Effects of human disturbance on the diet composition of free ranging animals

Effects of human disturbance on the diet composition of wild red deer (Cervus elaphus)

Sevvandi Jayakody, Angela M. Sibbald, Robert W. Mayes, Russell J. Hooper, Iain J. Gordon and Xavier Lambin

EUROPEAN JOURNAL OF WILDLIFE RESEARCH

Volume 57, Number 4, 939-948, 

 

Increasing disturbance in wilderness areas in the form of tourism related activities is a cause of concern.

 In this paper the authors analyze human recreational activities and its effect on the nutrition of free-ranging herbivores due to trade-offs between feeding in preferred habitats and perceived predation risk.

The researchers estimated diet composition for red deer in the Scottish highlands in spring, when recreational activity is high, and in winter when it is at lower level. Faecal samples from three habitat types, grassland, heather moorland and woodland, were collected at sites close to a busy track . Samples were also collected from less disturbed areas also.

The diet consisted of 39% grasses, sedges, herbs and rushes (GSHR) and 58% Calluna vulgaris and Erica spp.  in spring, against 14% grasses and 77% heather in winter, with small quantities of Vaccinium spp and Pinus sylvestris (tree) in both seasons.

In spring, faeces from disturbed grass and woodland sites indicated a diet with less GSHR and more heather and tree than faeces from less-disturbed sites. The authors say this could be due to an increased need for vigilance in exposed grassland and the need to seek cover. Faeces from all disturbed sites in winter indicated a diet with more GSHR and less heather than faeces from less-disturbed sites. It is presumed that this could be due to a seasonal decline in recreation and increase in hunting activity reversing the disturbance levels at the different sites. Hunting is not normally carried out in areas used by the public for recreation.

The authors conclude that nutritional benefits may accrue to deer if disturbance near open grassland are brought down.

Depredations caused by human nitrogen additions

Latest research has come up with the finding that human nitrogen additions to terrestrial ecosystems increase the terrestrial carbon dioxide uptake from the atmosphere. Nitrogen inputs to biosphere have more than doubled since the 1860s.  Fossil fuel burning and the application of fertilizers in agriculture are the villains.

When added to nitrogen-limited ecosystems, more nitrogen inputs can stimulate plant growth and/or suppress soil respiration. This in turn leads to increased ecosystem carbon storage.

The researchers used a process-based model of the terrestrial biosphere to evaluate the overall impact of anthropogenic nitrogen inputs on terrestrial ecosystem carbon and nitrous oxide fluxes between 1700 and 2005. They show that anthropogenic nitrogen inputs account for about a fifth of the carbon sequestered by terrestrial ecosystems between 1996 and 2005, and for most of the increase in global nitrous oxide emissions in recent decades. Nitrous oxide emissions   are largely due to intensive agricultural practices. The researchers estimate that carbon sequestration due to nitrogen deposition has reduced current carbon dioxide radiative forcing by 96±14 mW m⁻². However, this effect has been offset by the increase in radiative forcing resulting from nitrous oxide emissions, which amounts to 125±20 mW m⁻².

Journal Reference:

Sönke Zaehle, Philippe Ciais, Andrew D. Friend, Vincent Prieur. Carbon benefits of anthropogenic reactive nitrogen offset by nitrous oxide emissions. Nature Geoscience, 

A rapid assessment tool for locating habitat extension areas in a changing landscape

A rapid ecological network assessment tool and its use in locating habitat extension areas in a changing landscape

Journal for Nature Conservation (September 2011), 19 (4), pg. 236-244 

Nicola McHugh; Stewart Thompson

This paper deals with spatial targeting of habitat extension area in the South Midlands of the UK. Even though the focus is on UK the  ideas discussed in this paper has relevance in other areas also. It could kick start similar projects in other countries.

Habitat fragmentation, habitat loss, isolation of habitat patches and reduced connectivity are hampering the way our landscapes function. Built development is a big villain. The authors of this paper say a conservation planning tool which considers these vexatious issues in tandem with planned landscape level change, whilst incorporating species and habitat specific details, is necessary if we are to ameliorate the ecological impact of built development.

The researchers developed a landscape scale modelling for a case study area in the South Midlands of the UK. The aim was to investigate spatial targeting of habitat extension areas. Ecological networks and ecoprofiles were employed to guide the location of these extension areas. The ability of extension areas to contribute to landscape functionality was determined spatially.

