Providing evidence to improve practice

The journal, Conservation Evidence

Our online journal publishes research, monitoring results and case studies on the effects of conservation interventions. All papers include some monitoring of the effects of the intervention and are written by, or in partnership with, those who did the conservation work. It includes interventions such as habitat creation, habitat restoration, translocations, reintroductions, invasive species control, and education or integrated conservation development programmes, from anywhere around the world.

A volume is created each year with peer-reviewed papers published throughout the year. We now accept Short Communications as well as standard papers.

Special issues contain new papers on a specific topic.

Virtual collections collate papers published in the journal on specific topics such as management of particular groups of species.

To search for papers on a specific topic within the journal select 'Advanced search' on the Home page, enter your keyword(s) and within the Source box type: "conservation evidence".

Mammal management



The value of tourism for gaur Bos gaurus in the Khao Phang Ma reforestation area at the edge of Khao Yai – Dong Phaya Yen World Heritage Site decreased when a large number of gaurs moved away from the watching area of the former grassland in the middle of the secondary forest. A major cause appeared to be an increase in the number and size of pioneer trees Macaranga siamensis that overshadowed their food patches. We constructed a 5.7 ha pilot plot where 407 pioneer trees were cut down in an attempt to attract gaurs back to the area. Since tree cutting was a controversial practice, especially with the local people, we engaged with, and were supported by, a local non-governmental organization throughout the process. We monitored the density of gaurs using the total counts of dung piles. The estimated density of gaurs was significantly higher in the pilot plot compared with an adjacent control plot (8.62 individuals/km2/day versus 3.95 individuals/km2/day), demonstrating a positive impact of tree felling in attracting this species back to an area.

 

Boma fortification is cost-effective at reducing predation of livestock in a high-predation zone in the Western Mara region, Kenya
Sutton A.E., Downey M.G., Kamande E., Munyao F., Rinaldi M., Taylor A.K. & Pimm S. (2017), 14, 32-38

Lions Panthera leo kill livestock in the pastoral steppe of East Africa. The subsequent lethal retaliation by livestock owners has helped reduce lion numbers by more than 80% and driven the species from most of its historic range. This conflict is especially intense along the western edge of the Maasai Mara National Reserve in Kenya, where some of the densest lion and livestock populations in Africa overlap. We evaluated the effectiveness of implementation for one proposed solution – the Anne K. Taylor Fund’s subsidized construction of fortified, chain-link livestock fences (‘bomas’) – in reducing livestock loss to depredation. Between 2013 and 2015 we collected 343 predation reports, based on semi-structured interviews and predation records. We used these data to study the impact of subsidised boma fortification on the depredation of cattle, sheep and goats. Of 179 fortified bomas, 67% suffered no losses over one year whereas only 15% of 60 unfortified bomas had no losses over one year. Furthermore, losses of greater than five animals per year occurred at only 17% of fortified bomas, compared to 57% of unfortified bomas. The overall reduction in losses to predation at fortified bomas equated to savings of more than $1,200 USD per household per year.

 

 

The pine marten Martes martes is a woodland specialist that favours above-ground arboreal den sites to rest and breed in. Sheltered, elevated den sites are particularly crucial for meeting the needs of breeding females and a scarcity of suitable sites may be a critical constraint upon pine marten populations. An artificial den box for pine martens was designed and 50 boxes were installed in part of Galloway Forest, south-west Scotland, in order to (a) increase the availability and diversity of suitable den sites for breeding female martens and (b) aid monitoring of the marten population. The boxes were monitored for signs of use once per year. A proportion of the boxes was occupied by martens every year and the boxes were used by breeding females to raise their young. The den boxes can be implemented as a habitat enhancement and conservation tool, particularly in commercial forests, and used to monitor marten populations and breeding success. We recommend that conservation programmes for pine martens should consider the installation of den boxes as a habitat enhancement and monitoring tool.

