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".

Volume 9

The role of 'Conservation Evidence' in improving conservation management
Sutherland W.J., Mitchell R. & Prior S. V. (2012), 9, 1-2

Effective global conservation will depend upon us learning from the experiences of those on the front line of conservation practice. In the chase for impact factors,  many journals have moved away from what they often disparagingly refer to as ‘case studies’ and are looking for papers with greater generality. Interestingly, research shows there is very little relationship between impact factors and the usefulness of the research to conservation (Sutherland 2011). It is increasingly difficult to publish papers that simply test an intervention. We believe that conservation practice would be more effective in both cost and conservation outcome if evidence based interventions were used.

Conservation Evidence was launched in 2004 with the objective of filling the gap of determining effectiveness of interventions and in the last nine years has published 261 papers from 23 countries. We welcome original papers that examine the key conservation practices of  habitat management (Robertson 2010), species management (de Clavijo 2010), invasive plants (Visser, Louw & Cuthbert 2010)  and reintroductions (Ortiz-Catedral & Brunton 2010), but also are very pleased to receive papers that look at other approaches, such as changing attitudes and education (Balakrishnan 2010).

The Gujjar Rehabilitation Programme (Uttarakhand, India) is an integrated approach focusing on environmental conservation and providing better livelihood opportunities for pastoral Gujjar communities. The primary objective of this present study is to assess the response of rehabilitated Gujjar families to the resettlement Programme. Socio-economic assessments (e.g. livelihood status) of affected people at the two resettlement sites (Pathri and Gaindikhatta) were conducted. Resettled Gujjars reported enhancement of their livelihoods and many more children receiving schooling. Additionally, state government departments and several NGOs are making efforts to strengthen the prospects of Gujjar women through training and education programmes.

A significant adder, Vipera berus, population was identified within the Upper Thurne river catchment during baseline surveys in 2009. An adder bank (hibernacula) was constructed in the autumn 2009 in advance of flood defence works at Horsey in 2010 to mitigate any temporary loss of hibernation and natal den sites. Reptile fencing was erected around the adder banks and some adjacent grazing marshes in February 2010 to create reptile enclosures. During March to May 2010, 119 adders were moved to the adder banks from the flood banks that were then stripped of vegetation and topsoil to discourage animals from re-entering the working corridor. Sections of the adder fencing were removed in mid-May to allow animals to disperse to their summer foraging grounds. Surveys during summer 2010 indicated breeding success within the banks. Pre hibernation surveys in 2010 recorded a peak count of 22 animals, and a spring emergence survey of the adder bank in 2011 identified 17 individual adders. A further four were recorded using an adjacent store of rush, Juncus, bales. Monitoring through summer and autumn 2011 identified a further 16 individual animals on or close to the adder bank, including six gravid adders. Eighteen out of the 33 adders recorded using the adder banks in 2011 were recaptures. Fifteen ‘new’ adders (i.e. not relocated during the 2010 mitigation) were subsequently identified as using the adder banks to hibernate or give birth. The total cost of constructing the adder banks and erecting/dismantling the reptile fencing was £63,500.

During the construction of a water storage tank for a hydroelectric plant, areas of natural habitat of the Reunion day gecko were destroyed by embankments of deposited excavated material.  To offset this impact and encourage the gecko’s return, 40 artificial egg laying site (AELS) were established in the area between September 2009 and July 2010. An AELS provides the gecko with a site for oviposition, shelter and basking. Since their installation, the number of AELS used for reproduction increased from 11.8 % (4/34) in June 2010 to 20% (8/40) in September 2011. Also, the number of eggs has progressively increased: 10 in June 2010, 23 in September 2010, 36 in March 2011 and 41 in September 2011.

In New Zealand, invasive non-native mammals threaten the survival of native species such as the North Island brown kiwi (Apteryx mantelli). At Whangarei Heads, in northern New Zealand, community groups are working with local and national government agencies to protect kiwi populations. The abundance of kiwi there has been monitored since 2001 using annual counts of calls. Trapping of invasive mammals began in 2002, and their relative abundance is assessed from annual capture rates. Capture rates of stoats (Mustela erminea), weasels (M. nivalis), cats (Felis catus), rats (Rattus spp.) and possums (Trichosurus vulpecula) have declined significantly since trapping began, suggesting their abundance has been suppressed. Ferrets (Mustela furo) were already scarce when trapping began, and have been reduced to undetectable levels in most years. Numbers of hedgehogs (Erinaceus europaeus) have shown little response to trapping. Kiwi populations were apparently in decline before pest control began, but have since increased. Kiwi call rates in 2011 were the highest so far recorded at Whangarei Heads. Stoats are considered one of the main threats to kiwi, and our data suggest that kiwi numbers remain low unless stoat abundance is reduced below a catch per unit effort threshold of ~0.1 stoat per trap per year.

