Imagine doing behavioural research on a population of lions on the beautiful plains of the Serengeti. Your aim is to find out where they go. Why? You want to preserve them for future generations. One major implication in protecting an animal, is knowing where they go. If you want to protect and conserve any animal, you will need to know some things about how they go about their everyday life. You need to know ‘what’ the animals are doing and ‘where’. Where are they migrating, feeding, mating and giving birth? And different animals in a population might have different agendas, so it is also important to know what the subgroups, such as males/females/young/adults, are doing similarly, or differently. After all, if you are trying to save a species from extinction, you will not only need to protect one small part of the population. What use is it if you are protecting an area which only males frequent, while the females might be dying off elsewhere? Or if you are only protecting their mating grounds, but not their feeding grounds?
Who wouldn’t want to follow these guys around all day long?
Each morning, you get up before sunrise, go out into the vast African plains in a rugged 4×4 vehicle, to find the lions. You find tracks to follow or listen to the majestic roars bouldering across the bushveld. After locating the lions, you patiently observe and follow from a safe distance, trying not to disturb their natural behaviour. You work long hours, and get amazing data on where the different prides hunt, rest, mate, where the females go to give birth and where the bachelor males wonder to. If you keep this up for quite a while, you might be seeing yearly patterns. Prides moving north in the winter, south in the summer, following migrating prey. This all sounds amazing, but also quite the feat to find out, isn’t it?
Now imagine that same lion population living in an area with extremely dense fog. On the very, very best of day you might be able to spot an animal 30 meters away. On bad days you might happen to stumble upon the lions when you are only 3 meters away. And then just imagine that these are quite odd lions that leave no tracks or emit any sounds to follow or record. And these lions also need to continuously move, there is no resting or sleeping, making it harder for you to find and catch up to them. To top it all of, these lions also live in an environment where you, as a human, can only spend a few hours a day. If you exceed these limits, you end getting sick or possibly even die.
This gives a clearer picture of what it’s like to study far-roaming pelagic animals. Manta rays, whale sharks, billfish, great whites; they all live in places and have habits that make it incredibly hard to study them.
When the water is like pea soup, these guys might be swimming right by you and you wouldn’t even notice!
It is probably quite obvious by now that these animals are quite hard to get your head around. You can’t jump in the water with a SCUBA tank strapped to your back and go trailing a manta or whale shark all day. It is simply impossible due to issues such as decompression sickness, fatigue, cold and obviously the somewhat thicker nature of water compared to air. You cannot follow the animal everywhere. Would you like to swim down to several hundred meters depth, or over a kilometre deep? It would mean certain death. If you do decide to follow your research subject, you are also quite likely influencing the animal’s normal behaviour. How would you feel if someone was trailing you for hours, maybe even days on end, from only 30 meters away? And remember, that 30 meter figure, is on a good day. And you can really only follow one animal at a time, so it will take you a long time to figure out what the entire population is doing.
Can you see that little antenna sticking out? These sophisticated tags allow us to track these large pelagic animals
Fortunately, devices have been developed that can help see where animals, both terrestrial and aquatic, go. Perhaps a simple way to study the movements of your pride of ions would be to attach a small GPS device onto an animal, leave it on for as long as the battery allows, then find the animal again, get the GPS back and download the data, which should give you quite precise information on the animals whereabouts. But, you have to find the animal again to get the data. And you would have to design a GPS device that is small and light, battery-efficient, super robust, able to withstand prolonged exposure to water, heat, rubbing up against stuff, moving around and so on.
For marine animals, it doesn’t get any simpler. For starters, there are few habitats that are more hazardous to scientific equipment than the marine environment. Corrosive salt water and bone crushing depths come to mind. Add to that that GPS doesn’t even work underwater, and once again, the marine environment is presenting us with quite a few more challenges.
So how do we try to overcome those challenges I hear you ask? I will leave that for my next blog.
* Written by Daniel van Duinkerken. This post was originally posted on www.marinemegafauna.org