Probability Of Local Extinction Research Articles

Hyper-diverse antigenic variation and resilience to transmission-reducing intervention in falciparum malaria

Intervention efforts against falciparum malaria in high-transmission regions remain challenging, with rapid resurgence typically following their relaxation. Such resilience co-occurs with incomplete immunity and a large transmission reservoir from high asymptomatic prevalence. Incomplete immunity relates to the large antigenic variation of the parasite, with the major surface antigen of the blood stage of infection encoded by the multigene and recombinant family known as var. With a stochastic agent-based model, we investigate the existence of a sharp transition in resurgence ability with intervention intensity and identify molecular indicators informative of its proximity. Their application to survey data with deep sampling of var sequences from individual isolates in northern Ghana suggests that the transmission system was brought close to transition by intervention with indoor residual spraying. These results indicate that sustaining and intensifying intervention would have pushed malaria dynamics to a slow-rebound regime with an increased probability of local parasite extinction.

No city for wetland species: habitat associations affect mammal persistence in urban areas.

The fast rate of replacement of natural areas by expanding cities is a key threat to wildlife worldwide. Many wild species occur in cities, yet little is known on the dynamics of urban wildlife assemblages due to species' extinction and colonization that may occur in response to the rapidly evolving conditions within urban areas. Namely, species' ability to spread within urban areas, besides habitat preferences, is likely to shape the fate of species once they occur in a city. Here we use a long-term dataset on mammals occurring in one of the largest and most ancient cities in Europe to assess whether and how spatial spread and association with specific habitats drive the probability of local extinction within cities. Our analysis included mammalian records dating between years 1832 and 2023, and revealed that local extinctions in urban areas are biased towards species associated with wetlands and that were naturally rare within the city. Besides highlighting the role of wetlands within urban areas for conserving wildlife, our work also highlights the importance of long-term biodiversity monitoring in highly dynamic habitats such as cities, as a key asset to better understand wildlife trends and thus foster more sustainable and biodiversity-friendly cities.

Modelling the sustainable harvest of wild populations for the conservation of a threatened amphibian

AbstractHarvesting wild populations is increasingly used to support conservation initiatives, including translocations, captive assurance colonies, and breeding programs. Best‐practice guidelines recommend that population viability analyses should be developed to assess the potential impact of harvest on source populations, allowing quantification of the risk incurred by the conservation programme. We developed a stochastic population model to assess the relative impact of harvesting southern bell frogs (Litoria raniformis) from three well‐studied populations. We compared the probability of local extinction when harvesting from three life stages (spawn, tadpoles, and adults) and at 21 harvest proportions (from 0 to 1, in 0.05 increments). Source populations with an estimated average of 100 adult frogs and with three or fewer breeding opportunities every 5 years showed increased risk of local extinction and lower minimum adult populations from all harvest strategies. Sources with an estimated average population >600 adult frogs and breeding opportunities in at least eight out of every 10 years were more resilient to harvest. For these populations, harvesting up to 25% of spawning masses or late‐stage tadpoles had a negligible impact on the probability of local extinction and caused a slight decrease in the minimum adult population. Harvesting adults impacted source populations more strongly than harvesting spawn or tadpoles. Our model highlights the importance of frequent breeding opportunities to offset the effects of harvesting L. raniformis. Populations sustained by environmental water delivery should be prioritized for the two consecutive breeding seasons following harvest in the absence of natural wetland inundation. We demonstrate a tractable approach to assess and compare the relative risk of wild harvest for threatened amphibians, with implications for the conservation of our focal species, L. raniformis. We encourage conservation practitioners to implement population viability analyses prior to wild harvest, whenever sufficient demographic information is available to build the requisite models.

Decline in small mammal species richness in coastal-central California, 1997-2013.

