30 September. This is the last stretch of the trip. The last chance of finding bees before starting to wrap up this expedition. It has been a mixed bag for finding bees for studying vibrations. Perhaps is the cool, rainy days we have encountered, or Spring, or trying to cover too much ground, or any other reason that makes field work in a new continent hard. But it has been a blast and somehow we have managed to scrape a few measurements in bees across Australia. Today is our last push and the bright sun and blue skies with relatively little wind are promising.
We leave Hervey Bay after exploring some Solanum torvum growing behind the campground. We drive down the Bruce Highway and Daniel has an inspired suggestion to get off and explore a side road. With the corner of my eye I spy a large shrub with bright yellow flowers in a spike. ‘Stop here’, I ask Daniel who pulls over near a farm. We climb down to the river bank where I saw the plant and confirm is the (exotic) Senna didymobotrya with large, buzz pollinated flowers. Within seconds we hear the deep buzz of a large carpenter bee (Xylocopa sp.) above our heads. With some tricks and patience we sample a few bees including Xylocopa. We are thrilled of this strike of luck to locate the bees that will allow us to close the trip with more observations.
A farmer comes by intrigued by our excitement at a weedy plant and we tell him about the Buzz Bus, he allows us to go deeper up the river bank to look for more buzz pollinated flowers of Solanum and Senna that he says are plentiful here. ‘Just watch out for the carcasses of the feral pigs we shot last week!’, he warns us. We find many bees of different species and collect buzz after buzz in our mobile lab. This is the most productive day of the whole Eastern trip!
The day has been a complete success, and we pull over late in the afternoon on our next campsite at the edge of a pine plantation. How here to cut down Eucalyptus forests to plant Scott Pines (Pinus sylvestris), while the rest of the world cut their native forests to plant Eucalyptus?
The usual brush turkeys watch us set up camp, and we spend the evening cooking, measuring and photographing bees. A pair of kookaburras huddle together above our heads as the sun sets. The campsites light up their fire pits as the darkness quickly engulfs everybody. Tomorrow we head to Brisbane to return the Buzz Bus and end three weeks of wonderful fieldwork.
29 September. Today we continue our drive south, guided by the records of invasive Solanum that we have been able to find online through the patchy internet reception we can get. The first stop is in Granite Creek in a rest stop that advertises free coffee for tired drivers. The parking area off the road is an invasive plant paradise. Surrounded by a national park, here you can find a wide range of invasive plants from around the world. The invasives include Solanum americanum, Tecoma stans, Argemone ochroleuca, Thunbergiaalata, Verbascum virgatum, and others. But we are here for buzz pollinated Solanum and find plenty of S. mauritianum, S. seaforthianum, and even tomato (Solanum lycopersicum). The perennial honeybee is here trying clumsily to get pollen from S. mauritianum without ever vibrating. Monarch butterflies (Danaus plexippus), another exotic organism, seem to also thrive in this part of Australia and I tell Daniel about their wintering grounds in western Mexico. There, the monarch butterflies can be found in enormous numbers, hanging from conifer trees, resting after their long migration from the USA and Canada. Or at least they used to be there in large numbers when I visited; who knows how they are coping with the brutal deforestation going on in the forests of Michoacan. Here in a roadside of Eastern Australia, lonely monarchs flutter a bit lost. The grass is tall and as we walk around, I think of snakes hiding in the grass. No wild bees here in the cloudy, cool morning, so we drive again.
Eventually we make it to our next destination in Hervey Bay. This is a touristic town on the coast, but with plenty of records of the plants we look. It is getting late (drives in Australia are long), and we go to the Botanic Gardens where we find some stingless bees.
