Book Recommendation

Trophic Cascades

Predators, Prey, and the Changing Dynamics of Nature

John Terborgh, James Estes

Publisher: Island Press
456 p. 7"x10"
ISBN: 9781597264877

Here is a very good book on Trophic cascads, the top-down regulation of ecosystems by predators. Trophic cascades are often turned topsy-turvy by human interventions. The book bucks the idea of "bottom up" regulation of ecosystems. It graphically describes the consequences of apex predator elimination which results in a chain reaction, or "cascade" of effects down to the lowest level of the trophic ladder.

In recent years Trophic cascads have started assuming increasing influence in the development of conservation and management strategies.

Marco Polo Sheep is an international traveller

An analysis of DNA from fecal samples by researchers from WCS has come up with the finding that Marco Polo sheep in the Pamir Mountains of Afghanistan are genetically connected to sheep in neighboring Tajikistan and China, despite the difficult terrain.

The researchers involved are Dr Richard.B. Harris of the University of Montana, Dr John Winnie, Jr.of Montana State University, Dr Gordon Luikart, Stephen, Dr J. Amish, and Dr F.W. Allendorf of the University of Montana, and Dr Albano Beja-Pereira, Vânia Costa, and Dr Raquel Godinho of the Universidade do Porto

The research team collected fecal samples from 172 individual sheep from five different areas in Afghanistan, Tajikistan to arrive at their conclusions.

The research highlighted the fact that non-invasive methods of determining population trends and relatedness are extremely valuable in devising conservation strategy for animals that are elusive and difficult to track. It also highlighted the need for international cooperation between Afghanistan, Tajikistan, and China.

Long-term preventive conservation is preferable to short term firefighting

When should we save the most endangered species?

Howard B. Wilson,Liana N Joseph,Alana L. Moore and Hugh P. Possingham

Article first published online: 12 JUL 2011

Ecology Letters (2011)

In this paper the authors emphasizes that long-term preventive conservation measures are far better than short term firefighting

Conservationists have always been bothered whether to give priority to cost-effective actions or whether focusing solely on the most endangered species will ultimately lead to preservation of the greatest number of species. Conservation funding tends to be short-term in nature and on the whole biased to more endangered species.

By framing this debate within a decision-analytic framework, the researchers show that allocating resources solely to the most endangered species will typically not minimise the number of extinctions in the long-term, as this does not account for the risk of less endangered species going extinct in the future.

Short term fire fighting can be resorted to when our planning timeframe is short or we have a long-term view and we are optimistic about future conditions.

On the whole this paper is very thought provoking.

Connectivity, patch based graphs, and conservation

Patch-based graphs of landscape connectivity: A guide to construction, analysis and application for conservation

Paul Galpern Micheline Manseau and Andrew Fall

Biological Conservation
Volume 144, Issue 1, January 2011, Pages 44-55

Here is a good paper that deals with connectivity and the use of patch based graphs.

Connectivity is a major conservation priority. Maintaining connectivity and mitigating the fragmentation of habitat is critical for landscape processes. For modelling the functional connectivity of landscapes, Graph theory (also known as network analysis), has become sine qua non for many researchers and managers.  The authors of this paper say they conducted a review of studies that use graph theory to model connectivity among patches of habitat (patch-based graphs), with the intention of identifying typical research questions and their associated graph construction and analysis methods.

The researchers identified and examined nine questions of conservation importance that can be answered with these types of graph models. They discussed appropriate applications of these questions and presented a guide for using graph methods to answer them. They also examined how the connectivity predictions of patch-based graphs have been assessed and emphasize the importance of empirical evaluation.

The researchers sign off like this “. Our findings identify commonality among diverse approaches and methodological gaps with an aim to improve application and to help the integration of graph theory and ecological analysis.”  “As a final caveat, we urge those using patch-based graphs in a decision-making process to assess the relative importance of conserving connectivity compared to, for example, conservation decisions based only on the amount and quality of habitat. This remains an important area for further theoretical and empirical consideration”

Snap-buckling observed in vertebrates for the first time

Snap-buckling is usually seen in plants and insects. It is akin to the opening and closing of a snap hair clip

 The best example of snap-buckling in plants is the Venus flytrap, which uses it to catch insects.

For the first time Snap-buckling has been observed in vertebrates and it happens to be in hummingbird.

