Construction of energy landscapes to understand the movement and distribution of foraging animals

Construction of energy landscapes can clarify the movement and distribution of foraging animals

Rory P. Wilson Flavio, Quintana and Victoria J. Hobson

Proc. R. Soc. B 7 March 2012 vol. 279 no. 1730975-980

The movement energetics of animals is dictated by variation in the physical characteristics of the environment. Knowledge about these characteristics helps us to interpret movement ecology but determination of the landscape-dependent energy expenditure of wild animals is not an easy proposition.

The researchers here used accelerometers in animal-attached tags to derive energy expenditure in 54 free-living imperial cormorants Phalacrocorax atriceps and construct an energy landscape of the area around a breeding colony. A review  of the space use of another 74 birds over 4 years showed that foraging areas selected varied considerably in distance from the colony and water depth, but were characterized by minimal power requirements compared with other areas in the available landscape.

The researchers say their study accords with classic optimal foraging concepts, which state that animals should maximize net energy gain by minimizing costs where possible and show how deriving energy landscapes can help understand how and why animals distribute themselves in space.

Start Active, Stay Active

A report on physical activity for health from four countries’ Chief Medical Officers

This blog usually confines itself to nature related affairs, with accent on wildlife. I am veering off a wee bit here. Here is a report on physical activity for health compiled by Chief Medical Officers of four countries that I finished reading just now. I think the report deserves to be read widely. It certainly will give a boost to your fitness regime. Go ahead and read it HERE

Toilet paper and the decline of Tigers

                                                      Photo Credit: WWF: US

It was with great fascination that I read this report by WWF about how American consumers are unwittingly contributing to the destruction of endangered rainforests in Sumatra by purchasing certain brands of toilet paper and in turn causing a decline of tigers. The brands mentioned are Paseo and Livi. They source fibre from Asia Pulp & Paper (APP), a paper products company criticized by environmentalists and scientists for its destructive forestry practices.

 WWF estimates that APP has destroyed nearly 5 million hectares of forest in Sumatra since it began operations in 1984.

The report titled “Don’t Flush Tiger Forests: Toilet Paper, U.S. Supermarkets, and the Destruction of Indonesia's Last Tiger Habitats” is available HERE

Western grey whale is on the edge of extinction – Act now

The western grey whale is teetering on the edge of extinction. There are probably fewer than 130 remaining. Of these 130, less than 26 are breeding females. Every year, they come to feed off the coast of Sakhalin Island, Russia, but now a new oil platform threatens the survival of this critically endangered whale.

WWF want the banks behind the project, BNP Paribas, Credit Suisse and Standard Chartered, which has two platforms in this area already, to demonstrate that they can be a force for good and oppose plans for another oil platform. 

WWF is organising a sign up campaign to tell the banks to act to save the whales.

Please go to WWF site and sign up to express your solidarity. Click HERE to go to the site

Here is a critique of camera trap study

Critique of density estimation from camera-trap data

Rebecca J. Foster, Bart J. Harmsen

The Journal of Wildlife Management

Volume 76, Issue 2, pages 224–236, February 2012

Camera trap study comes in very handy while estimating the densities of elusive terrestrial mammals. It involves two steps.

1) Fitting conventional closed population capture–recapture models to estimate abundance

2) Using ad hoc methods to determine the effective trapping area.

To guide wildlife management, the methodologies per se has to be accurate, robust, and reliable.

The researchers here critically reviewed 47 published studies and discuss the problems associated with contemporary population estimates of elusive species from camera-trap data.

The focus was on

1)      Individual identification

2)      Sample size and capture probability

3)      Camera location and spacing

4)      The size of the study area

5)      Ad hoc density estimation from the calculation of an effective trapping area

They also discuss the recently developed spatially explicit capture–recapture (SECR) models as an alternative approach that does not require the intermediate step of estimating an effective trapping area.

Here are the recommendations of the researchers

1) Greater transparency in study design and quality of the data

2) Greater rigor when reviewing manuscripts

 3) More attention is to be given to the survey design to ensure data are of sufficient quality for analysis

Scientists from Exeter University capture on film the process by which plants alert each

Scientists from Exeter University have captured on film the process by which plants alert each other about lurking dangers.

When a plant comes under attack it releases a gas which warns neighbouring plants.

