Copyright Urban Mole 2016
A beautiful aspect of winter is the chance to rise in the dark at the start of the day. If you’re fortunate, your coffee may be brewing as the sky pales and you catch a flock of crows flying hundred-fold under the last stars, calling out or soaring in ragged spirals before playfully chasing each other onwards to their feeding grounds. The flocks can number in the thousands, taking several minutes to pass, coming from roosts that may contain hundreds of thousands. What better way to enjoy breakfast?
The Corvidae Family is one of the intellectual power houses of the Aves Class, easily rivalling Class Mammalia, whose Hominidae Family we’re perhaps more familiar with (despite our attempts to distance ourselves). Genus corvus, a large subset of the Corvidae, is where you’ll find the crows, rooks, ravens, jays, and magpies, among many others. It’s also where you’ll find tool making, social play, aggression, reconciliation, bonding, brinkmanship, and pilfering.
Studying the Corvidae further diminishes the moral boundary we impose between humans and non-humans by demonstrating that other animals employ mechanisms for maintaining social homeostasis, regardless of whether we adopt Frans de Waal’s view of near-equivalent human moral frameworks in certain species or Daniel Dennett’s rebuttal of said and replacement with proto-morals. The evidence points to human morals not being peculiar to the species, but occupying a point upon a spectrum of animal moral behaviour.
So what observations have been made? Magpies have been seen grieving over the death of one of their own, stepping forward to gently move its body before gathering grass to lay by its side[1]. Ravens are known to form monogamous relationships with their breeding partners. Jackdaws, rooks, and ravens form strong affiliation bonds whilst in sexual immaturity, with the long lived ravens remembering these bonds for years. (Interestingly, corvids share a similar relationship dynamic with primates: males get on well with other males, and males and females get on well, but female–female relationships are temperamental) [2]. Corvids deploy tools when foraging for food. Not only that, some species, such as New Caledonian crows, carefully fashion tools to standardised patterns: hooked tools for poking insect larvae out of tree holes, and stepped-cut Pandanus leaves for sweeping under leaf detritus. The tools are taken on foraging expeditions, which means the crows know not only what prey to expect when they arrive, but also what tools to make to hunt them [3]. Corvids cache food surpluses (as do many animals), but jays have been observed distinguishing between perishable and non-perishable items. If they’ve cached both types, and a sufficient period of time has elapsed, they’ll ignore the perishable items (which would by then have spoiled) and retrieve the non-perishable items [3]. Ravens pay attention to nearby conspecifics (potential pilferers) when caching; they also exploit dead angles to cache their food unobserved [4]. They can even track the gaze of other individuals — conspecifics or humans — to determine whether they are looking at something hidden from the raven, an ability found in human children from around two years old [5].
Another indicator of animal intelligence is play. Ravens have been observed sledging down snow covered hills on their bellies, rolling downhill on their sides, hanging upside down from branches, carving snowballs and playing tag, and even engaging in aerial feats more often associated with human skydivers: “two individuals flew towards each other, grasped each other by their beaks and descended slowly with their wings and tails spread like two black parachutes. After several seconds they disengaged and flew off separately.” [1]
It’s incredible that our own advanced state of cognitive evolution affords us the ability to observe and analyse the manifestations of other intelligent life on earth, all of which are bound to a common double helix. Incredible, too, to think that the corvids were once walking underneath the trees as theropod dinosaurs 50 million years before our earliest primate ancestors were swinging from them. And now they flock in great numbers to nearby fields as I watch and wait for my coffee to brew.
References:
[1] Bekoff, M. (2009) ‘Animal emotions, wild justice and why they matter: Grieving magpies, a pissy baboon, and empathic elephants’, Emotion, Space and Society 2, pp. 82-85
[2] Braun, A., Bugnyar, T. (2012) ‘Social bonds and rank acquisition in raven nonbreeder aggregations’, Animal Behaviour 84, pp. 1507-1515
[3] Emery, N. J., Clayton, N. S. (2004) ‘The Mentality of Crows: Convergent Evolution of Intelligence in Corvids and Apes’, Science 306, pp. 1903-1907
[4] Bungyar, T. (2005) ‘Ravens, Corvus corax, differentiate between knowledgeable and ignorant competitors’, Proceedings of the Royal Society B: Biological Sciences vol. 272, issue 1573, pp. 1641–1646
[5] Bugnyar, T., Stöwe, M., Heinrich, B. (2004) ‘Ravens, Corvus corax, follow gaze direction of humans around obstacles’, Proceedings of the Royal Society B: Biological Sciences vol. 271, issue 1546
Leave a Reply