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In human-modified landscapes, where large bird and mammal species are often functionally extinct, bats are the main seed dispersers. However, the role of seed dispersal by bats for the maintenance of habitat dynamics in fragmented landscapes is still not understood, with information lacking on landscape-level effects of plant–bat interactions. We present some key topics related to spatial ecology of bats and discuss the potential influence of habitat fragmentation on several aspects of seed dispersal by Neotropical bats. We suggest that future studies need to evaluate bat–plant networks along habitat-loss and fragmentation gradients at the landscape level, including changes in land-cover types and habitat structural complexity, going beyond patch-based analysis. By advancing on the comprehension of ecosystem functioning in fragmented landscapes, we will better understand the bat-modulated seed-dispersal process, supporting regeneration and restoration programs that benefit from bat-based functions.
Context. The translocation of southern hairy-nosed wombats (Lasiorhinus latifrons) has been suggested as a management tool to alleviate conflicts with the agricultural sector because of the damages caused by their burrowing activity. Translocation is widely used for removing problem animals from conflict areas, but its effectiveness is rarely adequately evaluated and often fails to resolve conflicts. Furthermore, translocations often result in low survival, extensive movement, and the non-establishment of translocated animals.
Aims. The present study assessed the viability of translocation as a damage-mitigation tool for L. latifrons, by examining the (1) capture success of L. latifrons, (2) survival and establishment of translocated L. latifrons, and (3) reduction of L. latifrons activity at source sites.
Methods. Thirteen L. latifrons individuals were translocated from conflict zones on agricultural properties and released on a private grazing property >60 km from capture sites. The behaviour of translocated L. latifrons individuals was monitored using GPS and/or VHF technology, and compared with that of 12 resident animals. Motion-sensor cameras monitored the source sites to determine recolonisation rates.
Key results. The capture and removal of problem individuals were time-intensive and infeasible on a large scale. Post-release mortality was not observed, although nine translocated and nine resident L. latifrons individuals went missing soon after release. Translocated (n = 4) L. latifrons displayed high site fidelity, but initially ranged further than residents (n = 6), before settling into similar behaviour patterns. Lasiorhinus latifrons activity was not reduced at the source sites, with neighbouring wombats recolonising warrens within 1–2 weeks.
Conclusions. Translocation is not a suitable human–wombat conflict mitigation tool but may prove useful for restoring declining populations.
Implications. These findings support the growing body of evidence that translocating problem animals is not suitable for resolving conflicts and alternative methods such as the use of deterrents may be more appropriate.
Context. The Baudin’s cockatoo is one of three black cockatoo species endemic to Western Australia and is listed as Endangered by state and federal governments. Although there is a Recovery Plan in place for this species, conservation efforts are hindered by gaps in knowledge regarding the species movement ecology.
Aims. To identify key foraging and roosting habitat for Baudin’s cockatoos and to determine differences in flock movements, including the spatial extent of movement, in Urban, Peri-urban and Forest regions using telemetry data.
Methods. Wild Baudin’s cockatoos that had been injured and undergone rehabilitation were equipped with satellite PTT (platform transmitter terminal) and GPS tags and released back into wild flocks. The study birds, and the flocks into which they integrated, were tracked in the field to collect telemetry and observational data. Satellite data were used to define the types of movement behaviour (resident, ranging, migratory), and GPS data were analysed to determine key foraging and roosting habitat, and to calculate home range area estimates.
Key results. There was a significant difference in flock movement between the Urban/Peri-urban regions and the Forest region in terms of daily distances moved and distances between roosts, with these parameters being far greater for the Forest region. Additionally, flock sizes were larger in the Forest region compared with the Urban and Peri-urban regions. In Urban and Peri-urban regions, key habitat comprised remnant vegetation in urban green space (nature reserves, parks and private property), and roadside and riparian vegetation, which served as movement corridors in the landscape.
Conclusions. The research shows that it is important to maintain vegetation connectivity in the landscape. This enables Baudin’s cockatoos to utilise key patches of remnant vegetation in their non-breeding wintering grounds in Urban and Peri-urban regions of the Perth Peel Coastal Plain. Further research on the movement ecology of Baudin’s cockatoos should focus on habitat suitability modelling, which, in combination with the identified key habitat sites, will benefit the decision-making process in relation to conservation management of this endangered black cockatoo species.
