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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ecology and conservation of the raccoon dog (Nyctereutes procyonoides) in Japan

Saeki, Midori January 2001 (has links)
Raccoon dogs (Nyctereutes procyonoides viverrinus Temminck) were used as a model species to study wildlife management and conservation issues in the countryside of Japan. Radio-tracking data were used to analyse habitat use, movements, home range configuration and stability, social aspects, and factors influencing raccoon dog behaviour. Comparisons were drawn with European badgers (Meles meles Linnaeus) in the UK in order to highlight aspects of movements and habitat use of omnivorous Carnivores. Two key issues concerning the conservation of raccoon dogs in Japan were investigated: road-kills and agricultural damage. The Japan Highway Public Corporation provided road-kill data on the National Expressways, and a questionnaire survey was conducted on agricultural damage to local governments, authorities of wildlife administration. Socio-cultural issues on wildlife conservation in Japan were critically reviewed and discussed. Two types of habitat users appeared to exist in the study area. One type of raccoon dogs ('mountain type') inhabited a more semi-natural environment, including secondary forest and herbaceous areas, whereas a second type ('village type') inhabited more managed environments, such as rice fields and cropland. The results suggested that habitat selection occurred at home-range and location scales and differed between the two types of raccoon dogs. The mean size of home range of the raccoon dogs was 111 ± 16.9 ha (95% kernel estimate) and 160±34.5ha (95% maximum convex polygon (MCP)). There was no significant difference in home-range size between age classes or sexes. Seasonal home ranges were larger in yearlings than adults, and largest in autumn; and there was no difference between sexes. Season affected nightly movements, i.e. mean inter-fix speed, mean 100% MCP, and mean range span over the night; however, sex and age did not. All variables of nightly movement were smallest in winter. The mean fractal dimension of movements, i.e. degree of 'tortuousity' with self similarity, was 1.226 and significantly differed from 1.0 (a straight line) and 2.0 (a Brownian random movement). The mountain type had significantly larger fractal dimension than the village type, possibly reflecting habitat complexity and/or heterogeneity. Badgers generally preferred pasture and avoided arable habitat, but showed some variability by year and at scales of selection. A Badger Removal Operation may have influenced habitat selection of the badgers. The mean size of home range of badgers was 56.1 ± 7.7 ha (95% kernel estimates) and 56.2 ± 7.3 ha (95% MCP). The mean fractal dimension of the badgers' movements was 1.198 and was significantly different from 1.0 and 2.0. The raccoon dogs and the badgers showed similarities in movements, such as nightly home range, range span over night, and fractal dimension of movements. Sexual differences in spatial use existed in badgers but not in raccoon dogs. Road-kills of raccoon dogs appeared to be the highest, in percentage terms, of all wildlife species in Japan and this figure was linearly related to the traffic. Some road-features, such as whether the road was in a cutting and its proximity to water, were positively associated with road-kills, while the presence of coniferous plantations as roadside habitat was dissociated with road-kills. Nationwide estimates of road-kills of raccoon dogs, based on available data for National Expressways only, were made with different assumptions. Conservative estimates put the number of road-kills at 110,000 - 370,000 per year. The potential for road-kill numbers to be used, after controlling for traffic data, as an index of population trends, is discussed. In a questionnaire survey of agricultural damage sent to 46 prefectures, all respondents (96%) reported some damage by wildlife, and over 80% of respondents reported macaque and boar damage, while nearly 70 % reported raccoon dog and deer damage. Sixty-nine agricultural products were reported to have been damaged by wildlife, and 41 of these by raccoon dogs. Maize and fruits were major crops damaged by raccoon dogs. Although about a half of respondents employed culling, its effectiveness is unclear. Although Japan seems far behind other developing countries in its approach to wildlife conservation issues, the situation could be substantially improved through increased scientific understanding and education. Radical changes may be also required in the legal status of wildlife and its management schemes.
