Six members of the club participated in the Annual CWAC event on Sunday morning. This involved trying to count all the waterbirds along the section of the Klein River lagoon that is open to the public. It was a daunting task and we counted many birds, mainly Red-knobbed Coots, but also many others. It was a beautiful morning and we really enjoyed the peace and quiet of the water’s edge.
The annual CWAC (Co-ordinated Waterbird Count) will take place on Thursday 18 July. Interested persons are asked to contact Lester at 078 593 8977. Participants will meet at Fernkloof at 8:00 am and be divided into two teams, which will then proceed to selected locations along the perimeter of the Klein River Lagoon to count the waterbirds present.
You will need to bring Hats, Binos, Enthusiasm, Clipboards and Pens to record your sightings. The whole exercise should take a couple of hours, but the results last forever!
Birdlife SA and Ekapa Mining have released the following statement:
1. It is the unfortunate responsibility of BirdLife South Africa and Ekapa Mining, following their intensive work at Kamfers Dam during the past month, to announce that a mass rescue of over 5000 Lesser Flamingo chicks will very likely be necessary in the next two weeks.
2. Despite a recent increased in the flow of sewage effluent into Kamfers Dam, the water level of the dam is dropping rapidly and it is highly probable that the dam will dry up completely in the next two weeks.
3. Further compounding this problem, BirdLife South Africa has been monitoring the productivity of blue-green algae (cyanobacteria) in the dam using remote sensing methods and in consultation with specialists. We predict that a rapid drop in the density of algae in the dam is imminent – possibly within a week if there is no rain. Blue-green algae are the primary food source for flamingos at Kamfers Dam so the delicately balanced system that supports the Lesser Flamingo population may well collapse before the dam dries up completely.
4. Our most recent counts indicate that 5250 Lesser Flamingo chicks are currently present in the crèche at Kamfers Dam. The age of these birds varies from about 20-60 days old. We estimate that conditions at the dam – both water levels and algal densities – would have to remain favourable for at least another two months for all these youngsters to develop to the point that they can fly with the adults to alternative feeding sites.
5. A concerted effort has been made during the past few weeks to address the effluent reticulation problems that have so drastically reduced the flow of water into Kamfers Dam. Despite limited initial success, current inflows are not sufficient to stem very rapid evaporation rates.
6. Storms in the area during the first half of February were encouraging but associated rainfall was not sufficient to fill the dam. Unfortunately, there is no significant rainfall forecast for the next two weeks, while temperatures are predicted to be high.
7. The details of the current situation (and the possible, imminent need for a mass rescue
operation) has been reported to Les Abrahams, the Acting Head of Department of the Northern Cape Department of Environment & Nature Conservation, and to the Department of Environmental Affairs. We have suggested that an urgent meeting be held in Kimberley, with all relevant role-players present. The main aim of this gathering will be to discuss and assess options for the immediate future of the flamingos at Kamfers Dam, which probably include the need to capture, housing and care for >5000 Lesser Flamingo chicks. The details of this meeting will be announced on Monday 25 February.
8. It should be noted that Kamfers Dam is at the current time no longer suitable for the release of the c. 1000 flamingo chicks held in facilities in Gauteng, Cape Town and Durban.
9. Should it be required, the rescue of more than 5000 flamingo chicks would be an intervention of unprecedented scale and complexity. It will present massive logistical, veterinary, husbandry, rehabilitation and financial challenges, and will have to involve expert biologists, zoo-keepers and veterinarians, supported by a large number of dedicated volunteer carers, and coordinated with military precision to stand any chance of success.
1. BirdLife South Africa has conducted constant, on-the-ground monitoring of the Kamfers Dam’s flamingos, and especially of the breeding colony, for the last four weeks. The aims of this monitoring effort have been (a) to determine signs of nest or chick abandonment in the
breeding colony and advise on the need for further rescue operations, (b) to try to minimise
disturbance of the colony, and (c) to monitor water levels, algal productivity and overall flamingo numbers. We have also liaised closely with Ekapa Mining on ways to source additional water for Kamfers Dam, in collaboration the Sol Plaatje Municipality.
2. BirdLife South Africa and Ekapa Mining have developed a sophisticated, remote method of counting the flamingo chicks in the crèche(s).
