Wallace returned from South East Asia, bringing back a collection of some 1000 species new to science and a pair of living birds of paradise

2013 marks the 100^th anniversary of the death of the Victorian scientist from whom Operation Wallacea draws both its name and its inspiration. It is ironic that Alfred Russel Wallace’s finest moment – his 1858 discovery of natural selection – has in many ways compromised his place in history, pairing him permanently with Darwin, but as a junior partner. Wallace has been condemned always to play Watson to Darwin’s Holmes. This is unjust, as Wallace was in his own right one of the superstars of Victorian science. He was also the discoverer of what would become known as Wallace’s Line, the biological discontinuity between Australasia and Asia; he was the father of a whole new science, biogeography; and he was arguably the leading tropical biologist of his day.

Wallace was born into genteel poverty in Usk, Wales, in 1823. He received little formal education but developed a serious interest in natural history when he met Henry Walter Bates (of Batesian mimicry fame) and was converted to beetle collecting. Eager to experience biological diversity in its tropical citadel, Wallace and Bates travelled to Brazil in 1848 to collect specimens. They would sell duplicate specimens to fund their trip.

In 1852, Wallace headed back to England. He had assembled a remarkable collection, including some 10,000 bird skins, and some 30 living specimens, and he was looking forward to a triumphant impact on London scientific circles. But Wallace’s ship caught fire in the middle of the Atlantic. As the ship’s lifeboats circled the burning wreck, Wallace watched as four years of his life literally went up in flames, and, worst of all, as his living specimens fled to the bowsprit, only ultimately to be engulfed by the flames. Wallace and the crew then spent 10 days adrift in open boats before being rescued.

Theory of evolution

Back in England, Wallace realised that he had to do it all over again. This time he headed to SE Asia. The eight years (1854-62) of Wallace’s travels in what are today Malaysia, Indonesia, and New Guinea rank among the greatest scientific journeys, and the book that resulted, The Malay Archipelago, is a classic. It was also during these years that Wallace came of age as a biologist: hitherto, he had published natural history and taxonomic notes, but, in 1855, he suddenly emerged in print as a fully fledged evolutionary theorist. The paper, known as the Sarawak Law, unveiled what is essentially half the theory of evolution: Wallace argued that species gave rise to new species through a genealogical process. All that he needed now was a mechanism to produce adaptation.

Semioptera wallacii

Next came biogeography. Island-hopping between Bali and Lombok, Wallace noticed that Lombok’s birds were of Australasian stock whereas Bali’s were Asian. Wallace had identified the boundary between two of the major biogeographic regions, a boundary later dubbed ‘Wallace’s Line’. Then, in February 1858, while collecting on the island of Halmahera in the Moluccas, Wallace was stricken with a high fever, probably malaria. In the midst of the flickering delirium, he glimpsed that missing evolutionary mechanism, natural selection. He wrote out a brief summary of his ideas, and sent it to the one senior scientist he knew to be interested in the topic, Charles Darwin.

Darwin, who had been quietly developing his evolutionary ideas over the previous 20 years, was mortified. Science, even for Victorian gentlemen, is about being first, and Darwin saw his precedence usurped by Wallace. In the end, Darwin’s colleagues contrived an arrangement that would preserve Darwin’s claim to precedence and yet not do Wallace an injustice. They presented a joint Darwin-Wallace paper at the Linnean Society on 1 July 1858, and Darwin knuckled down to produce On the Origin of Species, which appeared in November 1859. Wallace, thousands of miles away, was not consulted.

Wallace returned from South East Asia in 1862. This time his collections, including some 1000 species new to science and a pair of living birds of paradise, made it to London without incident. He plunged into his new life with vigour, publishing a series of remarkable papers. In one, for example, on a group of butterflies in SE Asia, he gave a definition of species that is strikingly similar to today’s ‘Biological Species Concept’, which is typically seen as a 20^th century idea: “Species are merely those strongly marked races or local forms which when in contact do not intermix, and when inhabiting distinct areas, are generally believed to have had a separate origin, and to be incapable of producing a fertile hybrid offspring”.

Alfred Russel Wallace

Wallace once described himself as “more Darwinian than Darwin” because of his rigid insistence on the primacy of natural selection in evolution, but he nevertheless disagreed with Darwin on human evolution: partly because he had become a spiritualist, Wallace believed that natural selection alone could not account for our species.

