Hunting Pressure Research Articles

Using camera trap data to characterise terrestrial larger‐bodied mammal communities in different management sectors of the Dja Faunal Reserve, Cameroon

AbstractCamera trap surveys can be useful in characterising terrestrial larger‐bodied mammal communities in Central Africa forests. Two 40‐trap, minimum of 100 days, survey grids conducted in the Dja Faunal Reserve of southern Cameroon showed differences in the mammal communities of two sites 32 km apart. Mammal richness, diversity, guild structure, body‐size patterns and relative abundance of taxa were measured by trapping rates and occupancy of the two mammal communities. One of the survey sites was (a) less rich in terrestrial mammal species; (b) missing disturbance‐sensitive felids and white‐bellied duiker (Cephalophus leucogaster, subsp, leucogaster, Gray, 1873); (c) greater in abundance of some disturbance‐tolerant species; and (d) lower in abundance of larger‐bodied species. Several indicators suggest a higher hunting pressure at this site, and this may be a contributing factor to these differences.

Effect of protection status on mammal richness and abundance in Afromontane forests of the Udzungwa Mountains, Tanzania

The effectiveness of Protected Areas (PAs) in reducing hunting pressure on mammal populations in tropical forests has rarely been examined at a community-wide level. In African forests, commercial and subsistence hunting are widespread, but assessments of mammal abundance and distribution patterns are often lacking. We investigated patterns of occupancy and abundance for 27 species of medium- to large-bodied mammals (>2 kg) within Tanzania's Udzungwa Mountains Afromontane forests, a global biodiversity hotspot. We sampled 22 forest sites within 10 forests under varying degrees of protection, elevation, distance to extractive communities, and levels of law enforcement. We sampled 251.7 km of recce line transects during dry seasons (July–November) between September 2007 and July 2010. We found a strong positive effect of protection status on species richness and on encounter rates of the most commonly encountered species. Consistent with the levels of resources and enforcement within each PA category, there was a significant progression in species richness and abundance from Forest Reserves through Nature Reserves to sites within Udzungwa Mountains National Park. Protective status closely reflected levels of disturbance. Snaring activity, and distance to ranger posts were identified as significant predictors of overall species richness and encounter rates for mammal species, including endemics. The species-area relationship for our study species was found to be largely overridden by levels of protection. Our findings demonstrate PA effectiveness in Afromontane forests and reinforce concerns over hunting pressures particularly the threat posed by snares.

A little-known endemic caught in the South-east Asian extinction crisis: the Annamite striped rabbit Nesolagus timminsi

AbstractThe Annamite mountains of Viet Nam and the Lao People's Democratic Republic (Lao) are an area of exceptional mammalian endemism but intensive poaching has defaunated much of the region, creating an extinction crisis for the endemic species. To make efficient use of limited conservation resources, it is imperative that conservation stakeholders obtain basic information about poorly known and threatened endemics. We present the first comprehensive information on the ecology, distribution and status of the little-known endemic Annamite striped rabbit Nesolagus timminsi. We used a systematic camera-trapping design to study the species in five areas in Viet Nam and Lao. In 29,180 camera-trap-nights we recorded 152 independent events at 36 of 266 stations. We obtained an additional 143 independent detections across 12 stations from a supplementary non-systematic survey. We analysed activity patterns and social behaviour. We also used single-species occupancy models to assess factors that influence occupancy at the landscape scale. We used N-mixture models to obtain local abundance estimates in one target area. The Annamite striped rabbit was found to be nocturnal and primarily solitary. Species occupancy was best explained by a proxy for past hunting pressure, with no significant relationships to current anthropogenic or environmental factors. Local abundance was 0.57 individuals per camera-trap station for one of our sites, and estimated to be zero at the other site where hunting appears to have been more intense. Our results provide information on priority areas for targeted anti-poaching efforts and give the first conservation baseline for the species.

