A look at imponderables of optimal reserve spacing

Risk spreading, connectivity, and optimal reserve spacing

Shane A. Blowes1 and Sean R. Connolly

Ecological applications, Volume 22, Issue 1 (January 2012)

Dispersal and the spatial covariance of demographic fluctuations are the two important processes that determine the dynamics of spatially structured populations. The researchers  say Spatially explicit approaches to conservation, such as reserve networks, must consider the tension between these two processes and reach a balance between distances near enough to maintain connectivity, but far enough to benefit from risk spreading.

Here  the researchers model this trade-of and show how two measures of metapopulation persistence depend on the shape of the dispersal kernel and the shape of the distance decay in demographic covariance. They then go and have a look at the implications of this trade-off for reserve spacing. They say the relative rates of distance decay in dispersal and demographic covariance determine whether the long-run metapopulation growth rate, and quasi-extinction risk, peak for adjacent patches or intermediately spaced patches; two local maxima in metapopulation persistence are also possible.

When dispersal itself fluctuates over time, the trade-off also changes over time. Temporal variation in mean distance that propagules are dispersed (i.e., propagule advection) decreases metapopulation persistence and decreases the likelihood that persistence will peak for adjacent patches. On the other hand , variation in diffusion (the extent of random spread around mean dispersal) increases metapopulation persistence overall and causes it to peak at shorter inter-patch distances. Thus, failure to consider temporal variation in dispersal processes increases the risk that reserve spacings will fail to meet the objective of ensuring metapopulation persistence.

This study identifies two phenomena that receive relatively little attention in empirical work on reserve spacing, but that can qualitatively change the effectiveness of reserve spacing strategies:

1) The functional form of the distance decay in covariance among patch-specific demographic rates

(2) Temporal variation in the shape of the dispersal kernel.

The researchers conclude that sensitivity of metapopulation recovery and persistence to how covariance of vital rates decreases with distance suggests that estimating the shape of this function is likely to be as important for effective reserve design as estimating connectivity. Similarly, because temporal variation in dispersal dynamics influences the effect of reserve spacing, approaches to reserve design that ignore such variation, and rely instead on long-term average dispersal patterns, are likely to lead to lower metapopulation viability than is actually achievable.

England opts for 12 Nature Improvement Areas

Growing enlightened approach to conservation on a landscape scale has prompted authorities in England to plumb for 12 Nature Improvement Areas (NIAs), where wildlife and ecosystems will be protected and enhanced. It is also the result of the realisation that investing in nature returns significant benefits to the economy.

The formation of 12 nature reserves is the outcome of the recommendations in “Making Space for Nature: A review of England’s Wildlife Sites and Ecological Network” Chaired by Professor Sir John Lawton CBE FRS. The report stressed the need to add new areas and the urgent need to link them together.

The authorities hope that larger landscapes can buffer people and wildlife against the impacts of climate change.

The report “Making Space for Nature: A review of England’s Wildlife Sites and Ecological Network” is available HERE

A new way to augment existing home range techniques

Time geography and wildlife home range delineation

Jed A. Long and Trisalyn A. Nelson

The Journal of Wildlife Management

Volume 76, Issue 2, pages 407–413, February 2012

In this paper the researchers introduce a new technique for delineating animal home ranges    : the potential path area (PPA) home range. The technique is simple and intuitive

PPA home ranges are based on existing theory from time geography. An animal's movement is constrained by known locations in space–time (i.e., n telemetry points) and a measure of mobility (e.g., maximum velocity).

Using the formulation the researchers provide, PPA home ranges can be easily implemented in a Geographic Information System (GIS).

The researchers say the advantage of the PPA home range is the explicit consideration of temporal limitations on animal movement. They identify the PPA home range as a stand-alone measure of animal home range or as a way to augment existing home range techniques.

Future developments are highlighted against the backdrop of the usefulness of time geography for wildlife movement analysis. To facilitate the adoption of this technique the researchers provide a tool for implementing the new method.

So guys go ahead and give it a try.