As we drive back to the campground I hear a strange noise coming from the trees. We stop in a park in the coastal road and we saw giant black fruits hanging from some trees. Something doesn’t add up. Then one of the fruits rattles, crawls on a branch and extends its enormous membranous wings. They are flying foxes! I couldn’t be more excited of seeing these giant bats (Pteroptus alecto) for the first time. There are several dozens in this tree and several more in the next one. A tree further down is also full with flying foxes and we realise that there are several hundred bats around us. As we approach the trees and look through the binoculars, I see a pair of eyes looking right back. The bats are becoming active and are well aware of our presence. Their terse fur, sometimes forming a lighter collar in some individuals gives these wonderful animals an elegantly sinister look. The bats stretch their wings, and you can almost feel the texture of the skin that stretches in their hands-turned-wings. They communicate and interact with one another. They keep their sights on us, and when a drunken woman hits their tree with a branch, they take off with the sound of leather cutting the wind. Their silhouettes swish across the blue sky of the dying daylight, and the trees rattle with their movement. I wish you could hear them.
27 September. It’s before 6:00am and we are waiting by the Broken River. We stand on the edge of a murky, slow flowing river guarded by tree ferns and lianas that touch the water surface. The muddy water hides a platypus somewhere. Bubbles raising to the surface and a cloud of mud in the water reveal the location of the almost mythical platypus. A small creature breaks the water surface, the colour of its fur barely distinct from the colour of the mud at the bottom of the river. Its duck-like bill chews rapidly, probably on invertebrates dug out of the bottom.
Before we can fix the binoculars or the camera it dives again. A little while later it re-emerges, its clawed paws stretched on the surface along with its flat tail giving us a glimpse just long enough to get a good view before the platypus dives again. We spend sometime admiring this extraordinary animal in silence. I think of the book I am reading (appropriately called Platypus Matters by Jack Ashby), and the story of how Europeans sought to settle the questions of whether the platypus lays eggs and feeds its young with milk, and, if so, what kind of strange mammal this is. Together with a handful of species of Echidnas (the hedgehog-like creatures that also lay eggs), the platypus forms an unusual branch in the family tree of mammals called the Monotremes. Platypus go by many names in different countries but is an animal well known despite its localised distribution and the fact that only one zoo outside Australia has a living platypus (San Diego Zoo). In Spanish the name is ornitorrinco.
If you squint you can see a platypus (ornitorrinco)
We pack and move to look for bees. We search first the montane forest, looking carefully in the few flowers that manage to grow in the understory of this dense forest. Palms grow at every gap in the canopy, and we see stag-horn ferns (another ‘platy’, Platycerium in the fern family Polypodiaceae) hanging onto every tree. These stag-horn ferns make their own hanging basket using modified leaves that catch debris and vegetation, and make long bifurcated leaves that extend like vegetal stag horns. Some of the ferns look so big that they seem capable to bring the smaller trees down with their sheer weight. A smallish goana (a large reptile also called monitor lizards) stays still by the water hoping we haven’t noticed it. We find some flowers and catch a glimpse of a bee. We stay still to see it foraging fast as lightning and zooming away in the vegetation in search for another rare flower. We wait for a while but the bee decides not to return.
We try our luck in the nearby pastures where a few farmers maintain cattle herds. The grassy mess of cattle farms has replaced here the ancient forest. Besides the grasses, several other non-native weeds make their home along the road. A spear thistle (Cirsium vulgare, Asteraceae) spreads its spiny leaves and shows off a purple inflorescence head. Mexican poppy (Argemone ochroleuca, Papaveraceae) grows here and there. In the 1930s, the Australian government leased land to young men on the condition of clearing out 35 acres of forest and transform it into cattle pastures. The exotic grasses and the cattle to go with it were considered more valuable.
Solanum mauritianum, a buzz pollinated species that is at home in cattle fields and disturbed sites
Along the dirt road, we spot our good-old Solanum mauritianum (Solanaceae). As other Solanum, this one loves the disturbance of the roadsides and pastures. We stop, and soon find the first bees. The sun is shinning and bees are busy buzzing the Solanum flowers for pollen. On the roadside we measure and photograph.
