1 Tahrcountry Musings: September 2011

Friday, September 30, 2011

International Year of Forests bibliography

Here is an excellent gesture from publishers Taylor & Francis and Routledg.


As part of a celebration of the International Year of Forests, they have compiled a collection of articles entitled “Celebrating Forests for People.”

This collection of articles includes more than 70 online, full-text articles from more than 50 journals. These are available for free to anyone, worldwide.

The full bibliography, with links to individual articles, is available here

World’s Most Threatened Sea Turtle Populations - International news release from IUCN

Top sea turtle experts from around the globe have discovered that almost half (45%) of the world’s threatened sea turtle populations are found in the northern Indian Ocean. The study also determined that the most significant threats across all of the threatened populations of sea turtles are fisheries bycatch, accidental catches of sea turtles by fishermen targeting other species, and the direct harvest of turtles or their eggs for food or turtle shell material for commercial use.
The recent report, produced by IUCN (International Union for Conservation of Nature) Marine Turtle Specialist Group (MTSG) and supported by Conservation International (CI) and the National Fish and Wildlife Foundation (NFWF), is the first comprehensive status assessment of all sea turtle populations globally. The study, designed to provide a blueprint for conservation and research, evaluated the state of individual populations of sea turtles and determined the 11 most threatened populations, as well as the 12 healthiest populations.
“This assessment system provides a baseline status for all sea turtles from which we can gauge our progress on recovering these threatened populations in the future,” explained Roderic Mast, Co-Chair of the MTSG, CI Vice President, and one of the paper’s authors. “Through this process, we have learned a lot about what is working and what isn’t in sea turtle conservation, so now we look forward to turning the lessons learned into sound conservation strategies for sea turtles and their habitats.”
Five of the world’s 11 most threatened species of sea turtles are found in the northern Indian Ocean, specifically threatened populations of both Loggerhead Turtles (Caretta caretta) and Olive Ridley Turtles (Lepidochelys olivacea) are found in the northern Indian Ocean in waters and on nesting beaches within Exclusive Economic Zones (EEZs) of countries such as India, Sri Lanka and Bangladesh.. Other areas that proved to be the most dangerous places for sea turtles were the East Pacific Ocean (from the USA to South America) and East Atlantic Ocean (off the coast of western Africa).
“The report confirms that India is a home to many of the most threatened sea turtles in the world,” said Dr. B. C. Choudhury, head of the Department of Endangered Species Management at the Wildlife Institute of India and a contributor to the study. “This paper is a wake-up call for the authorities to do more to protect India's sea turtles and their habitats to ensure that they survive."
The study also highlighted the 12 healthiest sea turtle populations in the world, which are large and currently populations facing relatively low threats. Five species, such as the Hawksbill Turtle (Eretmochelys imbricata) and the Green Turtle (Chelonia mydas) have populations among these dozen thriving habitats which include nesting sites and feeding areas in Australia, Mexico and Brazil. Other areas that harbor healthy turtle populations include the Southwest Indian Ocean, Micronesia and French Polynesia.
“Before we conducted this study, the best we could say about sea turtles was that six of the seven sea turtle species are threatened with extinction globally,” said Dr Bryan Wallace, Director of Science for the Marine Flagship Species Program at CI, and lead author for the paper. “But this wasn’t very helpful for conservation because it didn’t help us set priorities for different populations in different regions. Sea turtles everywhere are conservation-dependent, but this framework will help us effectively target our conservation efforts around the world.”

Have a look at the map of 11 most Threatened Sea Turtle Populations. Click HERE (2.81MB)

A new method for counting woodland birds.

Researchers from the Burgate-based Game & Wildlife Conservation Trust and the British Trust for Ornithology have developed a new method for counting woodland birds.  Dr Rufus Sage spearheaded the study. The new method provides conservationists with a rapid means of assessing whether habitat changes are affecting bird populations. It is a very efficient method of assessing breeding success in common woodland birds.

With the new method we get a much better insight into the processes that affect breeding success in woodland birds.

