How does birds avoid collisions with objects and each other?

Optic Flow Cues Guide Flight in Birds

Partha S. Bhagavatula, Charles Claudianos,Michael R. Ibbotson and Mandyam V. Srinivasan

Current Biology, 27 October 2011

The moment-to-moment challenges of rapid flight of birds through cluttered environments have always fascinated people. Australian scientists have unraveled the mystery surrounding how birds avoid collisions with objects and each other.

The researchers say the birds do this by using cues derived from the image motion that is generated in the eyes during flight.

The scientists investigated the ability of budgerigars to fly through narrow passages in a collision-free manner, by filming their trajectories during flight in a corridor where the walls are decorated with various visual patterns.

The researchers sums up like this “The results demonstrated unequivocally and for the first time, that birds negotiate narrow gaps safely by balancing the speeds of image motion that are experienced by the two eyes and that the speed of flight is regulated by monitoring the speed of image motion that is experienced by the two eyes.”

Conservation biology and wildlife management – Beyond classrooms and in to practical, real-world issues

The other day Ramesh, my friend wanted me to recommend a book that takes the reader beyond what has been learned in the classrooms of conservation biology and wildlife management. My immediate recommendation was “Problem-Solving in Conservation Biology and Wildlife Management” authored by James P. Gibbs, Malcolm L. Hunter, Jr and Eleanor J. Sterling. If you have better recommendations please share it here for the benefit of Ramesh. Ramesh would be delighted to get your recommendations.
 

 “Problem-Solving in Conservation Biology and Wildlife Management” gives a set of 32 exercises expressly created for students and teachers of conservation biology and wildlife management. The book empowers the readers to take what has been learned in the classroom to the field and apply it to practical, real-world issues.

 A wide range of conservation issues is dealt with: genetic analysis, population biology and management, taxonomy, ecosystem management, land use planning, the public policy process and a lot more. All exercises discuss how to take what has been learned and apply it to practical, real-world issues. Additional plus points are a detailed instructor's manual and a student website with software and support material.

James Gibbs is Associate Professor of Environmental and Forest Biology at the State University of New York’s College of Environmental Science and Forestry.

Malcolm J. Hunter Jr is the Libra Professor of Conservation Biology and Professor of Wildlife Ecology at the University of Maine, Orono. He is also the former President of the Society for Conservation Biology.
Eleanor J. Sterling is Director of the Center for Biodiversity and Conservation at the American Museum of Natural History and Director of Graduate Studies in the Department of Ecology, Evolution, and Environmental Biology at Columbia University.

Problem-Solving in Conservation Biology and Wildlife Management

Publisher: John Wiley & Sons, Inc.

Published on: 08/31/2011

Print ISBN: 9781405152877

Imprint: Wiley-Blackwell

By: James P. Gibbs, Malcolm L. Hunter, Jr., Eleanor J. Sterling

During breeding time Antarctic fur seals have uncanny ability to return to where they themselves were born

Extreme natal philopatry in female Antarctic fur seals (Arctocephalus gazella)

Joseph Ivan Hoffman and  Jaume Forcada

 Mammalian Biology  doi:10.1016/j.mambio.2011.09.002

Scientists led by Dr Joe Hoffman from the University of Bielefeld in Germany have discovered that majority of female Antarctic fur seals (Arctocephalus gazella) give birth to pups within 2 metres of where they themselves were born

The truly amazing fact is that these seals may have spent up to five years feeding hundreds of kilometres out at sea before coming home.

The scientist quantified fine-scale patterns of natal philopatry in an intensively studied colony of Antarctic fur seals, where a scaffold walkway allows individual locations to be measured to the nearest metre. Using subcutaneous PIT tags, they tracked the early life histories of 335 females born within the colony, of which 38 were resighted as breeding adults.

The researchers  found that individual females returned to as little as one body length (2 m) of their birth locations. Distances between natal and pupping sites were not correlated with female age, but tended to decrease with the number of seasons an individual was sighted ashore. The researchers say this suggests that breeding experience may be a better predictor than age of the ability of females to occupy preferred sites within fur seal colonies.

The mystery of how woodpeckers avoid head injuries cracked

Why Do Woodpeckers Resist Head Impact Injury: A Biomechanical Investigation

Lizhen Wang, Jason Tak-Man Cheung, Fang Pu, Deyu Li, Ming Zhang, Yubo Fan

PLoS ONE 6(10): e26490. Doi: 10.1371/journal.pone.0026490

Woodpeckers peck tree trunks at speeds of six to seven meters a second, dozens of times a minute. How they avoid head injury has remained a mystery till now. A team of bioengineers from School of Biological Science and Medical Engineering, Beihang University, Beijing, Department of Health Technology and Informatics, the Hong Kong Polytechnic University, and Li Ning Sports Science Research Center, Beijing has solved it

Two synchronous high-speed video systems were used to observe the pecking process, and a force sensor was used to measure the peck force. The mechanical properties and macro/micro morphological structure in woodpecker's head were investigated using a mechanical testing system and micro-CT scanning. Finite element (FE) models of the woodpecker's head were established to study the dynamic intracranial responses.

 The result showed that macro/micro morphology of cranial bone and beak can be recognized as a major contributor to non-impact-injuries. This biomechanical analysis makes it possible to visualize events during woodpecker pecking.

