scholarly journals Simultaneous estimation of seasonal population density, habitat preference and catchability of wild boars based on camera data and harvest records

2020 ◽  
Vol 7 (8) ◽  
pp. 200579
Author(s):  
Yuichi Yokoyama ◽  
Yoshihiro Nakashima ◽  
Gota Yajima ◽  
Tadashi Miyashita
Keyword(s):  
Population Density ◽  
Habitat Preference ◽  
Population Control ◽  
Individual Recognition ◽  
Spatial Scales ◽  
Simultaneous Estimation ◽  
Effective Population ◽  
Time Model ◽  
Wild Mammals ◽  
Wild Boars

Analyses of life history and population dynamics are essential for effective population control of wild mammals. We developed a model for the simultaneous estimation of seasonal changes in three parameters—population density, habitat preference and trap catchability of target animals—based on camera-trapping data and harvest records. The random encounter and staying time model, with no need for individual recognition, is the core component of the model—by combining this model with the catch-effort model, we estimated density at broad spatial scales and catchability by traps. Here, the wild boar population in central Japan was evaluated as a target population. We found that the estimated population density increased after the birth period and then decreased until the next birth period, mainly due to harvesting. Habitat preference changed seasonally, but forests having abandoned fields nearby were generally preferred throughout the season. These patterns can be explained by patterns of food availability and resting or nesting sites. Catchability by traps also changed seasonally, with relatively high values in the winter, which probably reflected changes in the attractiveness of the trap bait due to activity changes in response to food scarcity. Based on these results, we proposed an effective trapping strategy for wild boars, and discussed the applicability of our model to more general conservation and management issues.

scholarly journals Occurrence of parasitism by Dioctophyma renale in ring-tailed coatis (Nasua nasua) of the Tiete Ecological Park, São Paulo, Brazil

2009 ◽  
Vol 29 (12) ◽  
pp. 959-962 ◽  
Author(s):  
Liliane Milanelo ◽  
Márcia Bento Moreira ◽  
Lílian S. Fitorra ◽  
Bruno S.S. Petri ◽  
Melissa Alves ◽  
...  
Keyword(s):  
Population Control ◽  
Abdominal Cavity ◽  
Exploratory Laparotomy ◽  
Renal Tissue ◽  
Intermediate Hosts ◽  
Wild Mammals ◽  
Rigid Structure ◽  
Nasua Nasua ◽  
Males And Females ◽  
The Right

Dioctophymosis is a worldwide renal parasitosis caused by the Dioctophyma renale nematode, which results in progressive destruction of renal tissue. Aquatics annelids are considered the main intermediate hosts and the literature refers as permanent hosts of dogs, wild mammals and even humans. During procedures for population control of coatis (Nasua nasua) in the Ecological Park of Tietê (PET), was noticed the presence of parasitosis by D. renale. From 68 animals, males and females, young and adults, submitted to exploratory laparotomy, 51 were positive for the presence of worms, 9 were found only in the right kidney. In 10 cases, in addition to right kidney parasitism, worms were also observed in the abdominal cavity. In 24 cases D. renale was found only in the abdominal cavity and in 8 animals the right kidney was reduced to a small rigid structure. The study showed that the preferred site for parasitism of the worm, considered erratic, was the abdominal cavity in 66.66% of the cases.

scholarly journals Using Astragalus to Model Body Mass, Habitat Preference, and Population Density of Prehistoric Bovid Duboisia santeng (Dubois, 1891) in Eastern Java island in The Early Pleistocene

2020 ◽  
Author(s):  
Andri Wibowo
Keyword(s):  
Population Density ◽  
Body Mass ◽  
Habitat Preference ◽  
Regression Models ◽  
The Body ◽  
Early Pleistocene ◽  
Large Herbivores ◽  
Length Width ◽  
Fossil Records ◽  
The Relationship

Astragalus bone is one of the most important fossil records as it can reconstruct the prehistoric life. Respectively, this study aims to model the body mass, habitat preference, and population density of prehistoric bovid Duboisia santeng (Dubois 1891) in eastern Java island in the early Pleistocene. The astragali from 9 specimens were used to estimate the body mass and population density. Likewise regression models are used to analyze the relationship between astragalus lateral length, width, and body mass compared to the astragalus of extant Bovid species. The result revealed the body mass average was 60.3 kg (95%CI: 58.9-61.7) and this indicates the D. santeng belongs to large herbivores. While the population density was estimated at about 5.39 individuals per km2 (95% CI: 3.18-7.6).

scholarly journals Variation in space and time: a long-term examination of density-dependent dispersal in a woodland rodent