Current methods adopted are nest monitoring and mist-netting. This involves finding nests or catching live birds. Both require lot of man power. It is also expensive. On the downside it is not always successful. The new method overcomes the limitations and assesses the productivity of birds by counting fledglings in the field.
The researchers say the new method provided a sufficiently reliable estimate of fledging success based on just two or three visits per week between late May and the end of June and a surveyor can cover an area of about 10 to 15 ha in just two to three hours.

Details of the study is published in the on-line edition of the journal Bird Study

Thursday, September 29, 2011

Hector's dolphins teetering on the edge

Hector's dolphins, considered to be the world's most endangered sea dolphin, are found only around New Zealand. The population has plummeted from 30,000 to around 7,000. The dip is mainly due to nylon fishing nets that came into use in the 1970s. Gill nets are drowning at least 23 Hector's dolphins a year. Trawl nets also kill an equal no of dolphins every year. Other villains are the recreational use of gill nets, along with pollution, boat strikes and marine mining.

A subspecies known as Maui's dolphins is down to fewer than 100 mammals.

If things continue at the present rate it will wipe out 62% of the population by 2050.It could very well sound the death knell for the dolphins pushing them beyond the point of no return.

Environmentalists from round the globe have appealed to New Zealand Government to enforce stricter fishing codes to stem the tide.

Resource selection studies should be coupled with mechanistic data

Predators choose prey over prey habitats: evidence from a lynx–hare system

Jonah L. Keim, Philip D. DeWittt, and Subhash R. Lele

Ecological Applications  Volume 21, Issue 4 (June 2011)

In this paper the researchers recommend that resource selection studies should be coupled with mechanistic data (e.g., metrics of diet, forage, fitness, or abundance) when investigating mechanisms of resource selection.

Resource selection is grounded on the assumption that animals select resources based on fitness requirements.

There exists certain uncertainty in how mechanisms relate to the landscape. Despite this fact resource selection studies often assume, but rarely demonstrate, a relationship between modeled variables and fitness mechanisms.

Here using Canada lynx (Lynx canadensis) and snowshoe hare (Lepus americanus) as a model system, the researchers assess whether prey habitat is a viable surrogate for encounters between predators and prey. They simultaneously collected winter track data for lynx and hare in two study areas.

The researchers used the information criteria to determine whether selection by lynx is best characterized by a hare resource selection probability function (RSPF) or by the amount of hare resource use.
The results demonstrated that lynx selection is better explained by the amount of hare use (SIC = −21.9; Schwarz's Information Criterion) than by hare RSPF (SIC = −16.71), and that hare RSPF cannot be assumed to reveal the amount of resource use, a primary mechanism of predator selection.

The study amply demonstrates an obvious and  important distinction between selection and use that is applicable to all resource selection studies.

Wednesday, September 28, 2011

Ants that build wind turrets

Ants have been on the earth for perhaps 100 million years. Ant mounts are usually 6-8m in diameter, almost 1m high and weigh approximately 40 tonnes. This is truly an engineering marvel from these tiny animals. Here comes a piece of new research that is even more fascinating
Scientists have just discovered how the grass cutting ants Atta vollenweideri build nests that stay at the right temperature. This is achieved by building porous turrets. Their vast underground lairs may contain up to seven million insects that tend the fungal garden that feeds their young. The control of temperature is absolutely essential for the fungus to grow properly.
The researchers closely examined the question whether turrets are simply heaps of disposed soil, or result from the import and a particular spatial arrangement of materials. The scientists daily offered different building materials, i.e., clay, coarse and fine sands, which workers collected and deposited around a nest opening to construct a turret.  The researchers regularly changed the amount of each material that was available to them. Workers did not select particular materials to be imported for turret building, but were selective in their spatial distribution and assembly into the turret structure. Simulated rain damage to the nest was done by pouring water on to the structure. The ants aimed at the maintenance of a porous yet mechanically-stable structure
The ants invariably made turret walls that were highly porous and allowed air to flow through. The ants construct the turrets by stacking sand grains and little balls of clay that they mould with their jaws. They are able to sense minute differences in the density of the soil at different depths.
The researchers say Irrespective of the materials used, walls showed a marked regular porosity in the range 50–60%, with the exception of secondary galleries that occasionally permeated the turret structure, which evinced lower porosity and therefore a more compact microstructure.
Journal reference

