Honeybees may be able to detect changes in carbon dioxide levels, temperature, pressure and humidity, all of which enables them to forecast weather changes. Rain is one of weather changes and reasons why honeybees will work harder to get their jobs done.
Researchers from Jiangxi Agricultural University’s Honeybee Research Institute tagged 300 bees with tiny devices that enabled them to track the insects’ activity using a technique called Radio Frequency Identification. Tagged workers were introduced to their natal colonies, and monitored 24 h per day during a period of 34 days by an RFID reader (Picture 1).
One of the experiment colonies, honeybee Radio Frequency Identification (RFID) system and tag-marked workers. a: tag; b: recorder; c: reader. The tag has a diameter of 3 mm and is 0.08 mm thick and weighs 1 mg.
Picture 1. One of the experiment colonies, honeybee Radio Fre-
quency Identification (RFID) system and tag-marked workers.
a: tag; b: recorder; c: reader. The tag has a diameter of 3 mm
and is 0.08 mm thick and weighs 1 mg.
When tagged workers entered and exited a colony, the RFID system recorded their unique ID, time stamp and direction. Duration for each trip was calculated based on the exit and entrance time stamps after sorting the data based on each RFID.
They classified the foraging data in two categories, days that were followed by a sunny day, and days that were followed by a rainy day. They note that suggests bees are very good at detecting atmospheric changes, such as that of temperature, pressure, and humidity that often come along just before changes in weather are likely to occur.
Just before a rainy day, honeybees were found to spend more time flying around outside the hive, looking for nectar and pollinating plants, but on days following rainfall, when it would be perfectly sunny outside, bees were a bit lazier and stayed around at the hive longer. They also discovered that “quitting time” – the time of day that the last bees returned to the hive for the night – was later if the following day was due to be a wet one.
This behavior also suggests honeybees are very much preparers, and know when to take advantage of flowers and food-gathering before being disturbed by rain. They also use the time they have as it rains to use the resources they collect just before the rainfall.
By collecting food before rainy days, honeybees help ensure their survival even when a long period of bad weather may be afoot.
Because these changes are at the social level, and not just at individual level, the question remains how honeybee workers can communicate the need to work “harder” after perceiving the predictors for the impending weather changes, like rain. Future studies will focus on what factors in the weather system are perceived and how bees communicate the need for behavioral changes to the whole colony.
Looking forward for new informations!