Makes wing to the rooky wood.
Good things of day begin to droop and drowse,
While night's black agents to their preys do rouse."
Good things of day begin to droop and drowse,
While night's black agents to their preys do rouse."
Macbeth (3.2.50-53)
As it happened, the scene of the accident was right across from the veterinary emergency hospital. Though seeing as the feathered undertakers were already on site, there was little the doctors would have been able to do.
And the crows? well, they were in no kind of hurry; they're a gossipy lot and knew they had time, the whole Conrad debacle had taught them that much.
So that was how I got to thinking about crows; and about how little I knew about them. In truth, I have never really been crystal clear on the difference between crows and ravens, except that ravens conjure dark, deathly and mysterious Poe-esque images of 'Never—nevermore'; whereas crows make me think of farms and Kansas and Scarecrows and the Wizard of Oz.
I just haven't had any first-hand experience with either of them. When I worked in Animal Services, springtime brought with it injured and orphaned songbirds, waterfowl and birds of prey a plenty, but nary a single crow.
What I have since learned about them over the course of the past few days has only served to reinforce my humble opinion that animals naturally adapted to a given environment, be it land or sea or sky, are different from us, of course, less intelligent, to be sure (what need have they for rocket science?), but this does not make them any less worthy of humane treatment and understanding. They are, after all, as perfectly adapted to their environment as we are ours.
In the absence of at least an attempt at better understanding the species with whom we share this fair planet, we may find ourselves doing more harm to our own species than good: recall the ill-fated decision to kill and/or banish cats (and dogs) in parts of Medieval Europe during the Black Plague.
Besides, is it not our capacity for empathy, compassion and understanding that truly elevates us above the other branches of the tree?
And this is not me judging or preaching or being a fruity loon, I am admittedly a work in progress. I may gently scoop up spiders, potato bugs and all manner of creepy-crawlies and release them out the front door, but the fate of centipedes and mosquitoes remains one of quick, albeit excessive, flattening and dismemberment.
And yes, I do realize that suggesting we extend our understanding and compassion to the other branches of life's tree (when our own is in such an urgent state of disrepair) is asking a lot, but that doesn't mean it's not the right thing to do.
Oh, but I do digress ...
The genus Corvus, which includes crows, jackdaws and ravens, [3,15] are the subject of several population control schemes based on the belief that destroying them is necessary for the survival of other bird species. [16] (The ones that the crows call, 'dinner'.)
However, studies have revealed that, [16]
“if corvids are eliminated but other predators are not, the impact on the productivity of their prey would be positive in only 16% of cases; whilst without corvids and other predators, including carnivores, the productivity of other birds improves in 60% of cases.”
One way to distinguish between ravens and crows is that ravens are the larger of the two. [12]
Most breeding crows sleep in their territories during the breeding season, but join the roosts afterward. [12]
“One tagged crow (less than one year old) was seen at a compost pile in northern Pennsylvania with a flock of crows, and three weeks later it was back in Ithaca with its parents who were starting nesting. It helped the parents raise young that year, and remained in the area over subsequent winters.” [12]
With exceptions, infertility being the foremost, Crows do appear to form pair bonds, staying with the same mate year after year. [12]
The oldest captive crow documented died at age 59. [10]
Crows use at least 250 different calls to communicate [2], but to our ears they probably all sound a little something like, ‘caw’. [12]
The American crow is highly susceptible to the North American strain of the West Nile virus. [11] As such, crow deaths are often used as early indicators of potential human disease in the area. [2]
To trivia buffs, and/or poets, a group of crows is called a ‘murder.’
Among those who study crows, they are more likely to be referred to as a ‘flock.’ [12]
The term ‘murder’ has its origins in folklore, tales in which crows stand accused of all manner of deathly things, including conspiring to off one of their own. [2]
INTELLIGENCE
Crows have been well
documented at play, [4] an ability judged as essential in intelligent animals by many behaviorists. [8]
Crows have the ability to
recognize human faces. This was demonstrated when researchers at a Seattle
campus captured, tagged and released several crows while wearing creepy Michael
Meyers-esque masks. [6]
Word quickly spread among the
members of the crow community, for afterwards, whenever the researchers walked around
campus with the masks on, they would get dive-bombed. However, when the same
researchers walked around campus unmasked, their presence went unnoticed by the
crows. [6]
Crows not only interact with humans, but appear to show appreciation for those with food on offer by presenting them with gifts.. [9]
In studies where actions, as opposed to words have served as a measure of intelligence, crows have demonstrated a remarkable ability to reason their way through problem solving. [5]
“Research has found that crows exhibit strong behavioral signs of analogical reasoning—the ability to solve puzzles like 'bird is to air as fish is to what?' Analogical reasoning is considered to be the pinnacle of cognition and it only develops in humans between the ages of three and four.”