Visionary environmentalist

Wallace used his scientific prominence as a springboard for engagement in the social issues of the day. Always sympathetic to the underdog, he was an early socialist. Perhaps most significantly, he was also a visionary environmentalist. Long before the dawn of the conservation movement, Wallace wrote that we should take steps to prevent extinction. In words that are just as true today as they were when he wrote them in 1863, he implored his readers to ensure that species do not disappear “irrecoverably from the face of the earth, uncared for and unknown”. Let us celebrate Wallace’s remarkable legacy by heeding his words.

The data sets available in the new resource library have all been processed and produced by the actual scientists involved in the research

An innovative and novel resource for science and geography students is being launched this autumn, providing important datasets that students can freely access to guide and inform their learning activities.

Preparing 16-18 year students for key Science exams can be a challenging and often frustrating experience for teachers. Certainly in the UK and America there are fundamental changes occurring in many key examinations such as the American AP Biology and Environmental Science courses, UK Biology and Geography A levels and Scottish Science Higher exams.

There has been a universal and ever increasing emphasis placed on the analysis of scientific data, guided inquiry through learning activities and preparing students by extending their knowledge for synoptic examination questions.

One major problem facing science teachers has been finding good data sets to support all of these new initiatives and one survey in America suggested that over 50% of teachers found it really difficult to find such sets. Also many of the examples often used within present education fail to represent recent advances in research especially in the field.

There is now a wonderful new science resource known as WRL (the Wallace Resource Library) that is being made available to help science teachers and it can provide novel data sets for the classroom. Uniquely, these data sets have all been processed and produced by the actual scientists involved in the research.

“The struggle for wealth…ha[s] been accompanied by a reckless destruction of the stored-up products of nature, which is even more deplorable because more irretrievable. Not only have forest-growths of many hundreds of years been cleared away, often with disastrous consequences, but the whole of the mineral treasures of the earth’s surface, the slow products of long-past eons of time and geological change, have been and are still being exhausted, to an extent never before approached, and probably not equalled in amount during the whole preceding period of human history.” (From Alfred Russel Wallace’s 1898 book The Wonderful Century; Its Successes and Its Failures)

A growing resource

The Weston Foundation has provided the initial funding which has allowed Operation Wallacea to develop this new resource. It will become available this autumn and will be added to on a regular basis and build up into a significant ‘long-term’ resource for education.

WRL is being organized under a series of modular topic headings such as Animal Behaviour, Ecosystems (Coral reefs), Ecological Survey Techniques and many others which are especially relevant to teaching Ecology and Conservation.

These data sets all originate directly from Operation Wallacea research sites around the world (11 different countries) and in each country there is a long-term agreement that has been signed with the partner organisation to achieve a survey and management development programme. Over the past decade there has been a vast amount of very important scientific data produced and this is now being made available to schools around the world.

The diversity of organisms and habits involved is very wide ranging from butterflies being studied in the wadis of Egypt, cleaner fish behaviour on Indonesian coral reefs and elephant impact studies in Africa.

Each resource has been organised so that it can be used almost immediately by a teacher and it will appeal to all 16-18 year old science students but also stretch the most able. The examples provided will almost certainly be novel and exciting and should provide a real catalyst for learning and being enthusiastic about ‘your subject’. Each resource will also have backup material such as photographs, video clips, glossary of terms, curriculum links and eventually examples used by other teachers in their schemes of work; a list of keywords will make it easy to find material and link with other areas of the curriculum.

Data sets

The data sets all originate directly from Operation Wallacea research sites around the world in 11 different countries

One of the first data sets produced will be part of the Ecosystems Coral Reef module and it looks at a ‘real life’ research project into ‘the effect of light on the morphology of the great star coral found in the Caribbean’. The data has been collected and processed by the actual scientist involved and poses two key research questions for students to study. Students get involved in the analysis of a series of photographs and there is a detailed ‘walk through’ on how to analyse the data and make valid conclusions.

Other examples that will form part of the initial data sets are:

Animal Behaviour: calculating elephant hierarchies; impact of intertidal height on the feeding rates of fiddler crabs; time budgets of Mantled Howler Monkeys; effect of water quality on cleaner fish time budgets; and crop raiding behaviour of macaques.