A trial wild-wild translocation of the critically endangered grand skink Oligosoma grande in Otago, New Zealand
Whitmore N., Judd L.M., Mules R.D., Webster T.A., Madill S.C. & Hutcheon A.D. (2012), 9, 28-35

The in situ management of the critically endangered grand skink Oligosoma grande currently hinges on the on-going health of a single large sub-population at Macraes Flat, Otago. Given its vulnerability, it was considered desirable to establish additional sub-populations to ensure the long-term survival of the species. A spatial meta-population simulation of grand skinks at Macraes Flat suggested that this could be facilitated by the translocation of grand skinks into areas of predator protected habitat. Areas identified by modelling as suitable translocation sites were ground-truthed by an experienced survey team in 2008. In October 2009 we began a translocation trial. We moved nineteen grand skinks from three locations to the translocation site. The founder population was made up of ten juveniles and nine sexually mature grand skinks. Seasonal estimation of persistence and abundance using a photographic re-sight methodology allowed the short- and medium-term performance of the translocation to be assessed.  High initial persistence rates suggested immediate homing was not a factor of concern. After one year, all translocated juveniles had persisted, but only four of the original nine adults remained at the release site. While the loss of adults was to some extent offset by the birth of the young-of-the-year (total skinks start: n = 19, finish: n = 20) there was a moderate loss of ~ 10% in terms of the population’s expected reproductive value. Overall, we viewed the outcome as favourable and on that basis undertook a follow up translocation.

The White-winged Nightjar Eleothreptus candicans is a globally threatened nightbird of the open savannas of central South America. Previous observations, suggesting that the species has a preference for recently burnt habitats, have potentially been confounded by the increased detectability of individuals and the lack of availability of unburnt habitats following extensive wildfires. This study attempted to address these limitations by monitoring the response of three radio-tagged nightjars (which had already been tracked for ≥10 months) to an experimental burn, overlapping with 16–33% of their pre-burn home ranges, at Bosque Mbaracayú Biosphere Reserve in eastern Paraguay. Overall, 10 (24%) of the 42 nocturnal radio-tracking fixes obtained during eight weeks of post-burn monitoring were within the burnt area. One individual entirely avoided the burn parcel following the burn, but the other two showed no significant preference for the burnt area. None of the seven diurnal roost sites located during post-burn monitoring was within the burn parcel. This apparent lack of an active preference for burnt habitat, at least during the first two months immediately following a fire, adds weight to recommendations for more active fire management in the few protected areas where the species persists, in order to reduce the frequency of the periodic uncontrollable and extensive wildfires that typically occur at present.

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.

Coastal grazing marsh was flooded with seawater in a successful attempt to eradicate New Zealand pygmy weed Crassula helmsii at Old Hall Marshes in 2006. The abundance of Orthoptera and the presence of yellow meadow ants Lasius flavus were broadly similar between the flooded grazing marsh and unflooded ground in 2011 indicating that inundation did not have a deleterious impact on these non-target terrestrial insects. Ant hills in areas of lower ground within the flooded area, which were fully inundated in 2006, had a lower occupancy rate (44%) than those on higher ground (94% occupied), suggesting that unflooded refuges may be important.

We present the first population estimate for the little known and critically endangered Malherbe’s parakeet Cyanoramphus malherbi inhabiting Maud Island, New Zealand. From March 2007 to May 2009 we conducted surveys for the species at this site to document the status of this translocated population and to determine the relative value of Maud Island for the conservation of this species. Using a modified version of the mark-resighting method, we estimated that the Maud Island population of Malherbe’s parakeets has gone from an initial founder group of 11 captive-bred parakeets released on site, to a maximum of 97 during our survey period (assuming a 72% survival rate between trimesters). Out of a total of 221 sightings, 22% corresponded to un-marked individuals hatched on site. Our estimate of population size, coupled with the high reproductive potential of the species, suggests that translocation of captive-bred individuals to sanctuaries free of invasive predators is an effective management method for increasing the global population size of the species and eventually downgrade its IUCN threat category.

