Australian Museum blog series

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In April 2016, Professor Tim Flannery and the Australian Museum secured project funding for multiple expeditions to the Solomon Islands. The aim was to increase understanding of the mammalian biodiversity in these tropical islands, combining both current scientific methods and traditional local community knowledge to do so.

As the inaugural recipient of the Australian Museum Research Institute’s Expedition Fellowship for 2015/16, I spent much of 2016 in the field leading the expeditions to Malaita, Bougainville and Guadalcanal Islands.

The Australian Museum has now aggregated content (videos and blogs) from these expeditions into a single site here.

Links to individual blogs and videos produced in 2016 are also provided below.

BLOGS

Malaita’s Monster Rat – 6 DECEMBER 2016

Kainake and the kamare: Hot on the trail of Bougainville’s giant rats – 21 OCTOBER 2016

A view of Malaita from the clouds – 13 SEPTEMBER 2016

Through village gardens and into the mist – 9 AUGUST 2016

Welkam to Honiara – 11 JULY 2016

Walking in the footsteps of giants – 20 MAY 2016

Our current knowledge of the endemic mammals of the Solomon Islands Archipelago – 18 APRIL 2016

VIDEOS

AM Expedition: Solomon Islands, chapter 1, introduction to the project – JULY 2016

AM Expedition: Solomon Islands, chapter 2, introduction to Tyrone Lavery – AUGUST 2016

Solomon Islands Forest Life: information on biology & management of forest resources

SIFL_CoverSolomon Islands Forest Life is a terrestrial ecology and conservation textbook for secondary school students in the Solomon Islands. The book gives an overview of the terrestrial environments of Solomon Islands, their ecology, important species, and some of the key threats they face.

Chapters are:

  • Introduction to Environments
  • Flora (algae, bryophytes, ferns, gymnosperms, flowering plants)
  • Fungi
  • Fauna (invertebrates, freshwater fish, amphibians, reptiles, mammals, birds)
  • Critical Issues (forest resource management, deforestation, plastic and pollution, invasive species, climate change)
  • Guide to common forest life of Solomon Islands (species descriptions)
  • Glossary

All sections are lavishly illustrated with high quality photographs and graphics and can be downloaded and distributed freely from the following links:

Solomon Islands Forest Life – low resolution file download (17MB)

Solomon Islands Forest Life – high resolution file download (123MB)

The Solomon Islands are one of the most biologically rich archipelagos on earth. Huge proportions of the animals and plants found there are endemic, meaning they are found nowhere else on earth. These species are closely linked to the culture, livelihoods and well-being of people.

Commercial logging, mining and a fast rate of population growth threaten the forests of Solomon Islands and are placing increasing pressure on natural resources. This book aims to complement the already deep understanding of the terrestrial environment by Solomon Islanders, allowing them to learn more and assist them in understanding how to manage new threats.

SIML_coverSolomon Islands Forest Life and its companion Solomon Islands Marine Life, together provide a unique resource on the extraordinary natural world of the Solomon Islands.

Solomon Islands Marine Life was published in 2013 by Simon Albert, Ian Tibbetts and James Udy.

Chapters are:

  • Introduction to marine life
  • Marine plants (seagrass, marine algae, mangroves)
  • Marine invertebrates
  • Marine vertebrates (fish, turtles, sharks)
  • Critical issues (water quality, climate changes, marine resource management)
  • Guide to  marine life of Solomon Islands

It can also  be downloaded and distributed freely from the following links:

Solomon Islands Marine Life – low resolution file download (13.5MB)

Solomon Islands Marine Life – high resolution file download (194MB)

Please consider donating via this link to support printing and free distribution of Solomon Islands Forest Life to Solomon Islands schools. The cost of printing one copy is AUD$15.

Publication of this book would not have been possible without the contributions of Simon Albert , David Boseto, Tammy Davies , John Fasi, Corzzierrah Posala, Jonathan Richmond, John Schenk, Brian Weeks and Claudia Blomberg (review).