Ecological Assessment Techniques: mark release recapture of Hog Island Boas; analysis of bird point count data from a cloud forest; comparison of point count, transect and mist net data for assessing bird communities in lowland forests; camera trap data for estimating large mammal populations; and transect count versus helicopter surveys for large herbivores.

Coral Reef Ecosystems: comparison of fish communities on Indo-Pacific, Indian Ocean and Caribbean reefs; assessing coral cover from video transects; how light affects coral morphology; physiological adaptations of fish living in rock pools; and whether anemonefish vocalization is species specific.

Much of the research is novel, innovative and exciting and it will provide a real catalyst for learning within science education and really motivate 16-18 year old students. The data sets will also appeal to Geographers and Mathematicians and WRL should be considered as a genuine ‘cross-curricula’ resource for education. If anyone is interested in this new resource you can get further information from wrl@opwall.com.

Lionfish are voracious predators with few natural enemies and early indications are that they will significantly impact the ecological balance of Florida and Caribbean reefs

The expansion of exotic red lionfish into the western Atlantic may be explained by their tolerance of cooler waters, according to a new study.

The red lionfish, Pterois volitans, is perhaps the best recognised and most notorious group member of scorpion fishes – a large and diverse group that take their name from the potent sting they deliver using a formidable array of venomous spines. Prized by aquarium hobbyists for their showy looks and hardy nature, the fish are a bane to biologists struggling to manage exotic introductions in the Mediterranean and western Atlantic.

The Atlantic introduction is especially troubling as the fish have established persistent populations from North Carolina on the US eastern seaboard, to the Florida reef track, into the Gulf of Mexico and throughout the Caribbean Sea – all in less than 20 years. Lionfish are voracious predators with few natural enemies and early indications are that they will significantly impact the ecological balance of Florida and Caribbean reefs.

Temperature is thought to be an important environmental factor influencing red lionfish ecology in the Atlantic. While surprisingly little is known about their thermal ecology, it is clear that this tropical fish can feed, grow and reproduce in cooler Atlantic waters. In 2012 researchers with Operation Wallacea quantified thermal niche, preferred temperature and metabolic thermal sensitivity of native population of red lionfish from Hoga Island, Indonesia.

Temperature

The findings indicate that while the red lionfish thermal niche is not notably large, it is shifted towards cooler water temperatures. For example, lionfish could be acclimated to temperatures as low as 12.5°C and exhibited a preferred temperature of 23°C. A similar study on blue-spotted ribbontail stingrays from the same back reef habitat yielded considerably higher acclimation and preferred temperatures of 17.5 and 28.2°C, respectively.

This tropical fish can feed, grow and reproduce in cooler Atlantic waters

Together the results may explain the persistence of lionfish in cool US waters. Metabolic studies revealed that increasing temperature elevates biological rates exponentially, a feature consistent with the current hypothesis that warmer Caribbean Seasummer temperatures relative to the Pacific, have contributed to the rapid reproduction rate and alarming pace of lionfish expansion into the Caribbean.

The current plan is to repeat these studies with a Caribbean lionfish population at the Operation Wallacea site in Honduras. The potential exists to see significant changes in thermal tolerance characteristics between the two sites, owing to the small founding population in the Atlantic. Insights gained from these comparative studies will provide a better understanding of red lionfish thermal ecology between the two regions and how global climate change may effect lionfish distribution of both areas.

Cloud forest has high levels of biodiversity, serves as an essential source of freshwater, and is a globally endangered habitat type

Cloud forests are particularly vulnerable to disturbances such as anthropogenic encroachment, invasive species and climate change. Effective management therefore requires efficient early warning systems that detect changes in forest condition before it is too late to intervene. Until now monitoring schemes have been expensive, requiring high tech equipment and trained personnel, but using ecological indicators is a low cost alternative. A study into epiphytic ferns inNorthern Venezuela suggests that, with low levels of effort, time and cost, these species can be monitored and used as indicators of disturbance.