Catastrophic impact of wild boars: insufficient hunting pressure pushes snakes to the brink

AbstractClimatic changes, habitat loss and invasive species are important threats for many animal populations. Here, we report rapid declines and extinctions of adder populations monitored during 12 years in Belgium where none of the above causes was involved. This study provides the first large‐scale data showing that wild boars represent a major risk for snakes, pushing populations to extinction. Drastic population declines were observed in the sites impacted by wild boars (N = 14), while in other sites spared by wild boars populations remained stable (N = 9). Wild boars are highly fertile and their main predators have been extirpated from Western Europe; yet, recreational hunting kept populations in check during decades. Hunting pressure is currently insufficient to control the rapid expansion of wild boars, demographic outbreaks are increasingly frequent. Wild boars are omnivorous; they can destroy snakes directly and indirectly through the depletion of snake's preys and via the destruction of key microhabitats. Snakes exhibit limited dispersal capacities; they cannot escape local perturbations and thus are highly vulnerable. Because wild boars have a very eclectic diet, are prolific breeders and are able to devastate a range of habitats their negative impact under relaxed hunting pressure applies to a huge variety of organisms, including reptiles. Policies to limit wild boar populations are urgently needed. Recommendations to target reproductive females and piglets should be generalized and applied.

Estimating the population size of lemurs based on their mutualistic food trees

AbstractAimSpecies’ distributions and abundances are primarily determined by the suitability of environmental conditions, including climate and interactions with sympatric species, but also increasingly by human activities. Modelling tools can help in assessing the extinction risk of affected species. By combining species distribution modelling of abiotic and biotic niches with population size modelling, we estimated the abundance of 19 lemur taxa in three regions, especially focusing on 10 species that are considered Endangered or Critically Endangered.LocationMadagascar.TaxaLemurs (Primates) and angiosperm trees.MethodsWe used climate data, field samples, and published occurrence data on trees to construct species distribution models (SDM) for lemur food tree species. We then inferred the SDMs for lemurs based on the probability of occurrence of their food trees as well as climate. Finally, we used tree SDMs, topography, distance to the forest edge, and field estimates of lemur population density to predict lemur abundance in general linear models.ResultsThe SDMs of lemur food trees were stronger predictors of the occurrence of lemurs than climate. The predicted probability of presence of food trees, slope, elevation, and distance from the forest edge were significant correlates of lemur density. We found that sixteen species had minimum estimated abundances greater than 10,000 individuals over >1,000km2. Three lemur species are especially threatened, with less than 2,500 individuals predicted for Cheirogaleus sibreei, and heavy hunting pressure for the relatively small populations of Indri indri and Hapalemur occidentalis.Main conclusionsBiotic interactors were important variables in SDMs for lemurs, allowing refined estimates of ranges and abundances. This paper provides an analytical workflow that can be applied to other taxonomic groups to substantiate estimates of species’ vulnerability to extinction.

Where to go goose hunting? Using pattern-oriented modeling to better understand human decision processes

ABSTRACTTo predict hunting pressure at a regional level for the adaptive harvest management of a European goose population, we created a predictive model within an existing agent-based model framework. In this paper, we outline the inputs, outputs, and learning from developing this model, using pattern-oriented modeling (POM), to predict the regional distribution of goose hunting locations. Our results showed that social aspects (e.g., crowding, how far hunters are prepared to travel) may influence hunter decisions when choosing hunting locations. However, access to multiple hunting locations and knowledge of goose behavior and likely foraging areas were more important decision drivers. A crucial model outcome was the secondary prediction of the size of the potential pool of goose hunters. We believe that POM is a beneficial framework for those wishing to define, test, and ultimately develop better predictive models of human decision-making and subsequent behaviors and feedbacks.