Tyrone Lavery, Patrick Pikacha and Diana Fisher (The University of Queensland, Brisbane, ISBN: 978-1-74272-157-6)

The Critical Ecosystem Partnership Fund is a joint initiative of l’Agence Française de Développement, Conservation International, the European Union, the Global Environment Facility, the Government of Japan, the MacArthur Foundation and the World Bank. A fundamental goal is to ensure civil society is engaged in biodiversity conservation.

Extinction of another Australian mammal? Bramble Cay Melomys (Melomys rubicola)

The Bramble Cay Melomys (Melomys rubicola) had one of the most unusual and precarious distributions of all Australian mammals. As far as we know, the only place it occurred was  a tiny 4-5 hectare coral cay in the eastern Torres Strait, off the tip of northern Australia.

bramble copyJust how the species became isolated on such a remote coral cay remains a mystery. Given its close relatedness to Australian melomys, it’s been suggested it is a result of stranding by rising sea levels as ice melted following the Last Glacial Maximum. Surveys of adjacent inhabited Torres Strait islands have failed to detect Bramble Cay melomys, instead finding that the grassland melomys (Melomys burtoni) is a much more widespread species in the region.

Bramblecay

Bramble Cay, the only known location for Melomys rubicola

The remoteness of the cay, has meant that research targeted toward Bramble Cay melomys has been very limited. However, the few surveys and anecdotal reports that could be gathered suggested it was a species in decline. In an effort to prevent its loss from the cay, a recovery plan was prepared in 2008. The main recommendations of this plan were:

  1. Establish a Bramble Cay melomys monitoring program;
  2. Clarify the extent of and manage threats to the Bramble Cay melomys;
  3. Clarify taxonomy of Bramble Cay melomys in relation to PNG species;
  4. Facilitate community participation and education in Bramble Cay melomys recovery; and
  5. Manage the recovery program.

As far as we can tell, none of these recommendations were acted upon. It was not until 2011 that our research group (care of assistance from TSRA) was able to visit the cay specifically to provide an update on the status of Melomys rubicola. By this time it seems it was too late. The survey then, and on another two subsequent visits to the cay have failed to detect any sign of the melomys.

Given the small size of the cay and lack of vegetation, from this we can confidently affirm that Bramble Cay melomys is extinct from the only known part of its distribution.It appears that the extinction was caused by a combination of rising sea levels and storm surge events. Extinction of Bramble Cay melomys may therefore be the first mammal extinction caused by climate change.

In the Torres Strait, sea levels (measured at Goods Island) have been steadily rising over the past 15 years (Figure A below).

 

Screen Shot 2016-06-03 at 12.06.06 PMIn 2009 the rising seas were punctuated by a significant storm surge event that pushed sea levels up to 0.94 metres above predicted levels (Figure B).

Screen Shot 2016-06-03 at 12.06.27 PM.pngInundation of the cay by high sea levels likely had dire consequences for cay’s vegetation, and in turn the melomys. Comparisons of historical photographs show that there has been significant decline in the extent and quality of vegetation on the island – the melomys’ only food source. Debris found spread across the island provide evidence this vegetation decline has been the result of inundation by salt water.

There will be many that will argue the investment required to save this species from its apparent extinction is better spent on other species. Melomys rubicola was restricted to a single cay and was therefore unlikely to have major importance for the functioning of ecosystems or the survival of other species. However, given our country already holds the world’s worst extinction record for mammals – do we really have the right to pick and choose which of the remaining species we conserve?

 

 

 

Biogeography of mammals in the Solomon Islands and Papua New Guinea

The thousands of islands that span the southwest Pacific provide one of the world’s most valuable natural laboratories. Northern Melanesia’s islands are particularly useful. The Solomon, Bismarck, Trobriand, Admiralty and D’Entrecasteaux archipelagos are biologically diverse, and they are also relatively undisturbed with very few species extinctions having occurred.

