Why are pollinators important?
When you think about pollinators, images of honeybees likely pop up in your head. And rightfully so, after all, it seems like all people care about is bees as pollinators and that they spread pollen around and sustain plant populations.
Yet, there are so many other pollinators that you might have not heard of such as beetles, flies and wasps, butterflies and moths.
All of these pollinators share many things in common:
• They fly, allowing them to visit plants more quickly and therefore assist with producing seeds and fruit in many plant species.
• They eat the pollen and/ or nectar.
Primary pollinators (more than bees)
Butterflies
According to a study in 2011, more than 80% of land plants are pollinated by butterflies. Butterflies’ life spans differ between species. Butterflies and plants have been co-dependant on each other throughout their existence. Flowering plants provide butterflies with food, shelter and nectar. In return, butterflies help flowering plants reproduce via pollination. When a butterfly sits on a flowering plant to drink nectar, the flower’s pollen becomes attached and as the butterfly moves from flower to flower, the pollen gets transferred.
Hoverflies
Hoverflies are called flower flies because they are commonly seen during warmer months. They are considered the second most important pollinators after bees. Hoverflies look and function similar to bees, but they are flies. One key difference is their different body shapes. Some species commonly found in crops (e.g. Melangyna viridiceps and Simosyrphus grandicornis) have flat bodies. Another important distinction is the number of wings they possess. Hoverflies only have one pair of visible wings, while bees have two pairs. The efficiency of pollinating for hoverflies depends on the size and structure. Both these characteristics determine how far they can forage for nectar and the quantity of pollen that they transfer. Despite carrying less pollen than bees, hoverflies compensate for this by making a greater number of flower trips. They are crucial pollinators of wildflowers, soft fruits, and agricultural crops.
Moths
Moths are effective pollinators during the night. Flowers with pale or white colours that emit fragrance attract moths. When they are at rest, their bodies stick very closely to the surface of the flower as they drink nectar. When finished, moths carry pollen on their tongues. The co-dependent relationship between moths and plants can be seen with the Yucca Plant and the Yucca moth. Female yucca moths intentionally collect the pollen from one plant then finds a flower on an entirely new plant where they lay their eggs. They deposit the pollen on the new flower to ensure the flower produces fruit, that her larvae will use as food when they hatch.
Beetles
Pollination by beetles is heavily influenced by the evolution of angiosperm flowers. They are crucial pollinators to Mongolia flowers and spicebush. It is quite possible that millions of years ago, beetles helped shape early plant-pollinator relations, even before butterflies and bees! Beetles are considered primary pollinators of Magnolia plants. These flowers are bowl-shaped and provide shelter for beetles. Beetles pollinate these flowers and feed on their pollen. Beetles rarely visit flowers for the typical nectar interactions that other well-known pollinators are known for seeking, but rather protein-rich pollen.
Secondary pollinators
Seed dispersal is also very important for the conservation of biodiversity. All plant species that produce seeds must have a way to spread them. Seed dispersal is the transfer of seeds to their plant of origin to different areas. The structure of the landscape strongly influences how far the seeds are carried, regardless of if they were carried bymeans such as wind and water, or animals. As it is quite evident, seed dispersal is quite important for the survival of the plant species. If the plants grow too closely together, they will naturally be forced to compete for the same resources. Simply put, seed dispersal increases the chances of survival for many plant species because the seeds are spread out to ideal environments for growth. Here are some examples of seed dispersal animal species:
Mistletoebird
One of the many ways that animals disperse their seeds is by consuming them and excreting them out. Certain plant species, including many trees, attract hungry animals by keeping the seeds inside fleshy, edible fruit. The small mistletoe bird is the only Australian representative of the flowerpecker family, Dicaeidae. This small bird is also known as the Australian Flowerpecker. Females have grey heads and white below and they have a grey streak on their bellies. Males have a glossy blue-black head, wings and upper parts.
Though quite common, sightings of Mistletoe Birds are quite rare. The Mistletoe bird picks up the mistletoe berry seed from the tree and consumes it whole. They make excellent seed dispersal agents because although the fruits are eaten, the seed and its sticky coating pass through undigested. The Mistletoe bird performs several movements when they release their droppings, such as wiping the excreted seeds out on a nearby branch. Mistletoe is a parasitic plant that can grow only on the branches of other plants, so the Mistletoe bird’s unique seed depositing method glues the seeds exactly where they need to be.
Flying Foxes
Also known as fruit bats, flying foxes live in South Asia, Southeast Asia and Australia. There are two types of flying foxes: The Grey-headed flying fox and the Little Red flying fox in Australia. Flying foxes play a huge role in dispersing seeds and pollinating plants, ultimately keeping native forests healthy. While feeding, they pollinate plants. During flying, they disperse seeds in their droppings and carry bits of pollen from tree to tree. They are critical in ensuring the survival of Eucalyptus trees as they pollinate over 50 native trees. They rest during the day and fly out at night to feed.
Flying Squirrels
Tree squirrels are significant seed predators in conifer and mixed forests throughout colder and northern regions, but in some regions can act as agents of seed dispersal. In these forests, squirrels consume large quantities of seeds and even visit entire crops. Flying squirrels are found throughout the world such as in Europe, Asia, North America and Central America. They are smaller squirrels than other tree squirrels. They are between 8 to 10 inches in length. Despite their name, flying Squirrels do not have wings- therefore they do not fly, but rather glide. They have loose skin that extends from their wrists to ankles. There are two types of flying squirrels: Northern and Southern Flying Squirrels. Northern Flying squirrels can be found in coniferous trees situated on top of North America.
Autumn nights are the best to observe Southern Flying squirrels because during this season, they are active at night as they gather and hunt for food. They have a varied diet which includes nuts, acorns, fruits, bark, and fungi. They are essential to woodlands through their dispersal of acorns, nuts, and fungi. They disperse fungi pores through their droppings. They can be very beneficial for the growth of trees.
Emu
Emu is a large flightless bird, a cousin of kiwis and cassowaries. They also consume a large variety of plants, insects and spiders. They are situated throughout all of Australia. In Australia, they are our most important seed dispersers because of how large they are and their ability to disperse seeds long distances. How frequently they disperse their seeds and how far they do it from the parent plant is important for gene flow and genetic diversity. Without any teeth, emus eat by gulping and digesting and have an appetite for tasty food such as native cranberries, emu plums, quandongs and more.
It is quite evident that even though bees are considered the most important pollinators, there are other animals that are just as equally important, many of which we do not typically hear about. This means that there may be many more pollinators and seed dispersers that scientists will uncover in the future!
Author: Zeerak Ayaz