Bear-proof fences reduce livestock losses in the Tibetan Autonomous Region, China
Papworth S.K., Kang A., Rao M., Chin S.T., Zhao H., Zhao X. & Corrasco L.R. (2014), 11, 8-11

Tibetan brown bears Ursus arctos pruinosus in the Tibetan Plateau attack and kill livestock and ransack homes for food, causing significant economic costs for local herders. Although a government fund compensates herders for livestock lost to bear attacks in the Tibetan Autonomous Region (China), compensation may not reflect the real cost of losing livestock and payments can be delayed. We investigate whether bear-proof fences are a cost-effective method for reducing bear attacks and livestock losses. In January 2009, 14 bear-proof fences were constructed from wire mesh and steel posts around households which had previously experienced substantial losses to bear attacks in the Nagqu Prefecture of the Tibetan Autonomous Region. These households lost 162 animals to bears in the year before fence construction, whereas just three animals were lost in the year after fence construction. Fences were still standing 4.8 years after completion and any small damage has been repaired by households. For households that suffer substantial losses to bear attacks, bear-proof fences appear to be an effective and cost-saving intervention to reduce human-bear conflict.

Population density of endangered pileated gibbon Hylobates pileatus in 9 km2 of North Ta-riu watershed, located in the centre of Khao Soi Dao wildlife sanctuary, dramatically declined from 6.4 groups/km2 in 1979 to 2 groups/km2 in 2006. Opportunistic poaching during non-timber forest product (NTFP) collection and insufficient patrolling were considered the main cause of decline. An alternative strategy is needed to enhance pileated gibbon conservation. We applied diffusion of innovation theory to change and expand conservation behaviour among NTFP collectors, although this study does not endorse illegal NTFP collection. After a meeting with NTFP collectors in May 2009, a network of NTFP collectors for pileated gibbon conservation was successfully established with 16 members. The aim of the network was to abstain from poaching on pileated gibbon during NTFP collection. Interpersonal persuasion along with social marketing were used to expand the network. In December 2009, the network had expanded to 101 members. In 2012, six new groups of pileated gibbons (24% increase) were found in the North Ta-riu watershed. The density had increased to 2.8 groups/km2.

An experiment was conducted to determine if Natterer’s bat Myotis nattereri and brown long-eared bat Plecotus auritus exhibited an occupation preference between five different bat box types in an ancient, lowland mixed deciduous woodland in Buckinghamshire. Groups of Schwegler 2F, 2FN, 1FS, 1FF woodcrete boxes and 1 wooden Apex box were erected in 13 locations (5 around each tree). The box clusters were located on trees with a proven history of good box occupancy levels - part of a 10 year woodland bat box scheme. The group positions were evenly spaced along a transect line of 300m in homogenous habitat of predominantly semi mature Pendunculate Oak Quercus robur and Ash Fraxinus excelsior closed canopy with lapsed Hazel Corylus avellana coppice understorey. The temperature regimes of the boxes were compared and found to be similar, and consistent with the ambient temperature due to the shaded nature of the sites. Aspect was experimentally controlled by progressively rotating the box positions around the tree. The occupancy rates of the five boxes were compared and showed a selection bias towards two box types, influenced by seasonal bird competition.

Fuel wood is a key source of energy for many families in developing areas of China.  Fuel efficient stoves are often identified as a win-win solution for forest protections and public health/development in China and across the globe. However, the communication and connection between stoves and biodiversity conservation has been less clear, by both those who are promoting their use as well as those adopting the technology. Social marketing is the application of marketing principles used to sell products applied to “sell” ideas, attitudes, and behaviours to benefit the public good. The Campaign to Protect the Sichuan Golden Snub-nosed Monkey in the Yuhe Nature Reserve, Gansu Province, China, was initiated in 2008 in an effort to inspire communities to protect forest habitat in the reserve, and quickly adopt fuel-efficient stoves.  Results of this study show significant increases in knowledge, attitudes, and interpersonal communication pre and post campaign (16 – 49 percentage points).  Post-campaign (within 1 year) results concluded 28.0% and 43.1% of those surveyed within 1 year of and 2.5 years adopted the technology.  For those households that adopted fuel-efficient stoves, consumption and gathering time were reduced by 40.1% and 38.2% respectively.  Finally, preliminary research suggests that adoption of fuel-efficient stoves also lead to a reduction in forest destruction, with a 23.7 % reduction in the number of newly felled trees in areas where the stoves had been adopted by greater than half of the surrounding community.  The results of this study suggest that social marketing can be an effective tool for improving community knowledge and attitudes, decreasing destructive behaviour, and reducing threats to biological important forests in China.

