By: Anita Stone
It’s a bird! It’s a plane! No, it’s radar spotting trillions of migratory insects above us. Yes, overhead as far as the eye can see are swarms of migratory insects that take flight during spring and fall. And because we are now equipped to track airborne insects, we have been able to learn that several thousand tons of biomass in the form of migratory insects may travel up to hundreds of kilometers daily. The numbers are “stunning,” says Silke Bauer, an ecologist at the Swiss Ornithological Institute in Sempach. “Wow,” adds Larry Stevens, an evolutionary ecologist at the Museum of Northern Arizona in Flagstaff. “Can you image what these numbers look like in tropical settings, say, over the basins of the Amazon or the Congo?”
This is nothing short of amazing when you think about 3,200 tons of migratory insects being equivalent to the weight of 10 Boeing 777s. A 10-year-old study focused on flying insects finds that 3.5 trillion of them migrate every year. That is more than seven times the mass of all 30 million songbirds that leave England for Africa each fall. And this is only one part of the globe. Of this great mass, it is estimated that about 70 percent migrate during the daytime and the rest are nocturnal, according to research.
Although some insect migrations are well known, such as the flight of about 150 million monarch butterflies, weighing a total of 75 tons, it is amazing how they are able to fly between North America and Mexico each year. Backyard gardeners now plant milkweed for monarchs to ensure these winged jewels have plenty of food along the way. To prevent loss of habitat, many homesteaders are ensuring safety by constructing facilities to house these creatures. The new evidence is about other flying insect migrations and mass movements. The extent of invertebrate migration had never been measured until now, let alone its environmental impact, about which research is still ongoing.
An international team of scientists discovered that migratory insects are the biggest movement of biomass on the planet. We notice birds and butterflies, but not migratory insects, largely because of their high-flying altitude. Some migrate at heights up to 2,000 meters. Massive amounts of nutrients locked in tiny little bodies are moving between continents. Insects are a major part of our lives in farming, ranching and even in manufacturing. Climate change in insect migration patterns will ultimately impact the way we humans live.
Any change in migratory insect flight patterns during any season, as much as 200 tons of biomass, could affect insects in either direction in any given year, affecting our lives in unknown ways. During winter and summer months, these insects become fascinating because we pay little or no attention to them. There are reports from research that measure and reveal a flurry of daytime migrants, moving north in spring and south in fall with seasonal changes on a yearly basis. It is truly amazing to realize that all this activity is going on overhead and that we are generally unaware of these events.
Ecologist Jason Chapman states, “high-altitude insect migration represents the most import animal annual movement in ecosystems on the land, comparable to the most significant oceanic migrations.”
So why is studying this migratory insect event so important? One reason is the impact of climate change. Once again we evaluate the ecological impact of migrating insects because changes in climate could alter their travel paths with unknown effects. And because any changes in insect patterns could tell us about climate changes before any changes are discovered in other places.
Another reason is because mass insect travel affects humans and some insects will devour our crops, while some protect and pollinate plants. Also, many beneficial insects are not equipped to keep up with habitat loss, pesticide use and human climate changes. These issues create open-door activities for the bad insects to use in a negative way which can change our ecosystems. For this reason, many who are homesteading today are practicing natural pest control.
“Animal migration is a very complex behavior which took millions of years to evolve and is very sensitive to the climatic condition,” says Ka S Lim of the Radar Entomology Unit in England. “Global climatic change could cause the decline of many species, but equally other highly adaptable species thrive and become agricultural crop pests.”
Researchers and scientists believe that the larger insects have built-in compasses. “If high-flying insects have a compass sense, one would predict that, in addition to selecting a favorable tailwind, they would also orientate in the seasonally beneficial year on their way to Africa,” says Dr. Nir Sapir from the University of Haifa. “This is eight times more than the continued weights of all birds and bats migrating over the region annually.”
If you ever feel inclined to look up into the sky – really look up into the sky during the spring and fall seasons, and if you could catch a glimpse of a swarm of migratory insects moving in unison toward another location, it would be truly amazing. It would certainly be a realization and recognition of the power and mystery of our Mother Nature at work.