The white-eye populations from all four major islands are morphologically distinct from each of their neighbours

Recent work on bird populations on the Wakatobi archipelago has revealed that many smaller bird species are morphologically and genetically distinct from their mainland relatives. The outcome of this work could be that the Wakatobi islands qualify for Important Bird Area status.

Since 1999, we have been making occasional visits to islands in the south-eastern corner of Sulawesi, initially under an MOU between Trinity College Dublin and the Wakatobi Regency and with support from Haluoleo University in Kendari and more recently as part of the Bogor Agricultural University (IPB Bogor) and University of Hull research programme covering the islands of SE Sulawesi.

We have been focussing our investigations on the bird populations there, and have been mist-netting birds during these visits. This has provided us with a wealth of morphological data (over 1900 individuals) from more than 60 bird species caught on 12 different islands (including Buton, Kabaena, mainland Sulawesi).

After the status of the new species is confirmed, the Wakatobi islands will be able to lay claim to at least three endemic bird species

Sample recordings were made on each island, near the netting sites. This has allowed us to embark on phylogenetic analyses of the local bird populations to complement our morphological studies. The genetic studies are rewriting the textbooks: there are manuscripts in preparation to describe three new bird species from the Wakatobi islands (Wangi-wangi, Kaledupa, Tomia and Binongko, as well as Hoga).

Smaller bird species on Wakatobi

There are consistently different patterns between Buton/Sulawesi populations and Wakatobi populations that demonstrate a lack of mixing. This lack of mixing leads to reproductive isolation of the Wakatobi populations from the mainland and justifies their separation as full species.

In addition, a new, endemic resident species on Wangi-wangi was discovered in 2003. This new species has yet to be formally identified or named, as currently, no specimens exist in any museums. After the status of the new species is confirmed, the Wakatobi islands will be able to lay claim to at least three endemic bird species. That will qualify the Wakatobi islands for Important Bird Area (IBA) status under BirdLife International criteria, assuming all of the endemic bird species are considered to be “vulnerable” or “endangered”. If that does happen, the Wakatobi islands will instantly become Sulawesi’s most important IBA.

Differences between islands

While taxonomic categorisation is an essential aspect of any study, it is usually just the beginning. This has proven to be the case in the Wakatobi islands too. Once visits had been made to each of the four major islands on the Wakatobi, it became clear that each of the islands supported different numbers of the various species.

Even some satellite islands of the major islands differed in terms of the number of species present, and their relative abundance. These differences can provide insights into evolutionary processes and the types of barriers that isolate populations. For example, Wangi-wangi’s endemic white-eye (currently without an official name) occurs only on the island of Wangi-wangi, despite there being two satellite islands within 1km of the shore of that island.

Wakatobi Flowerpecker

By contrast, the Wakatobi-wide white-eye (due to be renamed in 2013) occurs on Wangi-wangi and its satellite islands. The beak shape of the Wakatobi-wide white-eye differs between Wangi-wangi and the satellite island of Oroho. This difference is due to competition for food between the two white-eye species on Wangi-wangi and is an example of character displacement.

In addition to such examples of localised competition, there is evidence of much wider scale effects on some of the bird populations across the archipelago. The white-eye populations from all four major islands are morphologically distinct from each of their neighbours. While these differences are ultimately the result of competition, it appears that the driving force behind them is human impact on the islands. That means human influences may be accelerating evolution! That would be a truly remarkable discovery.

Similar investigations (including studies on the Galapagos islands) have only shown human influence to slow the processes that lead to speciation. The work to date serves to highlight the possibilities for study within the terrestrial habitats of the Wakatobi and demonstrate the archipelago’s potential as a living laboratory.

The Wakatobi is just one archipelago within the 17,000 islands of Indonesia and there are other islands in south-eastern Sulawesi that still have poorly documented avifaunas. While ornithologists added 71 new species to Indonesia’s bird list between 1992 and 2007 (Indonesian Bird Checklist no. 2), it looks like there are still a few more to find.

The east coast of Africa is an important marine region that provides subsistence and economic resources to over 22 million people in Kenya, Tanzania and Mozambique

An ambitious project to collect data on the reef fish community structure along the whole of East Africa’s coast aims to provide a baseline understanding to underpin and inform future conservation efforts.