2019 ◽  
Author(s):  
Simon T. Denomme-Brown ◽  
Karl Cottenie ◽  
J. Bruce Falls ◽  
E. Ann Falls ◽  
Ronald J. Brooks ◽  
...  
Keyword(s):  
Time Series ◽  
Population Density ◽  
Local Density ◽  
Spatial Scales ◽  
Deer Mice ◽  
Population Densities ◽  
Density Dependent ◽  
Regional Population ◽  
The Relationship ◽  
Density Dependent Dispersal

AbstractDispersal is a fundamental ecological process that can be affected by population density, yet studies report contrasting effects of density on propensity to disperse. Additionally, the relationship between dispersal and density is seldom examined using densities measured at different spatial scales or over extensive time-series. We used 51-years of trapping data to examine how dispersal by wild deer mice (Peromyscus maniculatus) was affected by changes in both local and regional population densities. We examined these patterns over both the entire time-series and also in ten-year shifting windows to determine whether the nature and strength of the relationship changed through time. Probability of dispersal decreased with increased local and regional population density, and the negative effect of local density on dispersal was more pronounced in years with low regional densities. Additionally, the strength of negative density-dependent dispersal changed through time, ranging from very strong in some decades to absent in other periods of the study. Finally, while females were less likely to disperse, female dispersal was more density-dependent than male dispersal. Our study shows that the relationship between density and dispersal is not temporally static and that investigations of density-dependent dispersal should consider both local and regional population densities.

scholarly journals Population Genetic Structure of Raccoons as a Consequence of Multiple Introductions and Range Expansion in the Boso Peninsula, Japan

2021 ◽  
Author(s):  
Miki Hirose ◽  
Kazuya Yoshida ◽  
Eiji Inoue ◽  
Masami Hasegawa
Keyword(s):  
Range Expansion ◽  
Population Control ◽  
Large Population ◽  
Genetic Admixture ◽  
Effective Population ◽  
Genetic Barrier ◽  
Management Units ◽  
Multiple Introductions ◽  
Boso Peninsula ◽  
Chiba Prefecture

Abstract Raccoon (Procyon lotor) is a globally introduced invasive carnivore. Although controlling feral raccoon populations is important to reduce serious threats to local ecosystems, raccoons are not under rigid population control in Europe and Japan. We examined the D-loop and nuclear microsatellite regions to identify spatially explicit and feasible management units for effective population control and further range expansion retardation. Through the identification of five mitochondrial DNA haplotypes and three nuclear genetic groups, we identified at least three independent introductions, range expansion, and subsequent genetic admixture in the Boso Peninsula. Admitting that the currently recognizable two genetic clusters can be treated as different management units, these management units will soon fuse to a single but large population to which the effective population control will no longer be applicable due to the absence of a genetic barrier between southern and northern Chiba Prefecture.

scholarly journals Spread of new mutations through space

2022 ◽  
Author(s):  
Kyle Shaw ◽  
Peter Beerli
Keyword(s):  
Population Density ◽  
Population Size ◽  
Simulation Software ◽  
Effective Population ◽  
Random Drift ◽  
Rate Of Spread ◽  
Large Populations ◽  
Discrete Population ◽  
Explicit Simulation ◽  
New Mutations

The terms population size and population density are often used interchangeably, when in fact they are quite different. When viewed in a spatial landscape, density is defined as the number of individuals within a square unit of distance, while population size is simply the total count of a population. In discrete population genetics models, the effective population size is known to influence the interaction between selection and random drift with selection playing a larger role in large populations while random drift has more influence in smaller populations. Using a spatially explicit simulation software we investigate how population density affects the flow of new mutations through a geographical space. Using population density, selectional advantage, and dispersal distributions, a model is developed to predict the speed at which the new allele will travel, obtaining more accurate results than current diffusion approximations provide. We note that the rate at which a neutral mutation spreads begins to decay over time while the rate of spread of an advantageous allele remains constant. We also show that new advantageous mutations spread faster in dense populations.

scholarly journals Time-lapse imagery is cheap and timely in the fight against colonial species' decline

2021 ◽  
Author(s):  
Tom Hart ◽  
Fiona Jones ◽  
Caitlin Black ◽  
Chris Lintott ◽  
Casey Youngflesh ◽  
...  
Keyword(s):  
Machine Learning ◽  
Computer Vision ◽  
Parameter Estimation ◽  
Citizen Science ◽  
Large Scale ◽  
Individual Recognition ◽  
Spatial Scales ◽  
Time Lapse ◽  
Machine Learning Algorithms ◽  
Series Data