Density and distribution of a brown bear (Ursus arctos) population within the Caucasus biodiversity hotspot

Population declines and extirpations of large mammalian carnivores are major concerns for global biodiversity conservation. Many large carnivores are vulnerable to conflict with humans and attract conservation attention for their flagship appeal and ecological importance. Coexisting with carnivores requires an understanding of carnivore distribution and abundance relative to human activities and disturbances. Such knowledge is often hindered by the rare and elusive nature of carnivores and the lack of systematic ecological surveys in biodiverse regions facing high levels of threat. The Caucasus Ecoregion is one such biodiversity hotspot harboring several threatened mammal species for which there is a paucity of reliable data, including brown bears (Ursus arctos). Caucasus brown bear populations have declined significantly from historical times and may be isolated and vulnerable to disturbance from development activities such as mining, as well as increasing hunting pressure. To inform land-use planning and bear conservation in the Caucasus Ecoregion, we conducted systematic surveys in May–October 2015 in the foothills of the Caucasus Mountains within the Vayots Dzor region of Armenia. We used noninvasive genetic sampling, camera trapping, and statistical models that account for imperfect detection to estimate density and distribution of the bear population in the 1,000-km2 study area. Across 34 sampling sites, we obtained 3,163 camera-trap photos of brown bears and genotyped 28 individual bears (7 males and 21 females). Spatially explicit capture-recapture models revealed an unexpectedly high density of bears (59.4/1,000 km2; females = 44.6, 95% confidence interval, CI = 25.4–78.4; males = 14.8, 95% CI = 6.6–34.0), and multi-method occupancy models indicated that bears were distributed across most of the study area (ψ = 0.85; SE = 0.07). These results provide robust evidence that a significant population of brown bears persists in Armenia's Vayots Dzor region, despite a history of hunting and habitat loss that have driven declines in brown bear populations throughout much of the Caucasus Ecoregion. Continued persistence of this flagship species may be threatened by mining, poaching, and other anthropogenic pressures in the region, underscoring the urgent need for strategic conservation planning, impact mitigation, and expanded ecological monitoring within this biodiversity hotspot.

Defaunation impacts on seed survival and its effect on the biomass of future tropical forests

Large animal species, which provide important ecological functions such as dispersal of seeds or top–down control of seed predators, are very vulnerable in fragmented forests, being unable to survive in small fragments, and facing increasing hunting pressure. The loss of large animals affects two main ecological processes crucial for the tree reproductive cycle: seed dispersal of large seeds (e.g. provided by tapirs) and control of seed predator population (e.g. provided by large cats). The changes in both processes are expected to increase seed mortality since seeds are not dispersed away from conspecifics (causing increased pre‐dispersal mortality due to negative density dependent effects) and/or face increased predation after a dispersal event (post‐dispersal mortality). Although an extensive body of empirical knowledge exists on seed predation, the link between seed loss and adult tree community composition and structure is not well established, as well as the temporal scale seed changes affect adults. Using an individual‐based forest model (FORMIND), we evaluate the long‐term consequences of increased pre and post‐dispersal seed mortality on the future forest biomass retention of a Brazilian northeastern Atlantic forest. Our results show that forest biomass is significantly affected after 80–93% pre‐dispersal loss of large seeds, or post‐dispersal predation densities of 20–25 predators per parent tree. Large‐seeded tree species are at increased risk of local extinction causing up to 26.2% loss of forest biomass when both pre and post‐dispersal processes are combined. However, these changes can last up to 100 years after the occurrence of defaunation. In summary we conclude that large animal loss has the potential to reduce future forest biomass and tree species‐richness by impacting seed survival, and should be considered in the planning of biodiversity friendly landscapes as well as in calculations of the global carbon budget.

A simple method for calculating minimum estimates of previous population sizes of wildlife from hunting records.

