Part of the crow family, the rook is a familiar sight along some of Pembrokeshire’s field edge lanes – they roost and flock together in winter, building nests high up in the bare trees ready for spring.
The nests are made by binding together twigs with earth and then lined with moss, leaves, grass, wool or hair. Occasionally they will re-use or upgrade last year’s nest. They like to live near open fields to gather and socialise , but you may also get visits to the garden bird table in twos or alone. A large group is known as a parliament of rooks and they can be seen to seemingly admonish individuals within a rookery. My Nan told me that the higher the nests the better summer would follow so I hope that is true this year as the nests are very precariously near the top of the trees in our lane near Mathry.
Their faces can appear a little more grey and their beaks thinner than the crow, with a more peaked head and there are 1,100,000 pairs in the UK. When close, you can see iridescent blue, purple and green in their shiny plumes and they appear to wear baggy trousers.
Partners will share food and they sometimes hide it in the ground – caching. They even create small piles of false stones to distract from their hidden supplies. Chosen food includes insects, seeds, vegetables, especially root crops, and carrion.
Flocks are large and these very social birds are tolerant of each other, despite raucous tugs-of-war over sticks and stones and they can dominate smaller birds around a bird table.Highly intelligent, their raucous calls can be quite overwhelming when you are near a large group. Pair-bonded for life, they display a great variety of behaviour patterns to each other such as feeding, preening, vocalising and even copying each other. Mating rituals include strutting, bowing and cawing.Living for up to 20 years, they nest early in the year and often lay eggs by as early as late February, with the young leaving the nest by July. The eggs are smooth, glossy and may vary in colour from light blue to greenish-blue or green and are about 40mm long. in keeping with their strong bond, both parents feed the young, of which there will be between 3 and 9 , born after 16 days incubation and fledging about 36 – 36 days later.
“if you see crows they be rooks; if you see a rook it be a crow” note the reference to the plural…you only see crows in ones and twos or at least small family rooks, whereas rooks are always in large groups – thanks to Nes (Ian Cory) for checking this feature!