by Dave Goulson
Santa Lucia Cloud Forest Reserve is a community endeavour, created by a dozen or so local families who were struggling to make a living as small-scale farmers, and so decided on a different approach. They pooled their land to create a large nature reserve which now protects 735 hectares of forest. To make a living, they constructed the lodge for visitors, somehow lugging up everything they needed on the mules or on their own backs; how they got the glass for the windows up there in one piece I couldn’t imagine. They struggled for a while to make a go of it, with few visitors, until Mika Peck came along. Mika is a conservationist at Sussex University, a boyish forty-something with an infectious sense of humour who spends his life championing various rainforest conservation projects in Ecuador and Papua New Guinea. He got funding from an organisation called Earthwatch to bring a group of volunteers out to Santa Lucia to study the wildlife. The volunteers had to pay quite a bit for the privilege, and a chunk of this got passed on to the Santa Lucia folk, quite a windfall for their embryonic business. Mika and an Earthwatch team came back annually for four years, and the money was ploughed in to improving the lodge, building some more comfortable accommodation in satellite huts, and creating a working hot-water system (no small feat on the top of a mountain in the middle of nowhere). Mika then started running an undergraduate field course for students from Sussex University at Santa Lucia, and a couple of other universities followed suit, bringing in another reliable income stream. The future is far from certain, but for the moment they seem to be keeping afloat.
One of the fascinating things about the place is that it is run as a cooperative, with no one in charge. The numerous joint owners and their families all chip in, doing repairs to the plumbing, leading guided walks, cleaning the toilets – whatever needs doing, and seemingly always with a cheerful smile. Mika did confess that behind the scenes it can be pretty chaotic, particularly when it comes to making big decisions, but on the whole it seems to run remarkably well.
The forests of Santa Lucia are home to an impressive range of endangered mammals, including a good population of spectacled bears, the species to which Paddington presumably belongs (although he hails from neighbouring Peru). The bears have suffered greatly in recent decades, from loss of their habitat and illegal hunting – grotesquely, their paws sell for $20, while their gall bladders are highly valued in Chinese medicine (along with a seemingly random selection of body parts of other highly endangered animals), and can fetch $150 each. Given that the average monthly wage in Ecuador is just $30, it is easy to understand why an unscrupulous person with a gun might be tempted to shoot one.
Other mammals to be found in the forests of Santa Lucia include the jaguarundi, ocelot, oncilla, margay, tayra, kinkajou and the potentially dangerous puma, the largest remaining big cat (sadly, jaguars were hunted out in this region years ago, but the owners of Santa Lucia dream that they might one day return).
As you might imagine, the students were particularly excited at the prospect of seeing such amazing and exotic wildlife, perhaps even sighting a puma or a bear. Most had never had the opportunity to visit the tropics before. I, however, had an ulterior motive for being there. One of the other staff, Jeremy Field, who had visited this site many times before, had mentioned that there were bumblebees to be found. Jeremy isn’t a particular expert on bumblebees – he studies ‘primitively social’ wasps and bees, those that teeter on the edge between solitary and social lifefn2 – but he knows a bumblebee when he sees one. Almost nothing is known of the ecology or behaviour of the bumblebees that live in tropical South America; most species are known only from a few pinned specimens in museums. Jeremy had also mentioned that there were orchid bees to be seen, a group of spectacular, large and colourful bees found only in the neotropics. So a chance to see and study such little-known creatures, whilst also doing my day job – teaching students – was far too good to resist.
When we arrived at the lodge in the late afternoon we were served the most delicious cup of thick hot chocolate, made from cocoa beans grown in the valley below. It turned out to be a wonderful place to stay, both primitive and yet comfortable. Soon after we arrived it began to get dark, and in the tropics the transition from day to night is very fast as the sun seems to drop like a stone from the sky. We sat on the balcony as darkness fell, listening to the nocturnal creatures of the forest as they woke up and started serenading one another, or staking a claim to their territories. We could only speculate as to what made the many and various calls, some beautiful, eerie and haunting, others just insistent, incessant buzzes and rattles. Were they crickets, cicadas, frogs, nocturnal birds such as nightjars or potoos, or some other exotic creatures unknown to us? Fireflies began to flicker amongst the trees, and bats launched themselves from roosts under the eaves of the building. It had been more than a decade since I’d previously visited the tropics, and it was magical to be back.