Book recommendation

Reintroduction Biology: Integrating Science and Management

John G. Ewen (Editor), Doug P. Armstrong (Editor), Kevin A. Parker (Editor), Philip J. Seddon (Editor)

ISBN: 978-1-4443-6156-8

Hardcover, 528 pages

January 2012, Wiley-Blackwell

The formation of the IUCN/SSC Re-introduction Specialist Group was a milestone in conservation. Lot of advance has been made in the filed of reintroduction with the advent of the group. This book aims to further advance the field of reintroduction biology.

 The book advocates a strategic approach to reintroduction where all actions are guided by explicit theoretical frameworks based on clearly defined objectives. It covers topics like husbandry and intensive management, monitoring, and genetic and health management. 

 People wanting to bridge the research-management gap will find the book highly useful. The book is unreservedly recommended for Wildlife managers wanting to expand their thinking about reintroduction-related decisions and researchers aspiring to make useful applied contributions to reintroduction.

Rabbs' fringe-limbed tree frog – Only one frog left

                                           Photo courtesy: Zoo Atlanta

Rabbs' fringe-limbed tree frog (Ecnomiohyla rabborum) is named after conservationists George and Mary Rabb. The species was first identified by Mendelson, J.R. and an international team of scientists on a field expedition to Panama in 2005. Amphibian chytrid fungus has swiped out the population in the wild. They have not been observed in the wild since 2007.

The last known member of this species resides at the Atlanta Botanical Garden.

A guest post

Here is a guest post from Ramesh, my friend

Perils of unbridled Ecotourism

I was in Eravikualm National Park recently,just before the closure of the park, after a gap of 15 years. Sea changes have occurred there. Community participation in conservation has taken strong roots and the community obviously benefits from tourism.  But I was a little bit peeved by the overkill in terms of opening up areas for ecotourism. Remember, Eravikualm is the abode of Nigiri tahr, one of the most endangered animals in the world. Any activity that is taken up should not have any negative impact on Nilgiri tahr.

Ecotourism is increasingly being marketed in our wildlife reserves as a panacea for all ills affecting the parks. This does not augur well for conservation. Ecotourism isn’t always a win-win situation for nature and local people. We must always be on the guard against the deleterious effects of ecotourism.

The main disadvantages in wildlife reserves are

1) Crowding by visitors

2) Overuse and ensuing soil erosion

3) Disturbance to wildlife

4) Noise pollution

 Biologist Henrik Brumm of the Free University of Berlin has found that male territorial nightingales in Berlin had to sing five times as loud in an area of heavy traffic. Henrik is sure that this could be affecting their vocal musculature and he wonders what is going to happen in future if the noise levels keep going up. I shudder to think about the implications.

International Journal of Primatology sometime back reported that tourism was causing changes in primate behaviour and could be a causing infant mortality. This report was the result of a 19-year study, “Primate Tourism, Range Restriction and Infant Risk Among Macaca thibetana at Mt. Huangshan, China,” led by anthropologist Carol Berman of University of Buffalo.

Disease transmission from human beings is another great risk. Scientists in the Chobe National Park, Botswana, have documented how tuberculosis was passed on to mongooses which led to two outbreaks of the disease in the Park. Mongooses picked up the illness from contaminated rubbish heaps left in the Park by the tourists.

Deliberate feeding of food to wildlife is an activity rife with problems. This tends to alter natural behaviour patterns of the denizens of the wild. We have clearly seen in many areas what dependency of monkeys on the human provided food can do to the animals and the nuisance it creates for us. In the mad rush to obtain food the animals sometimes harms one another. I remember one of my friends telling me about one tourist trying to feed Nilgiri tahr with IJ (Indian junk, a term used by foreigners for the Indian fast food item, mixture). The incident occurred a few years back

I remember Mohanji once telling me how stress by visitors brings in energetic demands on animals which in turn affect their capacity to breed. This energetic demand could have more impact than poaching on animals.

Another danger of over-dependence on ecotourism is that public funds for supporting nature conservation may be reduced and this could negatively impact nature conservation in the long run.

Ecotourism is fine but it has to be practised judiciously if it is to benefit our wildlife.

Tailpiece: My visit to Eravikualm threw up this question? What has happened to all the officers trained in wildlife management? They are obviously an endangered lot.

