Bee populations in monitored hives experienced a sharp decline in pollen collection during late autumn 2025, coinciding with the onset of freezing temperatures and increased precipitation, according to recent observations. The data, collected from two hives, indicates a near cessation of pollen intake by late October, raising concerns about winter preparedness for the colonies.
Initial pollen intake was lower in both hives at the beginning of the observation period. However, a temporary increase was noted from week 34 onwards, likely attributable to increased flowering of clover, cruciferous plants, and phacelia, coupled with favorable weather conditions. This period of increased foraging provided a crucial boost for the bees as they prepared for the colder months.
The significant drop in pollen collection began around week 39, with intake dwindling to almost nothing by week 40. This decline correlated directly with falling night and day temperatures, as well as repeated frost events and rainfall, severely restricting bee flight activity. Temperatures dipped below 0°C (32°F) between October 1st and 4th, with daytime highs only reaching between 13.0°C (55.4°F) and 16.2°C (61.2°F). Rainfall between October 5th-7th and October 23rd-27th further hampered foraging efforts.
Due to the complete lack of pollen intake, the hives were relocated to a different site at the end of week 44. Pollen samples from weeks 43 and 44 were combined due to the extremely low collection volume during that period. Throughout the observation period, the two hives exhibited differing levels of pollen collection initially, but these differences lessened over time. This variation is thought to be linked to the developmental stage of each hive – specifically, the amount of brood present and the associated pollen demand for raising winter bees.
One hive, designated Hive 3, had a young queen introduced three weeks prior to being placed at the observation site, potentially influencing its developmental trajectory. Without conducting internal hive inspections, a definitive assessment of the internal development of each hive – brood levels, population strength – remains impossible. The observed differences in pollen collection therefore offer only inferences, not conclusive evidence, regarding the internal dynamics of the colonies.
The data reveals a clear correlation between the onset of frost and a reduction in pollen-gathering activity when temperatures fell below approximately 13°C (55.4°F). A brief improvement in conditions during week 42, with higher daytime temperatures and no precipitation or frost, did not result in a significant increase in pollen intake, despite the continued blooming of phacelia and cruciferous plants. By week 43, pollen collection had virtually ceased.
Experts emphasize the importance of late-blooming plants, such as Persian clover, white clover, Alexandrian clover, crimson clover, phacelia, and buckwheat, in providing essential nectar and pollen resources for bees during the late summer and autumn months, a period when natural forage becomes scarce. These plants, belonging to families like Asteraceae, Fabaceae, Brassicaceae, and Lamiaceae, are crucial for supporting bee populations as they prepare for winter.