The richness and composition of a small mammal community inhabiting semiarid California oak woodland may be changing in response to climate change, but we know little about the causes or consequence of these changes. We applied a capture-mark-recapture model to 17 years (1997-2013) of live trapping data to estimate species-specificabundances. The big-eared woodrat was the most frequently captured species in the area, contributing 58% of total captures. All small mammal populations exhibited seasonal fluctuations, whereas those of the California mouse, brush mouse, and pinyon mouse declined during the study period. We also applied a multispecies dynamic occupancy model to our small mammal detection history data to estimate species richness, occupancy (), detection (p), local extinction (), and colonization () probabilities, and to discern factors affecting these parameters. We found that decreased from 0.369 ± 0.088 in 1997 to 0.248 ± 0.054 in 2013; was lower during the dry season (May-September) than the wet season (October-April) and was positively influenced by total seasonal rainfall (slope parameter, = 0.859 ± 0.371; 95% CI = 0.132-1.587). Mean mammalian species richness decreased from 11.943 ± 0.461 in 1997 to 7.185 ± 0.425 in 2013. With highly variable climatic patterns expected in the future, especially increased frequency and intensity of droughts,itis important to monitor small mammal communities inhabiting threatened California oak woodlands.

Dynamic occupancy modeling of a cryptic ground-dwelling pheasant species in the Upper Blue Nile Basin in Ethiopia

Modeling the occupancy of species in the context of habitat components is a crucial step to deliver an appropriate conservation strategy. Accounting for imperfect detection in occupancy models helps to conclude on true species distribution and occupancy. We used dynamic occupancy modeling to investigate the influence of habitat covariates on occupancy dynamics of the Near Threatened Harwood’s Francolin (Pternistis harwoodi) in the Upper Blue Nile Basin in Ethiopia. We used direct observation and playback technique to collect presence/absence data both during a wet and a dry season in 2019 and 2020. By accounting for species’ imperfect detection, the model averaged estimates of occupancy probabilities (mean ± SE) across respective seasons were 0.81 ± 0.08 and 0.79 ± 0.07 and detection probabilities were 0.47 ± 0.08 and 0.62 ± 0.06. The colonization and local extinction probability estimates between seasons were 0.59 ± 0.20 and 0.12 ± 0.07, respectively. We demonstrate that occupancy probability significantly decreased with increasing both Normalized Difference Vegetation Index (NDVI: ꞵmean ± SE = −1.83 ± 0.66; 95% CI: −3.12, −0.54) and quadratic term of slope (SL2 = −1.51 ± 0.62; 95% CI: −2.73, −0.29) in the study area. Furthermore, human disturbance index (HDI: = −1.06 ± 0.54; 95% CI: −2.12, −0.004) significantly negatively influenced the occupancy of the species. As we hypothesized, the detection probability increased significantly as a function of average temperature (0.37 ± 0.13; 95% CI: 0.12, 0.63). There were no statistically significant associations among covariates and the dynamic parameters, yet important covariates such as NDVI slightly negatively influenced colonization, whereas HDI positively influenced local extinction. The aversion of the species towards human disturbance and its persistence at lower NDVI and lower slopes has important implications for conservation strategy in the area. The current study demonstrates empirical evidence of dynamic occupancy modeling for a cryptic ground-dwelling pheasant species in the Upper Blue Nile Basin. Further study is recommended to understand spatiotemporal species-habitat association at fine and landscape scales.

Functional traits drive the fate of Orthoptera in urban areas

Abstract The replacement of natural areas due to urbanisation represents a major threat to wildlife. Wild species may be classified according to their response towards urban areas. Such responses lead to persistence (exploiters and tolerant) or local extinction (avoiders) of species within cities, which in turn contributes to shaping the assemblages found therein, usually according to specific sets of ecological and morphological traits. Here, we focus on Orthoptera as a model group to test hypotheses on the relationships between species' traits and persistence in urban environments, using the city of Rome, Italy, as study area. By compiling and comparing species checklists for two distinct time frames, we assessed assemblage variation across the last three decades and revealed that local extinction of Orthoptera in urban areas is trait‐biased. Species with low mobility and fertility, and narrower—more specialised—climatic niches showed higher probability of local extinction. Our results point at both climate and land use changes as potentially major drivers of orthopterans' local extinction in urban areas, suggesting that strategies to increase natural habitat preservation and connectivity, and mitigate climate‐change induced events, may both prove effective in sustaining richer insect communities within urban areas.