Tom Milliken, TRAFFIC's expert on rhino horn trade interviewed

Have a look at this hard hitting interview

Visit msnbc.com for breaking news, world news, and news about the economy

Remote-controlled plane as a potent tool for conservation

The Orangutan Conservancy, and the Denver Zoo, Lian Pin Koh, an ecologist at the University of Zurich, and Serge Wich of the Great Ape Trust have devised an ingenious conservation drone equipped with cameras, sensors and GPS. The drone cost less than $2,000 and the user pre-programs each mission on a laptop computer. It offers a cost-effective way of counting wildlife over difficult terrain. The imagery is of far higher resolution than from satellites.

The researchers have put the drone to effective use to map deforestation and count orangutans in North Sumatra.

The drone certainly will be an effective conservation tool in difficult terrain. Tahrcountry exhorts conservationists to go in for this new tool and improve its functioning. I am very excited.

Have a look at the video

Geo-Wiki and efforts to fine tune land cover information available to policymakers and the research community

The other day I was discussing with my friend, Ramesh the strides made by Geo-Wiki project.

Geo-Wiki Project is a global network of volunteers whose desire is to improve the quality of global land cover maps.

Volunteers are asked to review hotspot maps of global land cover disagreement and determine, based on what they actually see in Google Earth and their local knowledge, if the land cover maps are correct or incorrect. The input is recorded in a database, along with uploaded photos. The aim is creation of a new and improved global land cover map.

There are many areas where the information derived from satellite imagery is conflicting. The men behind the Geo-Wiki project hope to resolve the conflict with help from volunteers across the globe. Here is a toast for the magnificent effort

Have a look at Geo-Wiki website and see whether you are in a position to contribute. Click HERE to go to the website

Getting to know IUCN

Have a look at this video from IUCN

Bridging the research--implementation gap

Graduate students in conservation biology: Bridging the research–implementation gap

Jason R. Courter, Biological conservation Pages 62-64 Volume 20, Issue 1

There is no denying the fact that there is a chasm between precept and practice when it comes to academic research and the practice in the field by mangers.

In this paper the researcher review common recommendations for bridging the Research–Implementation Gap in conservation biology, highlight the unique abilities of graduate students to contribute solutions to this problem, and propose ways research institutions and professionals can encourage graduate students to participate in this process.

While many may argue that the main purpose of graduate school is to focus on research, the researcher  argue that being exposed early to the broader issues of research and implementation enhances the graduate research experience, helps train students to become leaders in conservation science, and contributes both immediate and long-term solutions to the research–implementation problem.

On the whole this paper is very thought provoking and deserves a look in to. 

Discover IUCN (International Union for Conservation of Nature)

Have a look at this video produced by IUCN

Use of abundance data to detect species at risk of extinction may fail to detect initial declines in abundance

Variability in Population Abundance and the Classification of Extinction Risk

HOWARD B. WILSON, BRUCE E. KENDALL, HUGH P. POSSINGHAM

Conservation Biology, Volume 25, Issue 4, pages 747–757, August 2011

In conservation practice it is standard practice to Classify species according to their risk of extinction. The reliability of the classification depends on the accuracy of threat categorizations.  When it comes to errors in the process we have very limited info. It involves getting information from many sources. Understanding the quality of each source is de rigueur to evaluate the overall status of the species.

One common criterion used to classify extinction risk is a decline in abundance. Abundance is a direct measure of conservation status. So counts of individuals are generally the preferred method of evaluating whether populations are declining.

Using the thresholds from criterion A of the International Union for Conservation of Nature (IUCN) Red List (critically endangered, decline in abundance of >80% over 10 years or 3 generations; endangered, decline in abundance of 50–80%; vulnerable, decline in abundance of 30–50%; least concern or near threatened, decline in abundance of 0–30%), the researchers assessed 3 methods used to detect declines solely from estimates of abundance

1)      Use of just 2 estimates of abundance

2)       Use of linear regression on a time series of abundance;

3)      Use of state-space models on a time series of abundance.

The researchers generated simulation data from empirical estimates of the typical variability in abundance and assessed the 3 methods for classification errors.