Habitat extension areas identified by the approach increased the existing ecological network size by a factor of over 2.7:1. The extended areas were able to deliver the majority of habitat creation targets set out in regional Biodiversity Action Plans (BAPs).The authors say 100% of wetland, unimproved grassland and broadleaf and mixed woodland creation targets were met, whilst 75% of the lowland heath target could be achieved.

The researchers signs off with the following words “Semi-natural habitat mosaic areas of over 3700 ha which incorporated habitat of more than one type were identified, with such areas determined to be of importance in achieving landscape improvements for a wide range of species. We conclude that rapid assessment tools such as that employed in this research will have increased utility in conservation planning as the British landscape continues to experience both sustained and elevated levels of built development pressure.”

New Shark Species Found on way to dinner table

Here is a big surprise. Fish taxonomists found a previously unknown shark,   Squalus formosus n. sp, at a fish market in Taiwan. It belongs to the ‘highfin megalops group.  Members of this group have a short snout, high dorsal fins, robust dorsal spines, tricuspid denticles and a white posterior caudal margin. 

The new species is a one-meter-long short-nosed dogfish. It's distinguished from other dogfish species in the Squalus genus by a particularly upright first fin on its back, a strong spine, and a very short, rounded head.

The new species is described in August 26 issue of Journal of Fish Biology.

Squalus formosus, a new species of spurdog shark (Squaliformes: Squalidae), from the western North Pacific Ocean

W. T. White and S. P. Iglésias

Protecting wild species may require growing more food on less land

According to a new study published in the journal Science separating natural habitats from high-yielding farmland could be a more effective way to conserve wild species than trying to grow crops and conserve nature on the same land

The authors describe the pros and cons of land sharing and land sparing. Land sharing integrates both objectives on the same land. Land sparing aims for high yield farming combined with strategies for protecting natural habitats from conversion to agriculture

The research was done by researchers at the University of Cambridge and the Royal Society for the Protection of Birds. They collected information on more than 600 species in southwest Ghana and northern India. In these two areas demand for agricultural land is putting increasing pressure on wild species. 

The researchers evaluated current and future scenarios of food demand. They found that most species would have larger total populations if farming was restricted to the smallest area feasible along with protecting as much natural forest as possible. This is applicable to not only rare species but for common species as well.

Journal reference 

Reconciling Food Production and Biodiversity Conservation: Land Sharing and Land Sparing Compared

Ben Phalan,Malvika Oniall,Andrew Balmfordd,Rhys E. Green

Science 2 September 2011: Vol. 333 no. 6047 pp. 1289-1291 

Scientists it is time to dance

Science and TEDxBrussels present The “Dance Your Ph.D.” Contest

Turn your Ph.D. thesis into a dance. You can win $1000, achieve immortal geek fame on the Internet, and be recognized by Science for your effort.

The creator of the best Ph.D. dance gets a free trip and hotel stay in Brussels to be crowned the winner at the TEDx conference on 22 November 2011.

How to enter:

Turn your Ph.D. thesis into a dance.

Make yourself an account at www.vimeo.com.

Post the video at Vimeo.com.

Send the link by 10 October 2011.

The rules:

1. you must have a Ph.D., or be working on one as a Ph.D. student.
2. Your Ph.D. must be in a science-related field.
3. You must be part of the dance 

Better indicators of persistence in gap-analysis frameworks needed

Misleading results from conventional gap analysis – Messages from the warming north

Heini Kujala, Miguel B. Araújo, Wilfried Thuiller and Mar Cabeza

Biological Conservation
Volume 144, Issue 10, October 2011, Pages 2450-2458

Gap analysis is a widely used method for assessing the representation of species in protected area (PA) networks. The process consists of mapping three data layers

1) Land cover

2) Predicted distributions of vertebrate species

3) Stewardship layer. 

This data is then assessed to determine how much of a target species’ habitat is in protected areas.  From this assessment, planning decisions can be made about whether further protection is needed.

There is a rider here. Representation does not imply persistence. In this paper the researchers investigated whether gap analysis may result in misleading conservation guidelines by comparing the representation to two indicators of persistence.

The analysis was done with Finnish breeding birds and identified conservation priorities based on current distribution patterns. The levels of representation identified by gap analysis were very good. The researchers then compared the gap analysis results with recent population trends and projected changes in potential suitable climate under different climate change scenarios for the year 2050. The results show that that although high latitude species are well represented in PAs, they are currently declining and are projected to lose climatic suitability in the near future. Low latitude species with poor representation in PAs have increasing population trends and are generally expected to expand their ranges into protected areas in the near future.