3. Deep machine algorithm learning methods were used to analyse the high-resolution images taken from a drone that has flown over Kamfers Dam at high level, thus ensuring no disturbance of the dam’s flamingos. These drone flights have been done with the approval of the Civil Aviation Authority, and have yielded an accurate count of 5250 Lesser Flamingo chicks currently present on the dam.
4. Over the past few weeks the Sol Plaatje Municipality and Ekapa Mining have worked hard to address the effluent reticulation issues affecting water levels in the dam. A gravitational feed from Galeshewe to the Homevale Waste Water Treatment Works was repaired which resulted in an initial inflow of about 24 megalitres/day, but unfortunately this has now declined to and stabilised at about 14 megalitres/day. The current evaporation rate is estimated at about 22 megalitres/day. Further repairs to the reticulation system, including the pipelines and pump stations, will take several months, and no additional inflow of effluent is anticipated before early-May 2019. The Homevale Waste Water Treatment Works remains non-functional.
5. BirdLife South Africa and Ekapa Mining remain extremely concerned that in excess in excess of 20 megalitres/day of raw sewerage effluent if flowing into the veld at Platfontein farm, just west of Kimberley.
6. BirdLife South Africa (including its CEO, Mark Anderson), the Save the Flamingo Association, Ekapa Mining and/or the Department of Environment & Nature Conservation have, in one way or another, been involved in the study, monitoring and conservation of Lesser Flamingos at Kamfers Dam since the early-1990s. During the past 13 years this work has largely been to address the threats to Kamfers Dam and its flamingo population, and especially to address ongoing problems with the quality and quantity of water supplying the dam.
7. The on-site monitoring during the past month has been conducted by BirdLife South Africa staff, contractors and volunteers, especially Dr Andrew Jenkins, Tania Anderson and Robin Colyn, and with assistance from Ekapa Mining’s Jahn Hohne, Peter Hohne, Howard Marsden, and Greg Watcham.
8. BirdLife South Africa commends the various facilities in Gauteng, Cape Town and Durban, and their staff and volunteers who have worked exceptionally hard over the last four weeks to rear the chicks rescued from Kamfers Dam since 24 January.
9. BirdLife South Africa acknowledges the people and organisations who have supported its on-site work during the past month, especially Ekapa Mining and the Hans Hoheisen Charitable Trust. Several organisations, bird clubs and private individuals have generously donated money to support our work at Kamfers Dam. We are also grateful for the support received from Herbert and Brenda Booth, Kamfers Dam’s landowners.
10. For further information about Kamfers Dam’s flamingos, please contact Mark Anderson (CEO of BirdLife South Africa) at firstname.lastname@example.org.
She’s the pilot. The sole passenger. The navigator. The engine. The refueller. She’s Flight 95773.
It is the first day of autumn, one year ago. She lifts off on an epic 14 560 km journey. Part of this will be a five-day non-stop 5 912 km flight, mostly over the Indian Ocean, a journey one scientist describes as “amazing”.
She’s an Amur Falcon, a small bird of prey not much bigger than a pigeon. Falcon 95773 is built for long-haul flight. Her sleek tapered wings power her to speeds of more than 50 km/h and allow her to glide on thermals for long distances. The small shark-toothed markings on the feathers of her breast reveal she is an adult.
What makes this Amur Falcon special is that sitting on her back is a matchbox-sized GPS transmitter that will beam data to several satellites orbiting 850 km above the earth. Tracking 95773 will be expensive. The 5g transmitter on her back costs R26 000. Add another R26 000 to download the information from the satellites. She is one of 10 falcons that were trapped in Newcastle last January and fitted with transmitters.
The people behind the venture don’t believe in giving birds names, but they have given her, and nine other falcons, numbers. Each is the ID of the GPS Platform Terminal Transmitter (PTT) strapped to their backs. Hers is PTT 95773.
The bird lovers and scientists behind the venture are hoping these small birds with their tiny transmitters will solve one of ornithology’s great mysteries. Where 95773 is heading on that first day of autumn is known. The mystery is her route, not her destination: the breeding grounds of Mongolia. For a long time ornithologists have debated the route that Amur Falcons take to Mongolia. There have been attempts to plot the transcontinental migration, but all ornithologists have been able to rely on are odd sightings through east Africa and the Middle East. Whole legs of the journey have been missing. But advances in technology and the work of a handful of amateurs will change this. Here’s how the story goes.