Woodpecker skulls have evolved with several varied layers of protection that allow them to absorb the fierce up to 1,000 G. The unequal length of the upper and lower parts of their beaks, serves to steer the impact force downwards, away from the brain, when it hits the tree. The woodpecker’s brain is contained within a unique skull casing, constructed from uneven, spongy plates. The heart-shaped hyoid bone, which reaches from their beak, loops over the top of the skull to completely surround their brains. This firmly keeps the brain in place, especially during the head’s backwards motion.

 

The researchers sign off with the following words ‘The design of intelligent helmet or impact-related injury resistant device would be enlightened greatly by the optimizations of woodpecker's skull morphology and microstructure and is helpful in developing new concepts for minimizing head impact injuries in future work.”

 Yes better lightweight helmets could be on the way aided by the study of woodpeckers

 

Breaking new ground in Quantitative training for students of ecology

Introducing data–model assimilation to students of ecology 

Hobbs, N. Thompson, and Kiona Ogle

Ecological Applications, Volume 21, Issue 5

Here is a paper that advocates a new approach to quantitative training for students of ecology.

Quantitative training for students of ecology usually comprises two sets of topics.

The components are

1) Mathematical modeling

2) Statistical analysis.

Traditionally these two topics are taught separately, modeling courses stressing on mathematical techniques for symbolic analysis and statistics courses stressing on procedures for analyzing data.

Here the researchers plumb for a merger of two separate courses by outlining a curriculum for an introductory course in data–model assimilation. Traditional introductory material in statistics is replaced by an emphasis on principles needed to develop hierarchical models of ecological systems, fusing models of data with models of ecological processes.

Here is the outline of the course devised by the researchers

 (1) Models as routes to insight.

 (2) Uncertainty

 (3) Basic probability theory

 (4) Hierarchical models

 (5) Data simulation

 (6) Likelihood and Bayes

 (7) Computational methods

 (8) Research design

 (9) Problem solving.

The researchers say the outcome of teaching these combined elements can be the fundamental understanding and quantitative confidence needed by students to create revealing analyses for a broad array of research problems.

Applying eigenvalue perturbation theory (EPT) to select optimum networks of protected areas based on connectivity

Optimal networks of nature reserves can be found through eigenvalue perturbation theory of the connectivity matrix

Jacobi, Martin Nilsson, and Per R. Jonsson

Volume 21, Issue 5 (July 2011) Ecological Applications

A functional network of protected areas is sine qua non for optimal conservation and management of natural resources and biodiversity. Improved criteria to select functional networks of protected areas assume great significance.

Usually connectivity within networks due to dispersal gets scant attention. This is partly because it is unclear how connectivity information can be included in the selection of protected areas.

In this paper the authors present what they claim a novel and general method that applies eigenvalue perturbation theory (EPT) to select optimum networks of protected areas based on connectivity.

The authors say at low population densities, characteristic of threatened populations, this procedure selects networks that maximize the growth rate of the overall network. They claim their method offers an improved link between connectivity and metapopulation dynamics.

The framework designed by the researchers is applied to connectivities estimated for marine larvae. It amply demonstrates that, for open populations, the best strategy is to protect areas acting as both strong donors and recipients of recruits.

The researchers sign off saying,  “It should be possible to implement an EPT framework for connectivity analysis into existing holistic tools for design of protected areas.

The Kingfisher that flew from Poland to England

My British contacts have sent me this amazing story of a Kingfisher that flew to England from Poland and in the process set a record.

The kingfisher that had been ringed in Poland has been caught and released in Suffolk’s Orford Ness reserve. The Kingfisher must have flown around 1,000km. Once it is discovered where in Poland the kingfisher was ringed an accurate distance will be known.

Even though Kingfishers that have been rung in Germany and Spain have been caught previously this is a new record for the distance travelled.

The previous record set by a British kingfisher for migration was a bird ringed in Marloes, Pembrokeshire, and found in Irun, Spain

The dilemma of alternative land uses in conservation prioritization

Balancing alternative land uses in conservation prioritization

Atte Moilanen,Barbara J. Anderson,Felix Eigenbrod,Andreas Heinemeyer, David B. Roy, Simon Gillings, Paul R. Armsworth, Kevin J. Gaston, and Chris D. Thomas.

 Ecological applications, Volume 21, Issue 5 (July 2011)

As the population burgeons there is increasing pressure on ecosystems to provide various often-conflicting services.

Success of various conservation prioritizations will be much more effective if we assess the needs of competing land uses at the planning stage itself.

In this paper the researchers develop such methods and illustrate them with data about competing land uses in Great Britain, with the aim of developing conservation priority ranking that balances between needs of biodiversity conservation, carbon storage, agricultural value, and urban development potential.

The researchers say, “While both carbon stocks and biodiversity are desirable features from the point of view of conservation, they compete with the needs of agriculture and urban development.”

In their application, the researchers were able to successfully balance the spatial allocation of alternative land uses. The conflicts between various demands were much smaller than had they been developed separately. The researchers say proposed methods and software, Zonation, are applicable to structurally similar prioritization problems globally.

Are we biased in locating our Protected Areas?

High and Far: Biases in the Location of Protected Areas

Joppa, L., & Pfaff, A. PLoS ONE, 4 (12) (2009).

This is a 2009 paper, which I came across the other day. I found it very interesting.

About an eighth of the earth's land surface is covered under protected areas. Majority of these parks came up during the 20^th century. Even though it looks very rosy the fact remains that many of the current PAs were not created with a systematic eye to achieving conservation priorities. Across 147 countries' national networks, protected areas are non-randomly located on the landscape.