The Construction of Turrets for Nest Ventilation in the Grass-Cutting Ant Atta vollenweideri: Import and Assembly of Building Materials 
Marcela I. Cosarinsky and Flavio Roces

Journal of Insect Behavior
DOI: 10.1007/s10905-011-9290-8 Online

Monday, September 26, 2011

World Rivers Day

Today is World Rivers Day. More than a million people in over 60 countries will participate in the event. This annual celebration with its origins in British Columbia has now evolved into a global event. The day aims to highlight the importance of rivers around the world. It also gives a fillip to the protection of these important freshwater habitats that benefits people and wildlife alike.

The most threatened group of animals in the world are freshwater fish (36% threatened with extinction), compared to mammals (21%) and birds (12%). So the day assumes an added significance

Sunday, September 25, 2011

News from IUCN

This is from IUCN website

Freshwater Biodiversity Assessments in the Western Ghats


Western Ghats: Fishes, Molluscs, Odonates, and Plants

A two year (2010-2011) project funded by the Critical Ecosystems Partnership Fund (CEPF)
The Western Ghats assessment project was completed in September 2011.

The Western Ghats in India is one of the world’s most heavily populated Biodiversity Hotspots, providing for and supporting 400 million people through water for drinking, transport, irrigation, and hydroelectric power, together with food and resources to sustain livelihoods. However, the pace of growth of the Indian economy and rates of industrial and urban development are not in tune with the conservation needs of this freshwater ecosystem and the remarkably high diversity of species they contain. In most instances the development planning process does not consider the ecosystem’s requirements, mainly due to a lack of adequate information on the distribution and status of freshwater species and the threats they face. There is also little appreciation of the value of freshwater ecosystems to the livelihoods of many people, often the poorest in society. In response to this need for information and raised awareness, the IUCN Global Species Programme’s Freshwater Biodiversity Unit, in collaboration with the Zoo Outreach Organisation (ZOO), conducted the Western Ghats Freshwater Biodiversity Assessment to review the global conservation status and distributions of 1,146 freshwater fishes, molluscs, odonates and aquatic plants.
The geographic scope of the project included all major river catchments with their origin within the Western Ghats Biodiversity Hotspot. The Tapi, Krishna, and Cauvery systems are included, with freshwater species native to the Western Ghats states of Gujarat, Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu, as well as parts of Andhra Pradesh and western and southern portions of Madhya Pradesh, Orissa and Chattisgarh, assessed. The IUCN Red List Criteria, the world’s most widely accepted system for measuring relative extinction risk, were applied to assess the status of all species, with information on each species compiled by more than 40 experts from the Western Ghats and elsewhere.

Key Outcomes
•    The Western Ghats hotspot, originally designated for its plant species, is confirmed as a globally significant centre of diversity and endemism for freshwater species.
•    Close to 16% of the 1,146 freshwater taxa assessed are threatened with extinction, with a further 1.9% assessed as Near Threatened. Approximately one-tenth of species were assessed as Data Deficient.

•    Within the Western Ghats, catchments in the southern part of the region in Kerala, Tamil Nadu and southern Karnataka have the highest freshwater species richness and levels of endemism, but also contain the highest number of threatened species.

•    Although many protected areas are located within or near areas of the richest freshwater diversity, the southern Western Ghats region also experiences the highest level of threat to freshwater species.

•    The northern Western Ghats region within Maharashtra has a lower recorded freshwater diversity than the southern region. Although this trend supports the expected relationship between species richness and rainfall, the lower diversity is probably due to inadequate surveys in the freshwater ecosystems of the west flowing rivers of the northern Western Ghats.

