Effectiveness of signs of activity as relative abundance indices for wild boar

Daishi Higashide; Takeo Kuriyama; Shun Takagi; Yoshihiro Nakashima; Keita Fukasawa; Gota Yajima; Minoru Kasada; Mayumi Yokoyama

doi:10.2981/wlb.00869

Integrating spatial synchrony/asynchrony of population distribution into stock assessment models: a spatial hierarchical Bayesian statistical catch-at-age approach

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw036 ◽

2016 ◽

Vol 73 (7) ◽

pp. 1725-1738 ◽

Cited By ~ 6

Author(s):

Yan Jiao ◽

Rob O'Reilly ◽

Eric Smith ◽

Don Orth ◽

Keyword(s):

Relative Abundance ◽

Bayesian Model ◽

Population Distribution ◽

Stock Assessment ◽

Spatial Models ◽

Reference Points ◽

Hierarchical Bayesian ◽

Hierarchical Bayesian Model ◽

Spatial Synchrony ◽

Abundance Indices

Abstract In many marine fisheries assessments, population abundance indices from surveys collected by different states and agencies do not always agree with each other. This phenomenon is often due to the spatial synchrony/asynchrony. Those indices that are asynchronous may result in discrepancies in the assessment of temporal trends. In addition, commonly employed stock assessment models, such as the statistical catch-at-age (SCA) models, do not account for spatial synchrony/asynchrony associated with spatial autocorrelation, dispersal, and environmental noise. This limits the value of statistical inference on key parameters associated with population dynamics and management reference points. To address this problem, a set of geospatial analyses of relative abundance indices is proposed to model the indices from different surveys using spatial hierarchical Bayesian models. This approach allows better integration of different surveys with spatial synchrony and asynchrony. We used Atlantic weakfish (Cynoscion regalis) as an example for which there are state-wide surveys and expansive coastal surveys. We further compared the performance of the proposed spatially structured hierarchical Bayesian SCA models with a commonly used Bayesian SCA model that assumes relative abundance indices are spatially independent. Three spatial models developed to mimic different potential spatial patterns were compared. The random effect spatially structured hierarchical Bayesian model was found to be better than the commonly used SCA model and the other two spatial models. A simulation study was conducted to evaluate the uncertainty resulting from model selection and the robustness of the recommended model. The spatially structured hierarchical Bayesian model was shown to be able to integrate different survey indices with/without spatial synchrony. It is suggested as a useful tool when there are surveys with different spatial characteristics that need to be combined in a fisheries stock assessment.

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Comparison of odontocete populations of the Marquesas and Society Islands (French Polynesia)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315408002713 ◽

2008 ◽

Vol 89 (5) ◽

pp. 931-941 ◽

Cited By ~ 6

Author(s):

Alexandre Gannier

Keyword(s):

Relative Abundance ◽

Bottlenose Dolphin ◽

Bottlenose Dolphins ◽

Sperm Whale ◽

French Polynesia ◽

Society Islands ◽

Spotted Dolphin ◽

Abundance Indices ◽

Beaked Whales ◽

Using Data

Small boat surveys were organized to study cetaceans of the Marquesas (9°S and 140°W) and the Society Islands (17°S and 150°W) in French Polynesia. Prospecting took place from 12–15 m sailboats, between 1996 and 2001 with systematic visual searching. Boats moved according to sea conditions, at a mean speed of 10 km/h. Effective effort of 4856 km in the Marquesas and 10,127 km in the Societies were logged. Relative abundance indices were processed for odontocetes using data obtained with Beaufort 4 or less. In the Marquesas, 153 on-effort sightings were obtained on 10 delphinids species including the spotted dolphin, spinner dolphin, bottlenose dolphin, melon-headed whale and rough-toothed dolphin. In the Societies, 153 sightings of 12 odontocetes included delphinids (spinner, rough-toothed and bottlenose dolphins, short-finned pilot and melon-headed whales, Fraser's dolphin, Risso's dolphin and pygmy killer whale) and two species of beaked whales, the sperm whale and dwarf sperm whale. Relative abundance indices were higher in the Marquesas than in the Societies both inshore (0.93 ind/km2 against 0.36 ind/km2) and offshore (0.28 ind/km2 against 0.14 ind/km2). Differences in remote-sensed primary production were equally important, the Marquesas waters featuring an annual average of 409 mgC.m−2 · day−1 and the Societies of only 171 mgC · m−2 · day−1. The presence of a narrow shelf around the Marquesas also accounted for differences in odontocete populations, in particular the delphinids.

