Rodents are a key pest to agricultural and rural island communities of the South Pacific, but there is limited information of their impact on the crops and livelihoods of small-scale farmers. The rodent pest community is known, but the type and scales of damage to different crops on different islands are unknown. Knowledge about rodent pest management in other geographical regions may not be directly transferable to the Pacific region. Many studies on islands have largely focussed on the eradication of rodents from uninhabited islands for conservation benefits. These broadscale eradication efforts are unlikely to translate to inhabited islands because of complex social and agricultural issues. The livelihoods, culture and customs of poor small-scale farmers in the South Pacific have a large bearing on the current management of rodents. The aim of the present review was to describe the rodent problems, impacts and management of rodents on South Pacific islands, and identify gaps for further research. We compared and contrasted two case studies. The situation in Papua New Guinea is emergent as several introduced rodent species are actively invading new areas with wide-ranging implications for human livelihoods and conservation. In Vanuatu, we show how rodent damage on cocoa plantations can be reduced by good orchard hygiene through pruning and weeding, which also has benefits for the management of black pod disease. We conclude that (1) damage levels are unknown and unreported, (2) the impacts on human health are unknown, (3) the relationships between the pest species and their food sources, breeding and movements are not known, and (4) the situation in Papua New Guinea may represent an emergent crisis that warrants further investigation. In addition, there is a need for greater understanding of the invasive history of pest rodents, so as to integrate biological information with management strategies. Ecologically based rodent management can be achieved on Pacific Islands, but only after significant well funded large-scale projects are established and rodent ecologists are trained. We can learn from experiences from other locations such as Southeast Asia to guide the way.

Context. Oil palm plantations have become a dominant landscape in Southeast Asia, yet we still understand relatively little about the ways wildlife are adapting to fragmented mosaics of forest and oil palm. The bearded pig is of great ecological, social and conservation importance in Borneo and is declining in many parts of its range due to deforestation, habitat fragmentation and overhunting.

Aims. We assessed how the bearded pig is adapting to oil palm expansion by investigating habitat utilisation, activity patterns, body condition and minimum group size in a mosaic landscape composed of forest fragments and surrounding oil palm plantations.

Methods. We conducted our study in Sabah, Malaysian Borneo, in and around the Lower Kinabatangan Wildlife Sanctuary, a protected area consisting of secondary forest fragments (ranging 1200–7400 ha) situated within an extensive oil palm matrix. We modelled bearded pig habitat use in forest fragments and oil palm plantations using survey data from line transects. Camera traps placed throughout the forest fragments were used to assess pig activity patterns, body condition and minimum group size.

Key results. All forest transects and 80% of plantation transects showed pig presence, but mean pig signs per transect were much more prevalent in forest (70.00 ± 13.00 s.e.) than in plantations (0.91 ± 0.42 s.e.). Pig tracks had a positive relationship with leaf cover and a negative relationship with grass cover; pig rooting sites had a positive relationship with wet and moderate soils compared with drier soils. Ninety-five percent of pigs displayed ‘good’ or ‘very good’ body condition in forests across the study area. Pigs also aggregated in small groups (mean = 2.7 ± 0.1 s.e. individuals), and showed largely diurnal activity patterns with peak activity taking place at dawn and dusk. Groups with piglets and juveniles were more active during the day and less active at night as compared to overall activity patterns for all groups.

Conclusions. Our findings suggest that bearded pigs in our study area regularly utilise oil palm as habitat, as indicated by their signs in most oil palm sites surveyed. However, secondary forest fragments are used much more frequently and for a wider range of behaviours (e.g. nesting, wallowing) than adjacent oil palm plantations. These forests clearly remain the most important habitat for the bearded pig in the Lower Kinabatangan Wildlife Sanctuary, and their protection is a high conservation priority for this species.

Implications. Consistent bearded pig presence in oil palm is potentially an indication of successful adaptation to agricultural expansion in the study area. The apparently good body condition displayed by the vast majority of pigs in our study likely results from year-round cross-border fruit subsidies from surrounding oil palm plantations. The consistent diurnal activity displayed by groups containing piglets and juveniles may indicate predator avoidance strategies, whereas the substantial nocturnal activity we observed by other groups could suggest fewer threats for larger individuals. However, the overall effects of oil palm expansion in the region on bearded pig population health, foraging ecology, and movement ecology remain unknown.^A

Context. The bell miner (Manorina melanophrys) is thought to prefer the dense vegetation of Lantana camara, a dominating noxious weed, to nest in compared with native plant communities in northern New South Wales and south-eastern Queensland. As miner numbers seemed to have increased with increased availability of nesting habitat, larger numbers of despotic bell miners territorially reduce native avian diversity. The resultant high insect numbers in the canopy lead to dieback. It is unknown to what extent the native bell miner relies on lantana for nesting sites and if restoration through removal of lantana, resulting in an influx of native species, changes food availability and thus foraging behaviours.

Aims. The objective of our study was to understand the relationship between the presence of lantana and bell miners by determining: (1) bell miner behaviours in response to different understorey types; (2) bell miner nesting choices on a broad scale; (3) nesting preference for each site on a broad scale; and (4) whether nest height is related to fledging success.