The estimates of the proportion of falsely detected declines for linear regression and the state-space models were low (maximum 3–14%), but 33–75% of small declines (30–50% over 15 years) were not detected. Ignoring uncertainty in estimates of abundance (with just 2 estimates of abundance) allowed more power to detect small declines (95%), but there was a high percentage (50%) of false detections. For all 3 methods, the proportion of declines estimated to be >80% was higher than the true proportion

The researchers conclude that use of abundance data to detect species at risk of extinction may either fail to detect initial declines in abundance or have a high error rate.

Nilgiri tahr recovery plan

Several persons have requested me for a copy of the Nilgiri tahr recovery plan, prepared by, Easa, P. S., Alembath, M., Zacharias and J., Daniels.

Citation: Easa, P. S., Alembath, M., Zacharias and J., Daniels. Recovery Plan for the Nilgiri Tahr (Nilgiritragus hylocrius).Asia Biodiversity Conservation Trust and Care EarthTrust

Click HERE to access the pdf version

Surveys along unpaved roads can be a valuable, unbiased source of information for species distribution models

Predicting Species Distributions from Samples Collected along Roadsides

KYLE P. MCCARTHY, ROBERT J. FLETCHER JR,CHRISTOPHER T. ROTA and RICHARD L. HUTTO

Conservation Biology

Volume 26, Issue 1, pages 68–77, February 2012

Currently we do not know whether roadside sampling limits the accuracy of predictions generated by species distribution models. The researchers here tested whether roadside sampling affects the accuracy of predictions generated by species distribution models by using a prospective sampling strategy designed specifically to address this issue. They built models from roadside data and validated model predictions at paired locations on unpaved roads and 200 m away from roads, spatially and temporally independent from the data used for model building.

 The researchers predicted species distributions of 15 bird species on the basis of point-count data from a landbird monitoring program in Montana and Idaho (U.S.A.). They used hierarchical occupancy models to account for imperfect detection. The researchers expected predictions of species distributions derived from roadside-sampling data would be less accurate when validated with data from off-road sampling than when it was validated with data from roadside sampling and that model accuracy would be differentially affected by whether species were generalists, associated with edges, or associated with interior forest. Model performance measures (kappa, area under the curve of a receiver operating characteristic plot, and true skill statistic) did not differ between model predictions of roadside and off-road distributions of species. Performance measures did not differ among edge, generalist, and interior species, despite a difference in vegetation structure along roadsides and off road.  2 of the 15 species were found more likely to occur along roadsides.

The researchers contend that surveys along unpaved roads can be a valuable, unbiased source of information for species distribution models.

The battle to save Europe’s rarest seabird species

When a species bounces back from the brink, it is great news. It warms the cockles of the heart of conservationists worldwide. Here is one such happy news.

Zino’s Petrel (Pterodroma Madeira) is Europe’s rarest seabird. It is an endemic seabird of island of Madeira and breeds only there. The species was first described in 1903 by a German naturalist priest, Ernst Schmitz.

Zino's Petrel nests in burrows which they visit only at night. Quite a lot of depredation of eggs, chicks and adults has been causedin the past by introduced cats and rats. Conservation measures had enabled the population to recover to 65–80 breeding pairs. 

In August 2010 ravaging fires killed 25 young and 3 adults. Of the 13 young birds found alive, only one survived to fledge that year. Fire also brought in severe soil erosion, causing several nesting burrows to collapse. The species’ population was in jeopardy.

Recovery efforts were spearheaded by Natural Park of Madeira (PNM). With financial and logistical support from SPEA/BirdLife in Portugal, the RSPB/BirdLife in the UK and BirdLife International, about 100 natural nests were restored, while 60 new artificial nests were built. 

The efforts started bearing fruits in 2011. Monitoring of the breeding colony indicated that 45 nests were occupied – with eggs laid in 43 of them. Fledgling success was good, with 16 out of the 19 young birds eventually flying out to sea in October.

Tahrcountry joins conservationists worldwide in applauding the success.

A tribute to Dr Sue Mainka - IUCN news release

                                                              Photo:IUCN

The IUCN community is deeply saddened by the loss of its colleague and friend Dr Susan Mainka. Sue passed away on Sunday 12 February after a five-month battle with cancer. She made a huge contribution to IUCN, to the Species Programme and to maintaining the scientific rigour of our work. The Peter Scott Award for Conservation Merit was awarded to Sue by the IUCN Species Survival Commission on the 4th day of February 2012, in recognition of her pioneering work on the conservation of the Giant Panda, her leadership of the IUCN Species Programme, and her encouragement of conservationists worldwide, especially in Asia.