The researchers sign off with the following words “This study demonstrates with empirical data a mismatch between representation in PAs and population trends, resulting in misleading understanding of current PA effectiveness. The mismatch is linked to the latitude of species distributions and corresponds to expected future changes, indicating that the patterns are potentially driven by climate change. We therefore urge practitioners and researchers to include better indicators of persistence in gap-analysis frameworks even for short term assessments.”

Combinations of inexpensive methods can reduce monitoring costs substantially while yielding an equal or an increased performance.

Survey method choice for wildlife management: the case of moose Alces alces in Sweden

Johan Månsson, Cindy E. Hauser, Henrik Andrén & Hugh P. Possingham

Volumes / 2011 - Volume 17 / 2 / Wildlife Biology

Monitoring wildlife populations is sine qua non to determine whether management goals are achieved and to improve future decisions. Cost and accuracy of monitoring strategies weighs heavily while determining survey methods.

Here the researchers tested the relative performance of three survey methods: aerial survey, pellet-group counts and hunters’ observations, to get an idea about the management of Swedish moose Alces alces populations. 

Annual aerial survey was the most costly monitoring method (27,000€) and maintained the population within the desired range 72% of the time. The least expensive monitoring strategy (hunters’ observations; 1,600€) maintained the population within a desired range of 66% of the time. A combination of two relatively inexpensive survey methods (i.e. pellet-group counts and hunters’ observations; at an expense of 10,000€) maintained the population within the desired range in 76% of the simulated years.

A combination of annual pellet-group counts and hunters’ observations performed better than annual aerial surveys, but was considerably less expensive. 

The authors sign off with the following words” In wildlife management systems, where a variety of monitoring methods are used, the overall performance generally improves with monitoring expenditure, but very few studies explicitly account for expenditure. However, our study shows that combinations of inexpensive methods can reduce monitoring costs substantially while yielding an equal or an increased performance.”

Exciting news from UK

Here is some exciting news that I have just got from my contacts in UK.

On Wednesday July 27th at 14.22, the first of the three Dyfi osprey chicks fledged the nest at their Cors Dyfi reserve near Machynlleth. This is the first time that ospreys have successfully bred on the Dyfi since 1604. Untrammeled persecution over centuries led to the extinction of the osprey as a species in the UK

Have a look at the YouTube video

 

Incorporating imperfect detection methods for estimating abundance of mountain ungulates

Estimating abundance of mountain ungulates is a laborious task. It is very rarely conducted in a statistically valid manner. Rough terrain they inhabit, the group-living habits, relatively low density, and the difficulty of marking individuals contribute to making rigorous estimates of abundance logistically difficult task.

The usual way out is raw (uncalibrated). Although their drawbacks are very evident, biases are rarely quantified.

In September 2009, the authors of this paper took advantage of the presence of a radio-marked sample of argali Ovis ammon in the Ikh Nart Nature Reserve in south-central Mongolia, and the area’s comparatively forgiving topography to estimate abundance simultaneously using two independent methods: distance sampling and mark-resight sampling.

Distance sampling produced an abundance estimate of 539 (95% CI: 196-1,081) argali in a 330km2 study area on the same day the researchers visually counted189 animals. Mark-resight sampling using the Poisson log-normal model yielded an estimate of 747 (95% CI: 484-1,009) argali against a maximum223 animals observed in any given day.

The researchers say although both the techniques were imprecise, their similarity increases their confidence that neither estimator was highly biased. Because of budget or logistical restrictions, uncalibrated counts of mountain ungulates are often the only alternative. The researchers emphasize that such results should be viewed cautiously, and when possible, more rigorous approaches to estimating abundance should be taken.

Journal reference

Estimating abundance of mountain ungulates incorporating imperfect detection: argali Ovis ammon in the Gobi Desert, Mongolia