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Evaluation of three relative abundance indices for assessing dingo populations

Wildlife Research ◽

10.1071/wr9960197 ◽

1996 ◽

Vol 23 (2) ◽

pp. 197 ◽

Cited By ~ 67

Author(s):

L Allen ◽

R Engeman ◽

H Krupa

Keyword(s):

Relative Abundance ◽

Canis Lupus ◽

Activity Index ◽

Correlation Coefficients ◽

Target Species ◽

Wild Canids ◽

Population Reduction ◽

Abundance Indices ◽

High Level ◽

Level Of Agreement

Three methods of assessing relative abundance of wild canids were evaluated on a population of dingoes, Canis lupus dingo (Corbett), on a cattle station in south-westem Queensland. The tested indices relied on measurements of activity based on spoor. Two of the techniques attracted the target species to tracking stations through the use of a novel (fatty acid scent) or food-based (buried meat) attractant. The third index (activity) measured the number of dingo tracks crossing tracking stations placed at 1-km intervals along a road transect. All three indices had a high level of agreement for detecting differences in relative abundance, with correlation coefficients exceeding 0.85. When the stations were analysed in 1-km segments, the activity index proved the most sensitive, producing proportionally more positive responses than either of the other two indices irrespective of whether the tracking stations were assessed at 1-, 2-, 3- or 4-day intervals. Inconsistencies between indices existed, with the derived abundance indices not showing the anticipated reduction following population reduction. The effect of season and the interaction between dingo activity and index methodology are discussed.

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Spatial and temporal analysis of leopards (Panthera pardus), their prey and tigers (Panthera tigris) in Huai Kha Khaeng Wildlife Sanctuary, Thailand

Folia Oecologica ◽

10.2478/foecol-2019-0010 ◽

2019 ◽

Vol 46 (2) ◽

pp. 73-82

Author(s):

Apinya Saisamorn ◽

Prateep Duengkae ◽

Anak Pattanavibool ◽

Somphot Duangchantrasiri ◽

Achara Simcharoen ◽

...

Keyword(s):

Southeast Asia ◽

Wild Boar ◽

Relative Abundance ◽

Temporal Analysis ◽

Abundance Ratio ◽

Panthera Tigris ◽

Panthera Pardus ◽

Fine Grained ◽

The North ◽

Temporal Interactions

AbstractDespite their extensive distribution globally, recent reports indicate leopards are declining, especially in Southeast Asia. To support conservation efforts we analyzed the behavioral interactions between leopards (Panthera pardus), their prey, and tigers to determine if leopards fine-tune their activity to maximize contact with four prey species (sambar; wild boar; barking deer; banteng) and avoid tigers and if prey alter their temporal activity in response to variation in their relative abundance ratio with leopards. A lower density of sambar in the northern part of our study area and a lower density of wild boar and a higher density of tigers in the southern part allowed us to examine fine-grained differences in the behavior of leopards and their prey. We used camera trap data to investigate spatial and temporal overlap. Differences in tiger relative abundance did not appear to impact the temporal activity of leopards. Leopards had similar cathemeral activity at all sites with highest activity at dawn and dusk. This behavior appears to be a compromise to provide access to diurnal wild boar and barking deer and nocturnal sambar and banteng. Sambar showed higher temporal avoidance of leopards in the north where its RAI was lowest; in contrast, wild boar had the highest temporal avoidance in the south where its density was lowest. This is the first study in Southeast Asia to quantify spatial and temporal interactions between the leopard, its primary ungulate prey, and the tiger. It provides new insights for conserving this declining subspecies.

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Evaluation of Potential Overwinter Mortality of Age-0 Walleye and Appropriate Age-1 Sampling Gear

Journal of Fish and Wildlife Management ◽

10.3996/082017-jfwm-062 ◽

2018 ◽

Vol 9 (1) ◽

pp. 65-74 ◽

Cited By ~ 2

Author(s):

Jeffrey D. Grote ◽

Melissa R. Wuellner ◽

Brian G. Blackwell ◽

David O. Lucchesi

Keyword(s):

South Dakota ◽

Body Condition ◽

Relative Abundance ◽

Coefficient Of Variation ◽

First Year ◽

Selective Mortality ◽

Frequency Distributions ◽

Abundance Indices ◽

Overwinter Mortality ◽

First Year Of Life

Abstract Potential recruitment of age-0 Walleye Sander vitreus to adults is often indexed by the relative abundance of age-0 individuals during their first summer or fall. However, relationships between age-0 and adult Walleye abundance are often weak or nonsignificant in many waters. Overwinter mortality during the first year of life has been hypothesized as an important limitation to Walleye recruitment in lakes, but limited evidence of such mortality exists, likely due to difficulties in sampling age-1 Walleye during spring. The objectives of this study were to: 1) compare results from nighttime electrofishing to index relative abundance of age-1 Walleyes with relative abundance indices of minifyke nets in four eastern South Dakota lakes; 2) determine whether size-selective mortality was occurring in those four lakes; and 3) if size-selective mortality was occurring in these lakes, determine whether that mortality was attributed to body condition. We sampled four natural lakes in eastern South Dakota 2 wk after ice-off in 2013 and 2014. Precision of nighttime electrofishing (coefficient of variation = 216.6) was greater than that estimated for minifyke nets (coefficient of variation = 338.5) across both years. We detected no differences in length-frequency distributions of collected spring age-1 Walleye between the two gears. Age-0 fall relative abundance indices from electrofishing were significantly greater (P < 0.01) than spring age-1 nighttime electrofishing indices of relative abundance at three of the four study lakes, indicating that overwinter mortality may occur at a substantial rate during the first year of life for Walleye in these systems. Quantile–quantile regression plots showed evidence of size-selective mortality in three of four lakes sampled. However, body condition of age-0 Walleye appeared to have little to no influence on overwinter mortality. Instead, we suggest that smaller-sized walleye may be more vulnerable to overwinter predation. Collectively, these results provide evidence of previously hypothesized overwinter mortality within the first year for Walleye and indicate possibilities for indexing potential adult recruitment of Walleye just after this critical period.