The authors of this paper say many of the PAs are biased in their formation. The researchers try and examine each country's PA network for bias in elevation, slope, distances to roads and cities, and suitability for agriculture. Their analysis indicates that significant majority of park networks are biased to higher elevations, steeper slopes and greater distances to roads and cities. Another interesting feature is that within a country, PAs with higher protection status are more biased than are the PAs with lower protection statuses. In short parks are biased towards where they can least prevent land conversion. Hoekstra et al has previously shown us a clear bias in protection towards certain biomes and ecoregions.
All previous global studies have ignored political boundaries. This is a vital omission. Ecological processes cross borders but most PAs do not.

The authors categorically say investment in new PAs will need to be much more efficient. They should be based upon sophisticated conservation planning tools.

The researchers say their results support the idea that targeting and blocking threat may deserve higher priority in the future creation and management of PAs. Their results also highlight the increasing realization that future PA allocation must differ from historic protection strategies.

Sad news from Vietnam

Javan rhino is gone forever in Vietnam

Vietnam authorities and WWF have confirmed the sad news. The Javan (Rhinoceros sondaicus annamiticus) is extinct in Vietnam.

Genetic analysis of dung samples collected from Cat Tien National Park have affirmed that it belonged to a rhinoceros that was found dead in the park in April 2010. Poaching is the likely cause of the death, as the rhino found dead had bullet in its leg and had its horn removed. With this sad loss Vietnam has lost part of its natural heritage.

The Javan rhinoceros is now confined to one population, less than 50 individuals, in Ujung Kulon National Park in Indonesia

Transgenic seeds and biodiversity - Alarm bells from Mexico

Six scientists at the National Autonomous University of Mexico (UNAM) and the National Commission for Knowledge and Use of Biodiversity (CONABIO) have come up with the alarming finding that Wild cotton in Mexico has been contaminated with genetically modified material.

Wild cotton that harbors transgenes undergoes rapid evolution, with unpredictable consequences. The genetic diversity of wild populations is very high, and that of cultivated cotton is very low. Gene flow can reduce the differentiation between populations the scientist warn

Although seed migration out of fields of genetically modified crops may be low, once a single or a few transgenic individuals are dispersed into particular wild populations, they produce pollen that may fertilise local wild plants. Since transgenes are inserted within the nuclear genome, they can be dispersed both via pollen or seed.

The scientists warn that genetically modified organisms are going to contaminate all the varieties we have, and then we will have to depend on seeds from the big companies. Once we lose our native seeds, we won't have seeds to plant and the multinational seed companies are going to plunder us.

  

Journal reference

  

Recent long-distance transgene flow into wild populations conforms to historical patterns of gene flow in cotton (Gossypium hirsutum) at its centre of origin

A. WEGIER, A. PIÑEYRO-NELSON, J. ALARCÓN, A. GÁLVEZ-MARISCAL, E. R. ÁLVAREZ-BUYLLA, D. PIÑERO

 Molecular Ecology, Volume 20, Issue 19, pages 4182–4194, October 2011

Wildlife award for farmer – Shining example from UK

This year’s prestigious Silver Lapwing Award has been conferred on South Lincolnshire fen farmer Nicholas Watts. He had turned his Vine House Farm into a paradise for birds. He meticulously records all birds on the farm and implements conservation plans based on these surveys.

The award in its 34th year recognizes long-term commitment to wildlife conservation by the farming community.

Nicholas Watts was presented with the Silver Lapwing Trophy and a cheque for £1,000. He has the distinction of being the only person to have won the award twice.

We at Tahrcountry salute Mr Nicholas Watts and the organizers of this award. This award model is worthy of emulation by other countries.

The two remaining wild populations of the endangered Indian rhinoceros - A study based on DNA and its implications for management

Genetic differences between the two remaining wild populations of the endangered Indian rhinoceros (Rhinoceros unicornis)

Samuel Zschokke, Georg F.J. Armbruster, Sylvain Ursenbacher Bruno Baur
Biological Conservation, Volume 144, Issue 11, November 2011, Pages 2702-2709

Understanding the characterization of the genetic units within each species and their relationships to each other is of primary importance when it comes to the management of rare and endangered species.

The Indian rhinoceros (Rhinoceros unicornis) is an endangered species with a current population size of c. 2800 individuals. The researchers analyzed 26 individuals of known origin kept in captivity and 21 wild ranging individuals of the two remnant large wild populations in Assam (India) and Nepal.

Mitochondrial and microsatellite markers were used to determine whether the two geographically isolated populations show distinct patterns of genetic diversity, and whether the genetic diversity of the populations is influenced by past demographic bottlenecks.

The researchers identified 10 different mitochondrial D-loop haplotypes, of which 4 were specific to the Assam population (10 sequences examined) and 6 specific to the Nepal population (19 sequences).

Microsatellite analysis demonstrated a strong genetic differentiation between the Assam and Nepal populations and allowed to assign each individual to its origin with high confidence.

The analyses revealed the occurrence of a bottleneck in the Assam population much earlier than the reported bottleneck in 1908.  It also revealed that the Nepal population is a recent (probably post-glacial) colonization.

The researchers contend that their data suggests separate conservation programs (even for captive individuals) as long as the persistence of the entire species is not severely threatened. The two populations should be treated as separate management units. The microsatellite markers can also be used to determine the origin of confiscated material such as horns.