We are lucky enough to come across a territory guarded by male carpenter bees (Xylocopasp.). The male bees fight with one and other to defend a patch of Solanum, where the female bees come to collect pollen. They zoom around us and chase each other away. These are some of the most beautiful bees I have ever seen, and are restricted to Eastern Australia. The males of Xylocopa bombylans, have a metallic green-blue body that shifts to yellow-orange in the thorax. The iridescence of its exoskeleton is wonderful, and yellow hairs adorn their legs. The face carries an elegant ivory mask, and they are not shy or fearful of anybody entering their land. We spend a few hours observing these bees and studying their buzzes. This is a good day for the Buzz Bus!
In the evening we find a local campground, which used to be the school of the ranchers’ kids, and has now turned into a nice place to spend the night. We make a fire and enjoy a quiet evening under the stars. In the night, a rainstorm comes in and batters the roof of the Buzz Bus. I dream that the campsite is flooded and wake up to check whether we are at risk of being washed away. It looks fine, but the people in tents that were near us have had to move under the roof of the old school. The rain carries on all night.
25 September. Today we wake up early and head north of Yeppoon to the edges of Byfield. This is an area with large plantations of non-native pine forest, and scattered native vegetation in some hard to reach spots. The pines pepper the landscape even in the areas that are now part of a state forest. In the outskirts we get a bit lost looking for a watering hole and end up in a small side road. On the edges of the dirt road we spot Grevillea banksii (Proteaceae), a shrub that produces the type of handsome red inflorescences that Australian birds love. But instead of pollinating birds we notice some small native bees stealing nectar. Our first native bees for a long while!
Measuring buzzes
Quickly, we get to work and manage to capture a few specimens, which I later determine to be the stingless bee Tetragonula carbonaria (Apidae, Meliponini). These small bees resemble the stingless Trigona bees from the neotropics but have a rugged back (scutellum) that projects over the abdomen as if they were carrying a shield in their back. These bees refuse to produce defence buzzes and we record five individuals as non-buzzing. Although not unexpected, we are very happy to score this new species of a highly social, tropical bees as non-buzzing.
We keep searching nearby, and discover some bright magenta flowers in a small bush. This is plant clearly belongs to the family Melastomataceae, a curious tropical family in which the majority of species are buzz pollinated, which appears to be a highly unusual trait for an entire family. We are very excited about the findings of what then we established to be Melastoma malabatrichum, a species that others have studied before in the old tropics but for which I am unaware of pollination studies in Australia. In any case, it is the first time I see this species in the wild. The flowers are large with spread out petals and five bright yellow anthers carrying pollen at the centre of the flower. The anthers are poricidal, opening through small pores at the tips, which makes buzzing the most effective way to remove pollen from them. As they are nectar less, pollen is the only reward that this plant offers to visiting bees. But M. malabatrichum has a trick under its sleeve, because in addition of the five yellow anthers, each flowers carries a second set of purple anthers that mimic the colour of the petals. These inconspicuous anthers sneak behind the back of unsuspecting pollinators, which mostly ignore them while visiting the yellow anthers, and manage to put extra pollen in their back. The purple pollinating anthers are known as pollinating anthers, and the yellow as feeding ones. This is a classic example of heteranthery as studied by Charles Darwin and Fritz Muller in the middle of the XIX century.
Watching these mighty Melastomes, we see a large green bee zooming by, and in the excitement of seeing a buzz pollinator for the very first time in eastern Australia, I miss and let it escape! Bummer! We find more plants and wait patiently for it to come back. The mythical green bee never returns but instead we witness to black stripy buzz pollinators arrive to the melastome and we manage to catch them both. Hooray!
We go back to the Buzz Bus and record their buzzes. As the data is acquired by the computer we breath a sigh of relief of having the first buzzes of this trip.