2

Molecular mechanisms in energy metabolism during seasonal adaptation:aspects relating to AMP-activated protein kinase, key regulator of energy homeostasis

Kinnunen, S. (Sanni) 05 June 2018 (has links)
Abstract Non-pathological change in body weight and adiposity is one distinct adaptive feature that seasonal species undergo, and it can offer a novel way to study the mechanisms underlying body weight regulation and energy homeostasis. Changes in the expression and activity of metabolic enzymes are essential for the physiological adaptation seasonal species exhibit. AMP-activated protein kinase (AMPK) is a key regulatory enzyme that controls the energy homeostasis both on cellular and whole-body level. In this thesis, the main focus was to clarify how seasonal adaptation affects AMPK and its downstream target in lipid metabolism, acetyl-CoA carboxylase (ACC), in different metabolic tissues of two model species with diverse wintering strategies: the raccoon dog and the Djungarian hamster. In addition, the effect of periodic fasting on the raccoon dog skeletal muscle was studied. It was observed that seasonal differences in AMPK and ACC expression were evident mainly in adipose tissues of both species. AMPK was down-regulated in white adipose tissue (WAT) of the winter-adapted raccoon dog, whereas in the Djungarian hamster WAT, the abundance of AMPK increased in response to winter acclimatization. ACC expression was maintained or increased in winter in both species. The seasonal changes in AMPK and ACC expression observed, in particular, in adipose tissues reflects the wintering strategy of the species and presumably facilitates the lipid usage and/or preservation during wintertime scarcity. Raccoon dogs were quite resistant to the prolonged wintertime fast, as no changes were observed in AMPK and ACC expression levels in the WAT, liver or hypothalamus between the fasted and fed groups. Skeletal muscle function also appears to be well preserved, as there were no changes in the expression of proteins involved in insulin signaling, and the fiber type composition and muscle energy reserves were not affected. This thesis offers novel information on protein level changes in metabolic adaptation. / Tiivistelmä Useat luonnonvaraiset eläinlajit ovat fysiologisesti sopeutuneet ravinnonsaannin vuodenaikaisiin vaihteluihin. Vuodenaikaisrytmiin kytketty rasvakudoksen määrän vaihtelu ja siihen liittyvät aineenvaihdunnalliset muutokset tarjoavat mielenkiintoisen tutkimuskohteen ruumiinpainon säätelyn ja energiatasapainon ylläpidon molekulaaristen mekanismien selvittämiseen. Oleellinen osa fysiologista sopeutumista ovat muutokset energia-aineenvaihduntaa säätelevien proteiinien ekspressio- ja aktiivisuustasoissa. Yksi keskeinen elimistön energiatasapainoa kontrolloiva entsyymi on AMP-aktivoituva proteiinikinaasi (AMPK). AMPK toimii solunsisäisenä energiasensorina ja säätelee energiametaboliaa koko kehon tasolla. Tässä väitöskirjatutkimuksessa selvitettiin talviadaptaation vaikutusta AMPK:n ja sen kohdemolekyylin, rasvahappojen biosynteesiä säätelevän asetyyli-CoA karboksylaasin (ACC), ilmenemiseen ja aktiivisuuteen eri kudoksissa. Mallieläiminä käytettiin kahta eri talvehtimisstrategian omaavaa ja eri lailla ruumiinpainoaan säätelevää lajia, kääpiöhamsteria ja supikoiraa. Lisäksi tutkittiin pitkäaikaisen talvipaaston vaikutusta supikoiran luustolihakseen. Tulokset osoittivat, että molemmilla lajeilla AMPK- ja ACC-pitoisuuksissa on vuodenaikaisia eroja erityisesti rasvakudoksessa. Supikoiralla AMPK:n määrä väheni talviadaptaation seurauksena, kun taas kääpiöhamstereilla talviakklimatisaatio johti korkeampaan AMPK-pitoisuuteen rasvakudoksissa. ACC-pitoisuus puolestaan säilyi samana tai oli korkeampi talviadaptoituneilla yksilöillä. Havaitut muutokset AMPK:n ja ACC:n ilmenemisessä kuvastavat supikoiran ja kääpiöhamsterin eroja talvehtimisessa ja havainnollistavat entsyymien oleellista osaa rasvavarastojen vuodenaikaisessa