By Luke Andrews
Observing the decay rate in droppings requires similar skills to those used with dead bodies. In a Zambian National Park, this process is being observed in elephant poo. A conservation team wants to know the time taken for the faeces to decay and disappear. They will use this knowledge to estimate the number of elephants in the park and when an elephant was last in an area.
In Mosi-oa-Tunya National Park near Victoria Falls, The African Lion Environmental Research Trust (ALERT), a Conservation NGO, has a team studying this process. They drive around in a Land Rover on the hunt for elephant dung. Spotting a fresh batch, the team gets to work.
Data is recorded on the GPS location, number of dung balls present, gradient, vegetation type and tree cover of the site. These are noted along with the stage of desiccation. A photo of the droppings is taken, and the site is abandoned. The team will return in ten days time, and then every ten days until the droppings have disappeared.
So far, five stages of elephant dung decomposition have been identified.
The first is when the droppings are fresh and all the dung balls are in tact. There may well be flies, ants and dung beetles around. The next stage identifies when some dung balls have fallen apart due to decomposition. This is followed by the third stage, where all the balls have collapsed, and may be infested with termites. This leads on to only plant material being discernible at the site, and the final fifth stage when there is no evidence of droppings remains.
This study holds parallels to considerations of decomposition in human bodies, which is also divided into stages. Forensic Anthropologists and Pathologists have developed these by studying decomposition on ‘body farms’. These are places where decomposition in donated bodies is studied. Data is collected by a team regularly returning to the site, recording their observations and photographing it.
It begins with the body being fresh and warm, before rigormortis, algormortis and livormortis set in. These are the stiffening of all muscles, the body temperature equalising with its surroundings and the pooling of blood in the lower portion of the body.
Next, the body tissue begins to break down. Putrefying bacteria digest tissue whilst insects and animals may scavenge the remains.
If placed in water the body begins to bloat and fall apart. As it swells the hands and feet fall off first, followed by the head, arms and legs, and then the torso separates from the lower abdomen.
This data is collected to help with criminal investigations. It allows Forensic experts to determine time since death or, at least, time since body deposition. Data on elephant dung is also used to identify the time since deposition.
I was lucky enough to join the team on one of their poo-study trips.
The day began early. We headed to the park in their car. A special GPS device was turned on and poo site co-ordinates were entered. Destination identified, we headed for the dung.
Once there, I clambered out of the jeep with ALERT Researcher, Dabwiso. We recorded data on the stage of desiccation and took a photo.
“This poo is very dry, but it is still a stage three”, said Dabwiso.
“This ball is still hard”. He began to scrape it with his nails trying to dislodge some plant material.
At another site he touched a ball and it fell apart.
“Definitely a stage four”, he said.
There are risks wandering around a national park, especially as we’re looking at elephant dung. The faeces is often deposited in areas the elephants love to frequent. This means that there is a high chance of us meeting one on the ground.
Arriving at a site surrounded by one of the elephants favourite food plants, myself and Dabwiso jumped out the car. We had just begun to enter the foliage when he suddenly turned around.
“Lets go back to the truck”, he said, looking worried.
Peering past him I saw a massive elephant.
Although sometimes alarming work, collecting this data on elephant excrement is important. It will allow ALERT to indirectly estimate the elephant population in the park. Observing the elephants may not give a reliable population estimate because research can only take place during the day. Some elephants may come no where near the roads during this time, meaning that their presence is not recorded. Looking at elephant poo helps to estimate the population.
“When in the park elephants produce dung. The more [fresh] dung, the more elephants”, said Dabwiso.
By returning to sites, the time taken for dung to decompose and disappear can also be estimated. This is useful for ageing the dung, allowing more accurate determinations of the number of individuals in the elephant population.
Research methods used on elephant faeces are similar to those used in forensic studies. The team at ALERT is studying elephant dung as an indirect method of estimating the population of elephants in the Zambian National Park. They plan to continue this part of their work for a while yet.
Photo Credit: Luke Andrews. Photo of Clausin, an intern with ALERT, studying some elephant droppings.