Hummingbird beaks are built to feed on flowers, but hummingbirds can't live on nectar alone. To get enough protein and nutrients they need to eat small insects also. The shape of a hummingbird's beak allows for “controlled elastic" and this allows it to snatch up flying insects in a mere fraction of seconds.

The researchers found that the hummingbird's bendy lower beak flexes by as much as 25 degrees when it opens. At the same time it also widens at the base to create a larger surface for catching insects. The extra speed leads to greater success in catching insects.

Details of the study will appear in the August 7 issue of Journal of Theoretical Biology

Conservation success story - Grand Cayman blue iguana is back from the brink of extinction

         Credit: Julie Larsen Maher/Wildlife Conservation Society.

We constantly hear about species on the brink of extinction. In many cases efforts to save them seem a distant possibility. Here is a rarity in conservation, a conservation effort that bucks the trend.

Blue Iguana Recovery Program in Cayman Island is well on its way to success. Blue iguana is the largest native species of Cayman Island. Coordinated by the National Trust for the Cayman Islands, the Blue Iguana Recovery Program—a consortium of local and international partners—has successfully released more than 500 captive-bred reptiles since the initiative's inception in 2002. In 2002 wild population of iguanas numbered less than two dozen. Conservationists expect to reach their goal of 1,000 iguanas in managed protected areas in the wild in a few years.


Recovery efforts to save the Grand Cayman blue iguana have mostly centered on the Salina Reserve, a 625-acre nature reserve located on the eastern side of the island. This year the efforts move on to newly established Colliers Wilderness Reserve also.

The importance of survey design in distance sampling

The importance of survey design in distance sampling: field evaluation using domestic sheep
Tom A. Porteus, Suzanne M. Richardson, and Jonathan C. Reynolds

Wildlife Research 38(3) 221-234 http://dx.doi.org/10.1071/WR10234

Wildlife managers and researchers regularly use distance sampling. Here is a paper that emphasizes the importance of survey design in distance sample. Management decisions are often made based on these estimates. Without knowledge of true population size it is not possible for wildlife biologists to evaluate how biased the estimates can be if survey design is compromised.

Here the researchers did a clever field evaluation using domestic sheep. Their aims were to use distance sampling to estimate population size for domestic sheep free-ranging within large enclosed areas of hill country. By comparing estimates against actual numbers, they examined how bias and precision are impaired when survey design is compromised

Both line and point transect sampling were used to derive estimates of density for sheep on four farms in upland England. In Stage I they used limited effort and different transect types to compromise survey design. In Stage II they increased effort in an attempt to improve on the Stage I estimates. They also examined the influence of a walking observer on sheep behaviour to assess compliance with distance sampling assumptions and to improve the fit of models to the data.

The results clearly demonstrated that distance sampling can lead to biased and imprecise density estimates if survey design is poor, particularly when sampling high density and mobile species that respond to observer presence. The researchers say in Stage I, walked line transects were least biased; point transects were most biased. Increased effort in Stage II reduced the bias in walked line transect estimates. For all estimates, the actual density was within the derived 95% confidence intervals, but some of these spanned a range of over 100 sheep per km².

The researchers have clearly shown that survey design is vitally important in achieving unbiased and precise density estimation using distance sampling. Adequate transect replication reduced the bias considerably within a compromised survey design.

The researchers sign off like this “Management decisions based on poorly designed surveys must be made with an appropriate understanding of estimate uncertainty. Failure to do this may lead to ineffective management.”

Tailpiece: We had sent mail to one wildlife warden regarding the poor design of some of his census techniques. We had also requested him to contact well versed scientists to set things right. He never responded. This post is intended to show him and his ilk how design flaws can throw the entire process out of kilter.

Sexual segregation in Giant Pandas

Different habitat preferences of male and female giant pandas

Dunwu Qi,Shanning Zhang,Zejun Zhang,Yibo Hu,Xuyu Yang,Hongjia Wang,Fuwen Wei

Article first published online: 5 JUL 2011 Journal of Zoology

DOI: 10.1111/j.1469-7998.2011.00831.x

Now here is a surprise. According to this study male and female giant pandas prefer to use different habitats. Using a combination of field surveys and sex identification through fecal DNA, the researchers investigated gender differences in habitat use in wild giant pandas through ecological niche factor analysis modelling. 