säätelyssä ja käytössä, mikä on edellytys eläinten selviämiselle yli talven niukkuuden. Lisäksi havaittiin talviadaptoituneen supikoiran olevan melko resistentti 10 viikon paastolle tutkittujen parametrien suhteen. AMPK- ja ACC-pitoisuus tai aktiivisuus ei muuttunut aineenvaihdunnallisesti oleellisissa kudoksissa (rasvakudos, maksa, hypotalamus) paasto- ja kontrolliryhmän välillä. Supikoiran lihasten toimintakyky vaikuttaisi säilyvän, sillä insuliinisignalointiin liittyvien entsyymien pitoisuus, lihasten solutyyppikoostumus tai energiavarastot eivät muuttuneet paaston myötä. Tämä tutkimus tarjoaa uutta tietoa proteiinitason muutoksista osana fysiologista sopeutumista.
3

Lietuvoje besiveisiančių usūrinių šunų (Nyctereutes procyonoides) ir rudųjų lapių (Vulpes vulpes) skeleto morfologinė analizė / Skeletal morphological analysis of raccoon dogs (Nyctereutes procyonoides) and red foxes (Vulpes vulpes) in Lithuania

Jurgelėnas, Eugenijus 11 May 2010 (has links)
Darbo tikslas: atlikti palyginamąją rudųjų lapių ir usūrinių šunų kaukolių, ilgųjų ir plokščiųjų galūnių kaulų osteologinę ir osteometrinę analizę. Darbo uždaviniai: 1. Išmatuoti ir palyginti usūrinių šunų ir rudųjų lapių patinų ir patelių kaukoles su apatiniais žandikauliais, krūminius dantis, plokščiuosius galūnių kaulus – mentę ir dubens kaulus ir ilguosius galūnių kaulus – petikaulį, dilbio kaulus, šlaunikaulį ir blauzdos kaulus. 2. Naudojantis gautais matmenimis atlikti tarprūšinį usūrinių šunų ir rudųjų lapių kaukolių su apatiniais žandikauliais, krūminių dantų, plokščiųjų galūnių kaulų – mentės ir dubens kaulų ir ilgųjų galūnių kaulų – petikaulio, dilbio kaulų, šlaunikaulio ir blauzdos kaulų palyginimą. 3. Apskaičiuoti kaukolių ir nurodytų ilgųjų galūnių kaulų – petikaulio, stipinkaulio, šlaunikaulio ir blauzdikaulio indeksus ir atlikti šių indeksų palyginimą tarp lyčių ir tarp tirtų gyvūnų rūšių. 4. Atlikti tarprūšinį kaukolių su apatiniais žandikauliais, plokščiųjų galūnių kaulų – mentės ir dubens kaulų, ilgųjų galūnių kaulų – petikaulio, dilbio kaulų, šlaunikaulio ir blauzdos kaulų morfologinį tyrimą palyginamosios anatomijos metodu. 5. Nustatyti tarprūšinius rudųjų lapių ir usūrinių šunų kaukolių vidinių struktūrų ir kaktikaulio ančių morfologinius ypatumus naudojant kompiuterinės tomografijos metodą. Pirmą kartą Lietuvoje atlikta palyginamoji usūrinių šunų ir rudųjų lapių kaukolių ir galūnių kaulų morfologinė analizė. Laukinės faunos osteologiniuose tyrimuose... [toliau žr. visą tekstą] / The aim of the present study is: to carry out a comparative osteological and osteometric analysis of skulls and long and flat bones of extremities of red foxes and raccoon dogs. The tasks include: 1. Measuring and comparison of the bones of male and female red foxes and raccoon dogs: skulls with jawbones, molars, the flat bones of extremities – scapula and pelvic bones – and the long bones of extremities – humerus, forearm, femur and crural bone. 2. Comparison of the bones of raccoon dogs and red foxes based on the obtained osteometric data about: skulls with jawbones, molars, the flat bones of extremities – scapula and pelvic bones – and the long bones of extremities – humerus, forearm bones, femur and crural bone. 3. Calculation of the indices of skulls and the indicated long bones of extremities – humerus, radius, femur and tibia – and comparison of these indices in the studied animals of different gender and species. 4. Morphological analysis of the bones – skulls with jawbones, the flat bones of extremities (scapula and pelvic bones) and the long bones of extremities (humerus, forearm, femur and crural bone) – of the studied species of animals by the method of comparative anatomy. 5. Determining the morphological features of the bones – internal structure of the skulls and frontal sinuses – of the studies species of animals (red foxes and raccoon dogs) by the method of computer tomography. The present work is a first attempt of comparative morphological analysis of the... [to full text]