Rapid and continuing regional decline of butterflies in eastern Denmark 1993-2019

Many butterfly populations respond negatively to land-use intensification in human-dominated landscapes. Networks of protected sites have been established with the aim to halt species loss. We undertook annual surveys of all occurrence sites of 22 uncommon butterfly species in eastern Denmark during the period 2014–2019 and compared to a systematic atlas survey done 1989–1993, in order to assess trends in regional occupancy of species. Three out of 22 species went regionally extinct between 1993 and 2015. One species sustained a single population through the study period. Logistic regression for the remaining 18 species showed 10 to be in strong decline from 1993 to 2015, two showed a declining trend and six had stable trends. For all species except one, the declining trend continued 2015–2019. For five species, a sustained strong decline was evident. In 1993, the total count of occurrence sites for all 22 butterfly species was 565, which by 2019 had declined to 158 sites (a 72 % loss over 26 years). From 2015 to 2019 alone, the total count of occurrence sites shrank from 200 to 158 (a 21 % decline over just four years). Legal protection of areas (Natura 2000 and Danish Nature Protection Act §3) was, unexpectedly, not associated with lower probability of local extinction for butterfly population. The observed sustained decline across species suggests an overall low efficiency of the network of protected sites, probably due to a combination of misguided management regimes and payment of extinction debts from the past.

Local colonisations and extinctions of European birds are poorly explained by changes in climate suitability

Climate change has been associated with both latitudinal and elevational shifts in species’ ranges. The extent, however, to which climate change has driven recent range shifts alongside other putative drivers remains uncertain. Here, we use the changing distributions of 378 European breeding bird species over 30 years to explore the putative drivers of recent range dynamics, considering the effects of climate, land cover, other environmental variables, and species’ traits on the probability of local colonisation and extinction. On average, species shifted their ranges by 2.4 km/year. These shifts, however, were significantly different from expectations due to changing climate and land cover. We found that local colonisation and extinction events were influenced primarily by initial climate conditions and by species’ range traits. By contrast, changes in climate suitability over the period were less important. This highlights the limitations of using only climate and land cover when projecting future changes in species’ ranges and emphasises the need for integrative, multi-predictor approaches for more robust forecasting.

Breeding season management is unlikely to improve population viability of a data-deficient migratory species in decline

A major challenge in conservation is developing effective approaches to mitigate population declines in the face of ongoing environmental change. For migratory species, it is often more feasible to implement management during periods of stationarity, like the breeding season, when populations are less mobile. However, such management strategies are only successful if the demographic rates targeted (e.g., reproductive rates) contribute substantively to population growth. Thus, evaluation of population growth rate sensitivity to variation in demographic parameters is needed to determine the most effective conservation strategies. This is especially true for small and declining populations that require targeted and urgent action to mitigate declines under current and future environmental change. Here, we used a coupled integrated population model-Bayesian population viability analysis (IPM-BPVA) to estimate demographic rates and population viability within the context of climatic and management-related changes for a data-deficient, declining population of black terns in the Upper Midwestern United States. We found that current conservation efforts during the breeding season are unlikely to reverse the declines observed within the last decade (from an average of 307 breeding pairs in 2013 to 53 in 2022). Rather, interventions aimed at increasing adult survival are projected to reduce local extinction probability by 30–46 % compared to no additional management or management targeting other rates, depending on the climate scenario. Our results highlight the importance of enhancing management efforts for migratory species during migration and nonbreeding periods, which constitute a much larger, and generally riskier, proportion of the annual cycle compared to the breeding season.