On January 10 last year, Professor Bernd-Ulrich Meyburg arrives in Newcastle, KwaZulu-Natal, from Germany. He’s a plastic surgeon with a passion for birds. Meyburg has made a name for himself in birding circles from the work he’s done in studying the migration paths of birds of prey. He says a book about the Lesser Spotted Eagle sparked his passion as a schoolboy in West Germany. On reading the book, the youngster becomes fascinated with the bird’s long migration to southern Africa.
By 1994 the fall of the Berlin Wall and access to satellite telemetry finally allow Meyburg to fulfil his childhood dream. He and his wife, Christina, fit transmitters to four adult Lesser Spotted Eagles and track the complete migration of one of the birds to Zambia. Transmitters become smaller and smaller and he then tracks the migrations of other raptors. In 2008 Meyburg is given a prototype transmitter to test. It weighs about the same as a teaspoon of sugar – just 5g. On August 9, 2008 he fits the transmitter to an adult female Eurasian Hobby he catches near Berlin. Meyburg follows the Hobby’s migration to Angola. It flies via the island of Elba, south into North Africa and arrives in Angola 49 days later. With this success, he wants to try the transmitter on something even smaller.
His choice: the Amur Falcon. His destination: Newcastle. The reason: just 1 km from the town centre is the largest-known roost of Amur Falcons in the world. Between December and March every year, an estimated 26 000 Amur Falcons take up residence in the tall pine trees that line Allen Street, a major thoroughfare through the town. The ideal spot to catch the falcons. The problem: how to do it. About two months before he arrives in South Africa, Meyburg approaches Birdlife Northern Natal. “He asked us if we would be able to capture the falcons using high-altitude nets,” veteran bird ringer Rina Pretorius remembers.
At the time Pretorius knows a lot about mist nets and catching birds, but she’s never heard of an Amur Falcon being caught using these nets. The problem: they fly too high, and if the birders want to catch them they will need to raise the nets tens of metres alongside the pine trees. Electricity giant Eskom and funding from the local municipality come to their rescue. Cables are strung through the trees, long poles erected and then they put in a pulley system to hoist the nets into the air. By December 12 they are ready for a trial run. Just after dusk Pretorius and the team achieve a South African first. They net their first Amur Falcon. By the end of the evening they have caught five more. Each bird is ringed and released.
It is time to call in the Meyburgs. Bernd and Christina arrive in Newcastle on January 10 and that evening join the bird catchers. They spread out their nets and prepare to raise them as Meyburg lays out the tools and transmitters on the table in the lapa. They are ready. In the fading light columns of falcons, thousands strong, reel above the roost site. So many that the standing joke among the ringers is not to look up with your mouth open…To draw the birds closer to the nets, the team uses a lure, a method known in ringing circles as “callback”. They have recorded the call of the Amur – kew kew kew… kew kew kew – and play it loudly on Pretorius’s bakkie sound system.
“The idea,” explains Sylvia Francis, another ringer, “is that birds follow (other) birds that make the most noise because they believe they have the fullest crops. What they plan to do is roost close by and then follow that particular flock, believing they know where there is a lot of food.” Soon the falcons begin descending, darting among the trees looking for a branch for the night. Then the mist net catches the first of four birds, including 95773, trapped that evening. The catchers untangle the birds from the net, place each in a small cloth bag, and take them to the lapa.
Falcon 95773 is the first to be weighed. “Bernd told me that I could do the first bird, because I had prepared all the infrastructure,” Pretorius says. The catchers have a strict rule: so as not to hinder the flight of the bird, the transmitter cannot weigh more than 3 percent of the bird’s mass. 95773 comes in at 160g. “Bernd suddenly got very excited, his eyes never left that bird,” remembers Pretorius. She rings 95773, measures her and takes a blood sample. Meyburg takes over. He fits a small wire harness across the bird’s chest to hold the transmitter high on her back and positions the antenna to follow the contour of her tail. This is when she becomes 95773. When they’re done, Pretorius, mindful of the raptor’s sharp beak, carries the bird into the open. Pretorius places her on a chair to give her a few moments to recover from the ordeal of her capture. Then 95773 lifts off into the night.
