Research carried out almost two decades ago showed that ocelots – those lovely spotted cats of South and Central America – play an important role in the germination of new trees in a rainforest ecosystem.
Here’s how. Agoutis – medium-sized rainforest rodents – collect and stash seeds from palm trees which they come back to at later date to feed on. This helps the palm tree disperse through the forest and protects the seeds that would otherwise be eaten by parasitic beetles and weevils that live underneath the trees.
But, of course, if the agouti returns to dig up its booty, there will be no regeneration because the seed will be eaten, and that’s where the ocelot comes in. When they hunt and kill one of the agoutis, the seed will be forgotten and has a chance to germinate and become a new tree.
The research was carried out on Barro Colorado Island on Lake Gatun in Panama, described by the Smithsonian Tropical Research Institute as “the most intensively studied tropical forest in the world.”
The island is visited by more than 400 scientists every year, and – in total – the institute estimates that work carried out on the island has led to an incredible 13,000 papers since it became a reserve in 1923.
There’s nearly 100 years of climate data, and long-term mammal monitoring project that was established in 1982, 44 years ago.
And the thing about Barro Colorado? It wouldn’t exist had the world not seen the need for a route from the Atlantic to the Pacific Ocean that didn’t involve going round Cape Horn at the bottom of South America. Yes, the Panama Canal.
Look at a map of Panama in close up and follow the route of the Panama Canal north from Panama City, and you’ll see how it expands into a large lake whose fingery dendrils seem to find their way into every crevice of the landscape.
It might look natural, but this is Gatun Lake, which was formed when the Chagres River was dammed at the beginning of the 20th century and which was a fundamental part of the creation of the Panama Canal.
The whole of this part of Panama, known as the Canal Watershed, is ecologically rich and mainly intact rainforest covering 340,000 hectares, an area roughly the size of Cornwall.
The 160 mammal species recorded here include jaguars, tapirs, white-lipped peccaries, howler monkeys, sloths and of course ocelots and agoutis, while there are more than 500 bird species, including one of the world’s largest birds of prey, the harpy eagle.
The lake is even a home to one of America’s rarest aquatic mammals, the Greater Caribbean manatee, those strange unworldly and ungainly sea beasts that are said to have inspired the myth of the mermaid.
They’re not common – this document says there may be only 16 in total, though it says this is probably a significant underestimate – and they were only introduced into the lake in 1964 in the hope they would feed on water hyacinths, which provide breeding habitat for mosquitoes.
The canal lock system almost certainly impedes their passage from the sea into the lake, though not completely – it’s speculated that at least one individual has somehow managed to swim from the Atlantic to the Pacific.
The history of the Panama Canal goes right back to 1513, when Vasco Nuñez de Balboa discovered that only a narrow strip of land 80km wide separated the Atlantic and Pacific Oceans. In 1534, a survey was ordered to assess the Chagres River as a possible route for a canal across the isthmus, but the challenge was considered impossible.
Momentum for a canal began to build in the mid-19th century, but it would take many years before this modern-day engineering marvel was completed – in fact, the first ocean-going vessel didn’t complete a passage through the canal until January 1914.
Today, some 13,000 ships a year – that’s 37 a day – use the canal every year, with container, dry bulk carriers, chemical tankers and vehicle carriers being the main vessel types. Cruise liners also use the canal, but not in the same numbers.
All these huge ocean-going ships pass within a few hundred metres of Barro Colorado – and yet the wildlife on this unique island continues to flourish and reveal ever more secrets to eager scientists.