Hunting records have proven useful for examining the historical status of wildlife populations. The number of animals harvested can provide information on past population sizes that would have been required to support harvest yields. Therefore, when statistical data on annual harvests are available, a minimum estimate of past population sizes can be calculated. A very simple method for estimating the sizes of historic wildlife populations using only annual hunting records and the maximum annual population increase rate is presented in this study. This method was applied to estimate past population sizes for Japanese sika deer (Cervus nippon yesoensis) in Hokkaido Island, Japan, using hunting records from 1873 to 1882, and assuming 15% and 35% population increase rates. The annual number of deer harvested during 1873 to 1882 ranged from 15,000 to 129,000. The minimum population size in 1873 was estimated as 349,000–473,000. This method was validated by applying it to the eastern population of Hokkaido Island in 1993 when the population size was approximately 260,000, and population sizes estimated by this method were 0.50–1.17 times the nominal population size. Thus, the population estimates from this method were approximately equal to or less than the expected population sizes, and this method can be used to obtain minimum estimates of wildlife populations. Because shorter durations of hunting records result in population size underestimates, it would be better to use hunting record of 10 years or longer in this method. In addition, the degree of underestimation may change with hunting pressure intensity on the populations, other causes of mortality, and maximum annual increase rates of the species. The method can be applied to any wildlife species for which records of annual harvest and maximum annual population increase rates of the species are available. The estimates obtained can provide benchmarks for the population size required for ecosystem conservation, and can be useful for wildlife management as they indicate the lowest limit to maintain the population.

Effects of logging on wildlife communities in certified tropical rainforests in East Kalimantan, Indonesia

Logging has been operated throughout Bornean tropical forests that harbor diverse fauna species. We examined the responses of ground-dwelling wildlife to logging intensity in two certified forest management units under the same climate and vegetation in East Kalimantan, Indonesia, in 2012–2016. A total of ten and 13 circular plots with a diameter of 1 km were established respectively, and 10–18 camera points were distributed randomly in each plot to record wildlife for two years. A total of 41 species of medium to large-sized terrestrial wildlife were recorded in the two management units. Canonical Correspondence Analysis (CCA) was performed to examine the response of wildlife community to the logging influences with the following three variables: forest intactness (as a surrogate of tree-species composition), above-ground carbon (as a surrogate of forest structure), and distance to the nearest village to represent hunting pressure. Forest intactness was the strongest factor affecting the assemblage of wildlife species in both management units, suggesting that changes in tree-species composition due to logging were a decisive factor influencing animal assemblage. Poisson Generalized Linear Model (GLM) was employed to examine the response of each species to forest intactness in each management unit. We found that eight out of the 32 tested wildlife species responded to forest intactness consistently between the two units, while the other species responded more individualistically. We suggest that consistent responses of several species, as well as individualistic responses of the other species to the changes of tree-species composition, determine the animal assemblage in logged-over Bornean rainforests. Sustainably managed logged-over forests in Borneo are a habitat for diverse wildlife community and therefore also require attention for biodiversity conservation.

Horn growth variation and hunting selection of the Alpine ibex.

Selective hunting can affect demographic characteristics and phenotypic traits of the targeted species. Hunting systems often involve harvesting quotas based on sex, age and/or size categories to avoid selective pressure. However, it is difficult to assess whether such regulations deter hunters from targeting larger "trophy" animals with longer horns that may have evolutionary consequences. Here, we compile 44,088 annually resolved and absolutely dated measurements of Alpine ibex (Capra ibex) horn growth increments from 8,355 males, harvested between 1978 and 2013, in the eastern Swiss Canton of Grisons. We aim to determine whether male ibex with longer horns were preferentially targeted, causing animals with early rapid horn growth to have shorter lives, and whether such hunting selection translated into long-term trends in horn size over the past four decades. Results show that medium- to longer-horned adult males had a higher probability of being harvested than shorter-horned individuals of the same age and that regulations do affect the hunters' behaviour. Nevertheless, phenotypic traits such as horn length, as well as body size and weight, remained stable over the study period. Although selective trophy hunting still occurs, it did not cause a measurable evolutionary response in Grisons' Alpine ibex populations; managed and surveyed since 1978. Nevertheless, further research is needed to understand whether phenotypic trait development is coinfluenced by other, potentially compensatory factors that may possibly mask the effects of selective, long-term hunting pressure.