There was no electricity, so we ate dinner by candlelight. The food was simple, rice and beans, but delicious nonetheless, particularly after the long, exhausting hike up through the forest. I could easily have eaten twice as much, and a cheese course wouldn’t have gone amiss, as the stomach bug hadn’t yet struck. It turned out that most of the ingredients for our food were grown in an organic garden next to the lodge; otherwise they were bought in the market of the nearest village, some eight kilometres distant, and had to be carried up by mule. This was proper, seasonal, low-food-miles eating – the nearest supermarket might as well have been on the moon. We went to bed early, exhausted, and excited about what we might find the following day.
I was woken the next morning by the purr of a hummingbird feeding on the flowering shrubs outside my window. The clouds had cleared from the valleys, and the sun was peeking over the mountains to the east. After a quick breakfast of fruit and yogurt washed down with lots of coffee, all of which I was to become reacquainted with later that morning, we set out on a walk in the forest to get our bearings. Mika knows these forests like the back of his hand, and he took the lead along a narrow, winding forest trail – I followed at the rear so that I could stop to look at anything that caught my attention. Huge, buttressed trees towered above us, festooned with epiphytes – plants that grow on other plants rather than having their roots in the soil. The branches of the trees were laden with orchids, bromeliads and ferns in enormous diversity; there are no less than 2,500 species of orchid alone in Ecuador. The moisture brought in by regular immersion of the forest in cloud allows these epiphytes to suck up enough water to thrive. The bromeliads have an additional trick – their leaves form gulleys that catch rainwater and feed it into a central well, so that each plant has its own tiny private water reservoir. These mini aerial ponds are themselves home to a multitude of wildlife, from hoverfly larvae to tadpoles.
In no time at all I spotted my first bumblebee, a male. I was alerted by a familiar buzz – lower in pitch than most other insects in the cloud forest. My movement had disturbed a bee perching close to the path, so I froze to see what it would do. It soon settled again, on the tip of a heart-shaped leaf of some low-growing forest plant, a foot or so above the ground, in an area of dappled sunlight at the side of the path. Most of the ones I found subsequently were in similar places. It didn’t look much different to familiar British species – about the same size and shape, black with two yellow stripes and a white bottom. If one were to chop off the front half of a garden bumblebee and glue it on to the back half of a tree bumblebee you’d have a pretty good imitation (though I guess that won’t mean a lot to most folk). I didn’t know it at the time but subsequent investigations – otherwise known as asking the bumblebee taxonomy guru, Paul Williams, at London’s Natural History Museum – revealed it to be a species named Bombus hortulanus.
The behaviour of this bee was very different to anything I had seen before. The bee was crouched, his antennae cocked forwards, his abdomen pulsing, in an alert, aggressive posture most unlike the generally relaxed behaviour one associates with bumblebees. He was restless,
shifting his position on the leaf feverishly every few seconds, and dashing out at anything that flew past. I soon realised that he was not alone – two other males were perched nearby, only a metre or so apart. They would chase any other flying insects that came near, and if they strayed too near to one of the other males in their foray they would be attacked, the two bees then swirling about in frantic aerial combat for a few seconds before each returned to their perches. They did not always sit in exactly the same place – each seemed to have a few favourite leaves, all close together, and they would alternate between them.
