Clay Licks: The Salty Oases of the Amazon Rainforest
December 21st 2022
Picture this: you are venturing deep into the hot jungle of the Amazon rainforest. The temperature is burning, you are sweltering under the high humidity and you are fighting off the mosquitos. You could be either walking along a narrow jungle trail along a stream underneath the looming green forest canopy or in a small boat navigating down a winding river.
Suddenly, you cruise around a corner to find on the edge of the river or path, there is a large brown opening, on the face of it a mosaic of striking colours and loud squawking. Probably the most intense display of colours you may have seen in the natural world. What you see in front of you is in fact a gathering of various parrot species, including the large and outrageously coloured macaws, such as Scarlett, red and green, and blue and yellow macaws.
A lot of them are clinging to the cliff edge, gnawing at its brown dusty surface, using their beaks to scrape off the brown crumbling substrate for consumption. With so many parrots flocking here it raises questions such as: why are they at this strange site in their masses, what materials does this cliff compose of that make them want to eat it and is only parrots that do this? If so why?.
What I have just described is known as a clay lick, known locally in Peru as a Colpa. I have had the privilege of being able to observe such a stunning scene with WorkingAbroad’s projects in Las Piedras, as well as elsewhere around Puerto Maldonado. I am now checking camera traps, some of which are set up at known clay lick sites in Peru. From both experiences, I have seen a wide range of different wildlife, including large gatherings of red and green macaws.
But what exactly is a Clay Lick?
A clay lick refers to a deposit of a soft rock known as clay that has been exposed, likely by a river eroding it or by weathering. Once the clay is exposed to the air, it becomes a known site that many animals will visit regularly.
Because these animals have been observed consuming the clay, researchers can assume that it is linked to their diet. One major mineral that humans depend on but take for granted is sodium (salt). Salt is a very rare commodity in a tropical rainforest, and is necessary for many life functions such as a functioning nervous system and muscles.
Salt content is high in these clay licks, along with other important minerals such as Magnesium. It is therefore widely accepted that animals, especially herbivorous mammals congregate at these clay licks to enrich their diet with salt.
What Biodiversity might you Encounter on the Clay Licks?
When I set my camera trap up in Tambopata, Peru, in just one week I recorded a diverse array of mammal species across different taxa. At night we captured an elusive arboreal bicoloured porcupine, a member of the rodent order, with its long prehensile tail and coated with quills from head to tail.
However, the most exciting capture was a lowland tapir, a large mammal closely related to horses and rhinos. It is the largest terrestrial animal in the Amazon basin and is seldom seen by people despite being so large! They are also important indicators of a rainforest’s health, with this species being among the first mammals to suffer decline when rainforests are disturbed and degraded.
A family of red howler monkeys visited on a daily basis as well as collared peccaries, a small wild pig species, and even a two-toed sloth had been seen!
So the fact that even arboreal animals such as monkeys, porcupines and especially sloths that don’t usually come to the ground, risk being another animal’s dinner to ingest clay suggests how much they value it in their diet.
For birds such as parrots, parakeets and guans to name a few, the benefits of clay go even further. Parrot species such as macaws are frugivorous, meaning their diet consists mostly of fruit. The fruit here in the Amazon can be highly acidic as a result of the acidic species of fungi that live here. This acidity in their stomachs can have long-term effects on the birds, weakening their immune system amongst other bodily functions, also making them more vulnerable to parasites.
What makes the Clay so Special?
Clay on the other hand has a high PH, meaning it is high in alkaloids which can help to neutralise these acids within the macaw’s stomach. This means that macaws can protect their long-term health by ingesting clay and neutralising harmful acids and plant-based toxins in the digestive tract, meaning they can enjoy the delicious fruits that they eat every day while reducing the chances of long-term health problems. Some parrot species will travel for up to 2 hours across many kilometres regularly to visit a known clay lick, suggesting how much of an impact this clay has had on their survival and well-being.
With this in mind, we can now understand the importance of protecting these sites, and this is what working abroad’s partners in Peru do when they protect large swathes of land. Deforestation and soil degradation from slash-and-burn agriculture means these special clay lick sites are lost forever, and all the animals that depend on them will suffer as a result.
I am currently staying in Tambopata, in the Madre de Dios region of Peru. I am lucky in that a clay lick is a short distance from camp and I have enjoyed capturing fascinating animals on my camera traps. Last night when we visited it on a transect, we were lucky enough to see a large porcupine! A very rare sight out in the rainforest.