Bird life at Brimham Rocks

The 70 boxes spotted around the site at Brimham are built to attract blue and great tits, pied flycatchers, nuthatches and redstarts. We also have several open-fronted boxes for spotted flycatchers, thinnish boxes for tree creepers and larger boxes for owls. We monitor the boxes on behalf of the British Trust for Ornithology (BTO), completing record cards for each bird box. After the cards have been completed we send them to the BTO, who compile all the information in the bird trends report, which is a telling review of our environment.

The rangers and volunteers start looking in the bird boxes around mid-April and visit the boxes throughout the spring, usually every 7-10 days. First they check for any nest building, usually shown by some moss with blue tits, who are always the first ones to build their nests. After a couple of weeks the nests become lined with hair and are fairly complete. Shortly after building their nests they lay their eggs, which can be buried beneath down feathers (to hide them from predators) while the birds are out feeding. The blue tits can also be quite aggressive and have even been known to spit at the team.

Following the blue tit it’s time for the arrival of the great tits with their nest building, and finally the pied flycatchers. The time scale for all these activities is usually two weeks once the eggs have been laid, then two weeks for the chicks to grow and fledge. 

The rangers, along with bird box volunteer Rob, work constantly to repair the bird boxes and keep them in good order. Squirrels often attempt to break into these cosy homes and some of the boxes just disintegrate. There can be quite a few casualties during the laying season with some eggs being abandoned, most probably due to the adults being predated; eggs can also be eaten by small mammals and some just don't hatch.

2019 has seen us surpass a terrific landmark as the 187 chicks from this year have taken us over 1,000 chicks milestone since we began recording back in 2014. We're really pleased to see that pied flycatcher numbers have steadily increased every year with 79 chicks this year, a 61% increase from 2018. Considering that this is an RSPB red listed species this is a considerable achievement and we plan to build more bird boxes next year in 2020. Redstarts, an RSPB amber listed species, have also continued to nest at Brimham this year.

Brimham Rocks has a varied and diverse number of birds that breed and visit the site not only during the breeding season but also in the winter. Bird monitoring is a useful scientific study and is a reflection upon the environmental health of the area. The team always looks forward to this time of the year with huge anticipation and excitement.