•    Aquatic plants and fishes are the most heavily utilized freshwater groups in the Western Ghats. Twenty-eight percent of aquatic plants are harvested for medicinal purposes, and 14% and 13%, as food for people and animals, respectively. More than half of all fish species are harvested for human consumption, and a growing percentage (37%) of species are captured for the aquarium trade. Eighteen percent of mollusc species are used as food for humans.

•    The main threats impacting freshwater biodiversity in the Western Ghats include pollution (with urban and domestic pollution ranking as the worst threats followed by agricultural and industrial sources of pollution), species use (including fishing and collection for the aquarium trade), residential and commercial development, dams and other natural system modifications, alien invasive species, agriculture and aquaculture, energy production and mining.
Key recommendations / conclusions
•    Taxonomic studies, inventories and monitoring of freshwater fauna and flora of the Western Ghats are urgently needed.

•    Many species are narrowly distributed within the Western Ghats, where destruction or alteration of a small catchment may lead to their extinction. Actions required include protection of key habitats, prevention of flow modifications where possible, conservation of specialized ecosystems such as Myristica swamps, prevention of agrochemical use in upper catchments, and regulation of tourism in critical habitats.

•    Improved enforcement of pollution laws is needed along with effective effluent treatment and better solid waste disposal protocols.

•    Investigations into the spread and impact of invasive alien fish and plant species are an immediate priority. A national policy on the introduction of alien species and their management is required.

•    Environmental impact assessment of development activities must be evaluated for their impacts to freshwater ecosystems.

•    Awareness programmes promoting better understanding of the values, sustainable use, and management of wetlands and rivers are crucial to eliminate public perception of wetlands as wastelands. 

•    Given the rapid rate of development across the region, politicians, legislators and other relevant stakeholders must be given access to key biodiversity information for freshwater ecosystems and this should be integrated within decision-making and planning processes.

•    Legislation to protect species and habitats exists across the region, but implementation and enforcement need to be more effective. Threatened and endemic species of freshwater fish of biological and socio-economic importance should be included within the National Wildlife Protection Act.  

•    Workshops involving local and regional stakeholders should be carried out to identify and prioritise a set of Freshwater Key Biodiversity Areas (KBAs) based on the potential KBAs identified in the current study. Management plans for these areas can then be implemented to benefit both the many dependant people and the rich biodiversity that these areas support.

The final report can be downloaded HERE

Friday, September 23, 2011

A plant that "bends down" to deposit its seeds

A new plant that "bends down" to deposit its seeds Spigelia  genuflexa  (Loganiaceae),  has been discovered in the Atlantic forest in the state of Bahia, northeastern Brazil. It is the first reported geocarpic species in the family.
After fruits are formed, the fruiting branches bend down and deposit the capsules of seeds on the ground. What is surprising is that sometimes the plant buries the seeds in the soft cover of moss.
The species is a short-lived annual. It is restricted to sandy-soil habitat with variable and heterogeneous microenvironment and is found only in two restricted localities.
The authors say a phylogenetic parsimony and Bayesian analysis of ITS sequences from 15 Spigelia species plus 17 outgroups in Loganiaceae confirms its independent taxonomic status: on the basis of sequence similarity and phylogenetic topology it is phylogenetically distinct from all Spigelia species sequenced so far.

Journal reference

Spigelia genuflexa (Loganiaceae), a new geocarpic species from northeastern Bahia, Brazil

Alex Popovkin, Katherine G. Mathews, José Carlos Mendes Santos, M. Carmen Molina, Lena Struwe

PhytoKeys 6 (2011): 47-65

Residential yards and conservation

The conservation value of residential yards: linking birds and people

Susannah B. Lerman and Paige S. Warren
Ecological Applications 21:1327–1339 Volume 21, Issue 4 (June 2011)

I found this paper very interesting. It gives a chance to look at urban wildlife from a new perspective.
Urbanization is undoubtedly one of the key drivers of loss of biodiversity throughout the world. In spite of this fact,the vegetation within an urbanized landscape is diverse.