Implications. This research has benefited the conservation management of Baudin’s cockatoos by providing information on key habitat through satellite tracking and outlining the importance of the connective features of remnant vegetation. We advocate for further telemetry studies combined with habitat suitability modelling to preserve the necessary habitat for the persistence of this species in the Western Australian landscape.
Context. Developing a new tool for wide-scale rat eradication is necessary for significant biodiversity gains. Underlying beliefs linked to public opinion can help guide policy makers to understand public concern and inform an effective discourse.
Aims. We investigated underlying beliefs linked to levels of support for a potentially disruptive tool, gene drive, compared with a traditional stepwise tool, aerial distribution of a new pest-specific toxin.
Methods. Using the theory of planned behaviour, we surveyed (n = 1200) a representative sample of New Zealanders to assess the level of support for the tool related to attitude, normative and control beliefs.
Key results. Attitude (e.g. gene drive is good/bad and gene drive is risky/safe) and two norms (e.g. people like me and people in my household) were key contributors to level of support for gene drive. Behavioural beliefs (if scientific evidence can prove it works, concern there are unknown consequences, a humane way to rid New Zealand of rats, and gene drive goes against natural way of life) were also significant. For aerial distribution of a new pest-specific toxin, the same attitudes and normative beliefs identified for gene drive also contributed significantly to the model. Four behavioural beliefs, namely, aerial delivery could affect areas outside the target zones, if there is scientific evidence, and it is impossible to make a pest-specific toxin that would not harm our native wildlife were also significant. The impact either tool may have on biodiversity was not significant in either model.
Conclusions. Decision making about both gene drive (a disruptive technology) and aerial distribution of a pest-specific toxin (a stepwise technology) is primarily influenced by attitudes, with a few beliefs also influencing decision making. Novelty of the tool does not affect the underlying beliefs that are influencing levels of support.
Implications. Public engagement that acknowledges and responds to these underlying beliefs, rather than a traditional campaign based on biodiversity and environmental gains, may be more effective at creating a constructive dialogue about if and how these tools should be used, and to avoid replicating the polarised debate about 1080.
Context. In recent years, multiple computer algorithms, which allow us to perform photographic capture–recapture analysis, have been developed. Their massive application, also in wildlife demographic and ecological studies, is largely due to the fact that these tools are non-invasive and non-expensive. To maximise the performance of these programs, it is essential to have a good photo-standardisation so as to avoid bias in the results. A lot of ‘non-standardised’ photos are not usable for capture–mark–recapture (CMR) analysis, entailing the loss of potentially exploitable data.
Aims. No study has accurately investigated the effect of the corporal bending of an animal on the performance of the interactive individual identification system (I3S) algorithm. For this reason, we assessed the effect of this photographic standardisation parameter (PSP) on the reliability of this algorithm.
Methods. We assessed the effect of the body position of Triturus cristatus between capture and recapture photos on the error rates of a group of standardised pictures, performing a generalised linear model analysis. We have also evaluated the effect of image correction (i.e. straightening of newts’ bodies) on the error rates (expressed by false rejection rates, FRRs) of the first (standardised) photo-group (G1) and of a non-standardised photo-group (G2). To perform this, we used I3S-Pattern+ for the photo-matching analysis and I3S-Straighten for the correction of the pictures.
Key results. The difference of body angles between capture and recapture pictures had a significantly increased error rates in G1. Digital correction of body bending reduced the error rates. For the pictures where corporal bending was not digitally corrected, the top 20 FRRs were 0.38 and 0.33 for G1 and G2 respectively. For corrected (straightened) pictures, the top 20 FRRs were 0.026 and 0.15.
Conclusions. Our findings showed a high impact of newt corporal bending and photographic treatment on the I3S algorithm reliability.
Implications. We provide some recommendations to avoid or minimise the effects of this PSP and improve photo-standardisation during and after CMR studies of species of Urodela. In this way, pictures that would be unusable in photo-matching software under current practice could become usable, increasing the available data to conduct a survey.
Context. Feral goats (Capra hircus) are a significant pest species throughout southern Australia. They threaten rare plants, contribute to soil erosion, compete with domestic stock, and are implicated in the decline of several native herbivores. Feral goats are a declared pest and control is often implemented.
Aims. We fitted feral goats with GPS collars in semiarid South Australia to determine whether they could provide valuable information for regional management.
