The study of dragonflies, and sometimes damselflies, is called Odonatology. Dragonflies are referred to as Odonates.
Though watching odonates is easily done with the naked eye, a pair of close focusing binoculars will definitely make it easier. Though some species can easily be identified, some others need to be caught and closely examined in order to distinguish them from other similar looking species.
Most dragonflies prefer to perch themselves close to water, and the length of time they remain perched can vary. Various species tend to have individual behaviors, and you could have dragonflies that prefer hanging on twigs, or flying very high off the ground, making it quite difficult to observe.
Because of their compound eyes, dragonflies can see in many directions at once. This makes them very sensitive to movement, and some dragonflies can be quite easily startled. They don’t see very well from the rear, however – so if you plan to study one, it’s best approached quietly from behind.
In order to properly identify odonates, you have to be familiar with the distinctive characteristics that can be found on the head, thorax, and abdomen of the dragonfly. This can be colors, shapes, or patterns. Roughly, the parts of a dragonfly are as follows:
5. Frontal thoracic stripes
6. Lateral thoracic stripes
7. Abdominal segments, of which there are ten
One can look up the anatomy of a dragonfly in order to be able to distinguish it from a damselfly.
Dragonflies can range in size from one inch to nearly six inches long. In order to identify one correctly, you have to make sure your size estimation is relatively accurate. This is easy if you have the dragonfly in hand. Otherwise, you can opt to measure them against something that can be measured, like a leaf that it was perched on, or your finger. Measuring the length of a dragonfly refers to the “nose” to the tip of its tail. The length of the wings are also measured, especially against the length of its abdomen.
It may seem like a no-brainer to determine what colour a dragonfly is, but bear in mind that there can be a lot of variations. Many species actually undergo changes in colour as they mature, as well as change as the temperature varies. Dragonflies are cold blooded, thus a dragonfly can become a darker colour in cooler weather, turning blue spots into purple or grey in cooler temperatures. Female dragonflies can also be coloured differently from the males, though most young males are coloured similarly to the females early in their life cycle. However, all dragonflies start out with hardly any colour, though some traces of their adult pattern may be visible. Some species, as they age, become pruinose – meaning they develop a bluish-white bloom that can cover their bodies and render their patterns obscure. Others can become darker, making their markings less distinctive.