Ganchimeg J. Wingard, Richard B. Harris, Sukh Amgalanbaatar & Richard P. Reading

Volumes / 2011 - Volume 17 / 1 / Wildlife Biology

Research-Prioritization Exercises and Conservation Policies

How Research-Prioritization Exercises Affect Conservation Policy

MURRAY A. RUDD

Article first published online: 25 JUL 2011   © Society for Conservation Biology

It is an undeniable fact that there is often a wide chasm between research and its impact on policies pertaining to conservation. The way forward should be better aligning of research with policy needs. With his idea in mind, some conservation scientists have embarked on a whole gamut of exercises to identify research questions that, if answered, would provide the evidence base with which to develop and implement effective conservation policies.
Here the researcher synthesized two existing approaches to conceptualizing research impacts. One widely used approach classifies the impacts of research as conceptual, instrumental, and symbolic.
Conceptual impacts occur when policy makers are sensitized to new issues and this in turn brings about changes in their beliefs and thinking process. Instrumental impacts occur when scientific research has a direct effect on policy decisions. The use of scientific research results to support established policy positions are a sign of symbolic impacts.
The second approach classifies research issues according to whether scientific knowledge is developed fully and whether the policy issue has been articulated clearly.
The researcher say exercises to identify important research questions have objectives of increasing the clarity of policy issues while strengthening science–policy interactions. This may act as a vehicle of transmission of scientific knowledge to policy makers. This also has the potential to accelerate the development and implementation of effective conservation policy.
 The researcher say identification of visionary science questions independent of current policy needs, prioritization of best practices for transferring scientific knowledge to policy makers, and identification of questions about human values and their role in political processes could all help advance real-world conservation science. He signs off with these words “It is crucial for conservation scientists to understand the wide variety of ways in which their research can affect policy and be improved systematically”.

Genes not responsible for the decline of Iberian Lynx

It was with great fascination that I read this paper on Iberian lynx (Lynx pardinus). It is perhaps the most endangered cat in the world. The population of the Iberian lynx has plummeted below 300 individuals in two isolated areas in Spain. Habitat destruction and the decline of its main prey, the European rabbit are the main causes of the decline.

Some people believe the lack of genetic diversity may spell doom for the species. Surprisingly a new study of DNA found in fossil bones,  have shown that the Iberian lynx has had very low genetic diversity, for at least 50,000 years.  How the lynx managed to pull on despite this low genetic diversity has flummoxed the scientists.

The scientists say they don't blame the genes for the decline in population. They blame it squarely on the lack of political will to save it.

Journal Reference:

Ricardo Rodríguez, Oscar Ramírez, Cristina E. Valdiosera, Nuria García, Fernando Alda, Joan Madurell-Malapeira, Josep Marmi, Ignacio Doadrio, Eske Willerslev, Anders Götherström, Juan Luis Arsuaga, Mark G. Thomas, Carles Lalueza-Fox, Love Dalén. 50,000 years of genetic uniformity in the critically endangered Iberian lynx.Molecular Ecology,

New Zealand - Flushing down the rainforests

An eight-month long investigation by Greenpeace, the Green Party and WWF-New Zealand into exactly where the toilet paper sold in New Zealand originates has come up with the shocking finding that Auckland based company Cottonsoft is sourcing its toilet paper from rainforests in Indonesia, home of the critically-endangered Sumatran tiger. Only 400 Sumatran Tigers are estimated to remain in the wild

Cottonsoft New Zealand is a subsidiary of the infamous conglomerate Asia Pulp and Paper (APP). APP has been blacklisted as a supplier by major companies around the world like  Kraft, Nestle, Unilever, Tesco and Carrefour. These companies do not countenance the unethical rain forest destruction of APP.

Greenpeace, the Green Party and WWF-New Zealand have appealed to retailers to stop stocking Cottonsoft and other APP Products until the company agrees to end rainforest destruction. 

Studies should be wary when pooling male and female data

Understanding sex differences in the cost of terrestrial locomotion

John J. Lees,Robert L. Nudds,Lars P. Folkow,Karl-Arne Stokkan,and Jonathan R. Codd

Published online before print August 17, 2011, doi:10.1098/rspb.2011.1334Proc. R. Soc. B

Here is an interesting piece of research done on birds that could be of great relevance for future research.

We know very little about the physiological consequences of the behavioural and morphological differences that result from sexual selection in birds. 

Here the research was done on Svalbard rock ptarmigans (Lagopus muta hyperborea). Svalbard rock ptarmigans exhibit distinctive behavioural differences during the breeding season. Males continuously compete for and defend territories in order to breed successfully. This in turn places large demands on their locomotor system. 

In this piece of research the researchers show that male birds have improved locomotor performance compared with females, showing both a lower cost of locomotion (CoL) and a higher top speed. They suggest that sex differences in locomotor capability may be due to sexual selection for improved male performance.

The researchers sign off with these words” While the mechanisms underlying these energetic differences are unclear, future studies should be wary when pooling male and female data”.