Methods. Nineteen feral goats (6 males and 13 females) were fitted with GPS collars between 2009 and 2018. Kernel-density estimates (KDE) were used to estimate annual and seasonal home range and core areas and habitat selection. The effect of monthly rainfall, daily maximum temperatures, and watering points on movement patterns was investigated.
Key results. Stock watering points and rock holes were used by some radio-tracked goats intermittently when available; however, goats survived and reproduced without the use of these water sources. The use of the radio-collared goats as Judas goats helped facilitate the removal of 9725 goats from a 50 000-ha area over 8 years. There was no significant difference between male and female annual or seasonal home ranges, with 95% MCP annual ranges of 11 533 ha and 15 996 ha for males and females respectively. Summer ranges were smaller than winter ranges. There was no difference in daily distance moved between sexes (average 3.4 km), but goats moved further in low-rainfall periods. Goats spent most of their time in mallee woodlands, the dominant habitat type available, but preferred shrubland of >1-m height and used less mallee woodland and shrubland of <1-m height than was expected from availability. During hotter periods, these habitat preferences became more distinct.
Conclusions. To reduce goat abundance on a property, active control and waterpoint closure need to extend more than 15 km from property boundaries, and shrubland habitat of >1-m height should be targeted for control after rainfall events when goats move less. Radio-collared goats provided important habitat-preference information to inform priority areas for goat control remote from water sources.
Implications. Closing artificial watering point and regular trapping and mustering at remaining waters is insufficient to remove residual goat herds without additional targeted control in preferred habitat.
Context. Green sea turtles are threatened by exploitation for food and medicine markets, with Asian populations facing the heaviest pressures. Sea turtle confiscations that happen out at sea can give a general area that poachers are targeting, but it can be difficult to determine the impact on specific nesting rookeries. Previous studies circumvented this difficulty by using genetic markers to identify nesting rookery origins of confiscated green turtles.
Aims. To determine the impact on nesting rookeries from the illegal harvesting of green sea turtles by Hainan fishermen and describe the genetic diversity of the Paracel Islands’ green sea turtle population.
Methods. In the present study, we sequenced 384 bp of mitochondrial DNA control region from 85 illegally traded green sea turtles rescued on Hainan Island, China, to investigate their population of origin. For reference-source data, we used previously published mtDNA haplotype data from rookeries from Australasian waters and mtDNA haplotype data from 16 newly collected samples from the Paracel Islands in the South China Sea, a previously unsampled area.
Key results. Ten and four mtDNA haplotypes, all being reported before, were detected from the Hainan confiscation and Paracel Islands rookery respectively. However, CmP19, an infrequent haplotype that has been found only in 10 green sea turtles previously, made up ∼45% of our rescued samples and ∼62% of the Paracel Islands sample, suggesting a potential association between CmP19 and the Paracel Island rookery. Haplotype diversity of the rescued green sea turtles was relatively high (h = 0.7143 ± 0.04), whereas nucleotide diversity was relatively low (π = 0.0031 ± 0.00), compared with other rookeries. Mixed-stock analysis suggested that the rookeries in the Paracel Islands (∼57%) and the Sulu Sea (∼29%) are experiencing the greatest impact from illegal harvesting by fishermen from Hainan and neighbouring countries.
Conclusions. The Paracel Islands population contains a unique genetic makeup compared with other studied rookeries, particularly the high frequency of the previously rare CmP19 haplotype. The current harvesting of green sea turtles by Hainan fishermen affects not only protected local populations (Paracel Islands), but also distant populations (Sulu Sea) in protected international waters.
Implications. Establishment of a large-scale Sea Turtle Nature Reserve in the South China Sea, including a special law enforcement team to monitor this National Marine Park, needs to be top priority to help curb illegal harvesting. The Paracel Islands represents a newly defined population, and conservation measures need to be taken immediately to preserve this distinct population.
Context. Management of human–wildlife conflicts is of critical importance for both wildlife conservation and agricultural production. Population models are commonly used to simulate population dynamics and their responses to management actions. However, it is essential that this class of models captures the drivers and mechanisms necessary to reliably forecast future system dynamics.
Aims. We aimed to develop a flexible modelling framework with the capacity to explicitly simulate individual interactions with baits (with or without the presence of other management tools), for which parameter estimates from field data are available. We also intended for the model to potentially accommodate multi-species interaction and avoidance behaviours.