4

Usūrinių šunų ir rudųjų lapių priekinės kojos griaučių morfometrinė analizė / Morphometric analysis of the skeleton of the foreleg of raccoon dogs and red foxes

Drazdauskaitė-Vaickelionė, Sandra 05 March 2014 (has links)
SANTRAUKA Šio darbo tikslas – atlikti rudųjų lapių ir usūrinių šunų priekinės galūnės ilgųjų kaulų morfometrinę analizę. Pagal gautus duomenis nustatyti skirtumus esančius tarp rūšių ir lyčių. Tyrimui panaudoti LSMU Veterinarijos akademijos Anatomijos ir fiziologijos katedroje sukaupti 12 – os suaugusių usūrinių šunų ir rudųjų lapių ilgieji kaulai: iš jų usūrinių šunų – 6 (3 patelės, 3 patinai), rudųjų lapių – 6 (3 patelės, 3 patinai). Atsiţvelgiant į tai, kad nebuvo pastebėta esminių ilgio ir pločio skirtumų tarp kaitės ir dešinės pusės galūnių, buvo tiriamos tik kairės pusės galūnės. Tirtas petikaulis, dilbio kaulai (stipinkaulis ir alkūnkaulis), plaštakos kaulai. Kaulai išmatuoti pagal (Bisaillon A., De Roth L., 1979) metodiką, naudojant mechaninį slankmatį 0,01 mm tikslumu. Pagal gautus duomenis išmatuoti septyni kaulų indeksai. Išmatavus ir palyginus usūrinių šunų ir rudųjų lapių patinų ir patelių ilguosius kaulus nustatyta, kad lapių patinų petikaulis, dilbio ir plaštakos kaulai ilgesni nei lapių patelių. Tarp kaulų pločio reikšmingų skirtumų nebuvo aptikta. Usūrinių šunų patinų petikaulis ir stipinkaulis ilgesnis nei usūrinių šunų patelių. Usūrinių šunų patelių alkūnkaulis ilgesnis nei usūrinių šunų patinų. Plaštakos kaulų ilgis ir plotis skyrėsi neţymiai. Palyginus tarprūšiniu poţiūriu, lapių patinų ilgieji kaulai ilgesni nei usūrinių šunų patinų. Tarp kaulų pločio esminių skirtumų nebuvo. Lapių patelių petikaulis ir dilbio kaulai ilgesni nei usūrinių šunų patelių... [toliau žr. visą tekstą] / SUMMARY Aim of this work – to perform morphometric analysis of the long bones of the foreleg of raccoon dogs and red foxes. To determine the differences between the sorts and sexes according to the data got. Long bones of 12 adult raccoon dogs and red foxes, kept at the Department of Anatomy and Physiology of Academy of Veterinary of Lithuanian University of Health Sciences, have been analysed: 6 – of raccoon dogs (3 females, 3 males), 6 – of red foxes (3 females, 3 males). Humerus, forearm bones (radius and ulna), and metacarpal bones have been investigated. Bones have been measured according to (Bisaillon A., De Roth L., 1979) method, using mechanical calliper (precision of 0.1 mm). Seven indexes of the bones have been measured according to the data got. When the long bones of female and male raccoon dogs and red foxes have been measured and compared, it has been determined that humerus, forearm and metacarpal bones of the male foxes are longer compared to the female foxes. Significant differences of the bone width have not been determined. Humerus and radius of the male raccoon dogs are longer compared to the female raccoon dogs. Ulna of the female raccoon dogs is longer compared to the male raccoon dogs. Length and width of the metacarpal bones were different marginally. When compared according to the interspecific point of view, long bones of the male foxes are longer than bones of the raccoon dogs. There were no essential differences between widths of the bones... [to full text]
5

Space use pattern, dispersal and social organisation of the raccoon dog (Nyctereutes procyonoides), an invasive, alien canid in Central Europe / Raumnutzung, Ausbreitung und Sozialsystem des Marderhundes (Nyctereutes procyonoides), eines invasiven, allochthonen Kaniden in Zentraleuropa

Drygala, Frank 14 December 2009 (has links) (PDF)