There is a global push for networks of marine protected areas (MPAs) as one ecosystem based mechanism of protecting marine biodiversity, reducing the impacts of overfishing, and to mitigate the effects of climate change. Early marine protected areas were placed largely in response to social or political pressures or knowledge of areas of high biodiversity or habitat complexity.

More recently, biological considerations have played a greater role, and systematic planning tools are frequently used to plan MPA networks (eg Great Barrier Reef Marine Park). Nonetheless, MPAs are generally a local-scale management tool irrespective of the conservation goal (an increase in biodiversity, biomass, fisheries via spill-over etc).

With the call to develop global, or continental scale networks of marine protected areas, very little consideration has been given to understanding the patterns and dynamics of communities at these large scales. However, it is the influence of biogeography and evolution and large-scale physical processes such as temperature and currents that determine species ranges, distribution, and abundance that essentially dictate the composition and structure of communities at local scales.

Given this, building a baseline understanding of the structure of communities along continental margins should be the first priority in pursuing large-scale networks of marine protected areas. Otherwise, for example, without these data, MPAs may fail to offer protection for restricted-range endemic species, or to protect areas of high biomass and low fishing effort that may offer some of the last refuges of spawning stock to prevent fisheries from collapsing.

East Africa

Underwater stereo-video cameras are being used to collect data on diversity, abundance and size-structure of reef fishes that are unbiased and free of observer bias

The east coast of Africa is an important marine region that provides subsistence and economic resources to over 22 million people in Kenya, Tanzania and Mozambique. Here, reef fish resources are an important component of the economy and subsistence, and over the last 20 years some sites have shown a 40 % decline in reef fish resources. Yet the ecology of these reef fish communities along this coast are some of the least understood in the world, despite being some of the richest.

Governments have shown the foresight to protect marine biodiversity and conserve fisheries resources for future generations by establishing MPAs throughout the region, although improvements in management and the size and number of MPAs are needed.

To facilitate future MPA planning to protect reef fish resources, and to assess how current MPAs are performing in the context of a continental network, large-scale data on reef fish community dynamics and structure is required.

A multi-, large-scale approach is required for two reasons: 1) There are natural trends in the structure of marine fish assemblages along coastal/ latitudinal gradients; 2) the history and pattern of human exploitation of coastal resources will differ within and between national boundaries.

Therefore, the goals of the research are to collect rigorous and unbiased data on reef fish community structure (abundance, diversity, size structure and biomass) along the entire east coast of Africa, focusing on multi-scale sampling régime that surveys reefs at regular intervals (100-200km, guided by satellite imagery from www.asclme.org, and local knowledge) and both inside and outside MPAs.

This will provide the means to comprehensively assess the status of these resources and human impacts and provide a basis for establishing an understanding influence of climate change along this coast. This cannot be achieved with the current knowledge base, or sampling programmes that are in place.

Collecting data

We are using underwater stereo-video to collect data on diversity, abundance and size-structure of reef fishes that are unbiased and free of observer bias. These data are collected using scuba divers to collect twelve 25 m transects that are stratified by depth to a maximum depth of 25 m. At each sampling site benthic photoquadrats (for % cover) is also collected simultaneously. And the survey design is based around a hierarchical design of multiple sites nested within locations at each point along the coast.

The proposed sampling region will cover ~27^o of latitude and will be expected to show significant variation in fish abundance patterns and species composition over this range driven by latitudinal temperate profiles, coastal geomorphology, biogeography and anthropogenic influences.

This variation will be enhanced by the action of the southwards flowing Agulhas current which will have the effect of extending the range of tropical species into the southern regions of the latitudinal gradient.

Importantly, capturing the range boundaries of tropical and endemic species, the location of such range boundaries and understanding the role of temperature in their determination will be an important aspect of the future response of coastal fish species to fishing pressure and climatic shifts.

The resultant database will provide a means to not only assess MPA performance and design, but can also be interrogated for biogeographic studies, and provide local and national governments with tools for planning at a local and national scale. These data sets are extremely rare or non-existent in marine conservation, and such data will be an invaluable resource.