Female pandas frequent high altitude conifer forests and mixed forests on steeper slopes, whereas males roam about more widely, researchers discovered. Females stuck to these areas as they provide den sites for birthing and dense bamboo cover in which baby pandas can hide.

The researchers say these findings should be taken into account when breeding programmes for release of giant pandas back into the wild are devised.

First insights into Sumatran tiger–prey temporal interactions

Assessing tiger–prey interactions in Sumatran rainforests

M. Linkie AND M. S. Ridout

Journal of Zoology

Volume 284, Issue 3, pages 224–229, July 2011

Very little is known about Sumatran tiger–prey temporal interactions. Here the researchers are trying to unravel the mystery surrounding   Sumatran tiger ( Panthera tigris Sumatra)

The researchers quantify temporal overlap between the Sumatran tiger and five of its presumed prey species. This was from four study areas comprising disturbed lowland to primary submontane forest data from 126 camera traps.  Over 8984 camera days were used to estimate species activity patterns and, the overlap through the coefficient Δ (ranging from 0 to 1, i.e. no overlap to complete overlap). 

To determine confidence intervals associated with respective overlap a newly developed statistical technique was used.

Strong temporal overlap was found between tiger and muntjac Muntiacus muntjac (Δ=0.80, 95%CI=0.71–0.84) and tiger and sambarCervus unicolor (Δ=0.81, 0.55–0.85).

The authors signs off like this “ According to the foraging theory, Sumatran tigers should focus on expending lower levels of energy searching for and then capturing larger bodied prey that present the least risk. Hence, surprisingly, there was little overlap between the crepuscular tiger and the largest-bodied prey species available, the nocturnal tapir Tapirus indicus (0.52, 0.44–0.60), suggesting that it is not a principal prey species. This study provides the first insights into Sumatran tiger–prey temporal interactions. The ability to estimate overlap statistics with measures of precision has obvious and wide benefits for other predator–prey and interspecific competition studies.”

Do solitary foraging nocturnal small mammals plan their routes?

Do solitary foraging nocturnal mammals plan their routes?

Marine Joly and Elke Zimmermann

Published online before print April 27, 2011, doi:10.1098/rsbl.2011.0258Biol. Lett. 23 August 2011 vol. 7 no. 4 638-640

Here is a thought provoking paper on small mammals.

It is an established fact that large-brained diurnal mammals with complex social systems plan where and how to reach a resource. This is established by a systematic movement pattern analysis.

Here the researchers examined for the first time large-scale movement patterns of a solitary-ranging and small-brained mammal, the mouse lemur (Microcebus murinus). They used the change-point test and a heuristic random travel model to get insight into foraging strategies and route-planning abilities.

Seven lemurs were radio-collared and their foraging patterns examined. The researchers say the change-points coincided with out-of-sight keystone food resources. Travel paths were more efficient in detecting these resources than a heuristic random travel model within limits of estimated detection distance.

The researchers signs off suggesting that even nocturnal, solitary-ranging mammals with small brains plan their route to an out-of-sight target. Thus, similar ecological pressures may lead to comparable spatial cognitive skills irrespective of the degree of sociality or relative brain size.

Circumventing limitations of GIS technology

Greater Sage-Grouse Nesting Habitat: The Importance of Managing at Multiple Scales

Doherty, K.E., Naugle, D.E. & Walker, B.L. Greater Sage-Grouse Nesting Habitat: The Importance of Managing at Multiple Scales. Journal of Wildlife Management 74, 1544-1553 (2010).

The other day I was discussing with my friend Ramesh, the limitations of use of GIS in wildlife management.  GIS often takes in to account only landscape scale vegetation patterns. This is the result of extreme resolution required to know about local level vegetation characteristics from satellite imagery.  The starting point was a 2010 paper referred to above. Here is a paper that looks at the limitations of GIS. The researchers come up with alternate solutions to plug the loop.

A close look at habitat selection at multiple scales is essential to fully understand habitat requirements and dovetail it to the management needs for wildlife. The researchers used a hierarchical information-theoretic approach and variance decomposition techniques to analyze habitat selection using local-scale habitat variables measured in the field and landscape-scale variables derived with a Geographic Information System (GIS) for nesting greater sage-grouse (Centrocercus urophasianus) in the Powder River Basin (PRB), Montana and Wyoming, USA.