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The geometric mean of relative abundance indices: a biodiversity measure with a difference

Ecosphere ◽

10.1890/es11-00186.1 ◽

2011 ◽

Vol 2 (9) ◽

pp. art100 ◽

Cited By ~ 45

Author(s):

Stephen T. Buckland ◽

Angelika C. Studeny ◽

Anne E. Magurran ◽

Janine B. Illian ◽

Stuart E. Newson

Keyword(s):

Relative Abundance ◽

Geometric Mean ◽

Abundance Indices

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Biotic and abiotic factors modulating wild boar relative abundance in Atlantic Spain

European Journal of Wildlife Research ◽

10.1007/s10344-014-0807-2 ◽

2014 ◽

Vol 60 (3) ◽

pp. 469-476 ◽

Cited By ~ 4

Author(s):

Amalia Segura ◽

Pelayo Acevedo ◽

Oscar Rodríguez ◽

Javier Naves ◽

José Ramón Obeso

Keyword(s):

Wild Boar ◽

Relative Abundance ◽

Abiotic Factors ◽

Biotic And Abiotic Factors

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Seasonal variation of striped dolphins, fin- and sperm whales' abundance in the Ligurian Sea (Mediterranean Sea)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315407054719 ◽

2007 ◽

Vol 87 (1) ◽

pp. 345-352 ◽

Cited By ~ 27

Author(s):

Sophie Laran ◽

Violaine Drouot-Dulau

Keyword(s):

Relative Abundance ◽

Sperm Whale ◽

Line Transect ◽

Physeter Macrocephalus ◽

Monthly Basis ◽

Ligurian Sea ◽

Stenella Coeruleoalba ◽

Abundance Indices ◽

Fin Whales ◽

Acoustic Sampling

In order to investigate seasonal changes in cetacean relative abundance, a series of surveys were conducted between the French mainland and Corsica. From February 2001 to February 2004, thirty similar transects were conducted monthly, using the same dedicated boat and a consistent sampling protocol, including visual observation and passive acoustic sampling. A total effort of 5759 km was sampled, conducted at the same speed and in good sighting conditions. Relative abundances of striped dolphins (Stenella coeruleoalba) and fin whales (Balaenoptera physalus) were determined using standard line-transect methodology. The relative abundance of striped dolphins peaked in May and September (>1.3×10-2 ind.km-1), while a consistent minimum value (<0.6×10-2 ind.km-1) was obtained from December to April. A maximum relative abundance of fin whales occurred in August with 5.6×10-2 ind.km-1 and decreased to almost zero from November to January. For sperm whale (Physeter macrocephalus), a long diver species, frequency and abundance indices were determined using acoustic sampling. The highest acoustic relative abundance was observed from August to October, with more than 2×10-2 ind.km-1. Environmental parameters (sea surface temperature and chlorophyll) were computed for the sampling area from remote sensing imagery and pooled on a monthly basis, to correlate with relative abundance indices of the three species.

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Evaluation of quota management policies for developing fisheries

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-172 ◽

1998 ◽

Vol 55 (12) ◽

pp. 2691-2705 ◽

Cited By ~ 23

Author(s):

Carl Walters

Keyword(s):

Mortality Rate ◽

Relative Abundance ◽

Cumulative Effect ◽

Mortality Rates ◽

Reference Trajectory ◽

Fishing Mortality ◽

Small Probability ◽

Abundance Indices ◽

Management Policies ◽

Quota Management

Losses can be measured as deviations from a desired reference trajectory of quotas that would be taken if there were no uncertainty and are highly dependent on assessments prior to and during development. Simulations of assessment and quota setting under various quota setting rules indicate that variability in relative abundance indices can cause substantial losses, especially considering cumulative effect of early quota errors on later departures of biomass from that needed to produce the desired quotas, even if optimum fishing mortality rate is known in advance. Conservative assessments (low biomass estimates for which there is only a small probability that biomass is actually lower) are favored during development when loss is measured as the relative departure from the best quota for each year. But if loss is measured as absolute departure from the best quota, it is generally better to base the quota on the biomass estimate for which there is nearly a 50% chance that the stock is smaller. Deliberate overfishing (probing) is not favored under either loss measure. Losses can be reduced with minimum biomass surveys and closed areas that directly cushion fishing mortality rates from being more than 50% too low or high.

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