On 11 August 1999, a partial solar eclipse peaked at 12.25-12.26 hr in the northern Netherlands. The sky was overcast, ambient temperatures dropping from 17-18°C before 11,30 hr to <l4°C at 12.30 hr (at treetop level). A Honey Buzzard nest was kept under constant observation between 10.30 and 13.30 hr, from the top of a tall Douglas fir some 60 m away from the nest. Both the nest and its 360° surroundings could be overlooked. The nest contained two young of 45 and 43 days old, the oldest one (A) having recently fledged. The adult female, carrying a wasp’s comb, approached the nest at tree level from a southern direction at 12.35 hr; she kept her distance until 12.53 hr, approached the nest below tree level at 13.07 hr, dropped the comb during a short landing on the nest and disappeared immediately in an easterly direction. Both young had been active throughout the period of observation, watching the surroundings, preening, wing-flapping, flying short distances (young A) and begging at the sight of the female. Neither female nor young showed aberrant behaviour before, during and after the partial eclipse. On the other hand, foraging activities of social wasps, mainly Vespula vulgaris, gradually ceased after 11.30 hr, i.e, when the ambient temperature slowly started to drop below 14°C.