The authors say variance decomposition showed that local-scale measures explained the most pure variation (50%) in sage-grouse nesting-habitat selection. Landscape-scale features explained 20% of pure variation and shared 30% with local-scale features. The landscape-scale model produced was accurate in predicting priority landscapes where sage-grouse nests would occur and is, therefore, useful in providing landscape context for management decisions. It accurately predicted locations of independent sage-grouse nests (validation R²  =  0.99) and showed good discriminatory ability with >90% of nests located within only 40% of the study area.

The model also accurately predicted independent lek locations and supported predictions of the hotspot theory of lek placement. 

The authors signs off saying “ Local-scale habitat variables that cannot currently be mapped in a GIS strongly influence sage-grouse nest-site selection, but only within priority nesting habitats defined at the landscape scale. Our results indicate that habitat treatments for nesting sage-grouse applied in areas with an unsuitable landscape context are unlikely to achieve desired conservation results.”

Understanding the effect of human-driven changes on population performance of long-lived species

Decomposing variation in population growth into contributions from environment and phenotypes in an age-structured population

Fanie Pelletier,Kelly Moyes,Tim H. Clutton-Brock andTim Coulson

Published online before print June 29, 2011, doi:10.1098/rspb.2011.0827 Proc. R. Soc. B

Here is a new paper that attempts to understand the effect of human-driven changes on population performance of long-lived species. It is not an easy task. It is a real challenge to come to grips with the relative importance of ecological drivers responsible for natural population fluctuations.

The authors used a recently developed approach to decompose the observed fluctuation in population growth of the red deer population on the Isle of Rum into contributions from climate, density and their interaction and to quantify their relative importance. They also quantified the contribution of individual covariates, including phenotypic and life-history traits, to population growth.

Fluctuations in composition in age and sex classes of the population contributed substantially to the population dynamics. Density, climate, birth weight and reproductive status contributed less and approximately equally to the population growth.

The researchers signs off saying “ Our results support the contention that fluctuations in the population's structure have important consequences for population dynamics and underline the importance of including information on population composition to understand the effect of human-driven changes on population performance of long-lived species.

Light at the end of the tunnel for Dr Ullas Karanth

We all are aware of the trials and tribulations that Dr Ullas Karanth had to undergo while doing his research on tigers in Karnataka. He was hassled unnecessarily. Profesional jealousy added salt to the wound. But things have suddenly started looking very rosy for the renowned scientist.

Centre for Wildlife Studies headed by Dr Ullas Karanth  has been recognized as a "Centre of Excellence" by the Government of Karnataka for its contribution to conservation biology over the pas two decades. The ongoing project titled "Meta-Population dynamics of tigers in Malenad-Mysore Tiger Landscape (MMTL) of Karnataka" conducted in collaboration with the Karnataka Forest Department has come in for laurels.The Award was presented to  Dr. Ullas Karanth, by Chief Minister of Karnataka B. S. Yeddyurappa at a function held in Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore on 6th July 2011. 

My views on this mirrors what Dr. George Schaller said. In a congratulatory message to Dr Ullas Karanth he  said " It is so well deserved, and it's wonderful to  see that after years of getting hassled or your important work ignored you are finally recognized officially and valued”.

We wish Dr Ullas Karanth many more years of fruitful, research. You have shown the youngsters what grit can do.

Fresh lease of life for the blog

I have received several requests from friends to continue blogging. In deference to their wishes I have decided to start blogging again. I may not be able to blog with almost religious fervor that I am used to. I will try to post whenever I have spare time on my hands.

End of the road

After 6 years it is the end of the road for this blog.  I am discontinuing the blog. I thank all the readers who have given me great support for the past 6 years. Thank you very much

Smart-phones and wildlife conservation

Modern life styles have put a damper on wildlife conservation efforts across the world.  Conservationists have rued the use of many modern gadgets. To buck the trend here is a case where a modern invention is coming to the rescue of wildlife.

Scientists at the Zoological Society for London (ZSL) have announced the launch of a new "bat phone”, a smart phone application that ordinary people can use to track the movements of local bat species. It has has been developed for a global bat monitoring programme covering at least 16 countries. More than 900 species of bat can be tracked with the help of an ultrasonic microphone.

Smart phones, internet, online crowd sourcing and social networks are being judiciously put to use to further the cause of conservation. The citizens en masse act as field researchers collecting valuable data. The data is uploaded to a website that identifies each of the calls to build an accurate picture of bat populations. 