The Nam Et Phou Louey National Protected Areain the Lao People’s Democratic Republic contains the last confirmed breeding population of tigers (Panthera tigris) in Indochina.  There are two main threats to tigers, direct killing of tigers and the illegal hunting of wild ungulates, the tigers’ principle prey.  Villagers living around the National Protected Area rely on these same ungulates as an important source of protein in their daily diet.  The illegal hunting of tigers and prey for commercial trade is unsustainable and is driven by a lack of ownership by local villagers who engage in illegal activities and by government agencies that do not enforce the laws.  To reduce these threats the Nam Et Phou Louey National Protected Area is using a social marketing campaign in parallel with traditional enforcement to change the behavior of illegal hunters, village members, and government officials.  To determine campaign effectiveness, a survey instrument was developed to measure knowledge, attitudes and behavior change, which included both a control and pre and post surveys of target audiences.  The pre and post surveys indicate a significant shift along the theory of change from knowledge to behavior change.  The assumption is that over time this shift will also lead to threat reduction to, and thus increase of, tiger and prey populations.

Historical records over the last century suggest an overall decline in UK bat populations, with the cause speculated to include a decline in roost availability. In 2009, a noctule maternity roost was recorded in an ash tree within ancient semi-natural woodland in Milton Keynes, UK, where up to 75 bats including lactating females were recorded. In December 2011, the ash tree was accidentally felled by contract staff operating on behalf of the landowner whilst carrying out ride habitat and tree safety management as the tree was considered to be a public safety concern. A mitigation and compensation strategy was implemented, with a noctule maternity colony returning in 2012 and 2013. The landowner has subsequently altered internal working practices in relation to bats and trees. This case study exemplifies the need for sharing ecological data records within organisations, and to and from third parties. Good record keeping including photographic and video evidence together with a ‘rapid response’ procedure is demonstrated.

 

Reducing the impacts of leg hold trapping on critically endangered foxes by modified traps and conditioned trap aversion on San Nicolas Island, California, USA
Jolley W.J., Campbell K.J., Holmes N.D., Garcelon D.K., Hanson C.C., Will D., Keitt B.S., Smith G. & Little A.E. (2012), 9, 43-49

Padded leg-hold live traps were used as the primary removal technique in the successful eradication of feral cats Felis silvestris catus from San Nicolas Island, California, USA. Risk of injury to endemic San Nicolas Island foxes Urocyon littoralis dickeyi, a similarly sized and more abundant non-target species, was mitigated by using a smaller trap size, modifying the trap and trap set to reduce injuries, and utilising a trap monitoring system to reduce time animals spent in traps. Impacts to foxes during the eradication campaign were further reduced by having a mobile veterinary hospital on island to treat injured foxes. Compared to other reported fox trapping efforts, serious injuries were reduced 2-7 times. Trapping efforts exceeded animal welfare standards, with 95% of fox captures resulting in minor or no injuries. Older foxes were more likely to receive serious injury. Fox captures were also reduced through aversive conditioning, with initial capture events providing a negative stimulus to prevent recaptures. Fox capture rates decreased up to six times during seven months of trapping, increasing trap availability for cats, and improving the efficacy of the cat eradication program. No aspect of the first capture event was significantly linked to the chance of recapture.

European badgers Meles meles and their setts are legally protected in the UK. If setts are to be damaged or destroyed as part of development, humane exclusion of badgers is usually required in advance of works. Exclusion can be achieved by erecting one-way gates over sett entrances which allow badgers to exit but not regain entry. Natural England (the governmental conservation advisory body in England) recommends that exclusion is maintained for 21 days before construction work begins to ensure that the sett has been vacated. In this study, a large diameter (400 mm) water main was installed through a badger sett without exclusion of animals due to discovery of the sett only after construction work had commenced. The sett location and the presence of numerous European rabbit Oryctolagus cuniculus burrows interspersed with sett entrances would have made exclusion difficult. As an emergency mitigation measure, a 1.4 m deep, 40 cm wide trench was excavated 6 m from the sett entrances (located mostly in a lapsed field boundary using a combination of hand augering (to detect badger tunnels and chambers; these were then excavated by hand), followed by mechanical excavation. Subsequent to this, work to excavate the trench, lay the pipe through the sett and back-fill the trench took one week. Despite the disturbance caused by this approach, badgers were not excluded from the entire sett and the risk of killing badgers which may have been present below ground was significantly reduced; no badger or other large mammal activity was evident during the mitigation works.