Abstract Between October 1999 and October 2003, 30 adult and 48 young (< 1 year) raccoon dogs (Nyctereutes procyonoides) were monitored using radio-telemetry in an area of Germany which has been occupied by this invasive alien species since the early 1990s. Additionally, three pairs of raccoon dogs were observed by continuous radio-tracking during the first six weeks after parturition in 2003. Furthermore 136 raccoon dog pubs were ear-tagged between June 1999 and August 2006. No adult animals dispersed from the area during the study period and home ranges tended to be used for several years, probably for life. The average annual home range size, calculated using 95% fixed kernel, was 382.2 ha ± 297.4 SD for females (n = 30 seasonal home ranges) and 352.4 ha ± 313.3 SD for males (n = 32 seasonal home ranges). Paired raccoon dogs had home ranges of similar size, with pair sharing the same area all year round. Raccoon dogs occupied large core areas (85% kernel) covering 81.2% of their home ranges. The home ranges were at their smallest during the mating season. The slightly larger size of home ranges in winter suggests that, due to the temperate climate, raccoon dogs do not hibernate in Germany. Males and females formed a long-term (probably lifelong) pair bond. Same-sex neighbours ignored each other and even adjacent males/females showed neither preference nor avoidance. Thus, it can be assumed that the raccoon dog in Central Europe is monogamous without exclusive territories, based on the results of home range overlap analysis and interaction estimations. Habitat composition within home ranges and within the whole study area was almost equal. Although, percentage shares of farmland and meadow was 16.35% smaller and 12.06% higher within the home ranges, respectively. All nine habitat types (farmland, forest, settlement, water, meadows, maize fields, small woods, reeds and hedges) were used opportunistically by raccoon dogs. No significant, recognisable difference for habitat preferences between seasons was detected. Male and female raccoon dog showed equal habitat preference pattern. A comparison of active and inactive locations in different habitats found no remarkable differences. Habitat composition of individual home ranges was used to classify animals. If the percentage of forest within a home range exceeded 50% the individual was classified as a ‘forest type’ raccoon dog. If the percentage of forest habitats within a home range was less than 5%, the share of pastureland was mean 81.82% ± 16.92 SD. Consequently the individual was classified as a ‘agrarian type’ raccoon dog. Neither habitat preference nor habitat selection process differed between the two ‘types’. Habitat use and preference is discussed with relation to the ability of the raccoon dog to expand its range towards Western Europe. Males spent noticeably more time (40.5% of the time ±11.7 SD) alone with the pups than females (16.4% of the time ±8.5 SD). Females had noticeably larger 95% kernel home ranges (98.24 ha ±51.71 SD) than males (14.73 ha ±8.16 SD) and moved much longer daily distances (7,368 m ±2,015 SD) than males (4,094 m ±2,886 SD) in six weeks postpartum. The raccoon dogs being studied left the breeding den in the 6th week after the birth of the pups. In situ video observation showed that the male carried prey to the den to provide the female and the litter with food. A clear division of labour took place among parents during the period in which the pups were nursed: males guarded the litter in the den or in close vicinity of it, while the females foraged to satisfy their increased energy requirements. There were relocations of 59 (43.4%) ear-tagged young racoon dogs and mean distance from marking point was 13.5 km ±20.1 SD. Dispersal mortality rate was 69.5% among young raccoon dogs. Most animals (55.9%) were recovered nearer than 5 km from the marking point, whereas only 8.5% relocations were recorded further than 50 km from the marking point. There was no difference in the distances of relocations between sexes. Most (53.7%) relocations of ear-tagged young raccoon dogs were in August and September and, only 34.1% were recorded from October to April. Hunting (55 %) and traffic (27 %) were the major mortality factors. Radio-collared young raccoon dogs generally dispersed between July and September. The mean natal home range size (MCP 100%) with and without excursions was 502.6 ha ±66.4 SD (n = 9) and 92.1 ha ±66.4 SD (n = 17), respectively. There were no differences between sexes in the month of dispersal. The direction of travel for dispersing animals appeared to be random, with distances from 0.5 km to 91.2 km. A highly flexible dispersing behaviour is certainly one of the reasons which contribute to the high expansion success of the species.