BBC has published on its nature site a small video. Click here to go to the site and see the video

A test to know whether species with few records or recent last-sighting dates are likely to be extinct

Inferring Extinction of Mammals from Sighting Records, Threats, and Biological Traits

DIANA O. FISHER and SIMON P. BLOMBERG

Conservation Biology, Volume 26, Issue 1, pages 57–67, February 2012

Quantitative techniques exist for species with five or more sightings, to test whether a species is extinct on the basis of distribution of sightings. However, 70% of purportedly extinct mammals are known from fewer than five sightings. Such models do not include important indicators of the likelihood of extinction like threats, biological traits, search effort, and demography.

The researchers here developed a quantitative method that they based on species’ traits in which they used Cox proportional hazards regression to calculate the probability of rediscovery of species regarded as extinct. They used two versions of the Cox regression model to determine the probability of extinction in purportedly extinct mammals and compared the results of these two models with those of stationary Poisson, nonparametric, and Weibull sighting-distribution models. 

For mammals with five or more sightings, the stationary Poisson model categorized all but two critically endangered (flagged as possibly extinct) species in their data set as extinct. The results with this model were consistent with current categories of IUCN. The scores of probability of rediscovery for individual species in one version of their Cox regression model were correlated with scores assigned by the stationary Poisson model. They used this Cox regression model to determine the probability of extinction of mammals with sparse records.

On the basis of the Cox regression model, the most likely mammals to be rediscovered were the Montane monkey-faced bat (Pteralopex pulchra), Armenian myotis (Myotis hajastanicus), Alcorn's pocket gopher (Pappogeomys alcorni), and Wimmer's shrew (Crocidura wimmeri). The Cox model categorized two species that have recently disappeared as extinct: the baiji (Lipotes vexillifer) and the Christmas Island pipistrelle (Pipistrellus murrayi).

The researchers affirm that their new method can be used to test whether species with few records or recent last-sighting dates are likely to be extinct. 

No update for five days

As I am travelling to areas with no internet connectivity, there won't be any update for the next 5 days.
Have a wonderful time
Regards

More on monitoring - Capitalising on the resources devoted to monitoring activities

Conservation cornerstones: Capitalising on the endeavours of long-term monitoring projects

Greg J. Holland, Jerry S.A. Alexander, Peter Johnson, Andrew H. Arnold, Merril Halley, Andrew F. Bennett

Biological Conservation,Pages 95-101,Volume 145, Issue 1

Monitoring programmes have become the cornerstone of many biodiversity conservation programs. However it remains a fact that many monitoring programs do not deliver what we want, due to inherent flaws. In the absence of good monitoring program, informed management intervention would not be possible.

 Here the researchers use a monitoring program from south-eastern Australia as a case study to illustrate the potential of such endeavours. The brush-tailed phascogale (Phascogale tapoatafa), which is threatened, has been monitored at various locations between 2000 and 2010. The researchers present strong evidence for a decline in relative abundance during this period. They also describe relationships with environmental variables.

The results provide insights likely to come in handy in guiding future management of the species. While early detection of population declines is important, knowledge of the processes driving such declines is required for effective management intervention.

The researchers argue that monitoring programs will be most effective as a tool for enhanced conservation management if they test specific hypotheses relating to changes in population trajectories. According to them greater emphasis should be placed on rigorous statistical analysis of monitoring datasets in order to capitalise on the resources devoted to monitoring activities. Many datasets are likely to exist for which careful analysis of results would have benefits for determining management directions.

For people interested in managing land with a focus on improving habitats and encouraging wildlife in a natural way

Wild Land Management Standards website launched by John Muir Trust

The John Muir Trust has launched its new Wild Land Management Standards website which illustrates the principles that guide its management of wild land.

The site is aimed at other land managers and anyone interested in managing land with a focus on improving habitats and encouraging wildlife in a natural way. It offers a range of resources including a Wild Land Management Standards Handbook, management plan template and links to useful online resources.

Even though aimed at UK’s wild land supporting natural habitats and species it would come in handy for others also.

The website details 28 wild management standards falling into six categories: management planning; soil, carbon, water; biodiversity & woodland; deer & livestock; facilities & heritage; communities, visitors & awareness.