Effectiveness of camera trapping Vis-à-vis live trapping for sampling terrestrial small-mammal communities

A comparison of the effectiveness of camera trapping and live trapping for sampling terrestrial small-mammal communities
Natasha De Bondi , John G. White , Mike Stevens , Raylene Cooke 

Wildlife Research 37(6)

I just read a very interesting paper about the comparison of the effectiveness of camera trapping and live trapping for sampling terrestrial small-mammal communities

Camera-trap technologies are being increasingly used for surveys of medium to large terrestrial mammals. The authors content that the method also have significant applications for broad-scale surveys of small mammals.


In this study the researchers tried to compare results from camera-trapping surveys to those of the more traditional live-trapping techniques. The aim was to test the effectiveness of the techniques for detecting species, and the cost effectiveness of both approaches.


Surveys were conducted in 36 sites in the Grampians National Park, Victoria, Australia, between April and July 2009. A combination of Elliot and cage trapping and camera trapping were tried. 
Results were compared for both their ability to generate small-mammal presence data and their cost effectiveness.
Camera-trapping surveys compared favourably with those of live-trapping surveys. Similar species were detected across the sites. Camera trapping was definitely more cost effective than live trapping.


The researchers signs off saying “camera-trapping surveys of small terrestrial mammals may provide a new and cost-effective technique for surveying terrestrial small mammals.  Improving the replication and spatial coverage of studies has the potential to significantly increase the scope of research questions that can be asked, thus providing the potential to improve wildlife management”.

A grain of hope in the desert - News story about the latest red list from IUCN

16 June 2011 | IUCN News story

The regal Arabian Oryx (Oryx leucoryx), which was hunted to near extinction, is now facing a more secure future according to the latest update of the IUCN Red List of Threatened Species™. Its wild population now stands at 1,000 individuals.  

“To have brought the Arabian Oryx back from the brink of extinction is a major feat and a true conservation success story, one which we hope will be repeated many times over for other threatened species,” says Ms Razan Khalifa Al Mubarak, Director General of the Environment Agency-Abu Dhabi. “It is a classic example of how data from the IUCN Red List can feed into on-the-ground conservation action to deliver tangible and successful results.”

The Arabian Oryx, a species of antelope found only on the Arabian Peninsula, is locally known as Al Maha. It is believed the last wild individual was shot in 1972. This year, thanks to successful captive breeding and re-introduction efforts, the oryx has finally qualified for a move from the endangered category to Vulnerable on the IUCN Red List—the first time that a species that was once Extinct in the Wild has improved by three categories.

Although we are achieving successes, there are some alarming new findings. Of the 19 species of amphibian (frogs, toads and salamanders) that have been added to the IUCN Red List this year, eight are listed as Critically Endangered, including Atelopus patazensis, a species of harlequin toad from Peru, and Dendrotriton chujorum, a dwarf species of salamander from Guatemala. Amphibians remain one of the most threatened species groups with an estimated 41% at risk of extinction; the main threats they face include habitat loss, pollution, disease and invasive species.

In the case of New Caledonia’s endemic reptiles, which have been assessed for the first time, two thirds (67%) of species within this group for which we have sufficient data are at risk of extinction. Many of these reptiles are threatened by ongoing habitat loss and fragmentation as New Caledonia’s nickel mining industry continues to expand. This is compounded by the effects of introduced species; for example, deer and pigs damage remaining available habitat, and fire ants, which are invasive alien species, decimate lizard populations, leading to localized extinctions.

“The key to halting the extinction crisis is to target efforts towards eradicating the major threats faced by species and their environment; only then can their future be secured. The IUCN Red List acts as a gateway to such efforts, by providing decision makers with a goldmine of information not only on the current status of the species, but also on existing threats and the conservation actions required,” says Simon Stuart, Chair of IUCN’s Species Survival Commission.

A further new addition to the IUCN Red List is the recently discovered primate Wallace’s Tarsier (Tarsius wallacei). This forest-dwelling species was first described in 2010, and is found in just two small areas of Central Sulawesi, Indonesia. Unlike its cousin the Siau Island Tarsier (Tarsius tumpara), also new on the IUCN Red List this year and classified as Critically Endangered, Wallace’s Tarsier has been listed as Data Deficient. Species are classified as Data Deficient when not enough information is known to assign them to another category.