We go back to the field and wait for a while but no new buzz pollinators arrive. We spend the rest of the day exploring this and other parts of the region, but no more pollinators arrive. As the afternoon sets in, we pull over in a sign that says Capricorn Caves. The place is closing, but after some pledging they let us stay in their campsite that is under renovation. The nearby caves can be visited next day, and with the last rays of light of the day we walk in the beautiful forest that surrounds us.
Somehow we have found this little paradise of sharp karst in which caves occur above ground in small hills with ragged peaks. And below, we find a few well preserved fragments of dry tropical rainforest or vine scrub, where dense vegetation of broad leaves co-occur with woody vines that climb and twist among the trees. We see a few honeybees, wasps, beetles, spiders, but not native bees. As we walk a wallaby crosses my path and gets lost in the vegetation. I hear noises on my left and wait quietly to see a second wallaby come very close to me just to notice me and jump away in the forest.
Ahead in the path, Daniel is admiring some green ants, a type of ants that use silk to tie tree leaves together and build aerial nests. The hanging nests are sensitive to vibrations and touching the branches cause a horde of green ants come looking for the trouble maker. It is best to keep your distance from their armies. Daniel tells me that aborigines used to eat the ants which have a citrusy flavour, and to prove his point he tries one. Apparently they’re indeed lemon like.
In the camp, a brush turkey (Alectura lathami) has adopted us and she waits for our arrival to see if she can find any scrap of food near the Buzz Bus. She is disappointed.
That night I photograph bees for measurement and make some notes of what we have seen over the last days. We go to bed late and tired but hoping that the next day brings more bees. Above in the sky, we see Scorpio, the Southern Cross and a bright Jupiter. The flashes of the camera go on for a while.
21 September. Last night we stayed in a caravan park in Greenhough. The friendly staff treated us to a story of walking the Way of Santiago, a trail that extends 700km in a journey to Santiago de Compostela, Spain. The rusty showers and swallows nesting in the entrance to the laundry room adds character to a place that seems to exist in the strange dimension of roadsides. Unsurprisingly, we chat about David Lynch over breakfast.
In the morning, we continue driving south, and we start the day with procession of 1960’s race cars that pass us in the opposite direction. We try to stop more rarely, but patches of Solanum distract us. We reach then Badgingarra National Park and quickly becomes the highlight of the day. A lunch break under a willow look-alike tree that is more closely related to guavas and Eucalyptus (Myrtaceae) than to willows (Salicaceae). Then a quick walk (no wild bees in sight), and the flower fest continues. Too numerous to name them now, we continue recording and photographing flowers. David spots a striking buzz-pollinated flower in the family Malvaceae (think hibiscus, mallow flowers but then transform them into some sort of tomato flower mimic). We photograph it and continue talking about follow up projects.
Late that evening we reach Perth and pack and clean the Buzz Bus. David and I say good bye after I drop him off at his family home. It has been a fantastic trip and we make plans for the analysis and write up of the data we are collecting. It has been great to have David’s expertise and knowledge of the flora of Western Australia and I have learned lots from him over the last eight days on the road.
Tonight I will stay in a hotel near the airport. Tomorrow I fly to Brisbane to meet Daniel Montesinos and start the second leg of the expedition.
20 September. Today we start driving South. First, we use ghe morning to return to Kalberri and visit the canyon again. The sky is bright blue, is less windy and the temperature around 20C, so we are hopefull to find bees. Along the walk we spot a small flowered Solanum, again with purple flowers. The combination of purple to lilac corollas and bright yellow anther cones seems to be widespread across buzz pollinated taxa here with the exceptions of all species in the families Fabacaeae and The Dilleniaceae (Hibbertia) that we have seen so far. we come to the rim of the canyon and its candy-coloured red and white banded sedimentary rocks.
Later we continue the drive back and spot many amzing plnts long the rod, including second Solanum with the same colour pattern.