Modeling the effects of water regulation on the population viability of a threatened amphibian

AbstractThe regulation of river systems alters hydrodynamics and often reduces lateral connectivity between river channels and floodplains. For taxa such as frogs that rely on floodplain wetlands to complete their life cycle, decreasing inundation frequency can reduce recruitment and increase the probability of local extinction. We virtually reconstructed the inundation patterns of wetlands under natural and regulated flow conditions and built stochastic population models to quantify the probability of local extinction under different inundation scenarios. Specifically, we explored the interplay of habitat size, inundation frequency, and successive dry years on the local extinction probability of the threatened southern bell frog Litoria raniformis in the Murray River floodplains of South Australia. We hypothesized that the changes to wetland inundation resulting from river regulation are driving L. raniformis declines in this semiarid system. Regulation has reduced the inundation frequency of essential habitats below critical thresholds for the persistence of many fresh water‐dependent species. Successive dry years raise the probability of local extinction, and these effects are strongest in smaller wetlands. Larger wetlands and those with more frequent average inundation are less susceptible to these effects. Elucidating these trends informs the prioritization of intervention sites and the frequency of conservation interventions. Environmental water provision (through pumping or the operation of flow‐regulating structures) is a promising tool to reduce the probability of breeding failure and local extinction. Our modeling approach can be used to prioritize the delivery of environmental water to L. raniformis and potentially many other frog species.

Scalar structure in turbulent non-premixed NH3/H2/N2 jet flames at elevated pressure using Raman spectroscopy

This work presents the first quantitative Raman measurements of temperature, mass fractions, and mixture fractions in two turbulent ammonia/hydrogen/nitrogen-air diffusion jet flames simulating 14% (CAJF14) and 28% (CAJF28) partial ammonia cracking ratio with Reynolds numbers of 11,200. The precision and accuracy of the system were validated in laminar counterflow and laminar jet flames to ensure data quality. The scalar structure in turbulent flames is examined using conditional mean and rms radial profiles, scatterplots in mixture fraction space, as well as statistics conditioned on mixture fraction and physical spaces. These results are compared with opposed diffusion flow 1D simulation with multi-component transport model and Le=1 transport model to visualize the effects of differential diffusion on the scalar structure at various axial positions. Finally, localized extinction was found in CAJF14 but not for the more stable CAJF28, and the probability of localized extinction was less than 2.5%. The dataset is provided as supplemental material and can be used for the validation of numerical models.

Prevalence of stochastic processes in the fire-mediated reassemblage of the soil arthropod community of a pine forest

Wildfires are significant disruptors of established communities, but natural fire regimens are essential to sustaining biodiversity in fire-prone ecosystems. Besides plants, soil arthropods are highly affected by wildfires, but their communities are also highly resilient to such catastrophic events. It is known that both stochastic (local extinction, dispersion, and colonization probabilities) and deterministic (environmental and biotic filters) processes take part in the reassembly of biotic communities after wildfires. However, the contribution of stochastic and deterministic processes in reassembling soil arthropod communities after wildfires remains unclear, and it is largely unknown how this is affected by fire severity. This study reports on the trophic guilds, taxa composition, and alpha and beta diversity partitioning of a soil arthropod community over one year, considering unburnt forest and two levels of fire severity in a pine forest in the eastern mountainous region of Mexico. The wildfire had a positive effect on the abundance of saprophagous species, especially in moderate-fire severity sites. Overall, the diversity of the community of soil arthropods has increased over time since the fire. Taxa turnover contributed beyond random expectations to the observed beta diversity, suggesting that stochastic processes predominated in the reassemblage of the soil arthropod community. We conclude that the changes in the alpha and beta diversity of the postfire soil arthropod community were affected by the severity of the wildfire and by the time that had passed since the fire event, showing a capacity for recovery to this type of disturbance.