Methods. We expanded an existing spatially explicit, individual-based model to directly simulate bait deployment, animal movements and bait consumption. We demonstrated the utility of this model using a case study from Western Australia where we considered two possible exclusion-fence scenarios, namely, the completion of a landscape-scale and smaller-scale fences. Within each of these proposed cells, using data obtained from a camera-trap study, we evaluated the performance of two levels of baiting to control wild dogs (Canis familiaris), in contrast with the option of no control.
Results. The present study represents a substantial step forward in accurately modelling predator dynamics. When applying our model to the case study, for example, it was straightforward to investigate whether outcomes were sensitive to the bait-encounter probability. We could further explore interactions between baiting regimes and different fence designs and demonstrate how wild dog eradication could be achieved in the smaller cell under the more intense control scenarios. In contrast, the landscape-scale fence had only minor effects unless it was implemented as a preventive measure in an area where wild dogs were not already established.
Conclusions. The new component of the model presented here provides fine-scale control of single components of individual–bait interactions.
Implications. The effect of management actions (e.g. lures) that affect this process can be easily investigated. Multi-species modelling and avoidance behaviours can readily be implemented, making the present study widely relevant for a range of contexts such as multi-species competition or non-target bait uptake.
Context. In many countries, annual wolf surveys based on snow-track counts have become unreliable because of inconsistent snow coverage. We considered incidental observations by volunteers throughout the year as an alternative monitoring protocol.
Aims. We recruited interested citizens throughout Lithuania, including hunters, foresters and farmers, to estimate wolf distribution, abundance, pack numbers and group size from 2015 to 2018.
Methods. Observation-based records of wolves were collected using simple questionnaires that included time, location and method of observation (e.g. track, scat, vocalisation or prey-kill remains). We summarised 979 reports of 1938 observed wolves.
Key results. Volunteer reports suggested an increase in wolf distribution and abundance from 2015 to 2018. The observed number of wolf packs was estimated to be at least 100 by 2018, pack size increased to 3.6, and the share of single wolves decreased from 56% in 2015 to 40% in 2018.
Conclusions. We found that volunteer observations can provide useful information on wolf distribution, pack size and pack numbers. Our results support previous reports of expanding wolf populations in the Baltic region.
Implications. Results of our citizen-science effort by Nature Research Centre and Lithuanian Hunters and Fishers Association have been accepted by the Ministry of Environment as a complement to other surveys in Lithuania and should aid in developing an informed wolf-management policy.
Context. Damage to harvest storage systems by mammals and associated postharvest losses generate human–wildlife conflicts. Silo bags have been widely adopted worldwide as a type of temporary harvest storage for agricultural crops. The basis of silo-bag technology is the hermetic condition of the plastic lining. Breaks in this silo-bag lining by mammals generate damage of stored content and are a serious concern for farmers, who generally take actions against wildlife with consequent impacts on the environment.
Aims. We described the incidence and intensity of breaks in silo-bag linings by different mammal groups (armadillos, canids and rodents) in agroecosystems of central Argentina, and we analysed the influence of extrinsic and intrinsic factors on patterns of breakage of silo bags, and propose management options based on cultural methods tending to prevent damage and reduce human–wildlife conflicts.
Methods. Sampling was conducted during the austral summer and winter of 2018, at three sites in the Pampas of Argentina. At each site, we chose farms that were using at least one silo bag, described silo-bag characteristics, and recorded the number of breaks in silo bags generated by mammals.
Key results. We sampled a total of 306 silo bags from 38 farms. Damage incidence by mammals comprised 49% of silo bags sampled. Statistical analyses (GLMMs) revealed that damage intensity generally increased with storage time. Seasonality played a key role, with breakage being higher during summer for armadillos, when they are most active, and in winter for rodents, when they are most abundant. Damage by armadillos exhibited geographic variation and also decreased significantly with increasing distance to the nearest plot edge in which the silo bag was placed. Damage by rodents was higher for bags containing grains rather than forage.
Conclusions. Damage to silo bags by mammals was affected by both extrinsic (seasonal and geographical) and intrinsic (stored content, storage time and distance to nearest edge) factors; however, these effects varied according to the mammal group considered.
Implications. Relocation of silo bags away from plot edges could significantly reduce damage by armadillos, the most harmful mammals to silo bags.
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