야생동물 관리를 위한 행동 생태와 효율적 백신 적용

학위논문 (박사) -- 서울대학교 대학원 : 수의과대학 수의학과, 2021. 2. 채준석.최근 인간, 동물 및 생태계의 통합적 건강과 지속 가능한 보전을 위한 원헬스의 개념이 중요하게 다루어지고 있다. 이와 같은 관점에서 인간과 동물간 상호 균형을 위한 질병, 생태 및 종 보전을 포함한 종합적인 연구가 요구되는 실정이다. 이에 따라 본 연구에서는 야생동물의 보전과 매개질병 관리를 위해 수의•생태학적 관점에서 물떼새류의 포식자 방어행동 전략과 국내에서 적용중인 광견병 경구백신, 저병원성 조류인플루엔자 백신의 사용 분석 및 평가를 수행하였다. 첫째, 동물의 행동은 유전자와 환경적 인자의 결과물이며 종의 핵심적인 특징을 나타냄으로써 개체군 보전 및 관리에 가장 유용한 단서를 제공한다. 야생동물은 생존과 번식을 위한 다양한 포식자 방어행동을 하며, 특히 물떼새류는 번식지에서 날개가 부러진 듯한 교란행동을 하여 둥지와 유조로부터 침입자를 유인하는 특수한 방어행동을 하는 것으로 알려져 있다. 그러나 이는 진화적 관점에서 개체의 취약함을 드러내고 시간이 지남에 따라 포식자 적응 (학습)및 공격을 촉진시켜 궁극적으로 자연선택 및 생존에 불리할 것으로 여겨진다. 이에 따라 한국의 꼬마물떼새 및 흰목물떼새에서의 방어행동 단계 및 침입자 접근 실험을 통해 행동 전략과 의미를 분석하였다. 물떼새류의 방어 행동은 둥지이탈, 걷기, 까닥거리기, 움츠리고 뛰기/쪼그리기, 위협행동, 교란행동, 날기 (비행)의 총 7가지 단계로 확인되었다. 그 중 위협행동과 교란행동은 두 종의 물떼새에서 모두 단계적 구분 없이 동시적으로 나타났다. 물리칠 수 있는 침입자인 메추라기 접근의 경우 위협행동이 우세하게 나타났고, 교란행동은 낮은 빈도로 확인되었다. 반면 물리칠 수 없는 침입자 (천적)인 황조롱이 접근의 경우 위협행동은 비행을 통해서만 매우 드물게 나타났으며, 교란행동은 나타나지 않았다. 또한 위협행동과 교란행동은 번식 (포란) 후반으로 갈수록 높은 빈도로 관찰되었는데, 이는 시간이 지남에 따라 번식에 대한 투자가 증가될수록 알 또는 유조를 보호하기 위한 방어본능이 생존본능보다 우세해지는 것으로 판단된다. 따라서 물떼새류의 번식지에서의 단계적 행동전략 및 특이적 교란행동은 부상을 과시하여 침입자를 유인하는 것보다는 개방형 둥지의 단점을 극복하기 위한, 위협행동과 같은 직접적인 목적을 지닌 침입자에 대한 선택적인 방어행동 전략으로 사료된다. 둘째, 경구백신의 야외 적용은 전세계적으로 야생동물 유래 광견병을 차단하는데 효과적인 것으로 알려져 있다. 국내에서는 2001년부터 경구백신이 살포되어 왔으나, 효율적 살포 방법에 대한 연구는 부족한 실정이다. 이에 따라 경구백신의 야외 적용 효율성을 개선하기 위해 백신 목표 (대상) 종의 백신 접촉률을 고려한 다양한 야생동물 서식 환경에 따른 효율적인 백신 살포 지역을 분석하였다. 총 1,808회의 야생동물에 의한 백신 접촉 중 너구리, 개, 고양이 세 종이 백신 목표종으로서 945회 (52.2 %)의 접촉을 나타냈고, 한국에서 광견병의 주요 매개체가 되는 너구리가 가장 높은 접촉률 (34.1 %)을 나타냈다. 또한 백신 목표 종들은 하천 지역과 식생이 풍부한 저지대의 산지에서 백신 접촉률이 높게 나타나는 것으로 확인되었다. 전체 평균 백신 소모율은 95.2 ± 1.93 % 로 확인되었고 94.4 % 의 백신 살포지점은 2주 이내에 전부 소모되어 야생동물에 대한 경구백신의 기호성이 높은 것으로 판단된다. 따라서 식생이 풍부한 저지대의 산지 또는 하천지역에 경구백신을 살포하는 것이 한국에서의 광견병 경구백신 목표 종, 특히 너구리를 대상을 한 백신 적용에 효율적인 것으로 사료된다. 셋째, 백신의 야외 적용은 야생동물 매개질병을 통제하는데 가장 실제적 수단으로 평가되고 있다. 국내에서는 저병원성 조류인플루엔자 (H9N2형)의 발생을 차단하기 위해 2007년부터 백신을 사용해왔으나 관련한 사후관리 및 평가 연구는 부족한 실정이다. 이에 따라 국내에 적용되고 있는 저병원성 조류인플루엔자 백신 (H9N2형)의 2007 ~ 2017년 기간 동안의 사용 현황과 면역원성 (역가)을 분석하였다. 해당 기간 동안 백신의 총 판매량은 약671백만수 분으로 나타났으며, 2007년 10백만수 분에서 2016년 93백만수 분으로 사용량이 크게 증가하였다. 단가백신 보다는 다가백신이 사용량의 90 %를 차지하였고, 약 30 %의 백신은 정부에 의해 무상 공급된 것으로 분석되었다. 지역별 사육수수와 비례하여 경기도, 충청남도에서 각각 산란계, 종계 농가에서의 백신 사용률이 가장 높았다. 2009년 이래로 H9N2형의 야외감염은 없었으며, 해당 기간 동안 백신 사용 농가의 총 평균 항체가는 5.82 log2로 나타났다. 따라서 한국의 저병원성 조류인플루엔자 백신은 질병 발생을 감소시켜 비교적 성공적으로 적용되고 있는 것으로 판단된다. 다만 현재 사용되고 있는 백신주는 최근 야외 분리주와의 유전적 상동성에서 차이를 나타냄에 따라, 향후 질병 관리를 위한 효율적 백신 적용을 위해서는 지속적인 유전자 변이 감시 및 최신 유행주로의 백신주 교체가 검토되어야 할 것으로 사료된다. 결론적으로, 물떼새류의 특이적 방어행동은 침입자 유인보다는 개체군 보전을 위한 기본적인 생존 본능을 의미하며, 종 보전을 위해서는 다양한 야생동물 행동 전략 이해를 통한 인간의 침해 및 교란이 최소화되어야 할 것이다. 또한 백신의 야외 적용은 야생동물 매개질병 발생을 효과적으로 감소시켜 왔지만, 백신의 개량 및 적용 방법의 개선 등 지속적인 효율성 제고가 필요하다. 본 연구의 결과를 바탕으로 향후 행동을 포함한 다양한 관점에서의 동물 생태•질병 연구가 수행되어야 할 것이며, 이를 통해 야생동물 종 보전 및 질병 관리에 기여할 수 있을 것으로 생각된다.One Health has become an important concept in recent years, with the goal of achieving integrated health outcomes and sustainable conservation considering humans, animals, and ecosystems. A comprehensive framework based on animal ecology disease, and species conservation is necessary for understanding the mutual balance between humans and animals. In this study, field vaccinations against rabies and low pathogenic avian influenza (LPAI) in the Republic of Korea, as well as anti-predator behavior by plovers in breeding grounds were evaluated from