CONTEXT IS IN THE EYE OF THE PERCEIVER
Things go on around us all the time. Sometimes we react to it, sometimes we don't.
There are at least two things that influence if we do:
Can we physically perceive it?
How relevant is it to us right now?
The animal kingdom is riddled with examples of sensory abilities that we can barely imagine. Marine animals that can feel vibrations from other organisms under water with incredible precision, bats and dolphins that echo-locate in complete darkness and animals that can sense the electricity generated by the bodies of others. Many animals can perceive things that we can't perceive, which means that they can react to things that we are physically uncapable of noticing. Parrots might not be able to echo-locate, but they still experience the world differently than we do. Even if we look at vision, a sensory ability we share with them, how and what we actually see is very different.
For example, parrots can see spectrums of light (UVA) that we can't perceive. They require more intense light levels than we do for their vision to work optimally. Their visual field is also different from ours. Some birds even see the world a bit faster than we do - meaning that their brains process more images per second than ours. (Although to what extent this applies to parrots is yet unclear.) In practice this means that some light sources or even video that we perceive as continuos might appear as flickering to a bird. Knowing about the sensory abilities of the animals in our care is extremely important, but a bit beyond the scope of this particular resource. For now, what I am after is for the reader to reflect on the fact that behavior changes as the environment changes, and that parrots can be sensitive to some environemtal changes that we can't perceive. This in turn, means that we might sometimes observe changes in behavior or body language without being able to directly identify what initiates those changes.
This is also true when it comes to the behaviors themselves. Some movements can be so fast that humans can't perceive them, as evidenced by this video of courtship behavior in the blue-capped cordon-bleu by Ota, Gahr and Soma.
We also know that some parrot feathers reflect UVA light, and it's possible that this enhances some signals, like certain changes in feather position. This could make them easy to spot for other birds (in UV-light) whereas these changes might be much more difficult or even impossible for humans to perceive.
Is it relevant?
We see, hear and feel things all the time, but we only notice and react to a very tiny portion of what goes on around us. If we reacted to everything we would quickly run out of energy to do anything else. It's therefore important that our brains can sort input (what we perceive with our senses) effectively, so that we only put energy in to noticing and reacting to things that are likely to be relevant to us. What is relevant to an individual depends on, among other things:
The natural history of the species
Life history (previous experiences and learning)
All animals have evolved to be well adapted for life in a certain environment. Different species have evolved different sensory capacities and also different pre-dispositions to notice certain things that might be relevant for their ability to survive in their natural environment. Most parrots are much more likely to notice and react to a bird of prey soaring up high before a human does - both because of their visual aquity and field of vision, but also because, from a natural history viewpoint, noticing a bird of preyt might be the difference between life and death for a parrot, while it typically isn't relevant to the safety of a human. The takeaway here is to keep in mind that there are many things that parrots are much more likely to pay attention to, even if we're able to perceive them, that we don't notice or pay attention to simply because of our very different evolutionary histories. When we are trying to figure out what environmental change led to a certain change in the body language or behavior of a parrot, this is very important to keep in mind. Learning about the natural history of a species and what might be relevant to them from an evolutionary perspective enables us to practice noticing things in the environment that we normally wouldn't pay attention to. This is an extremely valuable skill when working with parrots.
What is relevant to us also changes during our lifetimes. A baby parrot will notice and react to different things (and in different ways) than an adult parrot. The same goes for an adult parrot in breeding condition versus one that isn't.
Past experiences also plays a big part in what we notice, of course. We can habituate to some things that end up not being worth our attention, and being sensitized to others. Someone that has an intense spider phobia might notice and react even to a moving dust rat that vaguely resembles a spider, while someone that couldn't care less about similar critters wouldn't. During our lives we learn that certain things are relevant because they lead to or are associated with other relevant things. I respond to my own ring tone because I know that one is relevant, but not other ones. I instantly notice my partners voice in a crowd, something that some parrots are also good at. I also react to someone saying my name, because I've learned that is often relevant to me. Similarly, if someone has had a bad experience they are usually very good at noticing and reacting to other things that might be have been associated with that experience.
Lastly, it's important to note that not everything we perceive comes from outside ourselves. Interoception - the perception of things that go on inside the body also plays a part in how we behave. Perceiving pain, fatigue, hunger or thirst are all notable examples of how our internal environment influences how we react to what goes on outside of us. A parrot might respond very differently when a hand is presented for it to step up on depending on if it is in pain or not. This will be explored further in part four.
In summary, it's not always clear to us exactly what in the environment is causing a certain change in behavior, and it can sometimes be difficult for humans to perceive the small changes in body language that often preceed bigger reactions.
If we do see a reaction, however, we can be sure something happened. Behavior always occurrs in a context.
The visual field of a senegal parrot.
This figure is from "Vision, touch and object manipulation in Senegal parrots (Poicephalus senegalus)" Demery et. al, 2011, Proc. R. Soc. B. 278: 3687–3693
(Used with permission.)
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Proc. R. Soc. B. 2011, 278; 3687–3693.
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Ota, N., Gahr, M. & Soma, M. Tap dancing birds: the multimodal mutual courtship display of males and females in a socially monogamous songbird. Sci Rep 5, 16614 (2015).