plant are highly poisonous, though quite beautiful!
There are numerous other examples of passive pollinator partnerships in the Sonoran Desert, but some of the most fascinating pollinators of this region take on a more active role.
Two’s Company, Three’s a Crowd: Obligate Pollination Mutualism (Active Pollination)
Most often, a plant is visited by and benefits from many different pollinators, even if they have a VIP pollinator. But a few plants and pollinators have co-evolved a unique partnership—an exclusive party of two! These pollinator partnerships are examples of obligate pollination mutualism where the pollinator demonstrates active, rather than passive, pollination. This means their life cycles depend on each other. The yucca / yucca moth and fig / fig wasp are two well-known examples of this fascinating relationship, but the senita cactus moth demonstrates active pollination as well! These mutualistic relationships are not necessarily benign. The moths and wasps act in their own self-interest, but overall the scales even out to benefit both species in different ways.
So what does active pollination look like? Let’s take the yucca as an example. After the male and female yucca moth mate in spring, the male’s life cycle is complete. Boy, bye! The female moth then visits the flowers of a yucca plant and uses special tentacles to remove and carry the pollen to a different yucca flower. She then inspects the flower to ensure that no other females have visited, ensuring that her young will have yucca seeds all to themselves. She deposits the pollen on the stigma, fertilizing it, and lays her eggs directly into the ovary of the flower. This completes the adult female moth’s life cycle.
As the eggs develop, the flowers are busy producing seed pods. The larvae hatch inside the ovary and begin to consume some of the still-developing seeds. Throughout the summer, the yucca caterpillars (the larva of a butterfly or moth) continue to feast, growing larger, as the seed pod begins to dry out and spread out. The caterpillars then chew their way out and fall to the ground, where they will cocoon underground, readying to become adult moths. The completion of their metamorphosis is, of course, perfectly timed with the blooming of the yucca flowers. So the cycle begins anew!
Join the Party: Take Action to Protect Pollinators
- Take the time to learn more about pollinators, and then share the knowledge with your family, friends, and community.
- Eliminate or minimize pesticide use.
- Give bees a place to nest. Leave some areas of soil uncovered, or build a bee condo! Bee boxes encourage solitary, non-aggressive bees to nest on your property.
- Plant for pollinators. Native plants help support our native bee population. No space is too small – even a window or patio box can become forage for local pollinators. Use this guide to get started.
- Support local bees and beekeepers.
- Support your local, organic farmers by joining a CSA or shopping at farmers’ markets.
- Donate your money or volunteer your time to pollinator advocacy and research organizations in your community. Here in Tucson, the Tucson Bee Collaborative is studying the incredible biodiversity of native bees in our region.
- Reduce consumption and practice general conservation efforts. Pollinators are dramatically affected by extremes in weather, which are more common as climate change puts pressure on native ranges and overwintering sites.
Written by Elena Makansi. Cover image by Liz Kemp.