The authors of this paper say this diverse vegetation gives a chance for testing whether certain landscape designs are better suited than others to support native biodiversity. They add that residential yards represent a large component of an urban landscape and, if managed collectively for birds and other wildlife, could offset some of the negative effects of urbanization.

Many urbanites have their primary interaction with the natural world in their front and back yards. Ensuring positive wildlife experiences for them is a key element in promoting urban biodiversity.
At the Central Arizona–Phoenix Long-Term Ecological Research site the researchers tested the efficacy of native landscaping in residential yards in attracting native birds. They also explored the links between socioeconomic factors, landscape designs, and urban gradient measurements with the urban bird communities.

 A redundancy analysis suggested that native desert bird species increased in abundance in neighborhoods with desert landscaping designs, neighborhoods closer to large desert tracts, and higher-income neighborhoods.
Variance partitioning showed that collectively these three sets of environmental variables explained almost 50% of the variation in the urban bird community. 

Results suggested racial and economic inequities in access to biodiversity, whereby predominantly Hispanic and lower-income neighborhoods had fewer native birds. They also found that residents' satisfaction with bird diversity was positively correlated with actual bird diversity.

The researchers conclude with the following words “Our study provides new insights into the relative importance of socioeconomic variables and common urban ecological measurements in explaining urban bird communities. Urban planners can use this information to develop residential landscapes that support the well-being of both birds and people.”

Thursday, September 22, 2011

Functional diversity should be incorporated into conservation and restoration decision-making

Beyond species: functional diversity and the maintenance of ecological processes and services

Marc W. Cadotte, Kelly Carscadden,Nicholas Mirotchnick

Journal of Applied Ecology

Volume 48, Issue 5, pages 1079–1087, October 2011 published online: 19 AUG 201

Here is a thought provoking paper on functional diversity and the maintenance of ecological processes and service

The goal of conservation and restoration activities is to maintain biological diversity and the ecosystem services that this diversity gives us. Traditionally these activities focus on species. This gives us only information on the presence and abundance of species. But how diversity influences ecosystem function depends on the traits and niches filled by species.

The authors say biological diversity can be quantified in ways that account for functional and phenotypic differences. A number of such measures of functional diversity (FD) have been created, quantifying the distribution of traits in a community or the relative magnitude of species similarities and differences.  Here the researchers review FD measures and why they are intuitively useful for understanding ecological patterns and how they are important for management.

The researcher adds “In order for FD to be meaningful and worth measuring, it must be correlated with ecosystem function, and it should provide information above and beyond what species richness or diversity can explain. We review these two propositions, examining whether the strength of the correlation between FD and species richness varies across differing environmental gradients and whether FD offers greater explanatory power of ecosystem function than species richness.”

FD can explain variation in ecosystem function even when richness does not.

The researchers sign off with the following words “FD measures those aspects of diversity that potentially affect community assembly and function. Given this explanatory power, FD should be incorporated into conservation and restoration decision-making, especially for those efforts attempting to reconstruct or preserve healthy, functioning ecosystems.”

Wednesday, September 21, 2011

Excellent article from IUCN site - Conservation is not about nature

DR J Zammit-Lucia has written an excellent article on conservation and people on the IUCN website. I enjoyed it tremendously. It is very germane and very useful.

Dr Joe Zammit-Lucia is an artist, author and independent scholar on conservation issues. He is President of WOLFoundation.org, a member of IUCN's Commission on Education and Communication and acts as Special Adviser to the Director General.

Click here to read the article

Tuesday, September 20, 2011

Appropriately managing above-ground vegetation carbon stores in a densely urbanized city

Mapping an urban ecosystem service: quantifying above-ground carbon storage at a city-wide scale

Zoe G. Davies,Jill L. Edmondson,Andreas Heinemeyer,Jonathan R. Leake,Kevin J. Gaston
Article first published online: 11 JUL 2011

Journal of Applied Ecology

Volume 48, Issue 5, pages 1125–1134, October 2011

This is a very interesting paper. The authors say even urban landscape can be put to use for carbon sequestration.

