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The truth about the Corvid-19 and what you need to know – part 5 – a look at the rook.


Last week I didn’t manage to make a Corvid-19 article in ths series, which doesn’t bode well for coming quickly out of the crisis, but on the plus side we do have some positive news about treatments emerging in the USA and the UK.   Today we continue our review with another Corvus genus member, one of the better known old-world corvids, the rook.

A rook in England, thanks to Adrian Pingstone for placing this fine photo in the public domain. 

We are presenting the info for each Corvid in a similar tabular form and there will be a publication available at the end of the series where you will be able to get hold of the combined table.

Common Name Rook
Other names None
German Saatkraehe
French Corbeau freux
Russian Грач
Polish Gawron
Scientific Name Corbeau freux
Number of species in the genus 45
Number of subspecies in this species 2
Literal meaning of Scientific name Fruit-gathering crow
Described by Linnaeus 1758
First attested in literature Known and written about from old times, in England referred to in a legal enactment by Henry VIII, who spells them “rokes”.
Wingspan (cm) 96
Length bill to tail (cm) 46
Distribution Distributed in all Europe and much of China, with a narrow belt going throug Russia in the middle. The western variant, C. f. frugilegis stretches over most of the range even as far as parts of China, but shares part of the range with C.f. pastinator.  They tend to live south of the 60 degrees parallel, especially in Winter, where those of more northerly ranges can fly further south for the worst of the winter, returning early in the spring while it is still snowing. The species tend to avoid territories preferred by ravens, so they prefer firelds to forests. They have been introduced to New Zealand where they are regarded as an invasive pest.
Remarks Most vegetarian than other crows. Less likely to exhibit high degrees of intelligence in interacting with humans. Their high nests in large company are known as “rookeries” and they probably have more collective ouns in English referring to groups of rooks than many other species do, and these include: ‘building’, ‘parliament’, ‘clamour’ and ‘storytelling’. They do not have as broad a range of vocalisations as other Corvus genus members, although there is some variety, but their signature rough call is what gives rise to their common name in English. In turn, their name has been applied to the chess piece and to an ungainly human novice or “rooky”.
Migrations Only the more northerly populations are migratory and only for the worst of the winter. The painting by Savrasov “the rooks’ return” shows returned rooks on a snowy backdrop, so they only flee the coldest snaps, not the temperate winter in and of itself. They have successfully urbanised in many large cities such as Moscow or Warsaw.
Sexual dimorphism Barely noticeable, other than a slight crest on some males, which are larger
Close relatives Other Corvus species may be closely related but hybridisation with rooks is rare.
Not close relatives thought to be close They remind one with their bald faces of coots, a water bird not at all closely related.
Cultural significance Although crows themselves have unpalatable flesh, the strictly vegetarian rook is more tasty, apparently – “rook pie” was a meal mentioned in the Pickwick Papers, however this is only palatable up to its maturity, and the season for shooting rooks for food is short. Already mentioned above, one of the finest paintings in my opinion in the world is “the rooks return” by Savrasov. In the main they have been regarded by humans as an agricultural pest, but despite this they remain quite a populous bird.

The Rooks Return, by Alexei Kondratyevich Savrasov, showing classic nesting behaviour and a return by rooks to a northerly location even before the thaw of the winter’s snow. Seen in Russia as a welcome harbinger of Spring on the way.

 

 

The truth about the Corvid-19 and what you need to know – part 4.


We continue our coverage of the real truth about the Corvid 19 with a move back home to Europe and a closer look at the bird most UK people will have in mind when they hear the word “crow”.

This is practically the type species of the Corvids, and so no Corvid-19 analysis worth its salt should overlook it without needing to eat it.

 

Photo of a Carrion crow scavenging in Dorset by Ian Kirk on CC 2.0 licence. Many thanks to the photographer.

We are presenting the info for each Corvid in a similar tabular form and there will be a publication available at the end of the series where you will be able to get hold of the combined table.

Common Name Carrion Crow
Other names Common crow
German Aaskraehe
French Corneille noire
Russian Чёрная ворона
Polish Czarnowron
Scientific Name Corvus corone
Number of species in the genus 45
Number of subspecies in this species 2 or 4 (see below)
Literal meaning of Scientific name Raven (Latin) crow (Greek)
Described by Linnaeus 1758
First attested in literature Known and written about from classical times.
Wingspan (cm) 100
Length bill to tail (cm) 52
Distribution Two distributions, one in Western Europe, the other in East Asia, with a large belt in between of the closely related hooded crow.
Remarks There are two subspecies of carrion crow and it is the most common crow in the UK, and this is what we would call it as I was growing up. One is the West European version and the other is the East Asian one. The bird which separates them is the hooded crow Corvus cornix which was previously considered a subpecies (or rather, four subspecies as itself has four subspecies). In Warsaw we never see fully black crows (ravens and rooks yes, but the crows per se are only hooded crows) and one rarely sees hooded crows in the UK. It is a loner and an omnivore including a penchant for carrion, hence the name.  The bird exhibits extraordinary intelligence and is able to mimic human vocalisations, close to the levels exhibited by ravens. They distinguish between different human and crow faces and hild grudges a long time against people or animals which disturb them. They tend to get into extensive conflicts with seagulls which prey on their nests.
Migrations Slightly migratory. Winter and summer areas are marbled on the map.
Sexual dimorphism Barely noticeable, other than a slight crest on some males, which are larger
Close relatives As mentioned above the carrion crow and the hooded crow are related and also they are known to be capable of fertile crosses but are apparently not to one another’s taste ( a phenomenon known as koinophilia)
Not close relatives thought to be close Confused with rooks, although they have white faces, and ravens which are much larger, but these birds are close relatives also, as is the very similar American black crow.
Cultural significance Countless cultural references exist, one that comes to mind is the “monstrous crow, as black as a tar barrel” in the Tweedle Dum and Tweedle Dee poem in Alice through the Looking Glass.

 

 

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