Methods. Fifty individual bell miners were observed within five colonies (four containing comparison quadrats of treated and intact lantana as part of a restoration study and one containing water vine for comparison as a pristine site; n = 10 per treatment) during four seasons. Five bouts of gleaning, probing or sallying were observed, noting height and plant species. Nest sites were examined over a large area, noting plant species present, nest height and plant height.

Key results. Bell miners used gleaning as the primary foraging tactic primarily in eucalypts (93%; n = 600, mean = 13.6 m ± 0.29, s.e.). Bell miners generally nested in understorey vegetation (83.5% of nests observed) at a mean height of 2.7 m in 37 different plant species, native and exotic. Nest height did not influence the probability of broods fledging.

Conclusions. Bell miners exhibit considerable nest plasticity, and the removal of lantana as an oft-used nesting habitat is unlikely to lead to relocation by this species.

Implications. Instead, future research needs to focus on canopy insect assemblages in bell miner colonies, a potentially more important determinant of bell miner distribution.

Context. There is concern that deer are shifting forests towards undesirable trajectories, and culling of deer is often advocated to mitigate these impacts. However, culling deer is expensive and sometimes controversial. To reliably ascertain whether such action is beneficial, management-scale experiments are needed. We conducted a management experiment to evaluate the benefits of culling deer in four New Zealand forests.

Aims. Our experiment tested the predictions that culling deer should increase (1) canopy tree seedling height relative growth rate (SHRGR), and (2) the foliar biomass of understorey species palatable to deer (FBP).

Methods. Each forest was divided into two 3600-ha areas, with deer culling randomly assigned to one area. Deer abundances were indexed using faecal pellet counts, and forest variables were measured at the start and end of the 8-year experiment. Deer were already at low abundance in one forest and were not culled there. We used structural equation modelling (SEM) with Bayesian variable selection to update our a priori graphical forest–deer model with data from all four forests.

Key results. Deer abundances were significantly reduced in one forest but increased or did not change in the other two forests in which deer culling occurred. Culling deer did not increase seedling height relative growth rate (SHRGR) or the foliar biomass of understorey species palatable to deer (FBP) in the three areas subject to deer culling compared with the three areas not subject to deer culling. SEM revealed no significant relationships between local-scale deer abundance and either SHRGR or FBP. Rather, tree basal area and the foliar biomass of unpalatable understorey species were important predictors of FBP and SHRGR, respectively, in some forests.

Conclusions. Our study revealed that culling deer, as currently practiced by New Zealand land managers, did not generate the desired responses in New Zealand forests, possibly due to deer not being culled to sufficiently low densities and/or because forest dynamics and abiotic drivers determined plant growth more than deer.

Implications. Managers should consider actions other than ineffective deer culling (e.g. creating canopy gaps) to alter the dynamics of New Zealand forests. Alternatively, managers will need to substantially increase culling effort above what is currently practised for this activity to substantially reduce deer populations and thus potentially alter forest dynamics.

Context. Passive infrared cameras have become a widely utilised method for surveying mammals, providing substantial benefits over conventional trapping methods. Cameras have only recently been tested for their ability to survey terrestrial reptiles, and have not yet been tested against other reptile survey methods for their comparative effectiveness.

Aims. To investigate the reliability of passive infrared cameras as a reptile survey method, compared with pitfall trapping. In addition, to test a refinement of a current protocol for using cameras to survey reptiles.

Methods. The study was carried out in the herpetologically diverse, semiarid Mallee region of Victoria, Australia. Paired camera and pitfall lines were set up at 10 sites within Murray Sunset National Park and results from the two methods were compared. A comparison of results from cameras with and without the use of a cork tile substrate was also made.

Key results. Cameras were just as effective as pitfall traps for detecting some common diurnal species – detecting additional species that pitfalls did not – but were significantly less effective overall. Cameras provided lower estimates of species richness and failed to detect nocturnal species. We also discovered that cork tiles, required in other environments for the cameras to be effective in detecting diurnal reptiles, were not needed here.

Conclusions. Cameras can be an effective, efficient non-invasive alternative to conventional trapping methods, such as pitfall trapping, for surveying some terrestrial diurnal reptile species. However, further investigation into using cameras for surveying nocturnal reptile species is still required.

Implications. If the methodological issues identified during this study can be overcome, passive infrared cameras have the potential to be a valuable tool for future herpetological research.

Context. The severity and prevalence of the amphibian fungal pathogen, Batrachochytrium dendrobatidis (Bd) is correlated with several environmental variables, including salinity, temperature, and moisture content, which influence the pathogen’s growth and survival. Habitats that contain these environmental variables at levels outside of those optimal for Bd growth and survival may facilitate the survival of susceptible host species. Therefore, manipulation of environmental salinity is a potential management strategy to help conserve Bd-susceptible species. However, host behaviour also influences disease dynamics, and the success of habitat manipulation programs depends on how hosts use this altered habitat.