I realised that the rest of our party had left me behind, so I quickly marked the spot with some coloured ribbon tied to a twig, and ran to catch up, while beginning to feel queasy. I pondered what I had seen – it was presumably some sort of behaviour related to finding a mate. The mating habits of bumblebees are somewhat enigmatic. Darwin was one of the first to study them, in his garden at Down House in Kent. The males of many species, including the garden bumblebee studied by Darwin, mark out circuits perhaps 200 metres long with pheromones, and then streams of them zoom round and round the circuit in the same direction like little sports cars with their engines revving, presumably hoping to impress a female. Oddly, virgin queens rarely if ever show any interest in their boy-racer antics. In other species, such as the tree bumblebee, the males are more direct; they hang around in excitable crowds outside nests that are producing new queens and simply try to grab them as they emerge. Males of a few bumblebee species gather on the tops of hills and there await the arrival of virgin queens, though once again no one has actually observed a virgin arriving. But I had seen all of these behaviours many times before, and the Ecuadorian males were clearly doing something altogether different.
I recalled that there is a fourth behaviour, described from a handful of North American and Asian bumblebee species such as the Nevada bumblebee (Bombus nevadensis), in which the males are fiercely territorial. In these species, the males are said to have distended, oversized eyes, helping them to spot any queens that hove into view. These boggle-eyed beasts fight over prominent perches, and use them as lookout posts from which to scan for potential mates and keep a beady eye on rivals. If they spot an incoming virgin queen they dash out to intercept her mid-air like scrambling fighter pilots, drag her to the ground and unceremoniously attempt forced copulation. Were these Ecuadorian bees adopting a similarly charmless strategy? They didn’t have boggle eyes, and didn’t seem to be perching in prominent positions, but otherwise the behaviour looked similar.
Over the next few days Jeremy and I were busy teaching the students how to identify insects and I was rushing to the bathroom every five minutes (composting toilets may be great for the environment but in tropical heat they aren’t somewhere you want to go often when already nauseous) so I had little time to devote to investigating the bees’ behaviour any further. With the students we forayed through the forests, armed with butterfly nets and sweep nets (the former for catching flying insects, the latter designed for bashing through undergrowth to catch resting insects). Just as with the kids at the Dunblane primary school, it was fun teaching the students how to use these nets – it is all too easy to flap around excitedly and achieve nothing other than frightening all the insects away. We explained to the students how to distinguish the different insect types, such as grasshopper, beetles, wasps or mantises. These are crude divisions that each encompass huge numbers of species, but identifying the insects any further was usually impossible. In the UK, we are spoiled with guides and keys that enable us to identify any insect to species. Our fauna has been described and studied in detail, and very few new species are likely to be discovered. In the tropics, however, any sweep of the net is likely to catch new species that have never been formally described by scientists. It is estimated that we have only named perhaps one-fifth of the species on Earth, and many of the four-fifths remaining are likely to be insects that live in tropical forests. Catching new ones is easy, but identifying which of the insects in a net are the new ones is enormously difficult. Sadly, there are a small and dwindling number of specialist insect taxonomists with the vast knowledge needed to distinguish anything new from the ones we already know about. Nobody seems to want to fund this sort of work any more.
Regardless of the ongoing effects of the Quito pastry, it was wonderfully exciting dashing about looking for insects in the forest. Jeremy was particularly funny; at university he is a quiet, gently spoken and unassuming chap, a well-respected professor and expert in the evolution of social behaviour in insects. In the field he was transformed with excitement, sprinting about with his butterfly net with all the enthusiasm of a ten-year-old – clearly he never grew out of his bug period. He has the added advantage of being enormously tall and gangly, able to snaffle high-up insects that I could not possibly reach, so I had to pull out all the stops to match him as we vied with one another to catch the most interesting specimens. We leaped and chased, turned over logs and stones, sifted through dung, and waded about in streams in search of interesting beasts. Between us we found all sorts of curious and marvellous creatures; I caught a dobsonfly, a rare, giant, primitive-looking relative of the lacewing with enormous but actually rather feeble jaws. Jeremy countered that with a bess beetle, a large, shiny, black creature that squeaked – apparently they communicate with their grubs in this way. I trumped that with a magnificent owl butterfly the size of a small bird, with huge eye-spots creating a life-size replica of the face of an owl. Jeremy went one better with a terrifyingly large tarantula hawk wasp, a velvet-black creature the size of my thumb that feeds its offspring on paralysed tarantulas (we were later lucky enough to see one dragging its helpless, limp prey – a rather beautiful blueish tarantula – back to its burrow).fn3 And so we went on, catching a fantastic array of insects, including slender stick insects, spiny, camouflaged bush crickets, moths that beautifully mimicked yellowing leaves, scurrying cockroaches, caterpillars adorned with outlandish spines and protuberances, and much more besides.