Five days later they meet their target of 10 birds: eight females and two males. With the first part of their mission over, Bernd and Christina Meyburg return to Germany. This is too early for the launch of her migration, but soon 95773 begins revealing part of the hidden life of an Amur Falcon. “We found out that she moved a lot at night between roosts,” says Pretorius. “The Roberts book said that they hunt only 50km from their roost, but we found her travelling to Memel and Standerton.” In Germany it is Christina Meyburg’s job to access the satellite website and download the data. The first glitch comes soon after the 10 birds are released: three of the transmitters stop working. No one knows why: it might be that there is a glitch with the transmitters, or it could be that three birds have died.
But not 95773. Her transmitter keeps beaming data, and what they learn is that for two months she wanders, criss-crossing northern KwaZulu-Natal, hopping between the different roosts, and then she moves into Swaziland. Amur Falcons favour open grasslands, where they gather in big flocks and feed on insects like dragonflies and flying ants. Sometimes they go for bigger prey, taking barn swallows on the wing. Meyburg and company suspect she is building up vital fat reserves for her journey ahead. Ornithologists refer to these rest stops as stopovers, migratory bird refuelling stations, where a bird can take time out to carbo-load for the next leg of the journey.
Then, at 11 a.m. on Friday, March 21 last year, the satellite sends the team the data that they have been waiting for. 95773 has begun her migration to the breeding grounds in Mongolia.
High above the Lebombo Mountains on the Swaziland border, she crossed into Mozambique. The mountains fell away and then she flew over the flat mopane forests of western Mozambique. She pushed northwards, guided by something we don’t yet understand. 95773’s flight across Mozambique was swift. For 24 hours, she kept on the wing, covering 1 036 km. Her journey cut northwards at an average speed of 43.2km/h. For a while she stuck close to the Zimbabwean border before turning slightly east towards Tanzania. After a night of flight she landed in southern Tanzania.
For the next eight days she slowly made her way north. She passed through Tanzania and then Kenya, and on March 30, arrived in southern Somalia. There she stopped for a couple of days. She began moving again on April 5 and progressed slowly into Central Somalia. There again she stopped to refuel, this time for five days. 95773 would have hunted, filling her crop with insects. She’d need the high protein found in the locusts, flying ants and dragonflies to give her the energy for the hardest and most dangerous part of her journey.
Back in South Africa the scientists waited, too – for the first time they would “witness” the transoceanic crossing of an Amur Falcon. For the first time the transmitter would tell us exactly where she was when she struck out across the featureless blue ocean. But this still left two of the great migratory mysteries unsolved.
The first of these was: how did she navigate? What was the guiding hand that took these long-distance travellers over thousands of kilometres to their exact destination? Somewhere deep inside the Amurs is an invisible compass that scientists have yet to find and understand. One theory is that it might take its bearing from the sun. But how then did it fly so accurately through the night?
Dr Craig Symes of Wits University speculates: “They possibly rely on celestial cues, or magnetic fields, or a combination of both. It’s also possible that different birds use different methods of navigation.” And then there’s the second mystery the transmitter could not answer. Do birds sleep while they fly? Some biologists believe that migratory birds forgo sleep during these long flights. Others suspect these birds have an autopilot switch that controls their flight and takes over navigation while the rest of the brain sleeps.
On the morning of Friday April 16, after her five-day rest, 95773 began a journey scientists have called “amazing.” She lifted off and began flying a course parallel to the Somali coast. Below her she would have seen dry scrub land as she passed within a couple of hundred kilometres west of the Somalia capital Mogadishu. Not far from the northern Somalia town of Ufeyn the falcon, with a wingspan about the length of an average home PC, and weighing a little more than a tin of tuna, left the horn of Africa.
Ahead of her was the blue of the sea, the Yemen gulf and an ocean crossing of more than 3 000 km. On the next day, Saturday April 17, she was tracked close to the Arabian coast at 6.46 a.m. South African time. Just before landfall on the Oman coast her compass told her to change direction, she turned slightly to her right, and the Arab peninsula fell behind her.
On Sunday April 18, two days after she had struck out across the sea, 95773’s position at 6.46 a.m. was near the Arabian coast. On Monday April 19 the satellite placed her 270 km southwest of Karachi, Pakistan at 5.45. Her oceanic crossing was nearly over. Hours later 95733 was again over land. But she flew on. 95773 had made the crossing in two days and five hours. She was the fastest of the seven remaining birds that continued to be tracked, the first to reach the shores of India.
