Today’s date is 03/14 (that is, in the foolish countries that put the month number first), so it has become ‘Pi day‘. Few realise that it’s also Albert Einstein‘s birth date… and mine!
To celebrate, I’ve decided to write about my preferred animal behaviour topic (thus far): the study of cognition in the wild!
(￣￢￣) Close enough
Why is it relevant? Because to understand the evolution of cognition in vertebrates, we need to examine animals’ abilities under natural conditions, where they face having to find food and mates, all the while evading all sorts of dangers. That way we can hope to identify some of the factors affecting the selection pressures at work. It is true that for some species, especially “smaller” ones, the line between the laboratory and the natural environment can get very blurry, if not inexistent. For “bigger” ones, though (like birds, mammals, and reptiles), the border is quite real. And those are the animals I’m interested in (again, thus far).
With doing something as messy as studying invisible processes in a rather uncontrollable environment comes
great responsibility an assortiment of challenges. Let me list some of them as mentioned by Healy and Hurley (2013) in their review on ‘What hummingbirds can tell us about cognition in the wild’:
- The participants may use different cues than in the lab, or use them differently, during tests;
- Their ‘answers’ may not reflect the psychological dimension you’re trying to measure (an issue shared with all kinds of tests, I’m afraid);
- How to make sure they’re motivated to actually participate?
- What task to use?!?!! Meaning: what dimension are we going to choose to extrapolate their cognitive abilities??
Quite alarming, isn’t it? Well, it can be less so if you’re thoroughly prepared.
First, you need to find a “logistically amenable to testing” species which, in Healy and Hurley’s case, were rufous hummingbirds Selasphorus rufus. They focused on the males because those guys are territorial, so they fight off conspecifics from their patch, and feed frequently enough that nice amounts of data can be collected each day.
Rufous Hummingbird Selasphorus rufus. Credit: jessi.bryan on Flickr
Then, the species’ ecology should be such that you can formulate predictions about the abilities that might have been ‘encouraged’ by evolution, the same abilities that you’ll want to investigate. This requires, in particular, knowledge of their sensory ecology, of how they apprehend the world and might apprehend your experimental task.
I won’t go into too much detail here about the methods used by the authors and their colleagues in their experiments. They describe them rather well in their paper (see below for a direct link to it). But I will tell you this: it involves artificial flowers, arranged differently depending on the ability studied. As an example, in studying 3D spatial cognition:
… when flowers were presented on a vertical pole …, birds found it difficult to learn which one of five flowers was rewarded but when the flowers were presented along a diagonal pole, the birds were relatively quick to learn which was the rewarded flower (Flores Abreu, Hurley & Healy, 2013). Here it appears that the addition of a horizontal component to the flower’s location may have facilitated the learning of its vertical component.
Another set of findings they discuss are related to the use of colour, or lack thereof, in learning flowers’ refill rates – rufous hummingbirds use this cue “only when space is not relevant”. They also seem to possess a somewhat episodic-like memory, meaning they can simultaneously retain information on the what, the where and the when of an occurrence.
They conclude by stating that more data from comparative research is needed to continue figuring out the interaction between cognition and natural selection, especially the benefits of cognitive abilities as they pertain to particular animals and to their ecological demands.
This ‘required research’ business is very cool! Because an increased number of people understanding the necessity of it means that, maybe, just maybe, my own interests in the topic could one day neatly align with a supervisor’s and, who knows, some grants committees’…
Healy, S. D., & Hurley, T. A. (2013). What hummingbirds can tell us about cognition in the wild. Comparative Cognition and Behavior Reviews, 8, 13-28. doi: 10.3819/ccbr.2013.80002 <– THAT’S THE DIRECT LINK