For me, perhaps the most exciting insects we saw, aside of course from the bumblebees, were the orchid bees. There were two types – one, a Euglossa species, shiny, iridescent green, a little smaller than a bumblebee. Like miniature hummingbirds, they hover by flowers without landing, using their long tongues to probe for nectar. They have a swift, darting flight, punctuated by pauses when they hover in mid-air, surveying their surroundings, their bodies absolutely motionless but their wings a blur. Interestingly, a local fly species has evolved to mimic both their metallic colour and their flight pattern, presumably to fool birds into thinking it also has a sting.
The second type of orchid bees were much larger and densely furry, with orange, black and yellow stripes – a species belonging to the genus Eulaema, according to Jeremy. When I first saw one I was fooled by the size and furry coat into thinking it was a bumblebee queen, but close up it was clear that this was no bumblebee – it had greatly enlarged thighs on each of its hind legs, something that all male orchid bees share. These oversized legs are hollow, with a small hole into the interior, and they are used to store fragrant, volatile chemicals: odours that are needed to attract and successfully woo a female. Males of most orchid bee species collect these chemicals from just one species of orchid, and the orchid has come to rely on the particular bee for pollination. In the perfume industry, a technique known as enfleurage is used to trap elusive scents from flowers by absorbing them into fat or grease. Male orchid bees use this same process; they excrete a drop of fatty liquid from the labial glands in their head onto the orchid flower, and once it has absorbed the scents of the flower they scoop it up and store it in their legs. The fats are then absorbed back into the body (without the floral scents) and recycled to the labial gland for use on the next flower, so gradually concentrating the floral scents in the leg chamber. Sometimes males have been seen to mug one another to steal these chemicals, pinning down a rival and sucking the fatty perfume from their legs rather than bothering to
visit the many flowers needed for them to collect legs-full for themselves. Nests of orchid bees are exceedingly hard to find in these tropical forests, but their social life is said to be intermediate between solitary and social bees. They are thought to live as small groups of females, each of equal status, and all laying eggs – right up Jeremy’s street, for they might give us a glimpse of an early stage in the evolution of much more complicated insect societies such as those of honeybees or ants – if only one could find the nests.
While I was getting all excited over orchid bees, Jeremy’s most prized find was two nests of some minuscule wasps called Microstigmus. These little creatures are nothing much to look at, being just three or four millimetres long, but they evolved a social lifestyle entirely independently of other groups of social wasp or bee. They feed on springtails and thrips, and live in a little nest made of silk, no bigger than a walnut and hanging from silken threads in a sheltered spot on a buttress of a tree trunk or under a large leaf. Jeremy had previously studied a different Microstigmus species in the Atlantic rainforests of Brazil and found that the males are actively involved in defending their nests, something that is extremely unusual in bees and wasps (usually the males are lazy creatures with just one role in life – mating). Hence he was keen to find out more about the life of this Ecuadorian species.
Despite our best efforts in capturing insects, we could not compete with Mika in impressing the students. He’d been out setting camera traps to capture images of the forest’s mammals, and in no time at all he had photographs of spectacled bears, ocelot and even a particularly large male puma, the latter only a few hundred metres from the lodge. In his excellent book Feral, George Monbiot argues that those of us living in countries that are now devoid of dangerous wild animals subconsciously miss the frisson of excitement they generate, and I’m inclined to believe that he might be on to something. It certainly made life more interesting knowing that such magnificent creatures were living all around us, particularly when we went out at night by torchlight onto the forest trails to see what we could find. Suddenly, our imagination turned every rustle of a mouse into the snuffling of a bearfn4 or the sound of a puma crouching to pounce.