On Tuesday April 20, at 4:12 a.m., satellites had her logged in eastern India; she was still on the move. And then on Wednesday April 21 she was near Mandalay in eastern Burma. Here 95773’s feet finally touched land, or more likely the branch of a tree.
The non-stop journey of five days had taken her an incredible 5 912 km at just under 50km/h. But her journey was not yet over. After a six-day stop, she continued moving slowly north east. On May 8 95773 arrived. Her transmitter recorded that she was in the middle of the Inner Mongolia Autonomous Region of Xilin Gol, about 450 km north of the Chinese capital of Beijing.
This was the heart of the Amur Falcons’ breeding grounds. She had travelled 14 560 km and she was just half way through her journey.
Some of the other birds hadn’t even made the ocean trip in one go. A male called 95775 had stopped over on Socotra Island, in the Arabian Sea for a couple of hours, before resuming his flight. “Maybe he had a girlfriend there he stopped to visit,” laughs Rina Pretorius, the bird lover who had helped trap 95775 and several other Amurs in Newcastle. His crossing was the longest at two days and 18 hours.
Shortly after 95773 arrived in Mongolia, the German bird lover who sparked the research, Dr Bernd-U Meyburg and his wife Christina, battled to get a fix on the birds from the weak signals. So no one knows what 95773 did for the next two months. Perhaps she found a mate, and reared a clutch of chicks, as millions of other Amur Falcons were doing in Mongolia.
Now the team had its longest wait. Would she fly home? They would know only when the transmission improved.
In late October an e-mail landed in Pretorius’s inbox. An excited Meyburg told Pretorius 95773 was on the move again. She and the other falcons had taken flight and were now in an area where all seven transmitters could beam information to the network of satellites high above. The wait had ended. Now science had the opportunity to record the full complete migration of an Amur Falcon.
On October 28, satellites picked 95773 up in Assam, in Northern India. The large female falcon was the first to leave, again leading the charge. From Assam 95773 passed over Nagpur and Bombay, then across the Indian Ocean. This time her ocean passage was shorter, a distance of just over 2 500 km, which she covered in two days of non- stop flight.
With landfall came the acacia scrub-land of Somalia, as 95773 turned south flying through East Africa. Like before, her journey was a mix of quick sprints and lengthy stop-overs. She cut her way further inland towards central Africa. Pretorius followed her progress as she inched closer to Newcastle. On the evening of November 27, she slept over in southern Zimbabwe, just 75 km from the border of South Africa. Twelve days later she crossed into South Africa. On December 11, she slept at Samcor Park in Pretoria and two days later satellites recorded her in Volksrust. The Newcastle roost now just 50 km away.
Three days later Pretorius received Meyburg’s latest e-mail update. Pretorius grabbed her camera, binoculars and rushed to her bakkie. The e-mail contained co-ordinates and with the help of Google Maps the veteran bird-ringer got a fix. Her chances were slim that mid morning. But she still drove through Newcastle towards the suburb of Lennoxton. She found the tall lone pine tree. Two kilometres away lay the roost from where, 11 months earlier, 95773 had taken off from a camping chair, carrying some special cargo. The tree was empty.
“I just wanted to see the bird, I was hoping maybe I would find her sitting on a nearby telephone line and I would identify her from the transmitter on her back, “she recalls. But Pretorius had missed 95773. The night before, in the rain, 95773 had landed in that pine tree in Newcastle.
Her touchdown ended one of ornithology’s greatest mysteries – a team of amateur birdwatchers had mapped the epic flight of an Amur falcon. 95773 had come full circle.
The falcon had landed.
Submitted by David Shreeve
Positive benefits of fynbos fires are short-term food opportunities for some species
Raptors are often attracted to fire and its charred results, moving in from adjacent habitats. This is particularly evident where predatory birds may flush out injured birds and animals or find other carrion. Jackal Buzzards, Steppe Buzzards and Spotted Eagle Owls are known to visit burnt areas immediately after smoke dissipates. After a relatively short time they move on.
Other species which may take advantage of the aftermath of fynbos fires
The Fork Tailed Drongo, Fiscal Flycatcher, Fiscal Shrike and Cape Grassbird are known to take up the debris of insects, arthropods and the seeds of various plants such as P. falcifolia and L. eucalyptifolium which are exposed about 2 weeks post fire.