(Oh, but it gets better. Read the full article in Scientific American, Crows Understand Analogies.)
After spending months teaching the wild crow in the following video problem-solving skills, researchers then set up a challenge to test its abilities. [1]
Are crows the ultimate problem solvers? - Inside the Animal Mind BBC Earth
Crows have been known to
change their course, and to continue to do so for generations, in order to
avoid farms where even a single crow has been killed in the past. [6]
When the rural community of
Chatham, Ontario Canada became besieged by a flock of over half a million crop
damaging crows, the mayor called for a massive cull. After a single crow was
shot by hunters, the remaining population took note and began to fly just high
enough to place them out of reach of the air rifles. [6]
The nidopallium caudolaterale (NCL),
the region association with cognition in birds, was found by researchers at Universitaet
Tübingen (2013) to have groups of neurons dedicated to specific tasks, one group
showing activity when a memory task required them to identify similar images,
and another when a memory task required them to identify different images. [7, 13]
- Even when challenged with new sets of images, the crows were able to quickly carry out both tasks, and to switch between them. [7, 13]
- The researchers then found that they were able to predict the behavioral decisions of the crows by looking at the activity of these groups of neurons. [17]
In a more recent Universitaet
Tübingen study (2015), Neurobiologists found that when dots of different sizes
and shapes were displayed on a computer monitor, crows were ignoring the
differences in appearance and arrangement, focusing instead on the exact number
of dots shown. [14]
Moreover, the researchers found that dedicated ‘number neurons’ were responsible for this recognition. [14]
Moreover, the researchers found that dedicated ‘number neurons’ were responsible for this recognition. [14]
From the studies’ authors:
"When a crow looks at three dots, grains or hunters, single neurons recognize the groups' 'threeness'.” Helen Ditz
"Surprisingly, we find the very same representation for numbers as we have previously discovered in the primate cortex. It seems as if corvids and primates with independently and distinctively developed endbrains have found the same solution to process numbers." Prof. Andreas Nieder
To see pretty much everything I just wrote about, encapsulated in a cinematic nutshell, regarder le suivant:
TO EAT CROW (Source: idioms.thefreedictionary.com)
1. Fig. to display total humility, especially when shown to be wrong. Well, it looks like I was wrong, and I'm going to have to eat crow.
2. Fig. to be shamed; to admit that one was wrong. When it became clear that they had arrested the wrong person, the police had to eat crow.
Fin
***
REFERENCES
[4] Rincon, Paul (22 February
2005). "Science/Nature
| Crows and jays top bird IQ scale". BBC News
[8] Bekoff, Mark & Byers, John (1998). Animal
Play: Evolutionary, Comparative and Ecological Perspectives.
[9] The girl who gets gifts from
birds / www.bbc.com / February 25, 2015]
[10] Growth and nutritional state of American
crow nestlings vary between urban and rural habitats. Ecological Applications,
19(4), 829-839.
[13] Universitaet Tübingen. "Crows are no bird-brains:
Neurobiologists investigate neuronal basis of crows' intelligence."
ScienceDaily. ScienceDaily, 28 November 2013.
<www.sciencedaily.com/releases/2013/11/131128103835.htm>.
Journal Reference:
Lena Veit, Andreas Nieder. Abstract rule
neurons in the endbrain support intelligent behaviour in corvid songbirds. Nature
Communications, 2013; 4 DOI: 10.1038/ncomms3878
[14] Journal Reference:
Helen M. Ditz and Andreas Nieder. Neurons
selective to the number of visual items in the corvid songbird endbrain. PNAS,
June 2015 DOI:10.1073/pnas.1504245112
Universitaet Tübingen. "Crows count on
'number neurons'." ScienceDaily. ScienceDaily, 8 June 2015.
<www.sciencedaily.com/releases/2015/06/150608152002.htm>.
[15] Robertson, Don (30 January 2000): Bird
Families of the World: Corvidae.
[16] Journal Reference:
Christine F. Madden, Beatriz Arroyo, Arjun
Amar. A review of the impacts of corvids on bird productivity and
abundance. Ibis, 2015; 157 (1): 1 DOI: 10.1111/ibi.12223
Plataforma SINC. "Bad reputation of crows
demystified." ScienceDaily. ScienceDaily, 23 January 2015.
<www.sciencedaily.com/releases/2015/01/150123081801.htm>.
[17] Understanding
an alien intelligence: Generalizations from the crow / ExtremeTech / John
Hewitt / January 14, 2014
IMAGE CREDITS