All works were carried out under Natural England licence and under the supervision of an ecologist and a Natural England Wildlife Management Adviser.

Lemur bridges provide crossing structures over roads within a forested mining concession near Moramanga, Toamasina Province, Madagascar
Mass V., Rakotomanga B., Rakotondratsimba G., Razafindramisa S., Andrianaivomahefa P., Dickinson S., Berner P.O. & Cooke A. (2011), 8, 11-18

The Ambatovy Project includes a large, open-pit nickel mine located in Madagascar's eastern humid forest, and an associated pipeline to remove laterite slurry off site. The area is recognized for its high biodiversity exemplified by the presence of at least 13 lemur species in forests surrounding the mine site. In order to reduce potential habitat fragmentation impacts on the lemur populations as a consequence of recent access road construction, seven crossing structures (referred to as 'lemur bridges') were erected within the mine footprint area and along the slurry pipeline that will remain in place until rehabilitated forest allows for movement over roads via the forest canopy. Two bridge designs were used due to differences in road width and vehicle traffic type. Lemur bridges have been monitored since their construction in January-February 2009. To date (10 August 2010), bridges have been used by six lemur species. Mine footprint type bridges (suspension bridge design) have been used more frequently than slurry pipeline bridges (plank bridge design) and, overall, there has been an increase in bridge use in 2010 when compared to 2009 (from 8 % to 24 % of total observations where lemurs are present in proximity to bridges). These results suggest that although a certain time period may be required for lemurs to locate and habituate to bridges, these crossing structures offer an effective mitigation measure to assist in reducing the impacts of habitat fragmentation.

Monitoring of badger tunnels using clay mats on nine Highways Agency road schemes was undertaken to establish their effectiveness in terms of use by large mammals (primarily European badger Meles meles), as well as the efficacy of tunnel design advice provided by the agency.  The results indicate that tunnels are an effective means of mitigating the effects of all types of new road schemes on badgers; 89% of the tunnels monitored were used.  The results suggest that no one factor is of over-riding importance in tunnel design; however, design features that appeared to be associated with the use of tunnels were good vegetation cover, habitat connectivity, good drainage and a tunnel width of at least 600 mm.

Managing competition between birds and bats for roost boxes in small woodlands, north-east England
Meddings A., Taylor S., Batty L., Knowles M. & Latham D. (2011), 8, 74-80

A total of 196 bat boxes were installed between 2005 and 2009 across 21 sites throughout the Highways Agency's (HA) 'soft estate' woodland in north-east England in support of the HA's Biodiversity Action Plan. The woodlands are typically small linear blocks (<3 ha) with trees mostly less than 40 years of age. Suitable natural cavity sites are thus very limited, hence the attractiveness of bat boxes as a conservation measure to enhance these woodland habitats. Monitoring in 2006-2007 had shown that in some areas (seven woodland sites) over 40% of bat boxes were being used by nesting passerine birds. Bird boxes were installed in an attempt to reduce bird occupancy of bat boxes. Provision of bird boxes significantly reduced bird use of bat boxes (a 50% overall reduction in occupancy) thus potentially making more bat boxes available for bat use. We also assessed if there was any relationship between the number/density of available bat boxes and level of bat occupancy to assess if there was a limit to the occupancy levels that could be achieved, thus determining an approach that could maximise benefits and cost effectiveness of box installation. Occupancy of bat boxes by bats appears not to increase above 30% utilisation with an increasing number of boxes on site after eight boxes. This suggests that, as bat boxes are installed three boxes per tree (as per best practice guidelines), the optimal number to install would generally be between nine to 12 boxes in these small woodland areas.