To help ensure that population density estimates were representative of actual densities, we radio-tracked 28 Trioceros deremensis and determined that they spend approximately ¼ of their time too high in the canopy for us to see in our surveys. We adjusted density estimates for species with similar habitat use to T. deremensis accordingly

Research into chameleons’ sensitivity to landscape alteration in East Africa shows that species vary in their response. Some species increase in population density as a result of habitat fragmentation, partially counteracting the population decline from habitat loss.

The Eastern Arc Mountains (EAM) of Tanzania and Kenya are a chain of 13 forested mountain blocks sometimes referred to as the ‘Galapagos of Africa’ due to their remarkable biodiversity and endemism. This is particularly true of the EAM herpetofauna, which includes at least 99 endemic or near endemic amphibians and reptiles. While one third of amphibians are endangered, only a handful of the reptiles have been assessed (~13%) and half of these are critically endangered or endangered.

Most of these taxa are closed-forest specialists, which is a concern given that the EAM have lost ~80% of their historical forest, and the remaining forest is highly fragmented. This land use change is a central cause of decline for many of these species. However, our recent work in the East Usambara Mountains, supported by the National Geographic Society and the US Fulbright Fellowship program, highlights that species likely vary in their sensitivity to this threat.

Transect surveys

To assess species’ responses to habitat change, we surveyed chameleons in one of the EAM blocks, the East Usambara Mountains. As one may suspect, locating chameleons in a rainforest poses a challenge. Rather than attempting to locate every individual in an area (an impossible task!) we used distance-based transect surveys that allow for the estimation of detection probability. In this way we could get accurate estimates of population densities quantitatively accounting for the chameleons we could not see.

Although locally abundant in undisturbed habitat, Rhampholeon temporalis (above) respond negatively to habitat fragmentation. Conversely, Kinyongia vosseleri (below) do well in small, disturbed forest fragments, and may benefit from increasing habitat fragmentation. Both species are collected for the pet trade, but neither has been assessed for the IUCN Red List

For one of the larger species we also used radio telemetry to account for the time that they spent high in the forest canopy where we could not see them. We repeated these surveys across a landscape that has been heavily fragmented by logging, tea plantations, and small-scale agriculture. In total, we estimated densities of three species of chameleon in 12 forest fragments that varied in size, shape, and isolation.

Responding to deforestation

An important step in determining species’ sensitivity to landscape alteration is to quantify their responses to particular aspects of landscape alteration. In this case, chameleon densities respond to a change in forest fragment area. This relationship can compound, or alleviate, the effect of habitat loss on a species. If a species requires large blocks of forest to maintain healthy populations, their population density is likely to decrease in small habitat patches. Conversely, if a species prefers edge habitat to the forest interior, their density is likely to increase in small forest fragments. In both of these cases, the configuration of the remaining habitat is very important.

For the three species we examined, one shows a strong negative response to decreasing fragment area, one shows a weak negative response, and one shows a weak positive response – it actually has higher population density in small fragments.

Estimating declines of total population

While understanding how species respond to landscape configuration is interesting in its own right, it also provides a tool to estimate regional-level declines (or increases) that have resulted from recent land use change. To do this, we developed GIS maps of forest cover for the East Usambara Mountains – a large proportion of these three species’ ranges. This allowed us to quantify how much forest cover has been lost and also how the remaining forest cover is distributed – ie how big each remaining forest fragment is.

Using the relationships we had established between forest fragment size and chameleon densities, we estimated the entire population size in the East Usambara Mountains for each of the three species and compared that estimate to the expected population size if no deforestation had occurred.

For each species, we extrapolated population densities across the East Usambara Mountains of Tanzania. This map shows the estimated density of Rhampholeon temporalis for a portion of the landscape. Fragments surveyed for chameleon density are outlined in black

All species experienced an overall population decline driven by high levels of deforestation. However, Rhampholeon temporalis and Trioceros deremensis’ estimated declines (over 50% from historic levels) are magnified by their sensitivity to fragmentation effects beyond simple habitat loss. Conversely, Kinyongia vosseleri, which responds positively to small forest fragments, has likely declined less than one third from historical levels – less than would be expected from deforestation.

Although developing these population models for each individual species provides valuable information for conservation and management, they are also labour and resource intensive. If we are able to predict how species will respond to habitat alteration, conservation efforts can be concentrated on the most vulnerable species.