Eradication of New Zealand flax Phormium tenax on Inaccessible and Nightingale Islands, Tristan da Cunha
Ryan P.G., Glass P.G., Glass T., Barendse J. & Cuthbert R.J. (2012), 9, 58-62

New Zealand flax Phormium tenax was introduced to Tristan da Cunha, an island in the central South Atlantic Ocean, in the 1800s. During the following century it was transferred to two other islands in the Tristan archipelago: Inaccessible and Nightingale Islands. Although not an aggressive invader, flax spread on both islands threatening their status as among the least disturbed temperate islands remaining in the Southern Ocean. In 2004 an eradication programme was initiated on both islands to clear flax using a combination of uprooting, cutting, crushing and spraying with herbicide. Despite some regrowth, follow-up operations greatly reduced the number of flax plants. Established plants are now confined to about 300 m of cliffs at the Waterfall on Inaccessible Island where clearing is hampered by the steep terrain. Further follow-up management is planned until the plant is eradicated from both islands.

Italian wall lizards Podarcis siculus campestris were accidentally introduced to a site in Buckinghamshire, UK with a consignment of stone originating in Italy. Many populations of this lizard and closely related species have been established outside their native range, sometimes from a small number of founders. Mindful of the potential for these lizards to establish in the UK, we decided on a “rapid response” intervention. We captured four lizards, including a gravid female, and removed them to a secure captive collection. The capture operation comprised two visits, with specialist advice assisting estate management and nature conservation staff. Vegetation around the stone was cut back to dissuade dispersal in an effort to contain any remaining lizards. The imported stone and surrounding area were placed under surveillance, and no further lizards were found over the course of two years. Good communications between landowners, a government agency and reptile specialists expedited this intervention. We conclude that this simple, low-effort example of rapid response has eliminated the risk of a non-native invasive species establishing.

This paper describes the results of a translocation rescue of the British endemic Isle of Man cabbage Coincya monensis ssp. monensis from a sand-dune ridge at Crosby, Merseyside, which was about to be excavated as a source of sand for a coastal protection scheme at nearby Hightown. Using methods developed during a 1992 translocation, over eight hundred 1st year plants, together with seed-pods, were moved by volunteers to two protected receptor sites at Crosby and Birkdale in August 2011. Monitoring the following summer located small surviving populations at the receptor sites but mortality of transplants appeared to be over 90%, seed germination and establishment contributing most individuals. Low success at Crosby seemed partly attributable to winter sand-blow and heavy public pressure, while vegetation overgrowth may have been an adverse factor at Birkdale. An unexpected finding was that the original Crosby colony survived the removal of most of its habitat, about 1300 plants being counted in 2012 on the levelled dune area. More than half were small seedlings, presumably derived from buried seed. Also, 234 Isle of Man cabbage plants were discovered on the new coastal defence bund at Hightown, having arisen from propagules transported from Crosby. Other known Sefton duneland colonies at Southport Marine Lake and Blundellsands were also monitored, the former having apparently declined to extinction.

At a site on Mar Lodge Estate, Scotland, a number of broadleaved trees were planted during the early 1990s. After fifteen years these trees were still barely higher than the tree tubes protecting them due to heavy browsing by deer. In 2004 a series of small exclosures were constructed around some of the trees using timber felled from a nearby conifer plantation. Fences were constructed with logs, which proved to be longer-lasting and sturdier than the woody debris used for protection elsewhere. The trees inside the exclosures are significantly higher than those which remain unfenced, and the ground vegetation has responded well. Deadwood fences have a number of benefits over traditional deer fencing: posing no threat to woodland grouse, having a lower visual impact in the landscape, and providing additional habitats for wildlife.

Many plant species require habitat disturbance and are therefore tolerant of low-level, anthropogenic disturbance, such as that created by traditional farming practices. Where such practices have declined, conservation management often includes artificial disturbance as a substitute.  Nationally important populations of rare plants associated with temporary pools and disturbed trackways had declined at Windmill Farm Nature Reserve on the Lizard Pensinsula in Cornwall (England). In light of the historic records for these plants, the presence of a seedbank in the soil was assumed, and was confirmed as likely when the deliberate disturbance of a trackway in 2004 was followed by germination of two rare plant species (Pigmy Rush Juncus pygmaeus and Yellow Centaury Cicendia filiformis). As a result, the adjacent very overgrown trackway was more fully excavated in 2009. Within eighteen months of management, both these species and two other characteristic plants of temporary pools (Pillwort Pilularia globulifera, Three-lobed Crowfoot Ranunculus tripartitus) germinated and re-established on the excavated site.  The existence of the historic records, together with surveys in both 2002/3 and 2010/11, enabled robust pre- and post-monitoring of the impact of the conservation management. The work shows that excavation has the potential to promote rapidly the recovery of plants associated with disturbance, with the greatest chance of positive results likely to occur when restoration exploits an existing soil seedbank.