When we talk about conserving pollinators, like other animals, they mostly need food and shelter. With insect pollinators, the larvae of many species have a very narrow range of foods (plants) they can eat—like the monarch butterfly larvae (caterpillars) and milkweeds.
And whether it’s birds, bats, or insects, all pollinators need appropriate nesting sites whether they're located on the ground or in a cavity, like a tree. Migratory pollinators also require overwintering sites.
However, for the past 25 years, many species of bees and other pollinators have experienced large drops in numbers. Here, we explore the primary threats to pollinators across North America.
Fewer places to feed and breed
Habitat that pollinators need in order to survive are shrinking. As native vegetation is replaced by roadways, manicured lawns, crops and non-native gardens, pollinators lose the food and nesting sites that are necessary for their survival. Remaining patches of prairie and meadow have become more disconnected. That makes it harder for pollinators to reach new breeding sites or find better habitat.
Migratory pollinators face special challenges. If the distance between the suitable habitat patches along their migration route is too great, smaller, weaker individuals may die during their journey.
The abdomen of a female snow miner bee (Andrena nivalis). A parasitic female stylopid has just given birth likely killing the bee in the process.
Imported species and diseases
Invasive plants crowd out native ones, reducing food and shelter for pollinators. Disease-causing organisms— including viruses, fungi and bacteria — can spread from non-native to native pollinators. Other stressors, such as poor nutrition and pesticide exposure, may intensify the effect of diseases.
Pesticides
While pesticides can help control crop pests and invasive species invasive species An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.
Learn more about invasive species , improper use can harm pollinators and other wildlife. Use pesticides only when necessary. Use the minimum amount required to be effective and target the application so that only the intended pest is affected.
Flowers are blooming earlier as temperatures warm, costing some pollinators the opportunity to feed. Some insects feed only on specific plants; if these blooms die before insects arrive, the insects go hungry and fewer plants get pollinated.
Rising temperatures may be contributing to a decline in bumblebees. Numbers of North American bumblebees have fallen nearly 50 percent since 1974. The biggest losses have occurred in places where temperatures have risen the highest.
Other climate change climate change Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.
Learn more about climate change effects — more flooding, shorter fire cycles and the spread of invasive species — threaten native habitats. This may directly affect pollinators if the host plant that a pollinator needs to survive is overtaken by another plant species.