Urbanization is a major driver of land-use change globally. But attempts to quantify and map ecosystem service provision at a city-wide scale are very sparse. Here the researchers examined the quantities and spatial patterns of above-ground carbon stored in a typical British city, Leicester. This was achieved by surveying vegetation across the entire urban area. They also took in to account how carbon density differs in domestic gardens, which the researchers say is indicative of bottom-up management of private green spaces by householders. Public land was also surveyed which the researcher say represents top-down landscape policies by local authorities. A comparison of a national ecosystem service map with the estimated quantity and distribution of above-ground carbon within the study city was also done.

These are the conclusions
An estimated 231to 521 tonnes of carbon is stored within the above-ground vegetation of Leicester, equating to 3·16 kg C m−2 of urban area, with 97·3% of this carbon pool being associated with trees rather than herbaceous and woody vegetation

Domestic gardens store just 0·76 kg C m−2, which is not significantly different from herbaceous vegetation landcover (0·14 kg C m−2). The greatest above-ground carbon density is 28·86 kg C m−2, which is associated with areas of tree cover on publicly owned/managed sites.

 The researchers clearly demonstrate potential benefits of accounting for, mapping and appropriately managing above-ground vegetation carbon stores, even within a typical densely urbanized European city.

Monday, September 19, 2011

New sparrow on the block

A new genetic study led by evolutionary biologist Glenn-Peter Saetre from the University of Oslo has come up with conclusive genetic evidence that sparrows recently evolved a third species. This is the Italian sparrow (Passer italiae)

The researchers studied populations of Italian and Spanish sparrows (P. hispaniolensis), that share the same habitat in the south-east of Italy.

The Italian sparrow, the researchers say is a cross between house sparrow (P. domesticus) and the Spanish sparrow.

Those species that, under natural conditions, tend not to interbreed comes under the definition of a distinct species. The Italian sparrow is not reproducing with the Spanish sparrow.  The Italian sparrow possesses mitochondrial (mt) DNA haplotypes identical to both putative parental species (although mostly of house sparrow type), indicating a recent hybrid origin. Geographic and reproductive barriers restrict gene flow into the nascent hybrid species. According to the researchers they will gradually, generation by generation, become even more genetically distinct.

Journal reference 
Hybrid speciation in sparrows I: phenotypic intermediacy, genetic admixture and barriers to gene flow
Molecular Ecology
Volume 20, Issue 18, pages 3812–3822, September 2011

Sunday, September 18, 2011

The crocodiles that swam the Atlantic

This weekend over a glass of beer I was discussing with my friend Ramesh, the incredible journey of the crocs that swam the Atlantic. The paper “A phylogenetic hypothesis for Crocodylus (Crocodylia) based on mitochondrial DNA: Evidence for a trans-Atlantic voyage from Africa to the New World” by Robert W. Meredith, Evon R. Hekkala, George Amato and John Gatesy provided fodder for the discussion.

The crux of the research emphasizes that crocodiles swam across the Atlantic Ocean from Africa in order to establish the species in the Americas. The researchers used nearly complete mitochondrial (mt) genomes (16,200 base pairs) for all described Crocodylus species, eight of which are new to their study, to derive a generally well-supported phylogenetic hypothesis for the genus.

The research clearly revealed that all four American species are most closely related to the Nile crocodiles of east Africa. It is assumed that they must have split away roughly 7 million years ago, quite a bit after Africa and South America began drifting apart 130 million years ago. By 7 million years ago, over 2800 kilometres of ocean lay between the two continents.

Palaeontologists have long speculated that crocodiles swam the Atlantic. Hekkala's finding provide concrete evidence in support of that hypothesis

Crocodiles are salt-tolerant and can go up to six months without eating and are able to process salt water through special glands. Females can carry sperm for couple of years after mating. This means that a single female could have crossed the Atlantic and produced a litter on the other side. Hekkala says out of the crocs that got lost at sea off the coast of Africa some may have been carried across on the westward-flowing equatorial currents. The sea journey could have taken some months.