Dynamic Occupancy of Wild Asian Elephant: A Case Study Based On the SMART Database from the Western Forest Complex in Thailand

Understanding distribution patterns is essential for the long-term conservation of megafauna, particularly the Asian elephant (Elephas maximus). We investigated the dynamic occupancy of Asian elephants in the Thung Yai Naresuan West Wildlife Sanctuary in Thailand. Asian elephant occurrences were recorded during patrol activities from 2012 to 2019. We applied a single-species dynamic occupancy model to examine the environmental factors influencing habitat occupancy of Asian elephant across multiple seasons. The best-supported model, based on the Akaike information criterion (AIC), indicated that the normalized difference vegetation index and elevation positively influenced the probability of colonization. In contrast, the distance to the nearest population source sites showed a negative association. The probability of local extinction was positively correlated with the distance to the nearest villages and population source sites. The predictive map indicated a higher probability of colonization in a remote mountainous region of the center of the protected area. Higher extinction probability was associated with areas of dense human activity and far from population source sites connecting the Asian elephant population to the east. This is the first study to utilize a patrol database for assessing the dynamic occupancy of Asian elephants across multiple years. Our model provides insight into the dynamic distribution patterns of Asian elephants within the wildlife sanctuary and the factors that most influence these patterns. Long-term ecological data provide crucial information for assessing biodiversity, population status, and the ecological processes of focal wildlife species and are valuable for both protected area management and conservation efforts.

What factors affect species richness and distribution dynamics within two Afromontane protected areas?

Context Biodiversity monitoring programs provide information on the status and trends in wildlife populations. These trends are unknown for most mammals within African montane forests, which harbour many endemic and threatened species. Camera traps are useful for assessing mammal populations, because they allow for the estimation of species richness, occupancy, and activity patterns. Aims We sought to explore the richness and distribution of small- to large-sized mammals by using occupancy models while accounting for imperfect detection in Volcanoes and Mgahinga Gorilla National Parks, in Rwanda and Uganda. Methods We used camera-trap data collected from 2014 to 2017 by the Tropical Ecology Assessment and Monitoring (TEAM) network and multi-season occupancy models with multispecies data to assess the dynamics of species richness and distribution in the Virunga Massif and the influence of site covariates on species detection probability, occupancy, colonisation and extinction. Key results We identified 17 species from 7047 trap-days, with most of them showing an uneven distributional pattern throughout the park. We found that average species richness per site increased from five to seven species in 2017. Average local colonisation was estimated at 0.13 (s.e. 0.014), but the probability of local extinction was 0.17 (s.e. 0.028) and negatively influenced by distance from the park boundary. Detection probability was highest for medium-sized species. For species distribution, we found that black-fronted duiker, Cephalophus nigrifrons, and bushbuck, Tragelaphus scriptus, declined in distribution but remained widespread in our study area, while all other species showed an increase in distribution over the study period. Conclusions Our approach allowed us to draw inferences on rare species, such as African golden cat, Caracal aurata, by estimating detection probability on the basis of shared covariate information with more common, widespread species. As such, we were able to estimate all occupancy parameters across the terrestrial mammal community. Implications The results of this study on the distribution of terrestrial mammal species can be used by park management to inform optimal ranger patrolling efforts for mitigating threats in areas of high species presence. Additionally, the results can highlight locations of potential human–wildlife conflicts on the basis of species commonly found along the park boundary.

Occupancy of wild southern pig-tailed macaques in intact and degraded forests in Peninsular Malaysia.

Deforestation is a major threat to terrestrial tropical ecosystems, particularly in Southeast Asia where human activities have dramatic consequences for the survival of many species. However, responses of species to anthropogenic impact are highly variable. In order to establish effective conservation strategies, it is critical to determine a species’ ability to persist in degraded habitats. Here, we used camera trapping data to provide the first insights into the temporal and spatial distribution of southern pig-tailed macaques (Macaca nemestrina, listed as ‘Vulnerable’ by the IUCN) across intact and degraded forest habitats in Peninsular Malaysia, with a particular focus on the effects of clear-cutting and selective logging on macaque occupancy. Specifically, we found a 10% decline in macaque site occupancy in the highly degraded Pasoh Forest Reserve from 2013 to 2017. This may be strongly linked to the macaques’ sensitivity to intensive disturbance through clear-cutting, which significantly increased the probability that M. nemestrina became locally extinct at a previously occupied site. However, we found no clear relationship between moderate disturbance, i.e., selective logging, and the macaques’ local extinction probability or site occupancy in the Pasoh Forest Reserve and Belum-Temengor Forest Complex. Further, an identical age and sex structure of macaques in selectively logged and completely undisturbed habitat types within the Belum-Temengor Forest Complex indicated that the macaques did not show increased mortality or declining birth rates when exposed to selective logging. Overall, this suggests that low to moderately disturbed forests may still constitute valuable habitats that support viable populations of M. nemestrina, and thus need to be protected against further degradation. Our results emphasize the significance of population monitoring through camera trapping for understanding the ability of threatened species to cope with anthropogenic disturbance. This can inform species management plans and facilitate the development of effective conservation measures to protect biodiversity.