Cloud forest has high levels of biodiversity, serves as an essential source of freshwater, and is a globally endangered habitat type. In this context successful environmental management requires monitoring tools that provide reliable information about fluctuations in ecosystem conditions. We applied this indicator species idea by linking variation in abundance, diversity and dispersal of epiphytic pteridophytes to variation in structure of a Venezuelan coastal montane cloud forest.

Fig 1. Numbers of individuals in the primary forest plots, ecotone plots and disturbed forest plots in comparison

Ecological indicators measure the extent of stress or the ecological response to stressors, providing a simple and efficient method to track the ecological health of an ecosystem. The choice of effective indicators is crucial for a successful monitoring programme. Our intention was to find highly abundant, easily assessed plant species that are sensitive to stresses on cloud forest ecosystems. They need to respond to stress in a predictable manner and to signify changes that can be prevented by appropriate interventions. Since cloud forests are abundant in epiphytes, which rely on the delicate equilibrium of hydrological and ecological conditions found in these environments, vascular epiphytes seemed a priori excellent candidates. Ferns are, moreover, easy to spot, count, identify and distinguish.

Disturbed vs undisturbed sites

We established six 20 by 20 m plots (400 m2), of which in each case three followed a perturbation gradient from primary forest to an ecotone and disturbed forest. To ease counting and identification in future monitoring schemes, we focused on the easily accessible under storey (first 2 m above the ground). Every counted individual was classified with regard to its species, position, host plant and compass-orientation [360°] on the host plant. Voucher specimens were deposited in the herbaria VEN, TUB and STU.

Data is easy to collect, meaning that it can be acquired cheaply and easily

We found decreased diversity and abundance of all epiphytic pteridophytes in disturbed sites, compared to pristine sites; also, the epiphytic fern community tended to more clustered and different orientations on their host plants or phorophytes at disturbed sites versus pristine sites.

Against expectations alpha diversity, the number of species that co-occur in the different habitat types, of epiphytic pteridophytes did not decrease significantly from the primary forest via the transition zone to disturbed forest (see Fig 1). The number of species declined from 32 species in the primary forest plots to 28 species in the transition zone and 26 species in the disturbed forest (Fig 1).

In contrast to diversity, epiphyte abundance considerably decreased by 75% from the primary forest to the disturbed forest (see Fig 2). Therefore the number of individuals may be a more sensitive indicator of environmental and microclimatic changes than species numbers, and is in addition easier to observe than clustering and orientation.

Fig 2. Abundance of the most frequent species in the different habitat types, H. trichomanoides, E. apiculata, E. bellermannianum, S. fraxinifolium and other species, showing a steep decline from the primary to the secondary forest

Suitable indicator species

Our results suggest that disturbance strongly affects diversity and distribution of epiphytic pteridophytes. In particular, we suggest the species Elaphoglossum apiculata, Hymenophyllum trichomanoides, Serpocaulon fraxinifolium and Elaphoglossum bellermannianum suitable as indicators for disturbance in the cloud forest of the Cordillera de la Costa, because they are common and their distributions seem to be strongly affected by disturbance.

Four fern species (particularly Hymenophyllum trichophyllum), which were restricted to the ecotone and disturbed forest, can be seen as indicators for disturbance. However, they do not alter the overall decreasing trend in abundance along the gradient. Vice versa nine species (especially Hymenophyllum undulatum), restricted to the primary forest, may indicate pristine conditions.

Long-term monitoring

For future applications of this method for long-term monitoring projects and as an early warning system, we recommend some improvements on our original study design. The limited plot number of this study should be increased to better represent overall habitat conditions. Indicator sites could be permanently established and marked, and checked every six months or yearly.

The advantages of this approach are clear. Data is easy to collect, meaning that it can be acquired cheaply and easily, if necessary by people without prior scientific education.

Healthy coral reefs are like noisy cities bustling with life and the sound emitted from them can be used by fish and crustacean larvae returning to the reef from the open ocean. Hoga Island Home Reef, by Dr Stephen Simpson

A study on sound recordings of reef noise from different habitats has revealed that the highest quality reefs are also the noisiest, potentially attracting more larval recruits using sound to orient towards reefs.

Nearly all fish and decapod crustaceans associated with reefs spend their larval stage in the open ocean after being broadcast from the reefs as eggs or hatchlings. They soon develop strong swimming abilities which allow them to counter the effect of sea currents and choose the direction in which to swim and eventually return to the reef.