Sue, who had a doctorate in Veterinary Medicine, joined IUCN in 1997 as Deputy Coordinator of the Species Programme of which she became Coordinator in 2001. In 2004, she transferred to the Global Programme Team as one of three Senior Programme Coordinators. In 2009, Sue was promoted to the position of Head – Science and Knowledge Management.

Sue's knowledge and expertise and her dry sense of humour will be missed by many.

If you would like to add some words of condolence or share your memories of Sue, please click here and go to IUCN website

Techniques for assessing population size of low-density wildlife populations

Estimating population size and density of a low-density population of black bears in Rocky Mountain National Park, Colorado

Roger A. Baldwin and Louis C. Bender

EUROPEAN JOURNAL OF WILDLIFE RESEARCH, online 19 January 2012

This paper deals with techniques for assessing population size of low-density wildlife populations.

The area of study was Rocky Mountain National Park (RMN) and the subject black bear (Ursus americanus)

Rocky Mountain National Park is home to a low-density black bear (Ursus americanus) population. A previous study (1984–1991) found bear densities among the lowest reported (1.37–1.52 bears/100 km2).

The researchers used three approaches to estimate population size and density

 (1) Minimum number known

 (2) Occupancy modelling

 (3) Catch per unit effort (CPUE)

The researchers used information from capture and remote-triggered cameras, plus visitor information, to derive a minimum known population estimate of 20–24 individuals and a median density estimate of 1.35 bears/100 km2.

Bear occupancy was estimated at 0.46 (SE = 0.11). The occupancy was positively influenced by lodgepole pine stands, non-vegetated areas, and patches density but negatively influenced by mixed conifer stands. They combined the occupancy estimate with mean home-range size and overlap for bears in RMNP to derive a density estimate of 1.44 bears/100 km2.

The researchers related CPUE to density estimates for eight low-density black bear populations to estimate density in RMNP. The estimate (1.03 bears/100 km2) was comparable to the occupancy estimate. The researchers say this approach may be appropriate for future population monitoring.

The researchers sign off with the following words “The use of corroborative techniques for assessing population size of a low-density black bear population was effective and should be considered for similar low-density wildlife populations.”

Incredible video from Uganda's Bwindi Impenetrable Park

Have a look at this amazing video from Uganda's Bwindi Impenetrable Park.  A family of mountain gorillas pay a visit to the camp and check out one of the guests. The man sits stock-still and then enjoys the scenario,while several gorillas groom his hair. I doff my cap for this guy. I am truly spellbound. It sure is a once in a lifetime experience.

Decisions related to species conservation and the relevance of ecological niche modelling methods

The importance of defining the geographic distribution of species for conservation: The case of the Bearded Wood-Partridge

Claudio Mota-Vargas, Octavio R. Rojas-Soto

Journal for Nature Conservation, Volume 20, Issue 1, Pages 10-17

 A proper understanding of the distribution areas of species has fundamental implications for the proper understanding of biodiversity and for decision-making in conservation. The authors of this paper say this is very well illustrated by the case of the Bearded Wood-Partridge (Dendrortyx barbatus), which is endemic to Mexico and was classified as threatened by the IUCN.

Recently Bearded Wood-Partridge was discovered in new locations and this increase in known location led it to be reclassified in a lower risk category.

In this study the researchers examine closely, delimitation and comparison of the Bearded Wood-Partridge distribution area utilising five different methods: minimum convex polygon; areographic; cartographic; ecological niche modelling; and, “free hand”.  Locality records were used to demonstrate the chronological order of appearance. 

An analysis of the  results show that the size and shape of the distribution area of this species vary depending on the number of records and on their spatial and environmental location, as well as on the particular delimitation method used.

The researchers say ecological niche modelling provides the best results in terms of spatial and numerical sensitivity as well as lower values of omission and a moderate extent of predicted areas. They suggest that decisions related to species conservation (categories of risk, areas of endemism, etc.), particularly those species of high geographical restriction, should be contingent on the formalised delimitation of distribution areas based on ecological niche modelling methods.