This past February, in Oaxaca, Mexico, the Commission for Environmental Cooperation held its first workshop on pollinator conservation. The organization, created by NAFTA, deals with environmental issues common to Canada, the United States and Mexico. This get-together of stakeholders from the three countries made it possible to determine the extent of pollinator decline in anthropized landscapes,1 and that there will be no simple solution to what is a multifaceted problem.
Abnormally high mortality rates in honeybee colonies and the biodiversity crisis in wild pollinators – two distinct issues
When we hear about pollinators in the media, most of the time they’re talking about the honeybee. Over the past 15 years or so in Europe, and then in the U.S. and Canada, mass mortalities have been reported on a scale rarely seen before. Québec hasn’t been immune to that situation, with beekeepers year in and year out losing an average of 20 percent of their hives here, primarily over the winter. There are multiple causes for this, some of them linked to the realities of a domesticated species: pathogen management, famine, beekeeping control, the use of systems that involve the application of numerous pesticides, rental and transportation of hives over long distances…
But wild pollinators face multiple threats in their natural environment, including the impacts of climate change, habitat destruction, pesticide drift2 and the transmission of pathogens. Competition for resources with honeybees can also have an impact on their communities. Wherever the density of honeybee hives is high when weighed against the availability of resources, that bee’s effectiveness means that the resource quickly becomes limited for wild species, which may then disappear from the environment.
Each has a role to play
The outstanding quality of the honeybee, apart from the production of honey, of course, is its great ability to get around. It’s estimated that a worker bee can exploit resources located more than three kilometers from the hive. That considerable mobility is crucial where pollination of large monoculture farms is concerned, especially when we know that most wild pollinators, with the exception of bumblebees, rarely travel distances of more than 200 meters from their nests. Wild pollinators are recognized for the degree of their pollination effectiveness. A study of 41 agroecosystems around the world showed that the rate of pollination success was almost always higher given the intervention of wild pollinators. However, it was also demonstrated that the activity of the honeybee and wild pollinators together had an additional impact. Their activity may therefore be complementary.
So, each has its role to play. Honeybees are essential in our agricultural landscapes, but may impose additional pressure on wild pollinators when used in less anthropized landscapes, or where there are less abundant resources. Consideration must always be given to hive density, because excessive density will have negative consequences both on wild pollinator communities and on the hives themselves.
1Anthropized landscape: a landscape that moves away from its natural state as a result of human activity.
2Pesticide drift: a combination of processes, such as the wind, resulting in part of a pesticide not reaching intended plants and being lost in the environment.