With support from the Mohammed bin Zayed Species Conservation Fund, our next step is to expand upon our study of chameleons in the East Usambaras to look more broadly across taxa and mountain blocks to examine the degree to which differences in species’ traits can explain variation in response to habitat change. Hopefully these efforts will yield a valuable conservation tool as well as ecological insights into how species’ traits influence their interactions with the landscape.

Species like C. splendens have been used to formulate a range of new biotic indices responding to acidification, flow velocity, siltation, morphology and salinity or reflecting community conservation importance

Macro-invertebrates – animals without backbones that can be seen with the naked eye – have been widely used for many years to assess environmental condition. In many ways macro-invertebrates are ideal bio indicators, as they are relatively straightforward to identify; they are reasonably long lived, enabling conditions to be retrospectively assessed; they are relatively sedentary, allowing the determination of spatial impacts/events; and, perhaps most important of all, they exhibit a range of responses to different pressures. Mayflies, for example, are generally very sensitive to poor water quality whereas most leeches are not. Macro-invertebrates, in effect, integrate effects on their environments throughout their lifetimes.

Although individual species have specific tolerance ranges and habitat requirements, a much more robust way of summarising environmental health is to look at the combined response of the whole community. This can be done in a number of ways, but one of the most useful and informative approaches involves the calculation of biotic indices.

Biotic indices

Biotic indices (or metrics, as they are increasingly being called) all work in the same fundamental way – individual species, genera or families (taxa) in a sample are scored according to their sensitivity or tolerance to the pressure the index is designed to detect. These scores are then combined to produce a single number or letter which can be used to infer and interpret the current state of the environment. Some indices are simple, just using the presence or absence of taxa in their formulation. Others are more sophisticated and additionally consider the abundance of different members of the community. This latter approach is generally better, as it enables the detection of more subtle environmental pressure gradients.

Biotic indices have been developed for a number of different target groups, including higher plants, algae, protozoa, and fish, but methods based on macro-invertebrates are by far the most common and widely used.

A much fuller understanding of ecological response and the controls and pressures acting on aquatic organisms becomes possible

Early invertebrate indices focused exclusively on water quality, as this was the prevailing pressure affecting rivers through much of the 20^th century. As early as 1902, Kolkwitz and Marrson developed the Saprobian system designed to detect organic pollution in Europe and this was followed by an increasing number of methods designed for local application. Water quality indices developed for use in the UK for example included the Trent Biotic Index, the Chandler Score and the Biological Monitoring Working Party (BMWP) score. Some of these methods are still in use today.

Additional pressures

While some river pollution problems persist, there has been a general improvement in water quality over the last three decades and this has led to the gradual recognition of other pressures affecting aquatic ecosystems. Aquatic macro-invertebrates are also very capable of detecting these additional pressures.

The presence of the damselfly larva Calopteryx splendens for example, indicates reasonably clean water, but what else can the occurrence of this species tell us? The answer is quite a lot. The species requires slow flowing water and a muddy bottom, so its presence will indicate slack flows and a silted river bed. It is also intolerant of acidification and raised salinity. The presence of emergent/floating vegetation and open meadows nearby will also be indicated, as these are needed for adults to display and feed. Species like C. splendens have now been used (along with other colonising invertebrates) to formulate a range of new biotic indices responding to acidification, flow velocity, siltation, morphology and salinity or reflecting community conservation importance.

A multiplicity of information consequently becomes available from a single invertebrate sample taken from a river and if this is considered alongside supporting data such as flow rates and habitat structure, then a much fuller understanding of ecological response and the controls and pressures acting on aquatic organisms becomes possible.

Furthermore, the calculation of new biotic indices has enabled an appreciation that responses to pressures are not simple, but are mediated by habitat structure. It can, for example, be shown that invertebrate communities living in physically modified rivers, are far less resilient and self-sustaining when subject to droughts and floods than populations colonising more natural rivers and streams.

A good summary of biological indicator methods can be found in: Conservation Monitoring in Freshwater Habitats (Editors Hurford, Schneider and Cowx) Springer 2010. ISBN 978-1-4020-9277-0, although some of the newer indices are not included in this overview.