The precise reason why the larval stage is spent in the open ocean is still under debate, but generally it is agreed that this strategy ensures that the larvae are far from the many reef associated predators during this vulnerable stage.

However, this strategy can only be beneficial if some of the larvae are able to return to the reef – not an easy task in the vast expanse of the ocean. Over recent years it has become clear that larvae use their sensory abilities to home in on a reef and two senses in particular have emerged as the most likely candidates.

The sounds of coral reefs can be recorded in the field using an underwater microphone known as a hydrophone. Apart from the hydrophone, the rest of the recording equipment is far from waterproof. Recording off Hoga Island (2007), by Dr Stephen Simpson

Experiments have shown that larvae can be attracted to the odour and the sound of a reef, both of which have the potential to be detected over distances up to 20 kilometres. Despite the importance of this phenomenon in determining population dynamics across reefs, there is still very little known about the sensory cues produced at the reefs, how they propagate through the environment and the actual sensory abilities of the larvae.

The sound of a reef

Like cities, reefs concentrate a lot of life in a small area and this, again like cities, makes them very noisy places.

The background ‘crackling’ sound is produced by hundreds of snapping shrimp while the ‘grunts’ and ‘croaks’ are from vocalising fish.

Each reef also has its own signature sound and our recent work using recordings of reefs of similar size in the Philippines has found that the  reefs within three different well managed Marine Protected Area (MPA) for the previous 10 years had significantly higher sound levels at the source (average sound intensity of 133.1 ± 2.2 dB re 1 µPa) compared to three overfished macroalgal and urchin dominated reefs (average sound intensity 122.0 ± 1.2 dB re 1 µPa).

The clear difference between recordings from different habitats may empower the fish and crustacean larvae not only to detect the location of the reef but to discriminate between good and bad reefs.

Frogfish larva from light trap on Hoga Island by Julius Piercy

This finding is important for the way we manage Marine Protected Areas (MPAs), underlining how the acoustic signature of the reef will also need to be considered if we want to improve the efficacy of an MPA. It also opens up the possibility of surveying and monitoring reef quality rapidly and cost effectively in the future.

Our future work on Hoga Island aims to identify if the difference in sound levels with habitat quality can be detected on smaller spatial scales to refine reef quality assessment surveys.

This will form part of a larger project which aims to develop a detailed map of the soundscape around Hoga Island up to 5 km away from the reefs, combined with behavioural experiments on fish larvae to determine how they respond to different reef sounds and over what distance they can detect reef noise.

Crop-raids are led by adult males who tend to be more willing to engage in risky behaviour than adult females

A study which took place on Buton Island, Indonesia on the crop-raiding behaviour of the Buton macaque has found that some troops spend up to a third of their time feeding on crops in farmers’ fields. They raid the farms, which are a mix of annual and perennial crops, in a highly co-ordinated way in terms of how they enter the farm and which crops they target. Farms are a risky place to be for the macaques as they tend to be quite open, with mostly ground cover crops and, of course, full of farmers!

Crop-raids are led by adult males who tend to be more willing to engage in risky behaviour than adult females, particularly those gestating or with infants. Work on risk taking behaviour predicted that juveniles may also be amongst the first to enter the farm, but in this study juveniles raided the farm when they could but neither took the initiative nor hung back.

Understanding how and when the monkeys crop-raid is essential for conservation

The monkeys’ behaviour varies depending on how far they venture in to the farm. When deep in the farm they rest, groom and socialise, whilst they show the most vigilance behaviour on the edges of the farm. This is most likely due to the fact that the monkeys only venture deep into the farm if they think it is safe to do so, ie when farmers are not actively deterring the monkeys. Safety in numbers is also important. The more monkeys present in a raid, the longer the raid lasted. What we don’t yet fully understand is whether the presence of more individuals enabled longer raids, or the longer raids encouraged more individuals to enter the farm.

Ten year study

This study began in 2002 and represents the first long term study of primate crop-raiding in Asia, and one of the longest in the world. Understanding how and when the monkeys crop-raid is essential for conservation. It provides vital information about the monkeys’ behaviour which can be used to develop management strategies and continue to promote tolerance towards the monkeys from the local people.