Overcoming Impediments to invertebrate conservation

The seven impediments in invertebrate conservation and how to overcome them

Pedro Cardoso, Terry L. Erwin,Paulo A.V. Borges, Tim R. New
Biological Conservation
Volume 144, Issue 11, November 2011, Pages 2647-2655

Invertebrates often get step motherly treatment in biodiversity conservation policies despite their high diversity and importance for humankind. In this paper the researchers identify seven impediments to the effective protection of Invertebrates.

They are 
(1)    Invertebrates and their ecological services are mostly unknown to the general public (the public dilemma);

(2)Policymakers and stakeholders are mostly unaware of invertebrate conservation problems (the political dilemma);

(3)     Basic science on invertebrates is scarce and under funded (the scientific dilemma); 
(4)     Most species are undescribed (the   Linnean shortfall); 

(5) The distribution of described species is mostly unknown (the Wallacean shortfall);

(6) The abundance of species and their changes in space and time are unknown (the Prestonian shortfall);

(7) Species ways of life and sensitivities to habitat change are largely unknown (the Hutchinsonian shortfall).

The researchers say recent advances in science facilitate overcoming these impediments in both policy and practice.


Here are the suggestions from the researchers 

For the political dilemma: red-listing, legal priority listing and inclusion in environmental impact assessment studies.  For the scientific dilemma: parataxonomy, citizen science programs and biodiversity informatics.
For the Linnean shortfall: biodiversity surrogacy, increased support for taxonomy and advances in taxonomic publications.
 For the Wallacean shortfall: funding of inventories, compilation of data in public repositories and species distribution modeling.
For the Prestonian shortfall: standardized protocols for inventorying and monitoring, widespread use of analogous protocols and increased support for natural history collections.
 For the Hutchinsonian shortfall: identifying good indicator taxa and studying extinction rates by indirect evidence.

Ecological limits to human disturbances – A case study involving trails

Human Activity Differentially Redistributes Large Mammals in the Canadian Rockies National Parks 

James Kimo Rogala, Mark Hebblewhite,Jesse Whittington,Cliff A. White,Jenny Coleshill and Marco Musian 
Ecology and Society 16(3): 16.

Burgeoning population is causing irrevocable havoc in many wilderness areas. Parks are susceptible to habitat degradation. Indirect habitat loss is also possible as a result from both natural and anthropogenic disturbances. This new study on the human impact on wildlife in some of Canada’s most popular national parks has identified limits at which trails can be used before ecological disturbance sets in. Even though the thrust is on Canadian Parks the results arrived at has implications for mangers worldwide.

The researchers say human activity on trails and roads may lead to indirect habitat loss, further limiting available habitat. Predators and prey may respond differentially to human activity, which in turn has the potential for disrupting ecological processes

The researchers investigated the relationship between wolf and elk distribution and human activity using fine-scale Global Positioning System (GPS) wildlife telemetry locations and hourly human activity measures on trails and roads in Banff, Kootenay, and Yoho National Parks, Canada. They observed a complex interaction between the distance animals were located from trails and human activity level resulting in species adopting both mutual avoidance and differential response behaviors. In areas < 50 m from trails human activity led to a mutual avoidance response by both wolves and elk. In areas 50 - 400 m from trails low levels of human activity led to differential responses; wolves avoided these areas, whereas elk appeared to use these areas predation refugia. These differential impacts on elk and wolves may have important implications for trophic dynamics.

As human activity increased above two people/hour, areas 50 - 400 m from trails were mutually avoided by both species, resulting in the indirect loss of important montane habitat.

The researchers contend that if park managers are concerned with human impacts on wolves and elk, or on these species’ trophic interactions with other species, they can monitor locations near trails and roads and consider hourly changes of human activity levels in areas important to wildlife.

The researchers sign off with the following words “The circadian cycle has been the finest temporal scale used by previous studies that associate wildlife distribution to human activity. Our research documented that wildlife avoidance occurs at finer spatio-temporal scales than previously studied. We found that wolf and elk selection of locations near trails and roads was dependent on hourly human activity levels and the distance to the human linear feature. A failure to properly address the scale at which wildlife respond to human activity could lead to mistaken conclusions about habitat selection. Proper assessment of the relationship between fine-scale human activity and wildlife distribution may have important implications for animal energy budgets, human-wildlife and predator-prey interactions, ecological trophic cascades, and wildlife viability.”

Theory and practice of conservation – Importance of quantitative recommendations

Quantitative recommendations for amphibian terrestrial habitat conservation derived from habitat selection behavior

Lukas Indermaur and Benedikt R. Schmidt

Ecological Applications 21:2548–2554, Volume 21, Issue 7 (October 2011)

When it comes to practice of conservation there is often a big slip  between the cup and the lip. Conservation managers rarely use scientific information when making decisions.

The grouse of the manger is that conservation scientists rarely provide their knowledge in a way that can directly be used by conservation practitioners. Often the reports are couched in words not understood by the practitioner.

In this paper the researchers show how quantitative recommendations for conservation can be derived.

Past research on terrestrial habitat selection behavior of toads (Bufo bufo and Bufo viridis) showed that wood deposits are a key resource in the terrestrial habitat. The researchers used habitat-dependence analysis to estimate the amount of this key resource, wood deposits, that individual toads require. Based on these estimates they quantified the requirements for wood deposits for a population. The also quantified the area that a population requires.

