Guest Author - Dawn Denton
Step 1 - Know the crocodile.
These reptile can grow to up to twenty three feet and even the small ones can inflict severe injuries. It is difficult to know how many crocodile attacks there are in Africa every year or how many deaths have been caused by crocodiles. This is because crocodile attacks are not always reported to the authorities. It is believed that in some areas of the continent crocodiles have caused more deaths than any other animal, although the hippopotamus does seem to be the most responsible for attacks in other areas. If you understand how the creature behaves, it is easier to catch it.
Step 2 - Identify how many crocodiles are nesting and laying eggs in the area.
Researchers go to amazing lengths to collect the data they need before they actually catch the crocodile to identity where and when they need to take action. In the wet season the research involves investigating samples of local crocodile populations and the rate of reproduction by using small boats to explore the area. They will also investigate the plant and animal life as well as the indigenous communities to get an overview of the relationship between the crocodile and its environment.
Step 3 - Practise on the little ones.
The best time to catch crocodiles is at night. Researchers use a strong flash light to temporarily startle the crocodile. This has the same effect as a temporary paralysis and thus makes it easier to pull the little crocodile from the water, although it is still quite a challenge. They are strong and have very sharp teeth, which even when it is in a stunned condition, can be pretty dangerous.
Once the crocodile is mobilized, the mouth is taped shut to make it easier to gather the information needed. The process of collecting measurements, observations and samples is done as swiftly as possible to reduce the stress to the creature before it is released back into the water.
Step 4 - Set the trap for the big crocodile.
The trap is usually in the form of a big cage and is positioned in the water on a sandy river ‘beach’ where the crocodiles like to bask in the sun. Rotten meat is used to lure the crocodile into the cage. The meat is attached to a pin that releases the door of the trap when it is disturbed. The crocodile is attracted to the rancid smell of the meat and swims into the cage. The pin is released and the door slams shut behind the crocodile.
Step 5 - Release the crocodile from the cage and render it safe for research.
This is where the researchers need to use their expertise to ensure they make the most of their time with the crocodile. First a noose is placed through the bars of the trap and around the crocodile’s neck. As the trap door is opened the crocodile swims out, attached to the noose and the researchers have to muster all their strength to reel the reptile in. Crocodiles are strong and the researchers need to be fast. It resists for a few minutes and as soon as lactic acid builds up in its system, it becomes too exhausted to continue the fight and it is dragged to the shore. It is important to get the crocodile out of the water as quickly as possible as the activity could attract other crocodiles from the surrounding area.
Step 6 - Collect the data.
The first task is to approach the crocodile from behind, use body weight to actually sit on its back and tape the jaw shut. Researches take urine samples and sometimes blood samples and a range of measurements. It is difficult to determine the gender of the crocodile as the sex organs are concealed in a type of vent so researchers need to feel inside the animal to identify the organs for accurate documentation.
An identity tag is attached to its body. If the crocodile is big enough, a radio tag is attached, which helps with more detailed data collection. This information will help to track the creature as well as understand how, when and where it travels. It is believed that a crocodile can travel over two hundred and fifty miles in just three weeks. Recapturing a tagged crocodile will also give information about crocodile population size.
Step 7 - Release the crocodile back into the river.
This needs to be done with care as the reptile has a powerful tail which can easily break a limb.
The Nile crocodile is the most common crocodile in Africa and is a key species to maintain the vital balance of the ecosystems and river wildlife. It is important for researchers to continue their work to ensure we preserve the delicate balance of the African ecosystem by devising conservation programs for these giant reptiles.