veterinary and ecological perspectives. Firstly, animal behavior is the result of genes and environmental factors. It is most important factor in the wildlife conservation and management of populations, because it represents a key characteristic of animals. Animals exhibit a variety of anti-predator behaviors to enhance survival and breeding success. Plovers (Charadrius spp.) exhibit unique anti-predator behavior when breeding by attracting intruders, using a broken-wing distraction display. However, feigning injury is not considered adaptive through natural selection because it encourages predators to attack in response to a weakness display. Furthermore, the effectiveness of this strategy should decline as predators learn and adjust their response over time. Thus, the first study investigated stages of anti-predator behavior and defensive strategy by Little ringed plover (Charadrius dubius) and Long-billed plover (Charadrius placidus) that bred along streams and rivers in the Republic of Korea. Seven stages of anti-predator behavior that were common to plovers: displacement, normal step, head bobbing, crouch run, threat display, distraction display, and flying away. The threat display and distraction display were exhibited at a similar stage in both species, with the level of defensive instinct increasing as the stages escalated. In particular, the threat display was dominant when Japanese quail (Coturnix japonica), i.e., a beatable intruder, approached, whereas the distraction display was used to a lesser extent. In contrast, minimal threat display and no distraction display were used when the Common kestrel (Falco tinnunculus), i.e., an unbeatable intruder, approached. The later period of incubation, it was increasingly used with the threat display and distraction display as the investment cost in breeding increased over time. Therefore, the stepwise anti-predator behavioral strategy and broken-wing distraction display by plovers are selective defensive behavior used as an extreme warning signal to defeat intruders and overcome weakness of the open nest, rather than attract predators. Secondly, the field distribution of the oral rabies vaccine (ORV) is effective in controlling the spread of rabies. In the Republic of Korea, although ORVs have been distributed since 2001, research on efficient distribution methods for the vaccine is insufficient for devising an informed strategy. Thus, the second study aimed to investigate efficient distribution locations based on the environment, contact rate, and consumption by target wildlife species in the Republic of Korea. The target species (Korean raccoon dogs, domestic dogs, and feral cats) accounted for 945 contacts (52.2 %), in total 1,808 contacts. Raccoon dogs (Nyctereutes procyonoides), a main reservoir of rabies in the Republic of Korea, had the highest contact rate (34.1 %) among all species. The contact rate by target species was highest at riparian sites and bushy mountainous vegetation, where raccoon dogs are abundant. Vaccines at 94.4 % of the distribution points were completely consumed within two weeks. The mean consumption rate was 95.2 ± 1.93 % during the overall study period. These findings suggest that the oral rabies vaccine attracts wildlife including domestic dogs and feral cats. Therefore, low sections of mountainous areas with bushy vegetation and/or neighboring riparian areas are rich in target