6

Space use pattern, dispersal and social organisation of the raccoon dog (Nyctereutes procyonoides GRAY, 1834) an invasive, alien canid in Central Europe

Drygala, Frank 16 August 2010 (has links) (PDF)
Between October 1999 and October 2003, 30 adult and 48 young (< 1 year) raccoon dogs (Nyctereutes procyonoides) were monitored using radio-telemetry in an area of North-East Germany which has been occupied by this invasive alien species since the early 1990s. Additionally, three pairs of raccoon dogs were observed by continuous radio-tracking during the first six weeks after parturition in 2003. Furthermore 136 raccoon dog pubs were ear-tagged between June 1999 and August 2006. No adult animals dispersed from the area during the study period and home ranges tended to be used for several years, probably for life. The average annual home range size, calculated using 95% fixed kernel, was 382.2 ha ± 297.4 SD for females (n = 30 seasonal home ranges) and 352.4 ha ± 313.3 SD for males (n = 32 seasonal home ranges). Paired raccoon dogs had home ranges of similar size, with pair mates sharing the same area all year round. Raccoon dogs occupied large core areas (85% kernel) covering 81.2% of their home ranges. The home ranges were at their smallest during the mating season. The slightly larger size of home ranges in winter suggests that, due to the temperate climate, raccoon dogs do not hibernate in Germany. Males and females formed a long-term (probably lifelong) pair bond. Same-sex neighbours ignored each other and even adjacent males/females showed neither preference nor avoidance. Thus, it can be assumed that the raccoon dog in Central Europe is monogamous without exclusive territories, based on the results of home range overlap analysis and interaction estimations. Habitat composition within home ranges and within the whole study area was almost equal. Although, percentage shares of farmland and meadow was 16.35% smaller and 12.06% higher within the home ranges, respectively. All nine habitat types (farmland, forest, settlement, water, meadows, maize fields, small woods, reeds and hedges) were used opportunistically by raccoon dogs. No significant, recognisable difference for habitat preferences between seasons was detected. Male and female raccoon dog showed equal habitat preference pattern. A comparison of active and inactive locations in different habitats found no remarkable differences. Habitat composition of individual home ranges was used to classify animals. If the percentage of forest within a home range exceeded 50% the individual was classified as a ‘forest type’ raccoon dog. If the percentage of forest habitats within a home range was less than 5%, the share of pastureland was mean 81.82% ± 16.92 SD. Consequently the individual was classified as a ‘agrarian type’ raccoon dog. Neither habitat preference nor habitat selection process differed between the two ‘types’. Habitat use and preference is discussed with relation to the ability of the raccoon dog to expand its range towards Western Europe. Males spent noticeably more time (40.5% of the time ±11.7 SD) alone with the pups than females (16.4% of the time ±8.5 SD). Females had noticeably larger 95% kernel home ranges (98.24 ha ±51.71 SD) than males (14.73 ha ±8.16 SD) and moved much longer daily distances (7,368 m ±2,015 SD) than males (4,094 m ±2,886 SD) in six weeks postpartum. The raccoon dogs being studied left the breeding den in the 6th week after the birth of the pups. In