We are targeting large patches of buzz pollinated bushes. The bees seem to be absent again today. A couple of honeybees visit them disinterestedly, gathering pollen in silence. these flowers offer no nectar, and it appears that a buzzing bee should be able to buzz large amounts of pollen from them. Yet honeybees, for reasons that remain unclear, are unable to buzz for pollen. The mute bees fly around looking for pollen grains. Why don’t they buzz? And where are all the native bees?
The frustration of driving hundreds of kilometres without being able to catch ny buzz pollinating bees is offset by the botanical treasure we see at every stop. Rare and fantastic flowers pop out from seemingly everywhere and every stop on the side of the road means finding 10-15 obviously new species for us. Banksias, Hakeas, Eucalyptus, Seringias, Cat’s paws, Kangaroo paws, daisies of all shapes, pea-flowered Fabaceae, yellow wattles…. the list goes on and on. Is this the most botanically diverse road trip in the World? How can all these species coexist in this mosaic of soil types? Floral displays carpet the vegetation and extend as far as you can see, with only agricultural fields bringing them to an end. We are in an amazing place at an amazing time of the year where plants of all kinds are pouring all their resources into producing millions of flowers. Bees and birds should be all over these plants, yet they re turning hard to spot. Is there a puzzle to solve with these missing pollinators or are we just unlucky?
The dearth of bees and the contrasting diversity of floral resources gives David and I plenty of material to speculate and develop projects and ideas. We might be leaving Western Australia with fewer bees than we anticipated, but we have ideas and inspiration to fuel us for a while. I have the feeling that I will be back in Western Australia sometime soon to study some of this buzz pollination systems.
18 September. We get a reliable tip off that the amazing ref flowers are nearby. We pick up camp and hit the road, until we see the old wind turbine of an abandoned water pump. On the side of the road, we spot the strange and beautiful wreath flowers (Lechenaultia macrantha). This unusual plant forma a low mat that produces a ring of flowers at its edge. But the botanical highlight is hidden in plain sight just besides the reeflowers. A small bush ripe with hundreds of purple flower buds lines the edge of the road a few meters from where we are. this interesting plant slowly opens its buds as the morning warms up and reveals another buzz pollinated wonder! the flowers of Seringia (Malvaceae), mimic Solanum flowers with its bright yellow stamen cone at the centre (more on the amazing morphology of Seringia later). The resemblance seems to work well, and we soon find plenty of bees visiting this plant.
Nearby, a pink Maleleuca is a magnet of small and large bees, and here we find an astounding Australian bee. The full ID will need to wait for the experts, but it appears that we have found Ctenocolletes aff. rufescens in the unusual family Stenotritidae. If confirmed, this is one of the most exciting findings of the trip so far. The family Stenotitridae is the smallest of all bee families, with about 21 species restricted to Australia, mostly in the west (Danforth et al. 2019. The Solitary Bees). A mysterious bee group sister to the most abundant bee family in Australia (Colletidae). I cannot wait to see the evaluation of the taxonomic experts, and start analysing the buzzes of this fantastic bee group!
Superficially similar to my favourite Australian bee, the blue banded bee, this gorgeous Ctenocolletes rufescens cannot restist the nectar and pollen of the Maleleuca brush flower. We manage to collect an measure this and other bees of all different kinds and sizes. Today has also been an excllent day for data colection. we spend the day here and later begin travelling north to our next destination.
A gorgeous bee, perhaps Ctenocolletes rufescens (Stenotritidae).
As we approach some low hills, David spots on the road a Western blue-tongue lizard. We stop to take a photo, and the monster warns us off from getting close by rapidly sticking out its blue tongue. we leave it looking grumpy on the side of the road.
As the day wears off, we decide to call in Geralton for the evening. After a few days on the road it will be nice to have hot shower and resupply on water and food.
17 September. Last night we arrived late to the Coalseam campground and as we set up for the night, a pair of reddish eyes looked back from the bush. A small kangaroo laid still in the branches just off the path. The night sky cleared out and treated us to some stunning views of the milky way.
