Honeybees don’t fly in the rain.
Flowering crops need insects for pollination and honeybees are vital for pollination of about 90 commercial crops around the world. Onions, carrots, strawberries, blueberries, apples & oranges as well as nuts, coffee, canola and even cotton all rely on the honeybee to increase yields to economically viable levels.
Today’s large-scale farms cultivate hundreds or thousands of acres of a single crop. Honeybee colonies are brought in and distributed throughout the fields or orchards (1-2 per acre) when the flowers are just coming into bloom and removed about 10 days to two weeks later.
So when a stretch of bad weather coincides with the brief time that the fruit trees, vegetable plants or berry fields are in bloom, the impact on crop yields can be disastrous.
The health of honeybee populations has become a cause for concern in recent years as beekeepers around the world are experiencing winter losses of 30 – 90% of their colonies. While these losses have largely been attributed to a phenomenon called Colony Collapse Disorder (CCD), local weather and climate also play a significant role in how well our most effective pollinators thrive – and survive.
How Weather Effects our Honey Bees and Food Supply
- When overwintering in colder climates, honeybees will form a cluster in the hive and strong colonies survive quite well if there is enough food and the temperature doesn’t vary too much or too often. On warm sunny days during the winter, bees will often break from the cluster to feed and take cleansing flights. But a sudden and severe temperature drop can catch the bees away from the cluster – resulting in loss of bees and a smaller cluster, which becomes even more vulnerable.
- A cool, wet spring season can prevent colonies from gathering the pollen required for the queen to resume laying, resulting in fewer foraging bees available for pollination when local crops come into bloom. Aside from the impact on crop pollination, weak colonies are more susceptible to disease and parasites.
- Inclement weather during the summer honey flow – when plenty of forage is normally available – will impact the bees’ ability to gather nectar to convert into honey. Instead of building up stores, the field bees are forced to stay in the hive and consume the honey already in the hive. By late summer, fewer flowers are blooming and the nectar flow decreases in most locations.
- Drought also prevents the bees from doing their job. Plants need water and drought-stressed flowering plants produce less nectar for the bees to collect. This also means beekeepers must feed their bees with syrup or sugar water to keep them alive. Not only do beekeepers have to pay out the extra expense for feed, they lose also the income they rely on from honey production.
- A rainy or cold early fall can further prevent the colonies from building up a sufficient quantity of “winter bees” required for them to survive through the coming season. As well, beekeepers rely on warm, dry weather in the autumn to carry out fall pest management activities, which can’t be done until the surplus honey has been harvested for sale.
Any one of these scenarios by itself would not necessarily put colonies at risk, but several badly-timed and prolonged weather events can take its toll over the course of a year and impact both the honeybees and our food supply.
Hobby beekeeper and veteran NASA Biological Oceanographer, Wayne Esaias is bringing his 25 years of experience studying climate and ecosystem change to dry land. Like most scientists, he has kept records of hive weights, which are a good indicator of colony activity and strength. He’s noticed over his two decades of beekeeping that local flowering plants in Maryland are blooming much earlier in the year than they used to. As both a beekeeper and a biologist, he’s trying to determine whether the pollinators and the plants are adapting to the changing climate at the same rate:
Flowering plants and pollinators co-evolved. Pollination is the key event for a plant and for the pollinators in the year. That’s where pollinators get their food, and that’s what determines whether the plant will set fruit. Some species of pollinators have co-evolved with one species of plant, and the two species time their cycles to coincide, for example, insects maturing from larva to adult precisely when nectar flows begin.
Esaias’ hope is to set up a network of beekeepers to collect hive weight data across the US which can be analyzed and compared with existing satellite imagery currently used to monitor seasonal plant growth activity. His greatest concern is that pollinators and the plants that sustain them, could adapt to change at different rates – causing them to go out of sync over time – with unknown implications for both bees and humans.
Because – as farmers know and consumers are fast learning – without a reliable supply of buzzy little pollinators, our global food crops are in jeopardy. And that means short food supply and higher food prices for all of us.