situ video observation showed that the male carried prey to the den to provide the female and the litter with food. A clear division of labour took place among parents during the period in which the pups were nursed: males guarded the litter in the den or in close vicinity of it, while the females foraged to satisfy their increased energy requirements. There were relocations of 59 (43.4%) ear-tagged young raccoon dogs and mean distance from marking point was 13.5 km ±20.1 SD. Dispersal mortality rate was 69.5% among young raccoon dogs. Most animals (55.9%) were recovered nearer than 5 km from the marking point, whereas only 8.5% relocations were recorded further than 50 km from the marking point. There was no difference in the distances of relocations between sexes. Most (53.7%) relocations of ear-tagged young raccoon dogs were in August and September and, only 34.1% were recorded from October to April. Hunting (55 %) and traffic (27 %) were the major mortality factors. Radiocollared young raccoon dogs generally dispersed between July and September. The mean natal home range size (MCP 100%) with and without excursions was 502.6 ha ±66.4 SD (n = 9) and 92.1 ha ±66.4 SD (n = 17), respectively. There were no differences between sexes in the month of dispersal. The direction of travel for dispersing animals appeared to be random, with distances from 0.5 km to 91.2 km. A highly flexible dispersing behaviour is certainly one of the reasons which contribute to the high expansion success of the species.
7

Space use pattern, dispersal and social organisation of the raccoon dog (Nyctereutes procyonoides), an invasive, alien canid in Central Europe: Space use pattern, dispersal and social organisation of the raccoon dog (Nyctereutes procyonoides), an invasive, alien canid in Central Europe

Drygala, Frank 03 December 2009 (has links)
Abstract Between October 1999 and October 2003, 30 adult and 48 young (&amp;lt; 1 year) raccoon dogs (Nyctereutes procyonoides) were monitored using radio-telemetry in an area of Germany which has been occupied by this invasive alien species since the early 1990s. Additionally, three pairs of raccoon dogs were observed by continuous radio-tracking during the first six weeks after parturition in 2003. Furthermore 136 raccoon dog pubs were ear-tagged between June 1999 and August 2006. No adult animals dispersed from the area during the study period and home ranges tended to be used for several years, probably for life. The average annual home range size, calculated using 95% fixed kernel, was 382.2 ha ± 297.4 SD for females (n = 30 seasonal home ranges) and 352.4 ha ± 313.3 SD for males (n = 32 seasonal home ranges). Paired raccoon dogs had home ranges of similar size, with pair sharing the same area all year round. Raccoon dogs occupied large core areas (85% kernel) covering 81.2% of their home ranges. The home ranges were at their smallest during the mating season. The slightly larger size of home ranges in winter suggests that, due to the temperate climate, raccoon dogs do not hibernate in Germany. Males and females formed a long-term (probably lifelong) pair bond. Same-sex neighbours ignored each other and even adjacent males/females showed neither preference nor avoidance. Thus, it can be assumed that the raccoon dog in Central Europe is monogamous without exclusive territories, based on the results of home range overlap analysis and interaction estimations. Habitat composition within home ranges and within the whole study area was almost equal. Although, percentage shares of farmland and meadow was 16.35% smaller and 12.06% higher within the home ranges, respectively. All nine habitat types (farmland, forest, settlement, water, meadows, maize fields, small woods, reeds and hedges) were used opportunistically by raccoon dogs. No significant, recognisable difference for habitat preferences between seasons was detected. Male and female raccoon dog showed equal habitat preference pattern. A