Today we wake up to a cool but sunny morning. We are on the bowl of a small valley of Australian bush surrounded by agricultural fields that hide beyond the edge of the valley. A thing line of coal cuts through the river bed at the bottom of the valley. Too thin to be commercially viable, a small pile of mine tailings and a closed down shaft is all that remains of the old mine. Before we start our drive, we decide to explore the trail up the valley rim, almost just for fun. and then, just across the river we strike gold.
Scattered not far from the trail’s edge, bushes full of golden flowers hold a surprise for us. The buzz-pollinated flowers of Senna artemisioides, in the pea plant Fabaceae, are at their peak. This is an amazing flower that has the typical poricidal anthers, the tube-like anthers that closely guard pollen grains. But within each flower there are two types of anthers in this species, a short set that attracts and feeds pollinators, and a second set of longer anthers that sneak underneath or besides the pollinator and showers them with pollen to fertilise flowers. These so called heterantherous flowers, have evolved many times in disparate groups.
The flowers of S. artemisioides (silver Senna) are thus buzz pollinated and heterantherous, and we soon start hearing the high-pitched sounds of buzz pollinating bees. We set in catching bees to measure in the Buzz Bus, and soon David and I have collected enough to keep us busy for a few hours. We do a couple more trips of collecting and measuring bees. there are many beautiful black bees with blue abdomens and they obligue and give away their defense buzzes. The data flows in through the accelerometer, and we get many minutes of bee buzzes for our library. As we continue exploring and measuring, we notice that there are at least three species or subspecies of Senna that differ in flower size, level of heteranthery and leaf size and shape. The bee highlight, though, is a large and beautiful bee wish a bronze thorax and black abdomen. Measuring this one requires extra care and wearing some cow hide gloves to avoid its sharp stinger. a true buzz pollinating champion.
After the best day so far for data collection, we round it up with views of the coalseam river, a small flock of green budgies, galahs, and a very large black cockatoo. We run into some friends of David, and we tell them about the Buzz project, eat together and sit around the fire eating marshmallows that they kindly share with us. We stayed in the communal fire for a while, watching the southern cross in the sky, Alfa Centauri, Jupiter, Scorpion, and hearing stories from the old timers that relish telling about naive explorers that have found that travelling in the Australian outback is more challenging than expected.
— They didn’t think their truck will get stuck in the sand— says Tony, as he recalls when they had to bail a pair of city dwellers in a two-wheel drive from an off road track—well, you are stuck now!
We decide to stay another night in this lucky place.
15 September. Today ahs been one of the most amazing botanical days in my life! After leaving Karda campground, we head directly to Leuseur National Park. Arriving here, I quickly realise why David has been so insistent in including this place in the itinerary. This is a true heaven of botanical diversity. A series of flat-topped hills in a valley formed by hardened rock and filled with the sand of ancient shorelines, this relatively small place holds meter-by-meter more plant diversity than a tropical rainforest! The diversity of plants is such that 60% of the plant species found in Mount Leusueur (named by French explorers that noticed its flat top while sailing the nearby ocean) are not seen in Mount Michelle, a mere 1.5km away. What should be a couple hours of exploration, turns into a full day affair, as we cannot walk more than a few steps before discovering another bunch of amazing flowers that blows away even seasoned, local botanists. Among the many incredible species we find a few buzz-pollinated taxa. This is so exciting! Monocots and dicots y diverse plant families converge here in the typical Solanum buzz-pollinated morphology. I am certain that soon we will be finding a trove of buzz-pollinating bees. But the cool, windy weather has other plans for us. We search everywhere but, although we find hundred of honey bees feeding on the flowers of Eucalyptus and Banksia, we see not a single wild bee. We continue looking until the sun is about to set, and yet no wild bees at all.
–Do you have a plan B?, asks David.
I do not. I still have hope that when the weather turns (we have had a string of cool, overcast, or rainy days in what is supposed to be one of the sunniest places in the world, we should be able to find bees. Let’s see what tomorrow holds for the Buzz Bus.