BirdsofNor_0Across Northern Melanesia there are ‘snapshots’ of speciation visible in birds. Small differences in the plumage of species on adjacent islands signify speciation in action. By studying these visible stages of evolution, researchers like Ernst Mayr and Jared Diamond developed some of the most influential theories of biogeography and evolution.

Much of their collaborative work is compiled in the The birds of Northern Melanesia: speciation, ecology and biogeography. Within this book, Mayr and Diamond addressed important questions such as why some species diversify faster than others, and whether former land bridges are influential on island species richness. They also illuminated broad patterns of species diversity, endemism, and the influences of oceanic barriers between islands. Effectively, Mayr and Diamond established Northern Melanesian birds as a model system for speciation, against which other groups of animals or plants can be compared. The colour plates and species lists they provided formed a rich database immensely valuable to other researchers.

In comparison with birds, northern Melanesia’s mammals have been rarely studied. Although species lists for many islands (e.g. New Britain and Solomon Islands) are improving, many islands (large and small) still remain to be surveyed by mammalogists. Because of the lack of survey data, there have been no attempts to analyse biogeographic patterns in mammals in a way similar to the analyses performed by Mayr and Diamond. In our most recent paper published in Mammal Review, using compiled species lists for 75 of Northern Melanesia’s islands and a range of analyses, we do exactly this.

spiny_rat

We used the published literature, museum databases and my own survey data to develop mammal species lists for 75 islands from the Solomon, Bismarck, Trobriand, Admiralty and D’Entrecasteaux archipelagos. We then used direct comparisons of family compositions, and Ochiai and endemism indices to compare mammal assemblages between island groups and a defined New Guinea source pool region. Generalised linear models and non-parametric multivariate analyses were used to identify, and rank, the importance of island variables for mammalian species richness.

Island size proved to be the island attribute most influential on mammal species richness. Among the smaller islands below 200km² in size, their level of geographic isolation became a more influential factor. When we analysed the data on bats independently, island size was again the most important factor. However, for all other mammals (rats and marsupials) the distance of the island from New Guinea was most important in determining how many species were present. This reflects the fact that these mammals do not have the abilities of bats to cross oceanic barriers.

When we examined the numbers of endemic species on different islands and archipelagos, Solomon Islands stood out as a region with a very high proportion of endemics. This is because there have been small radiations of unique genera of mammals in this archipelago. The monkey-faced bats (Pteralopex – 5 species) and Solomon giant rats (Solomys – 4 species) that are both unique to Solomon Islands contribute a large part of this endemism.

endemism

Endemism indices were calculated for islands and island groups using a modified version of the method employed for birds by Ernst Mayr and Jared Diamond. Higher values indicate a greater proportion of endemic species.

Our results also revealed some islands that are in need of survey focus because their mammal inventories were much lower than expected for their size. We suggest that large islands should remain the focus for future surveys and particularly the higher altitudes of large islands.

By defining biogeographic groups and island clusters with high endemism, we have offered a useful starting point for mammalian conservation strategies in Northern Melanesia. The large number of islands within Northern Melanesia offers many options for conservation of the region’s mammals. It is clear that more surveys and taxonomic research will help to further develop these types of analyses and potentially highlight subtle differences in nearby islands that will be important for conservation of Melanesia’s extraordinary mammals.

 

Discovery of New Georgia monkey-faced bat (Pteralopex taki) on Kolombangara Island – previously thought extinct

Tyrone Lavery & Diana Fisher

The New Georgia monkey-faced bat (Pteralopex taki) is a fascinating species of flying-fox endemic to the New Georgia group of islands, in the Western Province, Solomon Islands. The genus Pteralopex is itself unique to the Solomon Islands with all five known species being listed as either Endangered or Critically Endangered under the IUCN RedList.