The researches say although wood deposits vary strongly in size, they found little evidence for size preferences: only one species preferred smallest sizes of wood deposits.

The researchers report all the estimates in a way that can be directly used by conservation managers.

The researchers sign off with the following words “Habitat-dependence analysis is a simple and useful tool to quantify habitat requirements. Provisioning of wood deposits may improve the quality of terrestrial habitat for amphibians. Thereby, managers may increase the carrying capacity of terrestrial habitats and support elevated population densities”

Estimating age when multiple sources of data are available and traditional aging techniques are not practical.

Estimating age from recapture data: integrating incremental growth measures with ancillary data to infer age-at-length

Mitchell J. Eaton and William A. Link

Ecological Applications 21:2487–2497.  Volume 21, Issue 7 (October 2011) 

For answering ecological questions, modeling population demographics, and managing exploited or threatened species estimation of age of individuals in wild populations is of paramount importance. Determining age through the use of growth annuli and growth models are in vogue.

The researcher say many species either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age.

Many Length-at-age models used in fisheries overlook variation in growth rates of individuals and consider growth parameters as population parameters. More recent models of this genre have taken advantage of hierarchical structuring of parameters and Bayesian inference methods to allow for variation among individuals as functions of environmental covariates or individual-specific random effects.

In this paper the researchers describe hierarchical models in which growth curves vary as individual-specific stochastic processes. They demonstrate how these models can be fit using capture–recapture data for animals of unknown age along with data for animals of known age.

The researchers say they combined these independent data sources in a Bayesian analysis, distinguishing natural variation (among and within individuals) from measurement error. They illustrate using data for African dwarf crocodiles, comparing von Bertalanffy and logistic growth models.

The researchers describe hierarchical models in which growth curves vary as individual-specific stochastic processes, and they show how these models can be fit using capture–recapture data for animals of unknown age along with data for animals of known age. The von Bertalanffy was much better supported than the logistic growth model and predicted that dwarf crocodiles grow from 19.4 cm total length at birth to 32.9 cm in the first year and 45.3 cm by the end of their second year. Based on the minimum size of females observed with hatchlings, the researchers estimated reproductive maturity to be at nine years.

The analysis provides the means of predicting crocodile age, from a single measurement of head length.

The researchers contend that these size benchmarks represent thresholds for important demographic parameters; improved estimates of age, therefore, will increase the precision of population projection models. They say the modeling approach that they present can be applied to other species and offers significant advantages when multiple sources of data are available and traditional aging techniques are not practical.

 

Amur leopard captured on camera in China

Amur leopard has been captured on camera in China for the first time since 1949.

The elusive cat was photographed in a forest in Wangqing County, on the border of Russia and North Korea.

 Photo: credit  Peking University/ World Wildlife Fund 

In April, a video captured five of the elusive leopards in the remote forests of the Russian Far East. Have look at the video.On slow connections it might take couple of minutes for the video to load.

Loss and fragmentation of natural areas and its effect on connectivity

Assessing effects of land use on landscape connectivity: loss and fragmentation of western U.S. forests

 Theobald, David M., Kevin R. Crooks, and John B. Norman

 Ecological Applications, 21:2445–2458.

The accent of this paper is on US, but what is described is of relevance worldwide. The methodology described can be readily modified to examine connectivity for other habitats/ecological systems and for other geographic areas

Loss and fragmentation of natural areas is a big concern for conservation scientists and land managers worldwide. Deleterious effects of land-use change are adversely affecting connectivity and conservation of biodiversity.

The authors of this paper say there is an urgent need to develop practical approaches to identify where important lands are for landscape connectivity (i.e., linkages), where land use constrains connectivity, and which linkages are most important to maintain network-wide connectivity extents. Their effort was to develop an approach that provides comprehensive, quantitative estimates of the effects of land-use change on landscape connectivity and illustrate its use on a broad, regional expanse of the western United States.

The researchers quantified loss of habitat and landscape connectivity for western-forested systems due to land uses associated with residential development, roads, and highway traffic. They examined how these land-use changes likely increase the resistance to movement of forest species in non-forested land cover types and reduce the connectivity among forested habitat patches. They applied a graph-theoretic approach that incorporates ecological aspects within a geographic representation of a network.

The researchers found that roughly one-quarter of the forested lands in the western United States were integral to a network of forested patches. Of course, the lands outside of patches remain critical for habitat and overall connectivity. Using remotely sensed land cover data (ca. 2000), they found 1.7 million km² of forested lands. They estimate that land uses associated with residential development, roads, and highway traffic have caused roughly a 4.5% loss in area (20 000 km²) of these forested patches. Continued expansion of residential land is likely to reduce forested patches by another 1.2% by 2030. They also identified linkages among forest patches that are critical for landscape connectivity. 

The researchers emphasize that their approach can be readily modified to examine connectivity for other habitats/ecological systems and for other geographic areas, as well as to address more specific requirements for particular conservation planning applications

How to clean an oil-slicked penguin

I read this excellent article on how to clean an oil-slicked penguin in BBC online. Biologist Jeremy Gray, volunteering at the Oiled Wildlife Response Centre in Tauranga, New Zealand, after the Rena oil spill, explains in detail the procedure involved. It might come in handy for you. Read it HERE

Wildlife Management - Well-meaning management strategies not based on sound scientific evidence, may go haywires

While managing endangered species wildlife mangers often resort to food supplementation. Even though it has the potential for delivering immediate benefits there could be hidden dangers. This has been proved by recent research on Spanish Imperial Eagle, Aquila adalberti,

Spanish Imperial Eagle, Aquila adalberti, is one of the most endangered birds of prey in the world. For two decades, intensive food supplementation has been used in attempting to improve the breeding productivity of the bird.