An assessment of all 248 lobster species has been completed, with 35% being classified as Data Deficient, including the Caribbean Spiny Lobster (Panulirus argus). This species shows decreasing populations as a result of over-exploitation, but unfortunately very little else is known about it. An estimated 1.2 billion people worldwide rely on marine species for food and livelihoods, so obtaining reliable information on catch levels is essential.

“It is extremely important that we keep pushing forward with surveys of little-known species, as without adequate data, we cannot determine their risk of extinction and therefore cannot develop or implement effective conservation actions which could prevent the species from disappearing altogether,” says Jane Smart, Director, IUCN’s Global Species Programme.

Biodiversity loss is one of the world’s most pressing crises, with many species declining to critically low levels. Numerous extinctions are taking place unnoticed, and the number of species classified as Critically Endangered (those at most severe risks are increasing ). Estimations from the IUCN Red List indicate that extinctions are happening at anywhere from 100 to 1,000 times the ‘background’ or natural rate. The causes are many, including habitat destruction, land conversion for agriculture and development, climate change, pollution, illegal wildlife trade, and the spread of invasive species.

“Conservation does work and species can recover, as shown in the case of the Arabian Oryx. Using data from the IUCN Red List, an opportunity exists for governments and society to guide conservation programmes to put the brakes on species extinctions,” says Julia Marton-Lefèvre, IUCN’s Director General.
 

For more information, please contact:

Borjana Pervan, IUCN Media Relations, m +41 79 857 4072, eborjana.pervan@iucn.org
Lynne Labanne, Species Programme Communications,IUCN, t +41 22 999 0153, m +41 79 527 7221, e lynne.labanne@iucn.org
Kathryn Pintus, Species Programme Communications, IUCN, t +41 22 999 0154, e kathryn.pintus@iucn.org

Population regulation of territorial species and the complexity of the regulatory process.

Population regulation of territorial species: both site dependence and interference mechanisms matter

Marie Nevoux1,Olivier Gimenez,Debora Arlt, Malcolm Nicoll, Carl Jones and Ken Norris

Published online before print December 15, 2010, doi: 10.1098/rspb.2010.2352 Proc. R. Soc. B 22 July 2011 vol. 278 no. 1715 2173-2181

I read this paper the other day and found it very interesting.

It is assumed that spatial patterns of site occupancy are driven by habitat heterogeneity and this has a bearing in shaping population dynamics through a site-dependent regulatory mechanism. The authors say most studies have only focused on a single vital rate (reproduction), and little is known about how space effectively contributes to the regulation of population dynamics. They investigated the underlying mechanisms driving density-dependent processes in vital rates in a Mauritius kestrel population where almost every individual was monitored.

Different mechanisms acted on different vital rates. The breeding success was regulated by site dependence (differential use of space) and juvenile survival by interference (density-dependent competition for resources).

Although territorial species are frequently assumed to be regulated through site dependence, the researchers show that interference was the key regulatory mechanism in this population.  The integrated approach demonstrated that the presence of spatial processes regarding one trait does not mean that they necessarily play an important role in regulating population growth, and demonstrates the complexity of the regulatory process.

Monitoring carnivore populations at the landscape scale: occupancy modeling of tigers from sign surveys

Monitoring carnivore populations at the landscape scale: occupancy modeling of tigers from sign surveys

Kota Ullas Karanth1,, Arjun M. Gopalaswamy, Narayanarao Samba Kumar, Srinivas Vaidyanathan, James D. Nichols and Darryl I. MacKenzie

Here is a new paper from Dr Ullas Karanth et al, which is of great relevance to conservationists. It has appeared in the Journal of Applied Ecology. The paper lays emphasis on the use of surveys of large carnivore signs such as tracks and scats, to assess their distributions across large landscapes.

This is an application of an occupancy model Dr Ullas had earlier developed with Jim Hines and other colleagues at USGS and was used to assess tiger distributions in 30,000 sq.km landscape in Karnataka.

The method uses spatial replication and deals explicitly with the problem of imperfect detections, which is often a problematic issue with distribution surveys.The method has great potential for cost effective surveys of tigers and other similar wide-ranging species.  

Dr Ullas Karanth is currently working on further model extensions to link these data to rigorous estimates of tiger density from camera trap surveys at specific sites to generate tiger abundance estimates for larger regions.

This paper is a must read paper for wildlife researchers and managers. I recommend it unreservedly.