wildlife species (especially raccoon dogs) and are efficient locations for vaccine distribution to control rabies in the Republic of Korea. Lastly, vaccination represents a practical tool for the control of wildlife-borne infectious diseases. The Korean government has permitted the use of a single, inactivated vaccine strain to control H9N2 LPAI outbreaks, since 2007. However, overview of sales volume during whole vaccination periods, immunogenicity of commercial vaccines and variation of infection in field have not been identified yet. Thus, the last study was conducted to monitor sales activity and immunogenicity of commercial H9N2 avian influenza vaccines produced in the Republic of Korea from 2007 to 2017. Recorded sales of H9N2 vaccine were around 671 million doses, with 10 million doses sold in 2007, rising to a peak of 93 million doses in 2016. Multivalent combined vaccines made up around 90 % of all vaccine sales, and around 30 % of all vaccines were distributed by regional governments for free. The regional vaccination rate was the highest in Gyeonggi and Chungnam, respectively with proportional to the population of layer and breeder chickens. There have been no cases of field infection since 2009. The mean antibody titer was 5.82 log2 across the study period. Implementation of the H9N2 vaccination has been successful and reduced the outbreaks of disease in Korea. However, the current vaccine strain used in Korea have shown a difference in genetic homogeneity with recently isolated viruses, suggesting that continuous genetic monitoring of H9N2 viruses circulating in the field and updating the vaccine seed strain periodically are necessary. These results suggest that the unique defensive behaviors of plovers indicate instinct for survival, rather than attract predators. Behavioral strategies of wildlife should inform strategies to minimize human disturbance for species conservation. Additionally, although field vaccination has effectively reduced outbreaks of wildlife-borne diseases, the continuous development of vaccines and efficient vaccination methods are needed. Combined, these analyses emphasize the importance of integrative studies in the areas of animal ecology and disease, including behavioral studies, thereby contributing to disease management and wildlife conservation from the One Health perspective.ABSTRACT i LIST OF TABLES viii LIST OF FIGURES xi LIST OF ABBREVIATIONS xvii GENERAL INTRODUCTION 1 1. The concept of One Health 1 2. Animal behavior and defensive strategies 2 3. Zoonotic diseases and public health 3 4. Rabies and avian influenza 4 5. Disease management and wildlife conservation 6 CHAPTER I. Stages of anti-predator behavior by plover during breeding and the purpose of the distraction display Abstract 12 1. Introduction 15 2. Materials and methods 20 3. Results 26 4. Discussion 33 CHAPTER II. Efficient distribution of oral vaccines examined by infrared triggered camera for advancing the control of raccoon dog rabies in the Republic of Korea Abstract 62 1. Introduction 64 2. Materials and methods 69 3. Results 72 4. Discussion 74 CHAPTER III. Sales and immunogenicity of commercial vaccines to H9N2 low pathogenic avian influenza virus in the Republic of Korea from 2007 to 2017 Abstract 116 1. Introduction 118 2. Materials and methods 122 3. Results 124 4. Discussion 126 GENERAL CONCLUSIONS 141 REFERENCES 145 ABSTRACT IN KOREAN 175Docto