Genetic polymorphism and structure of wild and zoo populations of the fosa (Eupleridae, Carnivora), the largest living carnivoran of Madagascar

Cryptoprocta ferox, or fosa, is the largest living endemic carnivoran of Madagascar, with presumably high dispersal capacity, and for which no broad scale phylogeographic study has been conducted to date. This species is considered “Vulnerable” by the IUCN and the subject of a captive breeding program; approximately 113 individuals are held in 57 zoos. The aim of this study was to examine the genetic structure and polymorphism within both captive and wild populations, to determine possible lineage variation, and to make recommendations for the captive breeding program. For this purpose, we analyzed three mitochondrial (Cytochrome b, ND2, Control Region) and one nuclear (Beta-fibrinogen intron 7) markers. The results showed an overall low level of genetic polymorphism, likely related to its dispersal capacity, and some genetic structure possibly associated with geographical barriers, such as large rivers. The genetic diversity of the captive population was greater than that of wild individuals included herein, suggesting that the captive population encompasses a considerable proportion of the genetic diversity of the species. This genetic variability is presumably the consequence of frequent imports of wild animals into zoos from different areas of Madagascar, and subsequent exchanges between zoos. Based on the low overall genetic polymorphism of the species and the absence of deeply divergent lineages, we recommend the continued mixing of captive animals. Our results may help the management of the fosa in the wild and in captivity, which is crucial for a species that faces many threats in the wild, in particular habitat degradation and hunting pressure. In any case, enhanced protection of the species and its forested habitat is urgently needed.

Armed conflicts and wildlife decline: Challenges and recommendations for effective conservation policy in the Sahara‐Sahel

AbstractIncreasing conflicts and social insecurity are expected to accelerate biodiversity decline and escalate illegal wildlife killing. Sahara‐Sahel megafauna has experienced recent continuous decline due to unsustainable hunting pressure. Here, we provide the best available data on distribution and population trends of threatened, large vertebrates, to illustrate how escalating regional conflict (565% growth since 2011) is hastening population decline in areas that were formerly refugia for megafauna. Without conservation action, the unique and iconic biodiversity of Earth's largest desert will be forever lost. We recommend: (1) establishing strong commitments for change in global attitude toward nature; (2) engraining a culture of environmental responsibility among all stakeholders; (3) fostering environmental awareness to drive societal change; (4) reinforcing regional security and firearms control; and (5) implementing local research and wildlife monitoring schemes. We identify relevant international partners needed to tackle these challenges and to make strong policy change for biodiversity conservation and regional stability.

The draft genome sequence of forest musk deer (Moschus berezovskii)

BackgroundThe forest musk deer, Moschus berezovskii, is one of seven musk deer (Moschus spp.) and is distributed in Southwest China. Akin to other musk deer, the forest musk deer has been traditionally and is currently hunted for its musk (i.e., global perfume industry). Considerable hunting pressure and habitat loss have caused significant population declines. Consequently, the Chinese government commenced captive breeding programs for musk harvesting in the 1950s. However, the prevalence of fatal diseases is considerably restricting population increases. Disease severity and extent are exacerbated by inbreeding and genetic diversity declines in captive musk deer populations. It is essential that knowledge of captive and wild forest musk deer populations' immune system and genome be gained in order to improve their physical and genetic health. We have thus sequenced the whole genome of the forest musk deer, completed the genomic assembly and annotation, and performed preliminary bioinformatic analyses.FindingsA total of 407 Gb raw reads from whole-genome sequencing were generated using the Illumina HiSeq 4000 platform. The final genome assembly is around 2.72 Gb, with a contig N50 length of 22.6 kb and a scaffold N50 length of 2.85 Mb. We identified 24,352 genes and found that 42.05% of the genome is composed of repetitive elements. We also detected 1,236 olfactory receptor genes. The genome-wide phylogenetic tree indicated that the forest musk deer was within the order Artiodactyla, and it appeared as the sister clade of four members of Bovidae. In total, 576 genes were under positive selection in the forest musk deer lineage.ConclusionsWe provide the first genome sequence and gene annotation for the forest musk deer. The availability of these resources will be very useful for the conservation and captive breeding of this endangered and economically important species and for reconstructing the evolutionary history of the order Artiodactyla.