Many of the species in decline around the world are subject to different environmental stressors across their range, so replicated large-scale monitoring programmes, are necessary to disentangle the relative impacts of these threats. At the same time as funding for long-term monitoring is being cut, studies are increasingly being criticised for lacking statistical power. For those taxa or environments where a single vantage point can observe individuals or ecological processes, time-lapse cameras can provide a cost-effective way of collecting time series data replicated at large spatial scales that would otherwise be impossible. However, networks of time-lapse cameras needed to cover the range of species or processes create a problem in that the scale of data collection easily exceeds our ability to process the raw imagery manually. Citizen science and machine learning provide solutions to scaling up data extraction (such as locating all animals in an image). Crucially, citizen science, machine learning-derived classifiers, and the intersection between them, are key to understanding how to establish monitoring systems that are sensitive to – and sufficiently powerful to detect –changes in the study system. Citizen science works relatively ‘out of the box’, and we regard it as a first step for many systems until machine learning algorithms are sufficiently trained to automate the process. Using Penguin Watch (www.penguinwatch.org) data as a case study, we discuss a complete workflow from images to parameter estimation and interpretation: the use of citizen science and computer vision for image processing, and parameter estimation and individual recognition for investigating biological questions. We discuss which techniques are easily generalizable to a range of questions, and where more work is needed to supplement ‘out of the box’ tools. We conclude with a horizon scan of the advances in camera technology, such as on-board computer vision and decision making.

scholarly journals The distribution and behavioral characteristics of plateau pikas (Ochotona curzoniae)

ZooKeys ◽  
2021 ◽  
Vol 1059 ◽  
pp. 157-171
Author(s):  
Jun Qiu ◽  
Cang Ma ◽  
Ying-Hui Jia ◽  
Jin-Zhao Wang ◽  
Shou-Kai Cao ◽  
...  
Keyword(s):  
Population Density ◽  
Field Observation ◽  
Population Control ◽  
Water Source ◽  
Tibet Plateau ◽  
Behavioral Characteristics ◽  
Population Densities ◽  
Ochotona Curzoniae ◽  
Source Distance ◽  
Qinghai Tibet Plateau

Plateau pikas (Ochotona curzoniae) are regarded as one of the main causes of the degradation of alpine meadows in the Qinghai-Tibet Plateau (QTP). The population density of plateau pikas is directly related to the degree of grassland damage. In this study, field observation was conducted for one week in the southeastern QTP in August 2019. A random encounter model (REM) was used to estimate the population density of plateau pikas from photographs and videos, and the frequencies of different behaviors were calculated. In addition, the effects of water-source distance and terrain on the distribution of plateau pikas and the frequencies of different pika behaviors under different population densities were explored. The observations and knowledge derived from this study provide a reference for the population control of plateau pikas.

scholarly journals Molecular epidemiology of Leptospira spp. among wild mammals and a dog in Amami Oshima Island, Japan

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249987
Author(s):  
So Shinya ◽  
Yukinori Muraoka ◽  
Daigo Negishi ◽  
Nobuo Koizumi
Keyword(s):  
Wild Boar ◽  
Housekeeping Genes ◽  
High Rate ◽  
Wild Animals ◽  
Nested Polymerase Chain Reaction ◽  
Wild Mammals ◽  
Wild Boars ◽  
Black Rat ◽  
On This Island ◽  
Black Rats

Leptospirosis is a worldwide zoonosis caused by the pathogenic Leptospira spp. Canine and human leptospirosis sometimes occur on Amami Oshima Island, located in the Nansei Archipelago, southwestern Japan; however, information on the causative Leptospira spp. on this island is quite limited. This study aimed to investigate the molecular and serological characteristics of Leptospira spp. isolated from wild animals and a dog in Amami Oshima Island. We obtained seven Leptospira strains by culturing kidney tissues of wild animals, such as black rats (2), wild boars (3), and rabbit (1) as well as blood from a symptomatic dog. Using flaB sequencing and microscopic agglutination test with antisera for 18 serovars, the isolates were identified as Leptospira borgpetersenii serogroups Javanica (black rat), L. interrogans serogroup Australis (black rat and dog), and L. interrogans serogroup Hebdomadis (wild boar and rabbit). The sequence type (ST) of L. borgpetersenii serogroup Javanica was determined to be ST143 via multilocus sequence typing (MLST) using seven housekeeping genes. For L. interrogans, MLST and multiple-locus variable-tandem repeat analysis (MLVA) revealed identical ST and MLVA types in rat and canine isolates, whereas two STs and MLVA types were identified in wild boar isolates. The STs and MLVA types of rabbit and one of the wild boars were identical. Bacterial culture and flaB-nested polymerase chain reaction demonstrated a high rate of Leptospira infection in wild boars (58.3%, 7/12), whereas Leptospira spp. were detected in 4.8% of black rats (2/42). This study revealed diverse Leptospira genotype and serotype maintenance in wild mammals on Amami Oshima Island. MLST and MLVA indicated that black rats were a source of canine infection. Wild boars carry L. interrogans and are considered an important maintenance host because antibodies against serogroup Hebdomadis were detected in human and canine leptospirosis patients on this island.

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