Nectivores such as the Cape Sugarbird, Orange Breasted Sunbird and Cape Bulbul will immediately move away to neighbouring areas, however, this may be advantageous to genetic diversity as they colonise with other groups, returning only once the area has recovered. They are significant pollinators, playing a vital role in continuing fynbos survival.
Negatives are longer-term!!!!!
Fynbos Recovery Periods or seasons required for the fynbos habitat to recover vary. Usually, fire patterns are such that most fynbos bird species are able to simply re-locate temporarily to unaffected areas of similar habitat, at least until the affected areas recover. Some fynbos species take longer to recover, hence food sources can be limited. Neighbouring suburban gardens often become a refuge for the nectivores immediately post fire.
Frequency of fire impacts on the recovery of certain fynbos plant species, which in turn impacts on suitable nesting sites, for example the upper branches of Protea Neriifolia, preferred by the Orange Breasted Sunbird. This plant species is slow maturing, taking about 6 years to reach maturity, and produce fruit. If the fruit is burnt before ripening, no seeds will be dispersed! Densely concentrated growth of Leucodendron salignum indicates where an area has been burnt too frequently, compromising non-sprouting fynbos species, thus minimising preferred nesting habitats for some fynbos bird species.
The intensity of fires can significantly alter the fynbos profile of an area. Whilst some plant species may benefit from low intensity fire heat to allow for seed dispersal, other plant species can be eliminated by hi intensity fire. Total destruction of the underground parts of the plant and buried seeds can occur. Again, this impacts on breeding, nesting and the food source of endemic birds and may also lead to fragmentation of breeding sites.
Breeding season versus Fire season.
At the moment, most fires occur during hot Summer and Autumn months, when breeding is finished. Most fynbos birds breed during late Winter and early Spring, so impact on breeding is generally confined to loss of suitable nesting sites. However, if fires occur earlier in the breeding season, fynbos bird species most affected would be those nesting in fynbos scrub, such as Cape Grassbird, Karoo Prinia, Orange-breasted Sunbird, Neddicky, Grey-backed Cisticola and Cape Sugarbird. Some such as the Victorin’s Warblers concentrate into damp, south-facing stream-side kloofs, shielded from all but the fiercest fires.
Article submitted by Pat Redford
- Mike Ford (Hermanus Bird Club)
- “Fynbos Ecology and Management” Karen Essler/Shirley Pierce/ Charl de Villiers
- “Roberts Bird Guide” Hugh Chittenden
- “Sasol Birds of Southern Africa” Ian Sinclair
- “Birds Attracted to a fire in Mountain Fynbos” W.R.J. Dean, UCT
- Fernkloof Nature Reserve website
- “Vanishing Flora” Anneke Kearney
- “Walking with Paul Grobler” website
We will entertained in September by Sally Hofmeyr, an academic English editor and biologist. She has studied large terrestrial birds (including the Black Korhaan and Secretarybird) and how they are responding to environmental change. Since January 2016 she has been working full time for an online academic English editing company, while continuing with ornithological fieldwork — bird ringing, bird counts, and penguin monitoring — as much as possible.
The meeting starts at 18h30 and will be be preceded by the usual social get-together with drinks at 18h00.
There will be a talk on African Penguins by Dr Lauren Waller on Tuesday 17 April at 17h30 at the Green House. All HBC members are welcome. There will be a R20 donation to environmental education.
The Hermanus Botanical Society presents the second talk of 2018 on FRIDAY 20th April at 5.30pm in the Fernkloof Hall. Members of the Bird Club are welcome.
We are delighted to introduce to you, Dr Johann du Preez who has recently moved to Onrus.
His talk is on: Bird pollination strategies
We will be looking at both birds and plants in a new light after listening to Johann explaining the strategies applied by both birds and plants in order to ensure survival.
Johann du Preez is an emeritus professor who is now a full-time environmental consultant. He is a plant ecologist by training who worked for years in the Grassland biome of Southern Africa.
He contributed to the compilation of the latest vegetation map of South Africa, Lesotho and Swaziland by Mucina & Rutherford (2006).
He is a member of BirdLifeSA as well as the Hermanus Botanical Society.