Utilization Of A Large-Scale Wireless Sensor Network For Intrusion Detection And Border Surveillance

To control the border more effectively, countries may deploy a detection system that enables real-time surveillance of border integrity. Events such as border crossings need to be monitored in real time so that any border entries can be noted by border security forces and destinations marked for apprehension. Wireless Sensor Networks (WSNs) are promising for border security surveillance because they enable enforcement teams to monitor events in the physical environment. In this work, probabilistic models have been presented to investigate senor development schemes while considering the environmental factors that affect the sensor performance. Simulation studies have been carried out using the OPNET to verify the theoretical analysis and to find an optimal node deployment scheme that is robust and efficient by incorporating geographical coordination in the design. Measures such as adding camera and range-extended antenna to each node have been investigated to improve the system performance. A prototype WSN based surveillance system has been developed to verify the proposed approach

Behavioral Responses Of Breeding Ducks To Unmanned Aerial Vehicle Surveys And Best Practices For Breeding Waterfowl Surveys Using Unmanned Aerial Vehicles

Unmanned aerial vehicles (UAVs) have become a popular wildlife survey tool. As such, biologists are exploring the use of UAVs for surveying waterfowl. The most cited benefit of using UAVs over traditional methods is the idea of reduced disturbance, but this has had limited formal evaluation across species. We conducted UAV surveys with associated behavioral observations of ducks on wetlands and on nests during the 2019 – 2020 breeding seasons. We found species-specific behaviors among blue-winged teal (Spatula discors), northern shoveler (Spatula clypeata), and gadwall (Mareca strepera) including ducks noticing the aircraft, but reactions were generally less than traditional ground approaches suggesting that as technology increases efficiencies, UAVs may serve as an alternative tool for surveying breeding ducks

Perspectives in machine learning for wildlife conservation

Data acquisition in animal ecology is rapidly accelerating due to inexpensive and accessible sensors such as smartphones, drones, satellites, audio recorders and bio-logging devices. These new technologies and the data they generate hold great potential for large-scale environmental monitoring and understanding, but are limited by current data processing approaches which are inefficient in how they ingest, digest, and distill data into relevant information. We argue that machine learning, and especially deep learning approaches, can meet this analytic challenge to enhance our understanding, monitoring capacity, and conservation of wildlife species. Incorporating machine learning into ecological workflows could improve inputs for population and behavior models and eventually lead to integrated hybrid modeling tools, with ecological models acting as constraints for machine learning models and the latter providing data-supported insights. In essence, by combining new machine learning approaches with ecological domain knowledge, animal ecologists can capitalize on the abundance of data generated by modern sensor technologies in order to reliably estimate population abundances, study animal behavior and mitigate human/wildlife conflicts. To succeed, this approach will require close collaboration and cross-disciplinary education between the computer science and animal ecology communities in order to ensure the quality of machine learning approaches and train a new generation of data scientists in ecology and conservation