In 1992, Diana Fisher and Liz Tasker traveled to Vangunu and New Georgia to study the ecology of P. taki (a then undescribed species). At the time of their study, New Georgia monkey-faced bats were not known to occur on Kolombangara Island. Being a large island, connected to New Georgia during the last ice age, it was reasonable to assume the species should also occur on Kolombangara. Hence, Diana and Liz surveyed two sites – Vanga (a vocational school on the north west coastline) and a site inland from Hunda and Kena villages on the western coastline.

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The impressive volcano shaped Kolombangara Island as seen from Gizo Island

Despite their best efforts, the two researchers were unable to capture any monkey-faced bats on Kolombangara. They interviewed local informants who told them that indeed the species had once occurred there. However, they also relayed that the species had now become extinct. Kolombangara was extensively logged by Levers Plantations from the 1960s onwards, with much of the original lowland forest subsequently replaced by forestry timbers. Locals suggested that this loss of all primary lowland forest below 400m altitude had also effectively wiped out the New Georgia monkey-faced bat from the island.

In February 2015, as part of a project to resurvey Diana and Liz’s 1992 field sites, I was lucky enough to visit the Vanga and Hunda/Kena sites on Kolombangara. This time I was joined by two rangers from the Kolombangara Island Biodiversity Conservation Association (KIBCA). Vanga is the site of a vocational school that provides training in agriculture, mechanics and carpentry to students from right across the Solomon Islands, from Shortland Islands all the way to Temotu. Upon arrival at the school, we were told that Diana and Liz’s 1992 survey site was adjacent to the model garden, where students learn agricultural techniques. We were shown a nice place to camp and offered the use of a corrugated iron kitchen maintained by five boys from Shortland Islands.

IMG_1206

Our comfortable lodgings for a week long survey in the ‘model garden’ of Vanga vocational school, Kolombangara Island

We set about finding a suitable location for our nets and immediately identified a semi-cleared ‘flyway’ at the interface of the garden and forest that would offer a nice place to net for flying-foxes. Being careful not to trample the swamp taro that had been planted in our chosen site, we set about suspending our nets on ropes from trees that were positioned either side of the natural gap in the canopy.

Lowland forest at Vanga School relentlessly intrudes upon the model garden and requires constant maintenance by students. This interface between the garden forest proved an ideal location to capture monkey-faced bats

The lowland forest at Vanga School relentlessly encroaches upon the pineapple and cassava crops and requires constant maintenance by students. This interface between the garden and forest proved an ideal location to capture monkey-faced bats

Our first check of the nets was a little disappointing – only two captures and both species that are commonly captured in mist nets in Solomon Islands (bare-backed fruit bat – Dobsonia inermis, and Admiralty flying-fox – Pteropus admiralitatum solomonis). We processed these animals and released them again at the point of capture.

IMG_1181

A female New Georgia monkey-faced bat captured at Vanga, Kolombangara in February 2015

Our second check of the nets proved much more exciting. Again, only two captures but the characters of one individual immediately caught our eyes. Its broad square jaw, orange eyes and mottled white and black wings stood out clearly in the torch light – it was a monkey-faced bat! A New Georgia monkey-faced bat previously thought to be extinct on Kolombangara Island. Over the course of the week, we managed to capture six individuals. Unfortunately, we were not able to capture any at Hunda, but overall this was a remarkable result for a naturally uncommon species.

Adjacent to the Vanga gardens there are several large strangler figs (the preferred roosting habitat for New Georgia monkey-faced bats). I believe these must be providing sufficient refuge for this species to persist in the fragmented environment. A variety of fruit and nut trees in the gardens also probably provide enough resources for monkey-faced bats to forage in the area.

Having now completed all of the 1992 field sites, we can now begin to analyse the data and provide a better understanding of how flying-fox populations have changed between the 1992 and 2014/2015 surveys in the Solomon Islands Western Province.


This project is funded by the Critical Ecosystems Partnership Fund, Australia Pacific Science Foundation and Lubee Bat Conservancy

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