Aims. To assess if the Bd-susceptible green and golden bell frog, Litoria aurea, will select waterbodies with a salinity increased to S = 3; if this selection is affected by infection; and if a frog’s time in a waterbody of this salinity affects infection load or blood physiology.

Methods. We conducted a filmed choice experiment and a 3-year field study where infected and uninfected frogs could choose between fresh or saline waterbodies.

Key results. In both the laboratory experiment and field study, Bd-infected L. aurea spent a significantly greater amount of time in or closer to a waterbody than uninfected frogs. Experimentally infected frogs tended to prefer the saline water over fresh, but their choice of water usage did not differ statistically from uninfected frogs. In the field, frogs began to avoid ponds when salinities rose above S = 5.

Conclusions. Because both wild and captive, and infected and uninfected L. aurea readily selected waterbodies with a salinity of S = 3, this salinity could potentially be used as a passive method for reducing the severity of Bd when managing this species. However, further testing is needed to understand the efficacy of this treatment, and care must be taken to prevent salinities rising above S = 5, because this level seems to produce an avoidance response and therefore may not be suitable in every location.

Implications. Manipulation of aquatic habitats may be a worthwhile focus for Bd management in habitats where water level fluctuations are minimal.

Context. Duikers play a vital role in maintaining forest ecosystems, as both seed dispersers and prey. In West Africa, duikers are also an important source of food and income; however, it is likely that some species are now being hunted at unsustainable levels. So as to contribute to duiker conservation, we used line-transect data and additional information on dung and track counts to estimate relative abundance and establish distribution patterns of forest duikers in Côte d’Ivoire’s Dassioko Sud Forest Reserve (DSFR), a poorly known, remnant coastal rainforest. We also collected basic information on hunting pressure.

Methods. Forest duiker counts were made twice per month from July 2013 to March 2014 on six line transects of varying lengths (5.6–6.7 km) and in different regions of the DSFR, representing different habitat types. The number of sightings per kilometre walked, defined as ‘encounter rate’, was used to compute an index of relative abundance. We recorded all evidence of poachers and used these data to generate a poaching index (# poaching signs per kilometre) for different habitat types.

Key results. The DSFR has lost three of seven total forest duiker species and populations of the four remaining species are declining. Encounter rates were greatest for Philantomba maxwellii (0.46 indices km^–1) and accounted for 68% of total encounters. Cephalophus niger, C. dorsalis and C. silvicultor were encountered at similar (0.07 indices km^–1) but much lower rates. For all species, mean encounter rates were highest in degraded forest (0.38–0.73 indices km^–1), followed by secondary (0.2–0.44 indices km^–1) and primary (0.19–0.44 indices km^–1) forest.

Conclusions. Of the four forest duiker species still present in the DSFR, the black, bay and yellow-backed duikers are the most affected by anthropogenic pressures. Duiker abundance in the DSFR varies with habitat type. This variation is apparently influenced by differences in forest structure, poaching pressure and proximity to villages.

Implications. The study provides baseline data for future managing of ungulate populations in the DSFR. We recommend that a biomonitoring study of duiker populations be initiated immediately to help determine population trends, investigate habitat preferences, and help curb illegal hunting activities in this important forest reserve.

Context. Populations of many mammalian species are reduced as a result of clearcutting, despite the concurrent objectives of wood production and conservation of mammal diversity on cutover forest land. To help ameliorate this decline, green-tree retention (GTR) leaves large live trees after harvest to provide mature forest habitat and increase structural diversity of the regenerating stand.

Aims. To test the hypotheses (H) that, at 20 years after harvest, (H₁) abundance, reproduction and survival of the southern red-backed vole (Myodes gapperi), as well as (H₂) abundance and species diversity of the forest-floor small mammal community, would increase with the basal area (BA) and density of residual trees after harvest.

Methods. Small mammals were live-trapped in 2015–16 in replicated clearcut, dispersed retention, aggregated retention, patch cut and uncut forest sites in mixed forests of Douglas fir (Pseudotsuga menziesii var. glauca) and lodgepole pine (Pinus contorta Dougl. var. latifolia) in southern British Columbia, Canada.

Key results. Mean BA and density of overstory coniferous trees were significantly different at 20 years post-harvest, being higher on patch cut and uncut forest sites than on the clearcut and GTR sites. M. gapperi populations were significantly greater in aggregated retention and uncut forest sites than in the other sites, but demographic parameters were similar among sites, and therefore H₁ was partly supported. Mean total abundance of small mammals differed significantly among sites, with the highest overall numbers occurring in the aggregated retention (16.2), clearcut (13.6) and uncut forest sites (11.9). Mean species richness and diversity were highest in the GTR and clearcut sites. Thus, H₂ was not supported.

Conclusions. Recovery of M. gapperi in aggregated retention sites with 10 m² ha^–1 BA of residual trees, as a group, occurred at 20 years post-harvest.

Implications. Aggregated retention of residual trees should help provide some habitat to conserve forest mammals on harvest openings, but successional development up to 20 years post-harvest may be required.