Space use by passerine birds : a study of territory economics in robins Erithacus rubecula and dippers Cinclus cinclus

1. Cost constraints in models of territory size are based on time/activity/laboratory estimates that predict birds using larger territories will incur higher energy costs. The predicted form of the cost constraint may be linear, accelerating or decelerating depending on assumptions inherent in the models. The aim of this study was to assess the reality and form of the cost constraint by making direct measurements of the energy costs of territory use in birds that occupy territories of different size and shape; polygonal territories represented by the robin Erithacus rubecula, and linear by the dipper Cinclus cinclus. Free-living energy expenditure was measured using the doubly-labelled water technique, whilst simultaneously recording patterns of territory use by radio-tracking. 2. Territorial robins concentrated their activity in one or more foraging patches located in bushes. Range polygons containing all the foraging patches used by an individual provided estimates of territory area, and were generally of high eccentricity. A small proportion of robins was classified as non-territorial based on range polygon areas. Furthermore, while territorial robins showed high fidelity to ranges over the short term (days), non-territorial individuals were nomadic. Over the longer term (months), however, some territorial robins showed range drift. Dippers similarly used preferred core regions within ranges, although there was no selection for particular habitat features. 3. Because robins occupied territory polygons which varied from polygonal to highly linear, work was focused on this species to allow intra-specific comparison. Robins tended to commute between foraging patches by flying. It was appropriate, therefore, to describe territories in terms of a number of patches linked by a network of flight paths. This generated two further measures of territory size; the number of patches used and the total flight distance between patches. 4. The robins exploited a renewing food supply. Predictions were tested concerning the temporal scheduling of visits to foraging patches within territories. Patches tended to be separated by flight paths of similar lengths, and were visited in a regular sequence. Although the number of foraging patches used varied, all territories had similar total core areas. Robins using many small foraging patches commuted between patches more often and covered a larger total flight distance during each foraging circuit of the territory. The configurations of foraging patches were used in a highly linear manner. This was true even if the territory containing them was of low eccentricity. 5. Changes in structure and pattern of use varied predictably with territory size, and could be described mathematically. Based on this and published time/activity budgets, a suite of models was developed to predict how energy costs would vary with number of patches used and total flight distance between patches. Models were tested by directly measuring the energy expenditure of robins using different territories. The number of patches used and total flight distance between patches were both significantly correlated with energy expenditure, while territory area was not. One of the models showed a significant fit to the observed data, and suggested that the form of the energy cost constraint on territory size was linear. The effect of territory shape on energy costs was minimal. The implications of these results for models of territory size are discussed. 6. The slope and elevation of the energy cost constraint varied with the morphology of territory occupants. Based on this, an association of morphology with territory size was predicted; robins of lower mass and wing-loading using larger territories. The observed data supported these predictions, and suggested a possible genetic predisposition to particular patterns of territory occupancy in the robin

The avian dawn chorus across Great Britain: using new technology to study breeding bird song