Monkeys only venture deep into the farm if they think it is safe to do so

Patterns of crop-raiding varied throughout the study, with more raids taking place in the early years of the study. There were an average of 21 raids per farm in 2003 during the two month study period, decreasing to an average of one raid per farm in 2009 . The recent decrease in raids may be due to changes in wild fruit availability, farm layout and crops planted, crop yield or climate variables.

Advice given to local farmers from the study may also be having an impact. Farmers were advised on deterrence strategies such as fencing and the use of dogs to scare off monkeys, and crop-planting strategies (planting more vulnerable crops further from the farm edges) which may also have played a part; however, in 75% of raids no human (or canine) deterrence was witnessed.

Finally it’s possible that the number of monkeys in the area could have declined. In earlier years the monkeys were forced into raiding as their forest habitat was converted to farmland; if the monkey population subsequently collapsed (suggested by a decrease in the number of troops in the area), then there will be fewer monkeys in the area to raid. Only one troop in the area is habituated and that troop has declined in population size by 50% during the study, due in the main to a poisoning event by the local farmers.

Currently the levels of tolerance of the Buton macaque in this area are relatively high and there is some level of slightly uneasy co-existence going on. It’s therefore vital that we try to manage this situation before it escalates to a conflict situation.

Baird's tapir is the largest mammal in the Neotropics, but sightings generally prove elusive

A range of monitoring techniques, including non-invasive genetics, have been employed in a study on Baird’s tapir in Honduras, which has shown that the species will be locally extinct within a few years without prompt intervention. It is hoped that this study could provide a model for other projects by demonstrating how accurate scientific data, rigorously gathered using a range of techniques, is able to impact upon the conservation of an endangered species by informing management policies.

Studying an animal that you will never see presents special challenges, and requires inventive approaches to gathering information on aspects of natural history and demography that can normally be directly observed.

New approaches based on statistical modelling and non-invasive genetics allow for much more detailed questions to be answered than would be possible through traditional non-invasive approaches such as camera trapping and telemetry.

Population decline

Baird’s tapir (Tapirus bairdii) is the largest mammal in the Neotropics; it is also one of the most endangered, with a global population estimated at around 5,000, which is known to be declining at an alarming rate across its range from southern Mexico to northern Ecuador. A study funded in part by Operation Wallacea is looking at the conservation of Baird’s tapir in Honduras, and in particular in Cusuco National Park (PNC).

Using patch occupancy analysis statistical techniques, it has been possible to map the changes in patterns of Baird’s tapir dispersal over time, and to monitor and quantify a drastic population decline during this period

Research to date has highlighted the severity of the conservation situation for Baird’s tapir in PNC. Since 2006, surveys have recorded all encounters with tapir spoor (sightings, dung, footprints or signs of foraging) along a network of transects over 47 km in length.

Using patch occupancy analysis statistical techniques, it has been possible to map the changes in patterns of Baird’s tapir dispersal over time, and to monitor and quantify a drastic population decline during this period, which has coincided with an increase in human activity, deforestation and hunting in the park.

Non-invasive genetics

Genetic techniques are also being incorporated into this study, as genetic material can easily be derived through the amplification of DNA from faeces.

This technique was developed in the 1990s for work on grizzly bears, and is now the modus operandi for genetic work on animals too difficult – or too rare – to catch for tissue sampling.

Captured on camera trap

Faeces are being sought from all over PNC in an effort to sample as large a proportion of the population as possible. Using a genetic equivalent of ‘capture, mark, recapture’, it is possible to census the population and investigate genetic diversity, inbreeding rates and dispersal mechanisms.

The genetic health of the PNC population can be compared to that of a non-impacted population sampled in the east of Honduras; and population genetic considerations incorporated into future management strategies for the PNC population.

Informing management policies

The suite of monitoring techniques available to scientists today enables detailed studies to be carried out on even the most elusive species. Information derived from this study is already being used to inform local policy makers that without the implementation of appropriate conservation practices the population of Baird’s tapir in PNC will go extinct in the next few years.

New approaches are giving us a concrete picture of the plight of Baird’s tapir in PNC, and are enabling us to make scientifically-informed recommendations for their conservation. Hopefully these approaches will gain currency in conservation biology as a whole as we struggle to devise the most effective possible method of implementing management policies for endangered species.