In developing countries, direct incentives are increasingly perceived as the best solution to biodiversity loss as they reward individuals engaging in conservation-oriented activities quickly, tangibly and proportionately

The question of how to maximise the effectiveness of conservation programmes has been fundamental to conservation policy for decades. From the ‘fences and fines’ approach typified by early national parks to the ‘inclusive’ approach of community-based resource management, the debate continues as to how each conservation dollar (or, equally importantly, yen or rupee) is best spent.

Contemporary approaches which aim to ensure a financial return for individuals and communities engaging in conservation practices give rise to the question of whether we can put the right price on conservation.

Exclusion and enforcement

It is generally acknowledged that the strict exclusion of resource users from national parks does not result in positive conservation outcomes. Even back in the Middle Ages, European kings had to resort to fairly draconian measures to combat wildlife poaching in royal reserves, including offenders being blinded or having various limbs removed – or both. Whilst this may have succeeded in instilling fear amongst the populace, the fact remains that strict exclusion removes access to essential food and water resources, resulting in the perennial problem of enforcing strict no-take reserves.

Alternative approaches have emphasised that enforcement is facilitated when local resource users can accrue benefits from wildlife conservation associated with the development of activities which depend upon maintaining these resources – most commonly ecotourism. The realisation of these ‘indirect incentives’ cannot be guaranteed, however, as they reflect drivers at various scales including, for example, individual capacity to diversify into tourism, the quality of tourist infrastructure nationally and international events which directly impact upon the tourism sector.

Direct incentives

Consequently, recent attention has been directed towards ‘direct incentives’, wherein individuals or communities receive financial payments in return for activities which are compatible with conservation policy. These range from payments to farmers in return for undertaking environmentally friendly agricultural activities within the European Union’s Common Agricultural Policy to proposals under the Kyoto Protocol to pay communities directly for activities resulting in a reduction in deforestation rates – the REDD mechanism.

Putting the ‘right price’ on natural resources is in itself an inexact science yet is fundamental to all direct incentives approaches

In developing countries, direct incentives are increasingly perceived as the best solution to biodiversity loss as they reward individuals engaging in conservation-oriented activities quickly, tangibly and proportionately. All of these are commonly cited as drawbacks associated with the indirect incentives approach and, equally importantly, reflect the urgency associated with combating increasing rates of extinction and environmental degradation.

Economic values

Nevertheless, there are serious issues associated with direct incentives which merit consideration. Whilst there are various means available to put an economic value on natural resources, all involve a degree of subjectivity and are therefore open to debate.

We would all, for example, agree that charismatic or endangered species are particularly worthy of protection. However, how much would we as individuals be prepared to pay for that protection, knowing that we will likely never see a Sumatran tiger in the wild? How much would we be prepared to pay for knowing that future generations may be able to similarly benefit from its existence? These values, termed existence value and bequest value respectively, represent just two components of the total economic value of a natural resource. Consequently, putting the ‘right price’ on natural resources is in itself an inexact science yet is fundamental to all direct incentives approaches.

Secondly, the injection of cash to communities inevitably lends itself to abuse through the ability of local elites to appropriate an unequal share of the money available, which in turn leads to disillusion and resentment within other sections of the user community. This may eventually be manifest as open breaching of the regulations imposed as part of the direct incentives approach, with negative impacts upon the integrity of the resource being protected.

Thirdly, we must question the ability of direct incentives to enable effective conservation in the longer term which is the timescale through which any resource management programme must be effective. What, for instance, would happen if the payments to resource users are reduced? This is of major importance in that many direct incentives programmes are operated by NGOs and the private sector, with clear implications regarding the capacity to maintain payments at an agreed level.

Finally, there is an ethical dimension to this critique in that direct incentives approaches represent the ‘purchase’ of a resource by an entity, most frequently located overseas in a developed country, which previously had been owned or accessed collectively by locally resident resource users. There are clear overtones of colonial-era thinking implicit in such an arrangement which are of relevance if we are seeking to justify conservation policy.

This is not to say that direct incentives are unsuitable – indeed, there are circumstances and examples which demonstrate the opposite. However, we should be wary of assuming that paying off resource users is a viable long term conservation strategy. It remains just one alternative in the range of options designed to combine the needs of resource users and the wider imperatives associated with conserving what remains of our shared environment.

