Corvus frugilegus
Sometimes known as the seed crow, the rook is a close relative of the crow, jay, and magpie. Rooks lives throughout Europe, but there are not many in Scandinavia. They also exist in New Zealand, although they are not indigenous to that country. They were imported there in the 1860's and 1870's to help farmers control the population of some pests. Ironically, many of the farmers now consider the rooks themselves to be pests, as they have been known to destroy crops in order to find seeds to eat. In Scotland, rook pie (made from the breasts of young rooks) is a popular dish.
Physical Characteristics
The rook is very similar in appearance to the crow, although it is smaller and closer in size to a magpie. It is covered with glossy black feathers that have a subtle purple tint. The legs are only partially feathered. A greyish white area of skin encircles the base of the bill, covering the region between the eyes and the nostrils. This coloration does not happen until after the rook is more than 1 year old, and thus it can be used to identify an immature rook. Young rooks are often mistaken for carrion crows until they reach adulthood. The cry of the rook is short and raucous. As an adult, a rook achieves a length of 43-45 centimeters. Its wingspan is 90 centimeters. There is no sexual dimorphism in the species -- that is, there are no significant differences in appearance between male and female rooks.
Food Habits
Rooks are omnivorous, with approximately half of their diet coming from plants. They eat insects, worms, grubs, seeds, fruits, and vegetables.
Behavior
Although quite wary of humans, the room is very social among other birds. It travels in flocks, and often birds of other species can be found in their company. They live in communities and nest together in large groups called rookeries.
Habitat
Rooks prefer to nest high up in mature trees. Some rooks migrate seasonally, and others do not. In both cases, they typically live on farmland or open country.
Reproduction
Rooks breed monogamously, and a breeding pair can remain together for multiple years. In the Spring, a female rook will lay 3-6 eggs in her nest. The eggs are greenish and mottled grey and brown. It takes 19 days for the eggs to hatch. Approximately 1 month after hatching, the young are able to fly. Both parents help to feed and nurture the children after they hatch. Only one or two of the young usually survive the first year. The same nest may be used for multiple years by the same breeding pair, when possible.
Sources:
- http://www.hbrc.govt.nz/pdf/PCAP6.pdf
- http://www.biologiezentrum.at/biowww/en/austell/a022001.html
- http://www.stoke.gov.uk/museums/pmag/nathist/education/keystage/content/rook-keystage_3.htm
- http://mrw.wallonie.be/dgrne/ong/refuges/corfru.html
- http://www.birdguides.com/html/vidlib/species/Corvus_frugilegus.htm
- http://www.inra.fr/Internet/Produits/HYPPZ/RAVAGEUR/6corfru.htm
- http://www.nzbirds.com/Rook.html
- http://zoologie.forst.tu-muenchen.de/HEITLAND/BSWT/AVES/PASSERIFORMES/CORVIDAE/
CORVUS/corvus.frugilegus_01.html