Journal reference

A phylogenetic hypothesis for Crocodylus (Crocodylia) based on mitochondrial DNA: Evidence for a trans-Atlantic voyage from Africa to the New World
Robert W. Meredith, Evon R. Hekkala, George Amato and John Gatesy
Molecular Phylogenetics and Evolution
Volume 60, Issue 1, July 2011, Pages 183-191

Saturday, September 17, 2011

Developer builds new home for bats

It was with great fascination that I read this story in Somerset Guardian, about a builder building a home for a bat (a lesser horseshoe bat) after demolition work at the former Alcan factory in Midsomer Norton destroyed the roost.

Ecological survey done prior to the grant of permit to the builder had revealed that one male lesser horseshoe bat was using part of the former factory building and an underground duct as its summer roost.

Lesser horseshoe bats spend the winter months in caves, and the warmer months in outbuildings.

We at Tahrcountry salute this builder. Here is an example that is worthy of emulation by other builders. We exhort them to spare a thought for the urban wildlife.

Understanding encounters data, based on the interactions that produce them

Encounter data in resource management and ecology: pitfalls and possibilities

Aidan Keane,Julia P. G. Jones,E. J. Milner-Gulland1
Article first published online: 13 JUN 2011

Journal of Applied Ecology

Volume 48, Issue 5, pages 1164–1173, October 2011


Simple indices based on the number of encounters are ubiquitous in conservation practices. This encounter data comes through the interaction of two sets of behaviours, i.e. those of the data generators and those of the data collectors. When these behaviours do not conform to the assumptions used to model, analyses of encounter data may go haywires

The researchers here review the use of CPUE indices derived from patrol data, which have been promoted for the study of rule-breaking in conservation. They highlight potential sources of bias and mention how similar problems have been tackled for other forms of encounter data.

The researchers identify several issues that must be addressed for analyses of patrol data to provide useful information. This includes the definition of suitable measures of catch and effort, the choice of appropriate temporal and spatial scales, the provision of suitable incentives for ranger patrols and the recording of sufficient information to describe the spatial pattern of sampling.

In short this paper describes a common conceptual framework for understanding encounter data, based on the interactions that produce them. The researchers anticipate that an appreciation of these commonalities will lead to improvements in the analysis of encounter data in several fields, by highlighting the existence of methodological approaches that could be more widely applied, and important characteristics of these data that have so far been neglected.

Friday, September 16, 2011

When it comes to maintaining tropical biodiversity, there is no substitute for primary forests

Primary forests are irreplaceable for sustaining tropical biodiversity

Luke Gibson, Tien Ming Lee, Lian Pin Koh, Barry W. Brook, Toby A. Gardner, Jos Barlow,Carlos A. Peres, Corey J. A. Bradshaw, William F. Laurance, Thomas E. Lovejoy & Navjot S. Sodhi

Nature (2011) published online 14 September 2011

This new study conclusively proves that there is no substitute for primary forests when it comes to maintaining tropical biodiversity. Conversion of tropical forests for agriculture, timber production and other uses has produced vast, human-dominated landscapes which do not augur well for the future of tropical forests.

The researchers provide a global assessment of the impact of disturbance and land conversion on biodiversity in tropical forests. They used a meta-analysis of 138 studies. Under scanner were 2,220 pairwise comparisons of biodiversity values in primary forests (with little or no human disturbance) and disturbed forests. They found that biodiversity values were substantially lower in degraded forests. This varied considerably by geographic region, taxonomic group, ecological metric and disturbance type.

 Even after partly accounting for confounding colonization and succession effects due to the composition of surrounding habitats, isolation and time since disturbance, the researchers found  that most forms of forest degradation have an overwhelmingly detrimental effect on tropical biodiversity. The researchers conclude that their results clearly indicate that when it comes to maintaining tropical biodiversity, there is no substitute for primary forests.