Long-term occupancy dynamics of the threatened Cheat Mountain salamander and its competitors in relation to linear habitat fragmentation

Amphibians are declining globally and while many factors are contributing to this decline, habitat loss and degradation caused by climate and land use changes are among the most critical. Habitat degradation and increased interspecific competition are both concerns for long-term viability of the federally-threatened Cheat Mountain salamander (Plethodon nettingi) which is endemic to high elevations in West Virginia. In this study, we quantified the impacts of linear habitat fragmentation (i.e., a linear forest clearing for creation of a ski slope) on local colonization and extinction probabilities in adjacent forested habitat for the Cheat Mountain salamander and two co-occurring competitor species, eastern red-backed salamander (Plethodon cinereus) and Wehrle’s salamander (Plethodon wehrlei). We also quantified long-term changes in total occupancy of the species within the high elevation study area. We surveyed the salamander community annually from 1988 to 2021 using diurnal natural cover object searches at 43 plots, with 1988 representing three years following linear habitat fragmentation. For each species, we used dynamic occupancy models to identify and model influential covariates for initial occupancy, colonization, extinction, and detection probability. We found that distance to fragmentation was positively correlated with colonization probability for Cheat Mountain salamanders, indicating negative edge effects of the linear forest clearing. Distance to fragmentation was negatively correlated with colonization probability for eastern red-backed salamanders, potentially indicating this species benefited from increased solar radiation or reduced competition from Cheat Mountain salamanders. Predicted occupancy of eastern red-backed salamanders and Wehrle’s salamanders increased over the 34 year monitoring period, indicating potential for increased competitive interactions. Our study suggests that extensive linear habitat fragmentation could result in degraded habitat for Cheat Mountain salamanders in the adjacent forest, and that potential for interactions with competitor species is increasing in high elevation forest stands.

The Madingley general ecosystem model predicts bushmeat yields, species extinction rates and ecosystem‐level impacts of bushmeat harvesting

Traditional approaches to guiding decisions about harvesting bushmeat often employ single‐species population dynamic models, which require species‐ and location‐specific data, are missing ecological processes such as multi‐trophic interactions, cannot represent multi‐species harvesting and cannot predict the broader ecosystem impacts of harvesting. In order to explore an alternative approach to devising sustainable harvesting strategies, we employ the Madingley general ecosystem model, which can simulate ecosystem dynamics in response to multi‐species harvesting given nothing other than location‐specific climate data. We used the model to examine yield, extinctions and broader ecosystem impacts, for a range of harvesting intensities of duiker‐sized endothermic herbivores. Duiker antelope (such asCephalophus callipygusandCephalophus dorsalis) are the most heavily hunted species in sub‐Saharan Africa, contributing 34–95% of all bushmeat in the Congo Basin. Across a range of harvesting rates, the Madingley model gave estimates for optimal harvesting rate, and extinction rate, that were qualitatively and quantitatively similar to the estimates from conventional single‐species Beverton–Holt model. Predicted yields were somewhat greater (around five times, on average) for the Madingley model than the Beverton–Holt, which is partly attributable to the fact that the Madingley simulates multi‐species harvesting from an initially pristine ecosystem. Also, the Madingley model predicted a background local extinction probability for the target species of at least 10%. At medium and high levels of harvesting of duiker‐sized herbivores, the Madingley model predicted statistically significant, but moderate, reductions in the densities of the targeted functional group; increases in small‐bodied herbivores; decreases in large‐bodied carnivores; and minimal ecosystem‐level impacts overall. The results illustrate how general ecosystem models such as the Madingley model could potentially be used more widely to help estimate sustainable harvesting rates, bushmeat yields and broader ecosystem impacts across different locations and target species.

