Nature's calendar

Phenology expert

Despite it only being January, the first signs of spring are truly beginning to emerge and the Woodland Trust’s Nature’s Calendar project, where people can record the signs of the changing seasons, has burst into activity.

Nature’s Calendar is a citizen-science project where the public can record seasonal signs and observations in their area. The information is used by scientists and Government to see how the changing climate is affecting our plants and wildlife.

The project has received a surge in records over the last few weeks of birds nesting, shrubs coming into bud and snowdrops flowering amid the mild weather. We've also received sightings of ladybirds and butterflies.


These early signs are consistent with a long-term trend that has been identified through your data recordings on the Nature’s Calendar website, which suggest that spring is advancing earlier.

Any sightings recorded by the public are very important to the project but we also request people to look out for specific wildlife events. At the moment we’re specifically asking for people to record sightings of rooks nesting, and listening for song thrush singing.

Rooks breed together in large numbers; their closely packed clusters of nests in adjacent trees are known as a rookery. Nest building behaviour, either repairing old nests or creating new ones, can be seen any time from January onwards. This year, due to the heavy winter storms, many birds will probably have to start from scratch as many nests will have been damaged.

Rooks are most often seen in flocks in open fields or roadside, foraging on earthworms, grains and insects. It is believed that the importance of worms in the diet is one of the reasons for rooks breeding so early since they are easily found at this time of year when the ground is wet.

The average UK date for nesting rooks is March 4, but  this behaviour has been recorded as early as December.

For singing song thrush the earliest records we have seen in the 2000-2007 period is November; more recently it’s been mid to late December. The UK average date in recent years is February 17.

Sometimes in early spring, birds such as thrushes, blackbirds and robins can be heard singing at night. It is suggested that this could be because they are disturbed (perhaps by predators) or in urban areas because of street lighting allowing foraging and activity at night as well as the day. However there is some suggestion that highly territorial species sing at night in towns and cities because there is reduced acoustic interference – unlike the urban noise during the day – and this has a greater effect than light pollution on nocturnal singing. This is an interesting example of how some species (but sadly, by no means all) can successfully adapt to the man-made environments they find themselves in.

To find out what to record, when and how to get involved in helping to record the signs of spring visit our website.

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