Differential resilience of Amazonian otters along the Rio Negro in the aftermath of the 20th century international fur trade

Commercial hunting for the international trade in animal hides in the 20th century decimated many populations of aquatic wildlife in Amazonia. However, impacts varied significantly between different species and regions, depending upon hunting intensity, accessibility of habitat, and the inherent resilience of various species and their habitats. We investigated the differential responses of two Amazonian Mustelid species, the neotropical otter and giant otter, to commercial hunting pressure along the upper Rio Negro in Brazil, and examined historical factors that influenced spatial and temporal variation in commercial exploitation. We analyzed previously unanalyzed data from historical records of hide shipments to track changes in hide sales and prices for the two species in the late 20th century. We also gathered oral histories from older Baniwa people who had witnessed or participated in commercial otter hunting. These complimentary data sources reveal how intrinsic biological and social characteristics of the two otter species interacted with market forces and regional history. Whereas giant otter populations were driven to local or regional extinction during the late 20th century by commercial hunting, neotropical otters persisted. In recent decades, giant otter populations have returned to some parts of the upper Rio Negro, a development which local people welcome as part of a generalized recovery of the ecosystems in their territory as a result of the banning of animal pelt exports and indigenous land demarcation. This paper expands the scope of the field historical ecology and reflects on the role of local knowledge in biodiversity conservation.

Hunting regulation favors slow life histories in a large carnivore

As an important extrinsic source of mortality, harvest should select for fast reproduction and accelerated life histories. However, if vulnerability to harvest depends upon female reproductive status, patterns of selectivity could diverge and favor alternative reproductive behaviors. Here, using more than 20 years of detailed data on survival and reproduction in a hunted large carnivore population, we show that protecting females with dependent young, a widespread hunting regulation, provides a survival benefit to females providing longer maternal care. This survival gain compensates for the females’ reduced reproductive output, especially at high hunting pressure, where the fitness benefit of prolonged periods of maternal care outweighs that of shorter maternal care. Our study shows that hunting regulation can indirectly promote slower life histories by modulating the fitness benefit of maternal care tactics. We provide empirical evidence that harvest regulation can induce artificial selection on female life history traits and affect demographic processes.

Northern bobwhite foraging response to hunting

ABSTRACTPrey species must consistently balance the need for resource acquisition with the threat of predation. This balance is particularly true for gallinaceous birds, such as the northern bobwhite (Colinus virginianus), which are ground foragers and are often exposed to increased predation risk compared to arboreal foragers. We studied how bobwhites might mitigate the threat of human hunting pressure by altering their foraging strategy. We directly monitored hunting encounters with bobwhites, during October 2014–March 2015, and collected daily movement paths (n = 514) using radio‐telemetry. We performed first‐passage time analysis to infer foraging behavior by calculating bout frequency, area, duration, and timing. We found bobwhites mitigated exposure to human hunters by increasing foraging frequency coupled with a decrease in duration (15.4%) and area (7.1%) in response to hunting pressure. We observed a temporal shift in foraging away from peak hunting hours by 30 minutes when birds were recently exposed to a discharged firearm. Our results imply that hunting game species can disrupt timing of foraging and therefore influence allocation to competing activities such as anti‐predator vigilance. We propose implementing a dynamic harvest management regime that distributes hunting activity temporally and spatially to mitigate high hunting pressure and reduce behavioral effects on bobwhites. Careful planning of hunting activity should reduce its additive effects on natural mortality while improving hunter satisfaction. © 2018 The Wildlife Society.

Gestión cinegética racional ligada a la praxis de la caza y la recolección. ¿Entelequia aristotélica o quimera?