The researchers examined the impact of this intensive management action on nestling health, including contamination, immunodepression, and acquisition of disease agents derived from supplementation techniques and provisioned food.

The researchers found that fed individuals were often inadvertently “medicated” with pharmaceuticals (antibiotics and antiparasitics) contained in supplementary food (domestic rabbits). Individuals fed with medicated rabbits showed a depressed immune system and a high prevalence and richness of pathogens as against those with no or safe supplementary feeding using non-medicated wild rabbits. A higher presence of antibiotics (fluoroquinolones) was found in sick when compared to healthy individuals among eaglets with supplementary feeding. This in turn points directly toward a causal effect of these drugs in disease and other health impairments.

The researchers sign off with the following words” This study represents a telling example of well-meaning management strategies not based on sound scientific evidence becoming a “contraindicated” action with detrimental repercussions undermining possible beneficial effects by increasing the impact of stochastic factors on extinction risk of endangered wildlife.

Journal reference

When conservation management becomes contraindicated: impact of food supplementation on health of endangered wildlife

Guillermo Blanco, Jesús A. Lemus, Marino García-Montijano

Ecological Applications

Volume 21, Issue 7 (October 2011) pp. 2469-2477

UK is moving up a notch with landscape level conservation

The future belongs to landscape level conservation. National parks and other wildlife reserves are Ok, but they should never be seen as an end by itself. Many parks across the globe are becoming islands of isolation amidst teeming masses. Managing fragments will not deliver what wildlife requires in the long run.

Realizing the importance of landscape level conservation conservationists in UK are moving in a new direction, with reserves at the centre of a wider, landscape scale approach to protecting wildlife. At the focus is RSPB’s Futurescapes programme.  Within each Futurescape conservationists are working in partnership with farmers, landowners, local authorities and the community to ensure a living space for wildlife.

This effort by RSPB in association with other like-minded people and the local community is worthy of emulation by others.

Otter fecal genotyping studies and population estimation – Guidance for wildlife managers

The first river otter reintroductions in US occurred in Missouri and it is regarded as one of the most successful carnivore recovery programs in history.

The sticking point is that abundance estimates for river otter populations are difficult.  Here the researchers assessed the value of latrine site monitoring as a mechanism for quantifying river otter abundance. Analyses of fecal DNA to identify individual animals were tried.

The researchers say they optimized laboratory protocols, redesigned existing microsatellite primers, and calculated genotyping error rates to enhance genotyping success for a large quantity of river otter scat samples. The also developed a method for molecular sexing.

As a next step the researcher extracted DNA from 1,421 scat samples and anal sac secretions (anal jelly) collected during latrine site counts along 22–34-km stretches. These stretches represented 8–77% of 8 rivers in southern Missouri.

Error rates were low for the redesigned microsatellites. They obtained genotypes at 7–10 microsatellite loci for 24% of samples, observing highest success for anal jelly samples (71%) and lowest for fresh samples (collected within 1 day of defecation)

The team identified 63 otters (41 M, 22 F) in the 8 rivers, ranging from 2 to 14 otters per river. Analyses using program CAPWIRE resulted in population estimates similar to the minimum genotyping estimate. Density estimates averaged 0.24 otters/km.

The researchers used linear regression to develop and contrast models predicting population size based on latrine site and scat count indices, which are easily collected in the field. Population size was best predicted by a combination of scats per latrine and latrines per kilometer.

 The researchers contend that their results provide methodological approaches to guide wildlife managers seeking to initiate similar river otter fecal genotyping studies, as well as to estimate and monitor river otter population sizes.

Journal reference 

River Otter Population Size Estimations using Noninvasive Latrine Surveys

 Rebecca A. Mowry, Matthew E. Gompper, Jeff Beringer, Lori S. Eggert
pg(s) 1625–1636 Journal of Wildlife Management Volume 75 Issue 7

'Chivalrous’ behavior is not exclusive of humans or closely related mammals

I just tread this fascinating paper on insects displaying 'Chivalrous’ behavior.  Well, this is not something from science fiction, it is a fact recently established by scientific research.

Video observations of a wild population of field crickets (Gryllus campestris) by researchers showed males putting their life at risk to protect the females. When a mated pair is out together, males allowed a female priority access to the safety of a burrow, even though it meant increase in the risk of the male being eaten. The researchers say guarding males sire more of their mate's offspring, at a cost of reduced life span. Females benefit from being guarded by dramatically reducing their predation risk.

The usual interpretation of male guarding behavior is an attempt to manipulate females and prevent them from mating with rivals. The new study bucks this belief.

The researchers sign off with the following words” In contrast to conclusions based on previous lab studies, our field study suggests that mate guarding can evolve in a context of cooperation rather than conflict between the sexes.”

Journal reference 

Guarding Males Protect Females from Predation in a Wild insect

Rolando Rodríguez-Muñoz, Amanda Bretman, Tom Tregenza

Current Biology, 06 October 2011

Unexpected ecological impacts of alien species

Colossal Aggregations of Giant Alien Freshwater Fish as a Potential Biogeochemical Hotspot
Stéphanie Boulêtreau, Julien Cucherousset, Sébastien Villéger, Rémi Masson, Frédéric Santoul.
 PLoS ONE, 2011; 6 (10): e25732

Here is a very fascinating paper on the unexpected spin-offs from alien invasion. The researchers report consistent and previously undocumented occurences of aggregations of a giant alien freshwater fish, the Wels catfish (Silurus glanis) in Rhone river and its unexpected functional consequences in recipient ecosystems.