Click HERE to go to the site

Crash in bee population - indirect effect of pesticides

A study, led by Dr Jeffrey Pettis, the head of the US Department of Agriculture's Bee Research Laboratory has come up with solid evidence that pesticides may be a major cause of collapsing bee populations. Read this against backdrop of more than 70 of the 100 crops that provide 90 per cent of the world's food getting pollinated by bees.

Researchers found that bees deliberately exposed to minute amounts of the pesticide were, on an average, three times more likely to become infected when exposed to a parasite called nosema. Environmentalist has been crying themselves hoarse for sometime that new group of insecticides called neonicotinoids are behind a worldwide decline in honey bees.  Links between widely used pesticides and pathogens have been scientifically proved now.

Imidacloprid is the bestselling neonicotinoid. Neonicotinoids are "systemic" pesticides. They effectively become part of the plant, including the pollen and nectar that bees and other pollinating insects carry away.

The new study has evinced interest worldwide

Details of the study appears in the journal Naturwissenschaften

Top conservation award for Nik Lopoukhine, Chairman of the IUCN World Commission on Protected Areas (WCPA)

 Nik Lopoukhine, Chairman of the IUCN World Commission on Protected Areas has been selected by Canadian Parks and Wilderness Society to receive the prestigious J.B. Harkin Award for 2012. The award is for his lifetime contribution to protecting Canada’s parks and wilderness. The award will be presented at a reception on February 1, 2012 at 7 PM at the Canadian Museum of Nature, Ottawa.

The award is named after Harkin, the founder of Canada’s national parks system.

Mr Lopoukhine’s contribution to Canadian Park service is nonpareil. He devised Parks Canada’s fire management program.  As Director General of National Parks for Parks Canada, he was responsible for developing and implementing important components within Canada’s New National Parks Act, the Species at Risk Act and the National Marine Conservation Act Areas.

As the elected Chair of the IUCN’s World Commission on Protected Areas Mr Lopoukhine is very active internationally

Tahrcountry salutes this magnificent officer and wish him Godspeed in his conservation ventures.

Book Recommendation

The book gives tools and methods using Microsoft Excel and the powerful Open Source R program to carry out data handling. How to plan for data collection, how to assemble data, how to analyse data and how to present the results are explained lucidly. Tests like t-tests, correlation, ANOVAs, regression and the non-parametric equivalents find a place in the book. Screen shots of relevant examples are a plus point. 

·         Hardcover: 334 pages

·         Publisher: Pelagic Publishing Ltd (January 2, 2012)

·         Language: English

·         ISBN-10: 1907807136

·         ISBN-13: 978-1907807138

Effectively monitoring, populations of conservation concern - New single-sample approaches

Monitoring the effective population size of a brown bear (Ursus arctos) population using new single-sample approaches

TOMAŽ SKRBINŠEK, MAJA JELENČIC, LISETTE WAITS, IVAN KOS, KLEMEN JERINA, PETER TRONTELJ

Molecular Ecology, Volume 21, Issue 4, pages 862–875, February 2012

The ideal parameter for monitoring populations of conservation concern is the effective population size (N_e). It effectively summarizes both the evolutionary potential of the population and its sensitivity to genetic stochasticity.

Tracing the effective population size through time is difficult in natural populations. Here the researchers applied four new methods for estimating N_e from a single sample of genotypes to trace temporal change in N_e for bears in the Northern Dinaric Mountains. They genotyped 510 bears using 20 microsatellite loci and determined their age. The samples were organized into cohorts with regard to the year when the animals were born and yearly samples with age categories for every year when they were alive.

The researchers used the Estimator by Parentage Assignment (EPA) to directly estimate both N_e and generation interval for each yearly sample. For cohorts, they estimated the effective number of breeders (N_b) using linkage disequilibrium, sibship assignment and approximate Bayesian computation methods and extrapolated these estimates to N_e using the generation interval.

The N_e estimate by EPA is 276 (183–350 95% CI), meeting the inbreeding-avoidance criterion of N_e > 50 but short of the long-term minimum viable population goal of N_e > 500. The results obtained by the other methods are highly consistent with this result, and all indicate a rapid increase in N_e probably in the late 1990s and early 2000s.

The researchers contend that new single-sample approaches to the estimation of N_eprovide efficient means for including N_e in monitoring frameworks and will be of great importance for future management and conservation.

