Things you need to know about ROOKS!
Channel: A Shot Of Wildlife
Date: 2023-10-27

If you have ever seen a group of large black birds, nesting close together near to farmland, the chances are high that you’ve been looking at rooks. These are members of the crow family and their communal nesting sites are known as rookeries. 
Rooks are communal birds that nest, feed and roost in large flocks throughout the year. Sometimes there can be several hundred birds in one patch of trees. They are omnivores and use their featherless beaks to probe into mud for worms, beetles and other invertebrates. They will also occasionally eat carrion, birds eggs, grains and seeds and they will sometimes scavenge for scraps. They rely on large trees for nesting and roosting and their main habitat is agricultural areas, farmland and grassland although they can also be seen in urban places such as graveyards and large parks.  
Rooks form long lasting pair bonds and often remain monogamous for life. Each pair will start to build their nests early in the year, usually during February and March but sometimes as early as January. These are high in the branches of large trees and can be just a metre or so away from other nests. Living so closely together does mean that the twigs they use for nest building are in high demand, and they are known to steal twigs from eachothers nests. To prevent this, the female usually guards the nest site whilst the male collects twigs and mud to bind the nest together with. Once the nest is complete, it is lined with wool, moss, leaves and sometimes even hair before the female lays between 3 and 5 pale greeney blue eggs with darker patches. These measure about 4cm long and she will incubate these alone for 15 to 16 days before they hatch. Both parents feed the chicks in the nest for 32 to 34 days when they are ready to fledge. After this, the young birds are fed by their parents outside of the nest for many more weeks until they are able to look after themselves. Some will then disperse to other rookeries whilst some will stay in the same area where they were raised into the autumn. Young rooks look very similar to adults but their bills are black, have feathers running along their tops and they lack the featherless patch at their bills base. Each pair of rooks will only nest once per year, but will maintain a close bond with their partner outside of the nesting season, feeding and roosting together. Amazingly some rookeries can last a very long time, there are several in the UK that have been in the same place for more than 100 years. 
Just like other members of the crow family, rooks are really intelligent, they understand how to use basic tools almost to the same level as a chimpanzee and in one experiment a rook quickly learnt that adding rocks to water would raise the water level and make floating food that was previously out of reach available. 
There are around 980 thousand pairs of rooks in the UK, but this represents a decline of about 20% over the past 25 years. Outside of the UK they are found across mainland Europe, into southern Russia and as far east as northern China. They have also been introduced to New Zealand, where they are treated as a pest and there are ongoing efforts to eradicate them. In some of their northern ranges they sometimes move south in cold winters but over most of their range they are resident all year round. The oldest rook ever recorded lived for 22 years and 11 months exactly, but they have an average lifespan of about 6 years. Here is one of the rooks calls. 

Thanks to Fotolainen for providing some of the footage used in this video, the original video can be found here: https://www.youtube.com/watch?v=kw8FLD_vGBI&lc=UgzNVwOYcCSDswuaTmF4AaABAg.9wJ2R-ayCsV9wLb1M0UXDv

Some of the other footage and images used are creative commons, the originals and their licence details can be found at:
https://www.youtube.com/watch?v=mBnnwrT2Ifg&t=175s
https://www.youtube.com/watch?v=_xoZEotvFYE&t=126s
https://www.youtube.com/watch?v=aC61Mv-7eO4
https://www.youtube.com/watch?v=BJrAFbKXrXM
https://www.youtube.com/watch?v=b6VO76x7pbE
https://www.youtube.com/watch?v=qC5ku0-12h8
https://www.youtube.com/watch?v=OHBJTVzvhkA
https://www.youtube.com/watch?v=kOZLs_Nz088
https://www.youtube.com/watch?v=PB9dcqI6V_k
https://www.youtube.com/watch?v=golb96WlvGw
https://www.youtube.com/watch?v=w3QqxPbrcNw
https://www.youtube.com/watch?v=7e6dUoKR138
https://www.youtube.com/watch?v=eFg1fykWjrY
https://www.youtube.com/watch?v=SPRcXTtIcnY
https://www.youtube.com/watch?v=5RNqyT-KCmM
https://www.youtube.com/watch?v=m6BuA1zLQ64
https://www.youtube.com/watch?v=wIqn6M98qgs
https://www.youtube.com/watch?v=IVLOZF0YtE8
https://commons.wikimedia.org/wiki/File:Corvus_frugilegus_MWNH_1322.JPG
https://www.flickr.com/photos/17316292@N00/19217994243
#rooks #crows #ukwildlife