Evidence gathered by the researchers suggests that the mechanism responsible for the observed aggregations were not associated with schooling behavior, reproduction, and foraging or anti-predator behavior. Individuals were active, always swimming, but were not all pointing in the same direction as observed in polarized shoals. No synchronous movements were observed. In the case of schooling fish they maintain a minimum distance between conspecifics. Here the individuals were swimming while rubbing against each other. No mating behaviours were observed and groups occurred throughout the year at temperatures below the spawning threshold. The researchers contend that foraging behaviour was unlikely since no prey was captured and no foraging behaviour was displayed. All individuals were large enough to be released from any predation risk.

The fascinating observation is that defecation and excretion from dense aggregations of fish that rest over coral reefs provide important quantity of nitrogen and phosphorus that subsequently increase the growth rate of corals. The researchers say in some cases fish can translocate nutrients within the ecosystem by feeding in one location while defecating in another.  Heterogenous spatial distribution of fish can also create biogeochemical hotspots, i.e. places where nutrient release by animals exceeds the need of primary producers. The aggregations of alien fish studied by the researchers potentially represent the highest biogeochemical hotspots ever reported for freshwater ecosystems.

The researchers sign off like this "our study is unique in identifying unexpected ecological impacts of alien species. Our findings will be ground breaking news for many scientific fields including conservation biology, ecosystem ecology and behavioral ecology and anyone interested in biological invasion and the potential ecological impacts of alien species. Therefore, we believe that our manuscript will stimulate further research and discussion in these fields."

New Discovery – Jungle crows can identify symbols

Japanese researchers from Utsunomiya University have discovered that crows possess the ability to distinguish between symbols representing different quantities. This works down to the fact that crows have the same numerical cognition ability as humans.

 The birds successfully selected containers containing the highest quantity of food by identifying numbers marked on the lid. The crows were able to pick the correct box 70 percent of the time

When crows could discriminate five items (15 out of 20 correct choices in two blocks of 10 trials each), they received control tests for non-numerical cues such as element configuration, shape, and total filled area and novel quantity (3 versus 5, 4 versus 5, 5 versus 6, 5 versus 7 and 5 versus 8) tests. During training, jungle crows learned the discrimination task relatively quickly.

The crows were responding to quantity. The researchers say Jungle crows selected the familiar larger quantity in smaller sets (3 versus 5 and 4 versus 5) and the novel larger in larger comparisons (5 versus 7 and 5 versus 8) except that of 5 versus 6 quantities.

The researchers say the results suggest that jungle crows have a natural tendency to select the larger quantities and that decisions were affected by the numerical ratio and stimuli magnitude, indicating the use of analogue magnitude mechanism for numerical judgment, as is observed in other animals.

Journal reference 

Quantity discrimination in jungle crows, Corvus macrorhynchos 
Animal behaviour,  Pages 635-64, Volume 82, Issue 4 (October 2011)
Bezawork Afework Bogale, Naoki Kamata, Katano Mioko, Shoei Sugita

Six ways to never get lost in a city again – A nice BBC article

I just read this very nice article “Six ways to never get lost in a city again” and thought it would be nice to share it with you guys.

Are you one of those 'directionally dysfunctional' guys? If so you will find this very useful.

Smart phones, sat-navs or other GPS devices are OK, but they have their limitations. All it takes is a flat battery or a mechanical fault to throw things out of kilter. Natural navigation is what you need under this circumstance. Read the fascinating article HERE

Determining and analyzing multiple ecosystem services across a given spatial scale

Using plant functional traits to understand the landscape distribution of multiple ecosystem services

Sandra Lavorel,Karl Grigulis, Pénélope Lamarque,Marie-Pascale Colace,Denys Garden,Jacky Girel,Gilles Pellet,Rolland Douze

Journal of Ecology

Volume 99, Issue 1, pages 135–147, January 2

This paper deals with the problem of determining and analyzing multiple ecosystem services across a given spatial scale. Presently our understanding of these multiple ecosystem services leaves much to be desired. . The methodology given by the researchers will help us better comprehend the delivery of multiple ecosystem services.

The researcher say in their method spatially explicit single ES models based on plant traits and abiotic characteristics are combined to identify ‘hot’ and ‘cold’ spots of multiple ES delivery, and the land use and biotic determinants of such distributions. They demonstrate the value of this trait-based approach as compared to a pure land-use approach for a pastoral landscape from the central French Alps, and highlight how it improves understanding of ecological constraints to, and opportunities for, the delivery of multiple services.

Vegetative height and leaf traits such as leaf dry matter content were response traits strongly influenced by land use and abiotic environment, which has follow-on effects on several ecosystem properties, and this could therefore be used as functional markers of ES.

The authors’ continue like this  “Patterns of association among ES were related to the dominant traits underlying different ecosystem properties. The functional decoupling between height and leaf traits provided alternative pathways for high agronomic value, as well as determining hot and cold spots of ES. Traditional land uses such as organic fertilization and mowing or altitude summer grazing were also linked with ES hot spots, because functional characteristics supporting fodder production and quality are compatible with species and functional diversity.”
“Analyses of ES using plant functional variation across landscapes are a powerful approach to understanding the fundamental ecological mechanisms underlying ES provision, and trade-offs or synergies among services. Sustainable management of species and functionally diverse grassland could simultaneously aim at conserving biodiversity and locally important ES by taking advantage of correlations and trade-offs among different plant functional traits”.