Orchid’s fate hinges on two factors: a forest's age and its fungi

Scientists from Smithsonian led by Dr Melissa McCormick have established that a forest's age and its fungi are very important factors for the growth of orchids.

Around 10 percent of all plant species are orchids. This makes them the largest plant family on Earth. 

Orchids depend solely on microscopic fungi in the early stages of their lives.  Orchid seeds germinated only where the fungi they needed were abundant. Mere presence was not enough. The fungi in turn displayed a strong preference for older forests. 

The new discovery has great conservation significance. To save endangered orchids, planting new forests may not be enough. If the forests are not old enough or do not have enough of the right fungi our efforts at restoring orchids may not come to fruition.

Journal Reference:

Melissa K. Mccormick, D. Lee Taylor, Katarina Juhaszova, Robert K. Burnett, Dennis F. Whigham, John P. O’Neill.Limitations on orchid recruitment: not a simple picture. Molecular Ecology, 2012

Yeti crab farms its own food

Scientists have recently found a species of crab that cultivates bacteria on its claws, and then eats them. The discovery was made by DR Andrew Thurber, a marine ecologist at Oregon State University in Corvallis. Dr Thurber has named the crab Kiwa puravida, after a common Costa Rican saying that means 'pure life'.

Dr Thurber says K. puravida waves its claws to actively farm its bacterial gardens. They stir up the water around the bacteria, ensuring that fresh supplies of oxygen and sulphide wash over them and helping them to grow. The bacteria are the crab’s main food source. 

Have a look at the videos

Dr. Ullas Karanth conferred with the prestigious Padma Shri award

Dr. Ullas Karanth, who has conducted ground breaking research on the ecology of tigers and other large mammals, has been awarded India's fourth highest civilian honour, the Padma Shri, for the year 2012. Dr. Karanth has received this award for his outstanding contribution to Wildlife Conservation and Environment Protection.

Dr Ullas Karanth has published over 135 international peer-reviewed scientific papers and popular articles, and authored seven books in English and Kannada.

Tahrcountry congratulate Dr Karanth and wish him many fruitful years of wildlife research. He truly deserves this award.

Sumatran elephant on the critically endangered list

                                            Photo Credit:WWF Indonesia

The Sumatran elephant which has lost half of its population in a single generation has been placed on the list of critically endangered species by IUCN. It is now at risk of becoming extinct within decades. There is a loss of 69% of the animal's habitat over the past 25 years. Sumatra has experienced one of the worst deforestation rates in the world

The total wild population is around 2,800 only. WWF has called for an immediate moratorium on habitat destruction to stem the tide. Indonesia needs to keep a close watch on loggers and plantation owners. 

Multi-scale models offer an important tool for identifying conservation requirements at the fine landscape level

Using multi-scale modelling to predict habitat suitability for species of conservation concern: The grey long-eared bat as a case study
Orly Razgour,Julia Hanmer,Gareth Jones
Biological Conservation, Volume 144, Issue 12, December 2011, Pages 2922–2930

Habitat suitability modelling has been used traditionally to understand broad-scale patterns of species distribution. It also comes in handy to address conservation needs at finer scales.

Studies combining a range of scales for understanding ecological processes are rare. Here the researchers studied the ability of presence-only species distribution modelling to predict patterns of habitat selection at broad and fine spatial scales for one of most endangered animal in the UK, the grey long-eared bat (Plecotus austriacus).

Models were constructed with Maxent using broad-scale distribution data from across the UK and fine-scale radio-tracking data from bats at one colony. Fine-scale model predictions were evaluated with radio-tracking locations from bats from a distant colony. This was compared with results of traditional radio-tracking data analysis methods.

Broad-scale models indicated that winter temperature, summer precipitation and land cover were the most important variables limiting the distribution of the grey long-eared bat in the UK. Fine-scale models predicted that proximity to unimproved grasslands and distance to suburban areas determines foraging habitat suitability around maternity colonies. Compositional analysis identified unimproved grasslands as the most preferred foraging habitat type.

The authors say this strong association with unimproved lowland grasslands highlights the potential importance of changes in agricultural practices in the past century for wildlife conservation. They reiterate that multi-scale models offer an important tool for identifying conservation requirements at the fine landscape level that can guide national-level conservation management practices.