The avian dawn chorus is a period of high song output performed daily around sunrise during the breeding season. Singing at dawn is of such significance to birds that they remain motivated to do so amid the noise of numerous others. Yet, we still do not fully understand why the dawn chorus exists. Technological advances in recording equipment, data storage and sound analysis tools now enable collection and scrutiny of large acoustic datasets, encouraging research on sound-producing organisms and promoting ‘the soundscape’ as an indicator of ecosystem health. Using an unrivalled dataset of dawn chorus recordings collected during this thesis, I explore the chorus throughout Great Britain with the prospect of furthering our understanding and appreciation of this daily event. I first evaluate the performance of four automated signal recognition tools (‘recognisers’) when identifying the singing events of target species during the dawn chorus, and devise a new ensemble approach that improves detection of singing events significantly over each of the recognisers in isolation. I then examine daily variation in the timing and peak of the chorus across the country in response to minimum overnight temperature. I conclude that cooler temperatures result in later chorus onset and peak the following dawn, but that the magnitude of this effect is greater at higher latitude sites with cooler and less variable overnight temperature regimes. Next, I present evidence of competition for acoustic space during the dawn chorus between migratory and resident species possessing similar song traits, and infer that this may lead either to fine-scale temporal partitioning of song, such that each competitor maintains optimal output, or to one competitor yielding. Finally, I investigate day-to-day attenuation of song during the leaf-out period from budburst through to full-leaf in woodland trees, and establish the potential for climate-driven advances in leaf-out phenology to attenuate song if seasonal singing activity in birds has not advanced to the same degree. I find that gradual attenuation of sound through the leaf-out process is dependent on the height of the receiver, and surmise that current advances in leaf-out phenology are unlikely to have undue effect on song propagation. This project illustrates the advantage of applying new technology to ecological studies of complex acoustic environments, and highlights areas in need of improvement, which is essential if we are to comprehend and preserve our natural soundscapes

Integrating Technologies for Scalable Ecology and Conservation

Integration of multiple technologies greatly increases the spatial and temporal scales over which ecological patterns and processes can be studied, and threats to protected ecosystems can be identified and mitigated. A range of technology options relevant to ecologists and conservation practitioners are described, including ways they can be linked to increase the dimensionality of data collection efforts. Remote sensing, ground-based, and data fusion technologies are broadly discussed in the context of ecological research and conservation efforts. Examples of technology integration across all of these domains are provided for large-scale protected area management and investigation of ecological dynamics. Most technologies are low-cost or open-source, and when deployed can reach economies of scale that reduce per-area costs dramatically. The large-scale, long-term data collection efforts presented here can generate new spatio-temporal understanding of threats faced by natural ecosystems and endangered species, leading to more effective conservation strategies

Gyrfalcon Breeding Biology In Alaska

Thesis (Ph.D.) University of Alaska Fairbanks, 2010This dissertation addresses specific research needs identified by a panel of experts on Gyrfalcon biology and conservation convened on 3 September, 2003 at the Raptor Research Foundation Scientific Conference in Anchorage, Alaska. The first chapter is a significant update and revision of the 1994 Gyrfalcon Birds of North America (BNA) species account, using all published papers and available grey literature from 1994--2007 and personal expertise from over 3,000 hours of coordinated observations. The second chapter reports results from a spatially explicit model, based on the best available compiled data from Alaska, that predicted Gyrfalcon breeding distribution and population size across Alaska. The model predicted that 75% and 7% of the state had a relative index of nest occurrence of 60%, respectively. Areas of high predicted occurrence primarily occurred in northern and western Alaska. Using environmental variables, the model estimated the size of the breeding Gyrfalcon population in Alaska is 546 +/- 180 pairs. In Chapter 3, I used repeated aerial surveys to estimate detection probabilities of cliff-nesting raptors from fixed-wing aircrafts and helicopters. Detection probabilities ranged from 0.79--0.10 and varied by species, observer experience, and study area/aircraft type. Generally, Gyrfalcons had the highest detection probability, followed by Golden Eagles, Common Ravens, and Rough-legged Hawks, though the exact pattern varied by study area and survey platform. In the final chapter, I described for the first time in North America Gyrfalcon nest site fidelity, breeding dispersal, and natal dispersal using molted feathers as non-invasive genetic tags. Gyrfalcons were highly faithful to study areas (100% fidelity) and breeding territories (98% fidelity), but not to specific nest sites (22% fidelity). Breeding dispersal distance averaged 750 +/- 870 m, and was similar between sexes. Natal dispersal of three nestlings representing 2.5% recruitment varied from 0--254 km. Mean territory tenure was 2.8 +/- 1.4 yrs and displayed a bimodal distribution with peaks at 1 and 4 years. Mean annual turnover at one study site was 20%. Gyrfalcons in one study area exhibited low, but significant population differentiation from the other two study areas