Dates are very important in nature. Ospreys don't use a calendar, instead they take their cues from the natural turning of the seasons and changes in daylight hours.
British ospreys are a migratory species. Each spring they travel from their warm over-wintering grounds in west Africa (although around 5% stay in suthern Europe) to their breeding grounds in Europe. It is crucial that they get their timings right in order to achieve the best breeding productivity. If they get back too early in the year they risk both a cold spring where food is hard to come by and difficulty in finding a mate as there are few other ospreys are around. Get back too late and all of the nest sites and breeding birds are spoken for. In late summer or early autumn, once their chicks are grown and independent, the ospreys head back south for a winter in the warm.
The further north in Europe an osprey breeds then the later it tends to return. Ospreys in France return in February and early March whereas those birds breeding in northern Finland may not get back until late April. Breeding in the far north may have a shorter season but this is offset by the incredibly long daylight hours that enable these birds to fish more-or-less 'round the clock.
Below are all the key dates, corresponding to significant milestones for the Dyfi ospreys since they started to breed here in 2011. This handy table is published at the back of the DOP Calendar each year - look out for them in the online shop from each Ocrtober onwards.
Key dates 2024