Thanks, Ghislain, for the interesting read. Towards the end of the document the authors wrote: "It is unlikely that the availability of pollen is the only trigger that induces the switch from brood-filled colonies of short-lived workers to broodless colonies of long-lived workers because seasonal changes in pollen supply clearly do not account for the resumption of brood rearing that occurs before workers start foraging in spring." I hadn't realised that Canada goes so far south - 43 degrees, which suggests that if people are going to record and share information they should include their latitude and longitude as they may cause the graph to curve in different ways. I went across to my apprentice, Sarah's, Bee Happy Plants nursery this afternoon and, after I had placed the sensor of the aquarium thermometer in the hive, we discussed what she should record and the location was one item. She's 50 degrees and 50 minutes north. Also 330 feet above sea level. She will record the hive temperature reading daily at 10am and will place another thermometer next to the hive shaded from sun and wind so the influence of ambient temperature will be apparent. Weather and entrance activity are also on the list but she, not I, was taking notes so I may have missed something. Chris *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html