Our guest speaker this evening will be Christine Hagen and she will speak “New Horizons for Penguin Conservation”
This is the story about near-magical seabirds that criss-cross the globe, and small, lentil-sized blobs of plastic called nurdles. It is both astounding and worrying, writes DON PINNOCK.
Anybody who’s seen a colony with sometimes hundreds of thousands of nests just beyond pecking distance of each other and heard its mind-numbing cacophony will unfailingly wonder how each bird finds its way back to its nest.
This question became the lifelong pursuit of Gabrielle Nevitt, a professor at the University of California who first visited the Antarctic islands in 1991.
Seabirds like shearwaters belong to a family known at tube-noses because of a pair of exterior nostrils moulded to the upper side of their bills. It was originally thought this oversized snoot helped to disperse salt swallowed while grabbing fish, but Nevitt wondered if it might be meant for what noses are for: smelling.
She soaked absorbent tampons in a variety of fishy-smelling oils and attached them to kites which she flew from the back of a research ship – scientists are inventive people. The kites attracted crowds of petrels and albatrosses. She was ecstatic.
Sniffing around seabird rookeries, she came up with a plausible theory for their homing abilities: each pair and its nest had a particular smell, an aural barcode, and the birds had a phenomenal ability to detect it. The parts of tube-nose brains dealing with smell, it turns out, have six times as many smelling cells as mice with comparable brain size.
But smelly nests didn’t solve a much bigger puzzle. How do seabirds – which range forhundreds of thousands of kilometres and can spend years at sea without coming near land – unerringly find their way back to their nest when they need to breed?
The answer came following a chance meeting with Tim Bates, a chemist at the National Oceanic and Atmospheric Administration. He was investigating a gas called dimethyl sulphide (DMS) emitted by phytoplankton, the microscopic plants that live on the surface of the ocean.
When damaged, they emit the gas which, it seems, could provide aerosols around which clouds gather. Spraying DMS over large tracts of ocean could create cloud cover to counter global warming, but that’s another story.
Nevitt took off in another direction. Krill, the major food source for many seabirds, eat phytoplankton, producing clouds of DMS. Could shearwaters smell DMS?
Bates had sea maps of DMS concentrations. These coincided with krill concentrations and that’s where seabirds concentrate. Birds like albatrosses and fulmars, which hunt fish exclusively, were also zooming in because fish eat krill and follow krill concentrations. Nevitt had a proverbial ah-ha moment.
Seabirds, we now know, navigate the vast oceans by smell. Nevitt found they could smell one molecule of DMS at a concentration of less than one part per 10-billion.
DMS is undoubtedly not the only thing seabirds can smell. Turbulent coastal waters, upwellings around underwater seamounts, ocean currents all have their characteristic smell if you have the nose for it.
As chicks roam further and further, they build up smell maps that eventually allow them to range across two thirds of the planet and know precisely where they are. When wandering albatrosses leave their natal nest, they may not return to land for four or five years. The open oceans are their home. But at breeding time they never misplace their personal nest. In his book The Seabird’s cry, Adam Nicolson tracks their path in a long but delightful sentence:
“What may be featureless to us, a waste of undifferentiated ocean, is for them rich with distinction and variety, a fissured and wrinkled landscape, dense in patches, thin in others, a rolling olfactory prairie of the desired and the desirable, mottled and unreliable, speckled with life, streaky with pleasures and dangers, marbled and flecked, its riches often hidden and always mobile, but filled with places that are pregnant with life and possibility.”
There is, of course, a problem. There always seems to be one where humans are concerned.
By now most people know about the vast gyres of plastic sea trash in most oceans. But the bottles, crates, nets and bags are just part of the problem. An almost bigger issue are small, lentil-sized colourful plastic pellets called nurdles.
Billions are made each year and those that don’t become products generally end up in the sea. Fish eat the nurdles and sea creatures and birds eat the plastic litter. This has been going on for half a century and is now a planet-wide disaster.
Sorry, it gets worse. Small pieces of plastic, as they decompose, emit clouds of DMS which attracts seabirds. In the plastic soup there are plenty of things that look like krill, cocpoods and fish. Seabird numbers are plummeting and now we know why.
When our descendants look back on the planet-wide plunder we call civilisation, they’ll wonder why we didn’t notice the danger of extruding trillions of tons of plastic junk on to the land and into the sea. Will there still some albatrosses and shearwaters around? We can but hope. From the Daily Maverick