Thursday, September 15, 2011

Book Recommendation

Conservation biogeography

Richard J. Ladle& Robert J. Whittaker





Here is a good book on Conservation biogeography. This book provides the first comprehensive review of this exciting branch of science.

Conservation biogeography involves the application of biogeographical principles, theories, and analyses to problems confronting biodiversity conservation.  Many habitats have been completely destroyed or divided into tiny fragments.  Anthropogenic climate change threatens to completely redraw the geographic map of life on this planet. Conservation biogeography  provides policy makers with clearly crafted scenarios and options for the effective management of biodiversity.

  • Pub. Date: March 2011
  • Publisher: Wiley, John & Sons, Incorporated
  • Format: Paperback , 320pp
  • ISBN-13: 9781444335040
  • ISBN: 1444335049


Perils of deep-sea fisheries – A rethink urgently needed

Sustainability of deep-sea fisheries
Elliott A. Norse, Sandra Brooke,William W.L. Cheung, Malcolm R. Clark, Ivar Ekeland, Rainer Froese, Kristina M. Gjerde, Richard L. Haedrich, Selina S. Heppell, Telmo Morato, Lance E. Morgan, Daniel Pauly, Rashid Sumaila, Reg Watson
Marine Policy
Volume 36, Issue 2,
In the paper referred to above marine scientists from around the world is recommending an end to most commercial fishing in the deep sea. They recommend fishing in more productive waters nearer to consumers and underline the fact that with rare exceptions, deep-sea fisheries are unsustainable.  
The deep sea may the largest but it is the least productive part of the oceans. Most deep-sea fishes have far less population resilience and productivity than shallow-water fishes. Life processes happen at a slower pace than near the sea surface. The researchers say like old-growth trees and great whales, their biomass makes them tempting targets while their low productivity creates strong economic incentive to liquidate their populations rather than exploiting them sustainably (Clark's Law).
Deep sea fishes have long life history. Some of them live more than a century. Some deep-sea corals can live more than 4,000 years.  Deep sea fishing makes it difficult for them to repopulate. They can only sustain a very low rate of fishing. Populations’ sharks and orange roughy have taken a nose dive in recent years. Orange roughy take 30 years to reach sexual maturity and can live 125 years. Deep-sea fisheries can be sustainable only where the fish population grows quickly 
The researchers signs off with the following words “Instead of mining fish from the least-suitable places on Earth, an ecologically and economically preferable strategy would be rebuilding and sustainably fishing resilient populations in the most suitable places, namely shallower and more productive marine ecosystems that are closer to markets.

Wednesday, September 14, 2011

Duplication of hereditary information and its consequences

Scientists have discovered that plant lineages with multiple copies of their genetic information face higher extinction rates than their relatives. Competition with established, related diploid lineages renders polyploids susceptible to extinction. The research was headed by Dr Itay Mayrose, an assistant professor at the department of molecular biology and ecology of plants at Tel Aviv University in Israel.

Duplication of hereditary information is rare in animal evolution. But it is it is common in plants. Potatoes, coffee, bananas, peanuts, tobacco, wheat, oats and strawberries are a few examples of plants carrying multiple copies of their genetic material. This condition is called polyploidy. Most animals including humans are diploid. More than one-third of all existing plant species are polyploid.

The scientists looked at what are the advantages or disadvantages of going polyploid by making multiple copies of the entire genome and passing them on to the next generation? They analyzed more than 2,500 plant genomes with a computer-based, statistical approach. They found a trend that sets polyploid plant lineages apart from their diploid relatives. They also discovered plants that that became polyploid in their recent evolutionary past are less likely to diversify into new species and face a higher risk of extinction compared to their diploid relatives.

Journal reference

1) Recently Formed Polyploid Plants Diversify at Lower Rates
Itay Mayrose, Shing H. Zhan, Carl J. Rothfels, Karen Magnuson-Ford, Michael S. Barker, Loren H. Rieseberg, and Sarah P. Otto
Science 2 September 2011: 1257.Published online 18 August 2011

2) University of Arizona news