Gestión cinegética racional ligada a la praxis de la caza y la recolección. ¿Entelequia aristotélica o quimera? Desde los albores de su historia filogenética, el consumo de proteínas de origen animal ha tenido gran relevancia en la evolución de los humanos. La caza cooperativa representa una estrategia evolutiva estable a partir del momento en que los cazadores paleolíticos se especializan en la persecución de grandes animales. Todo este proceso implica la adopción de decisiones relacionadas con la gestión de la caza, algunas de las cuales siguen siendo utilizadas por los cazadores-recolectores contemporáneos. En estas sociedades que todavía practican la caza como medio de subsistencia, la composición de sus respectivas dietas y las técnicas de explotación empleadas son explicables bajo supuestos teóricos contenidos en la Teoría del Forrajeo Óptimo (TFO). Con objeto de poner a prueba dicha teoría, se han tomado en consideración cuatro decisiones que implican la adopción de diferentes estrategias de gestión por parte de los cazadores-recolectores: I) qué comer, II) dónde y cómo buscar el alimento, III) cuáles son el tamaño y composición más adecuados del grupo de cazadores-recolectores y IV) qué pautas de manipulación y reparto de las presas son más eficientes. La TFO se ha puesto a prueba en diversas ocasiones y, en un alto porcentaje de los casos estudiados, sus predicciones se ajustan a lo observado en distintas sociedades cazadoras-recolectoras. Esto significa que la maximización de los rendimientos de captura a corto plazo es su principal preocupación, en lugar de comportarse como “depredadores prudentes” o realizar una selección pasiva de sus presas en función del tamaño, accesibilidad y abundancia de las mismas. Dicho comportamiento no niega que los cazadores-recolectores actúen como conservacionistas pero descarta que esa sea la principal preocupación de su modo de vida. No cabe duda de que los pueblos indígenas tienen un amplio conocimiento del medio, pero no está claro si lo utilizan para mantener un balance con la naturaleza o para ser cazadores más eficientes Es más probable que la extracción sostenible se deba a una baja presión de caza en zonas donde abundan las presas, lo que constituye un epifenómeno en lugar de una estrategia deliberada de conservación. A tenor de los datos disponibles, seguir manteniendo el mito del salvaje ecológicamente noble es tan falaz como peligroso de cara a la solución de sus problemas presentes y futuros. Dicha concepción errónea deriva, en parte, de confundir sostenibilidad y conservación. No obstante, resulta oportuno recordar que las conclusiones derivadas de la presente revisión tienen un valor estrictamente académico y no justifican juicios morales improcedentes respecto a los derechos de los cazadores-recolectores.

Evidence for an additive effect of hunting mortality in an alpine black grouse Lyrurus tetrix population

In the Canton of Ticino in southern Switzerland data from the monitoring programme for black grouse from 1981 to 2016 (population density, lek size, sex ratio in chicks and adults) were analysed together with information on bag statistics and hunting regulations to evaluate if mortality from hunting had an additive effect. In the study population the proportion of cocks at the beginning of the study period was only 23%. As hunting regulations for black grouse were tightened in the late 1970s the observed proportion of males showed an increase in particular during the first years but remained much lower than what would be expected from the sex ratio among chicks assuming equal survival between the sexes. The observed low proportion of adult males indicates a lower survival rate and as a consequence a smaller than natural lek size. High reproductive success two years before had a positive effect on lek size. The correlation coefficient between hunting bag and population size index increased with increasing hunting pressure and showed a decline over the years. Bag size in the period with a high hunting pressure (1981–1999, many hunting days) was driven by population density whereas in the second period (2000–2016, few hunting days) it was driven by hunting regulations. Our analysis showed that hunting affects population structure and presents indirect evidence that mortality due to hunting is additive. The study also shows that hunting management has to be continuously adapted to changes in the size and structure of the population as well as changes in habitat conditions. It is therefore essential to continue long‐term monitoring of population size and of demographic parameters.

Corrigendum to: Distribution and relative abundance of forest duikers in Dassioko Sud Forest Reserve (coastal Côte d'Ivoire)

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 (5.6–6.7km) 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.