During electricity substation upgrading works at a site in Suffolk (England), five Eurasian badger Meles meles setts were closed (under licence) in 2009 as they were directly under the footprint of the works. As part of the licence agreement, mitigation included provision of three artificial setts. After completion of construction, monitoring indicated that all three setts displayed signs of occupancy and increased badger commuting and foraging evidence around their vicinity. In 2011, a remote motion-activated  infra-red camera was used to determine badger occupancy at a three-entrance outlier sett that also required closure during the badger breeding season. Previous extensive monitoring showed that badgers were unlikely to be present. However, a monitoring program using the remote camera was implemented to ensure that this was the case. When evident that badgers were not using the sett, it was destroyed under supervision of an ecologist. Being a novel, non-invasive monitoring technique this was done in liaison with the governmental statutory body, Natural England, but without the need for a licence. Remote monitoring techniques like this could be applied in similar situations where work is required during the badger breeding season (December to June) when licences are not normally issued.

Animal rescue centres release large numbers of captive-bred, rehabilitated or translocated animals into the wild annually but little is known about their post-release survival and behaviour. We developed a novel and innovative coupling of traditional radio-tags with new GPS loggers to track hand-reared Irish hare Lepus timidus hibernicus leverets after release into the wild. Cyanoacrylate SuperGlue® proved a poor fixative with two out of three leverets managing to detach their tags within 24 hours. Nevertheless, a total of 2,505 GPS locations were recorded every 60 seconds for one leveret over three nights (approx. 835 per night). The leveret dispersed <410 m from the original release site. It demonstrated exploratory behaviour including an ability to navigate accurately in a complex and unfamiliar environment returning to a habitual lie-up site each day. Its survival was confirmed up to 9 days post-release at which time its radio-tag detached, however, similarly aged leverets were sighted in the area for up to 2 months post-release (suggesting possible longer term survival). This is the first study to publish data from any GPS tagged lagomorph and provides 'proof-of-concept' that large quantities of behavioural data can be recovered from small mammals 1-2 kg. Further development of these techniques will be highly valuable to future studies.

 

A remote controlled camera proved a practical solution to survey a single, one-entrance outlying badger Meles meles sett in late January (outside the normal licensing period for disturbing badger setts), which was found to be present on the route of a proposed water pipeline. Upon ascertaining that the sett was almost certainly unoccupied, the sett was immediately taken apart and filled in following strict guidelines specified under the terms of the Natural England licence (supervised by the relevant authority), to allow pipe-laying activities to continue. Once the pipeline is installed and construction completed, badgers will be able to re-colonise the same area of ground.

 

A 'water pathway' was devised for allowing otters Lutra lutra to pass into an area enclosed by an electric fence to prevent fox access. After its construction, several otter spraints (some close to the water pathway) were subsequently found within the fenced area. There was no evidence that foxes Vulpes vulpes, entered by this route.

Creating a bat hibernaculum at Kingfishers Bridge, Cambridgeshire, England
Gulickx M.M.C., Beecroft R.C. & Green A.C. (2007), 4, 41-42

To provide a winter hibernation site for bats, an artificial cave was constructed at a nature reserve in eastern England. Subsequent to its completion, in the winter of 2005/06, two brown long-eared bats Plecotus auritus hibernated in the cave and in the subsequent winter one hibernated within it. It is considered likely that bat numbers will build up in future years.

Monitoring the use of dry culverts installed as underpasses enables their effectiveness to be evaluated. We used clay-based drain seals to record mammal tracks in three different culverts under a section of a major road in Northumberland, UK. Prints including badger Meles meles, American mink Mustela vison and hedgehog Erinaceus europaeus were recorded on the clay drain seals demonstrating animal movement in both directions through the culverts. The prints were well preserved and easily recognisable.

 

Following a community-based conservation programme started in 1996, with the endangered Matschie's tree kangaroo Dendrolagus matschiei as the project's flagship species, a joint proposal for the regions first protected area, comprising over 60,000 ha, was submitted to the regional government and approved in 2006.

Mink rafts positioned along stretches of the River Wensum proved very successful in terms of American mink Mustela vison detection and trapping effectiveness. Survey results indicated that there has been an expansion in the range of water voles Arvicola terrestris along the river from 2003 to 2005, perhaps in response to the removal of American mink.