Identifying management guidelines to control the invasive House Sparrow (Passer domesticus) within natural protected areas through the estimation of local colonization and extinction probabilities

Identifying management guidelines to control the invasive House Sparrow (Passer domesticus) within natural protected areas through the estimation of local colonization and extinction probabilities

What is the effect of poaching activity on wildlife species?

Poaching is a pervasive threat to wildlife, yet quantifying the direct effect of poaching on wildlife is rarely possible because both wildlife and threat data are infrequently collected concurrently. In this study, we used poaching data collected through the Management Information System (MIST) and wildlife camera trap data collected by the Tropical Ecology Assessment and Monitoring (TEAM) network from 2014 to 2017 in Volcanoes National Park, Rwanda. We implemented co-occurrence multi-season occupancy models that accounted for imperfect detection to investigate the effect of poaching on initial occupancy, colonization, and extinction of five mammal species. Specifically, we focused on two species of conservation concern (mountain gorilla [Gorilla beringei beringei] and golden monkey [Cercopithecus mitis kandti]), and three species targeted by poachers (black-fronted duiker [Cephalophus nigrifrons], bushbuck [Tragelaphus scriptus], and African buffalo [Syncerus caffer]). We found that the probability of local extinction was highest in sites with poaching activity for golden monkey and bushbuck. In addition, the probability of initial occupancy for golden monkey was highest in sites without poaching activity. We only found weak evidence of effects of poaching on parameters governing the occupancy dynamics of the other species. All species showed evidence of poaching presence affecting the probability of detection of the wildlife species. This is the first study to our knowledge to combine direct threat observations from ranger-based monitoring data with camera trap wildlife observations to quantify the effect of poaching on wildlife. Given the widespread collection of ranger-based monitoring and camera trap data, our approach is broadly applicable to numerous protected areas and has the potential to significantly improve conservation management. Specifically, the relationship between poaching activity and wildlife population dynamics can be combined with information on the relationship between ranger patrols and poaching activity to develop models useful for making wise decisions about ranger patrol deployment.

Can dynamic occupancy models improve predictions of species' range dynamics? A test using Swiss birds.

Predictions of species' current and future ranges are needed to effectively manage species under environmental change. Species ranges are typically estimated using correlative species distribution models (SDMs), which have been criticized for their static nature. In contrast, dynamic occupancy models (DOMs) explicitily describe temporal changes in species' occupancy via colonization and local extinction probabilities, estimated from time series of occurrence data. Yet, tests of whether these models improve predictive accuracy under current or future conditions are rare. Using a long-term data set on 69 Swiss birds, we tested whether DOMs improve the predictions of distribution changes over time compared to SDMs. We evaluated the accuracy of spatial predictions and their ability to detect population trends. We also explored how predictions differed when we accounted for imperfect detection and parameterized models using calibration data sets of different time series lengths. All model types had high spatial predictive performance when assessed across all sites (mean AUC>0.8), with flexible machine learning SDM algorithms outperforming parametric static and DOMs. However, none of the models performed well at identifying sites where range changes are likely to occur. In terms of estimating population trends, DOMs performed best, particularly for species with strong population changes and when fit with sufficient data, while static SDMs performed very poorly. Overall, our study highlights the importance of considering what aspects of performance matter most when selecting a modelling method for a particular application and the need for further research to improve model utility. While DOMs show promise for capturing range dynamics and inferring population trends when fitted with sufficient data, computational constraints on variable selection and model fitting can lead to reduced spatial accuracy of predictions, an area warranting more attention.