Three species of turtle can regularly be found around the popular tourist destination of Akumal in the Riviera Maya

Rising beach temperatures are posing a new threat to endangered sea turtles. A successful conservation project in Mexico is now looking to widen its scope to monitor ambient temperatures in turtle nests.

All sea turtles in the Caribbean are listed by the IUCN (2012) as endangered (green turtle, Chelonia mydas  and loggerhead turtle, Caretta caretta) or critically endangered (hawksbill turtle, Eretmochelys imbricate, and leatherback turtle, Dermochelys coriacea).

The major threat faced by these turtles is loss of nesting habitat in coastal regions. The increasing popularity of the Mexican Riviera Maya as a tourist destination, and beach erosion (man-made and natural) has drastically reduced the number of suitable nesting sites for the turtles in the Yucatan Peninsula. Moreover, light pollution along the coastline from hotels, bars and restaurants has steadily reduced the number of turtles that come in to nest.

Protecting nesting habitats

Sea turtles repeatedly return to the same beach to nest and provide no neonatal care once the eggs have hatched. Consequently, the characteristics of the nest determine whether the eggs will survive or not.

Placement of nests farther inland increases the likelihood of desiccation, and due to the distance the hatchlings have to travel to reach the sea, there is a greater chance that they will be preyed upon. Conversely, nests close to the sea increases the likelihood of egg loss due to erosion or flooding of the nest.

Nest site preferences of sea turtles therefore involve cost-benefit analyses by the females as they attempt to find the most suitable location to lay their eggs, and thus successful sea turtle conservation projects need to ensure that a wide range of potential nesting habitats are protected.

Three species can regularly be found around the popular tourist destination of Akumal in the Riviera Maya. The Hawksbill Turtle can be found feeding around the coral reefs just offshore and the local beaches are important nesting ground for the Loggerhead Turtle and the Green Turtle.

Although Akumal is also a popular tourist destination, the beaches are managed by a local NGO called Centro Ecológico Akumal. Daily patrols locate turtle nests and place protective barriers around them, and night patrols ensure that nesting turtles are not disturbed by tourists. Local residents have agreed to minimise light pollution by closing all shops, bars and restaurants before 11pm and local fishermen and tour boats abide by ‘no go’ areas in which areas of sea grasses are roped off so that feeding turtles will not be disturbed by boats.

The turtle monitoring team at CEA have also monitored the characteristics and success rates of nest sites in order to gather data on the range of habitats used by the turtles and ensure that they remain protected.

As a result of these efforts, the number of turtle nests and hatchlings are starting to increase over time, making the Akumal turtle project one of the few success stories in turtle conservation (see Figure below).

Climate change threats

However, the sea turtles appear to be facing a new threat in the form of changing beach temperatures caused by climate change. The sex of sea turtle hatchlings is determined by the temperature inside the nest. Embryos develop into males when the temperature is approximately 28°C (82°F), whereas the female embryo develops at approximately 31°C (88°F).

Turtle hatchling

If the temperature inside the nest is between these values, then both male and female turtles are created. If temperatures at Caribbean beaches slowly increase in line with climate change, then this will lead to a serious reduction in male hatchlings.

If these endangered sea turtles are going to survive in the long-term then not only do we need to protect their preferred nesting habitat, we also need to ensure that the potential nest sites have the correct temperature range.

Centro Ecologico Akumal and Operation Wallacea have now broadened the scope of the turtle nest monitoring project to include the placement of data loggers inside the nests in order to record ambient temperature during incubation. These data may then be matched to the nest site characteristics, hatchling success and sex ratios.

The team is currently raising funds to purchase a large number of data loggers to be used for the upcoming nesting season this summer. More information about the project and the option to make a donation are available from the website

Amphibian chytrid fungus has proven to be especially devastating to amphibian populations in Latin America

One of the first programmes to protect amphibian populations from extinction in the wild caused by disease is being set up in Honduras. The new rescue facility will treat infected tadpoles and froglets, raise them to adulthood, and then reintroduce the healthy adults back into their environment.

The endangered amphibians of Honduras are experiencing a storm of assaults from habitat destruction, climate change, and emerging infectious diseases. A growing number of species face an uncertain future unless ex situ management efforts are soon implemented to ensure long-term survival.

Since 2004, Operation Wallacea has been studying the amphibians of Cusuco National Park, Honduras (CNP), a small cloudforest where 16 endangered and critically endangered amphibian species can be found.