Social dominance in bank voles depends on the size of their genitals

Researcher Dr Jean-Francois Lemaitre from the University of Liverpool with colleagues in France and Switzerland, studying the social dominance in bank voles, (Myodes glareolus), has come up with the finding that social dominance for bank voles depends on the size of their genitals. 

Dominant males invariably had wider penis bones. The researchers say differences in the genitalia of dominant and subordinate males could be a factor contributing to the fertilisation advantage of dominant males under sperm competition. They also found evidence of positive allometry and a relatively high coefficient of phenotypic variation in the baculum width of male bank voles, consistent with an influence of sexual selection.

The researchers sign off like this” We conclude that dominant male bank voles may benefit from an enlarged baculum under sperm competition and/or cryptic female choice and that differences in penile morphology according to male social status might be important but as yet largely unexplored source of variation in male reproductive success.”

  

Journal reference

Genital morphology linked to social status in the bank vole (Myodes glareolus)

Jean-François Lemaître, Steven A. Ramm, Nicola Jennings and Paula Stockley

Behavioral Ecology and Sociobiology

DOI: 10.1007/s00265-011-1257-4

World’s largest shark sanctuary

Here is some great news. The Marshall Islands government has created the world's largest shark sanctuary

The sanctuary covers nearly two million sq km of ocean. Till now the sanctuary declared by Palau two years ago was the worlds biggest.

Commercial shark fishing and any trade in shark products will be banned. Any fish accidentally caught must be released alive.

Tahrcountry salute the Republic of the Marshall Islands for this magnificent move. The country may be small but the conservation effort is truly MEGA

Another book recommendation

Beyond Naturalness: Rethinking Park and Wilderness Stewardship in an Era of Rapid Change

David N. Cole, Laurie Yung

Island Press

Here is a book worth a read by managers of wilderness areas

The professed purpose of establishing the protected areas is to keep them in their “natural” state. The authors ask what does naturalness mean, particularly as the effects of stressors such as habitat fragmentation, altered disturbance regimes, pollution, invasive species, and climate change become both more pronounced and more pervasive? Ecosystems are not isolated entities they are dynamic systems with interdependencies, complexities, and uncertainties.

The book brings together leading scientists and policymakers to explore the concept of naturalness, its varied meanings, and the extent to which it provides adequate guidance regarding where, when, and how managers should intervene in ecosystem processes to protect park and wilderness values. Innovative ideas about how the areas should be managed are deliberated.

Donald Kennedy President Emeritus and Bing Professor of Environmental Science described the book like this “"Beyond Naturalness is a commentary on how we can preserve the sense of nature under change. The idea of pristine nature innocent of human presence was, we now know, mythical’ but this thoughtful book shows that sound policies can give us a rewarding nature with people in it."

·  Paperback: 304 pages

·  Publisher: Island Press; 1 edition (March 18, 2010)

·  Language: English

·  ISBN-10: 1597265098

·  ISBN-13: 978-1597265096

Book Recommendation

State of the Wild is a biennial series that brings together international conservation experts and writers to discuss emerging issues in the conservation of wildlife and wild places.

This volume has twenty essays intermixed with poetry, and photos that are a treat to the eye. The accent is on how destabilization and war affect wildlife and wild places. Topics discussed include “Can the work of saving wildlife and wild places help ameliorate tensions? Can conservation deepen political understanding? Can conservation help in post-conflict situations?”

Series Editor: Kent Redford
Volume Editor: Eva Fearn
Available in Hardcover and paperback: 264 pages
· Publisher: Island Press (February 2, 2010)

· Language: English

· ISBN-10: 1597266787

· ISBN-13: 978-1597266789

In elephants age does matter in leadership

Leadership in elephants: the adaptive value of age

Karen McComb, Graeme Shannon,Sarah M. Durant,Katito Sayialel,Rob Slotow,Joyce Poole,and Cynthia Moss

Published online before print March 16, 2011, Proc. R. Soc. B 7 November 2011 vol. 278 no. 1722 3270-3276

I found this paper food for thought. It provides the first empirical evidence that individuals within a social group of elephants may derive significant benefits from the influence of an older leader because of their enhanced ability to make crucial decisions about predatory threat, generating what the authors say important insights into selection for longevity in cognitively advanced social mammals.

The value of age is well recognized in human societies, where older individuals often emerge as leaders in tasks that require specialized knowledge. Against this axiom what part do such individuals play in other social species? We have very little knowledge. The information is nebulous. This paper clears the cobweb at least in respect of African elephant (Loxodonta africana).

Here, the researchers used a novel playback paradigm to demonstrate that in African elephants, age affects the ability of matriarchs to make ecologically relevant decisions in a domain critical to survival i.e. the assessment of predatory threat.

Groups consistently adjusted their defensive behaviour to the greater threat of three roaring lions versus one. Against these families with younger matriarchs under-reacted to roars from male lions despite the severe danger they represent.

The researchers say sensitivity to the key threats increases with matriarch age and is greatest for the oldest matriarchs, who are likely to have accumulated the most experience.

On the whole a very good paper