In recent years, Opwall surveys have indicated an overall decline in the presence of stream-associated amphibians and concurrent disease surveys reveal that many of these species carry a high level of infection with amphibian chytrid fungus. Chytrid fungus causes chytridiomycosis, an emerging disease bringing about global amphibian declines and extinctions and jeopardizing ecosystem stability.

Amphibian chytrid fungus has proven to be especially devastating to amphibian populations in Latin America, but the amphibians of Honduras have received little applied conservation attention.

Rescue and conservation

In response, plans are now underway to establish the Honduran Amphibian Rescue and Conservation Center. This facility and long-term programme is designed to ensure the survival of three Critically Endangered species in CNP: Plectrohyla dasypus, Plectrohyla exquisita, and Duellmanohyla soralia. Already threatened by illegal deforestation, amphibian chytrid fungus is further impacting each of these species by shrinking populations and pushing them closer towards extinction.

The foundation of this rescue effort is to annually supplement wild adult populations by collecting tadpoles and froglets from CNP, treating them for chytrid infection and raising them in a protected biosecure environment, and then reintroducing healthy adults back into CNP.

Long-term data previously collected in CNP suggests that the adult frogs possess a stronger resistance to chytrid than their younger counterparts and are more likely to survive infection in the wild. By increasing the number of breeding adults present in the wild, we will also promote an increase the volume of offspring produced. Although these offspring will still be vulnerable to chytrid, the sheer increase in volume is expected to result in the survival of a greater number of offspring in their natural habitats. This is because despite the high chytrid infection prevalence at metamorphosis, a small portion of the population appears to consistently escape the disease and has an opportunity to become future breeding adults. Simply raising the number of frogs in the overall population should proportionally increase the number of frogs in the group of “lucky” survivors and eventually, may reach self-sustaining levels that can reverse population declines on their own.

Meanwhile, a small number of adults will be retained to establish captive breeding populations to ensure the long-term survival of these three species in the event of sudden population crashes or extinctions, which remain highly likely at present. The proposed research centre will be located at Lancetilla Botanical Garden and Research Institute, in Tela, Honduras, where biosecure Isolated Amphibian Rooms will be constructed to maintain up to 600 amphibians in a chytrid-free environment.

Ecological roles

This programme will provide one of the first examples whereby amphibian populations are protected from disease-driven extinction in the wild caused by chytrid fungus, and not just protected in captivity. This is a critical aspect often overlooked; maintaining captive breeding programmes can prevent complete extinction of a species, but without active reintroduction efforts, individuals become permanently absent from natural habitats where they played important ecological roles.

The adult frogs are less affected by chytrid than their younger counterparts and can survive infection in the wild

Adult and larval amphibians provide a significant source of prey for other wildlife species in tropical ecosystems. In CNP, a number of snake species feed on amphibians, most notably the Palm viper (Bothriechis marchi) which has a specialised diet of frogs. This species is now believed to be in decline in response to the lower abundance of amphibian prey. The activity and feeding behaviour of larval amphibians has also been shown to affect aquatic ecosystem structure; their disappearance is likely to promote algal blooms, reduce aquatic invertebrate diversity, and reduce water quality. Therefore, this conservation programme also aims to publicise the need to protect not only the amphibians, but also the ecosystem services and balance they provide.

This programme is made possible by an international collaboration I have orchestrated between Jonathan Kolby and Operation Wallacea, Lancetilla Botanical Garden in Honduras, the Henry Doorly Zoo, Expediciones y Servicios Ambientales de Cusuco (ESAC) and Departamento de Vida Silvestre del Instituto Nacional de Conservacion y Desarollo Forestal Areas protegidas y Vida Silvestre (ICF). In 2013, activities will include construction of the biosecure amphibian husbandry rooms at Lancetilla, promotion of local capacity-building and training local Honduran staff, and the continuation of disease surveillance and population surveys in CNP.

Long-term funding to operate this research centre is actively being pursued so that the first collection of wild amphibians can occur in June 2014 with reintroduction targeted for the following year. For more information about this programme or for future opportunities to become involved in this project, please contact Jonathan Kolby (Jonathan.Kolby@my.jcu.edu.au).