comparison of active and inactive locations in different habitats found no remarkable differences. Habitat composition of individual home ranges was used to classify animals. If the percentage of forest within a home range exceeded 50% the individual was classified as a ‘forest type’ raccoon dog. If the percentage of forest habitats within a home range was less than 5%, the share of pastureland was mean 81.82% ± 16.92 SD. Consequently the individual was classified as a ‘agrarian type’ raccoon dog. Neither habitat preference nor habitat selection process differed between the two ‘types’. Habitat use and preference is discussed with relation to the ability of the raccoon dog to expand its range towards Western Europe. Males spent noticeably more time (40.5% of the time ±11.7 SD) alone with the pups than females (16.4% of the time ±8.5 SD). Females had noticeably larger 95% kernel home ranges (98.24 ha ±51.71 SD) than males (14.73 ha ±8.16 SD) and moved much longer daily distances (7,368 m ±2,015 SD) than males (4,094 m ±2,886 SD) in six weeks postpartum. The raccoon dogs being studied left the breeding den in the 6th week after the birth of the pups. In situ video observation showed that the male carried prey to the den to provide the female and the litter with food. A clear division of labour took place among parents during the period in which the pups were nursed: males guarded the litter in the den or in close vicinity of it, while the females foraged to satisfy their increased energy requirements. There were relocations of 59 (43.4%) ear-tagged young racoon dogs and mean distance from marking point was 13.5 km ±20.1 SD. Dispersal mortality rate was 69.5% among young raccoon dogs. Most animals (55.9%) were recovered nearer than 5 km from the marking point, whereas only 8.5% relocations were recorded further than 50 km from the marking point. There was no difference in the distances of relocations between sexes. Most (53.7%) relocations of ear-tagged young raccoon dogs were in August and September and, only 34.1% were recorded from October to April. Hunting (55 %) and traffic (27 %) were the major mortality factors. Radio-collared young raccoon dogs generally dispersed between July and September. The mean natal home range size (MCP 100%) with and without excursions was 502.6 ha ±66.4 SD (n = 9) and 92.1 ha ±66.4 SD (n = 17), respectively. There were no differences between sexes in the month of dispersal. The direction of travel for dispersing animals appeared to be random, with distances from 0.5 km to 91.2 km. A highly flexible dispersing behaviour is certainly one of the reasons which contribute to the high expansion success of the species.
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Space use pattern, dispersal and social organisation of the raccoon dog (Nyctereutes procyonoides GRAY, 1834) an invasive, alien canid in Central Europe

Drygala, Frank 03 December 2009 (has links)
Between October 1999 and October 2003, 30 adult and 48 young (< 1 year) raccoon dogs (Nyctereutes procyonoides) were monitored using radio-telemetry in an area of North-East Germany which has been occupied by this invasive alien species since the early 1990s. Additionally, three pairs of raccoon dogs were observed by continuous radio-tracking during the first six weeks after parturition in 2003. Furthermore 136 raccoon dog pubs were ear-tagged between June 1999 and August 2006. No adult animals dispersed from the area during the study period and home ranges tended to be used for several years, probably for life. The average annual home range size, calculated using 95% fixed kernel, was 382.2 ha ± 297.4 SD for females (n = 30 seasonal home ranges) and 352.4 ha ± 313.3 SD for males (n = 32 seasonal home ranges). Paired raccoon dogs had home ranges of similar size, with pair mates sharing the same area all year round. Raccoon dogs occupied large core areas (85% kernel) covering 81.2% of their home ranges. The home ranges were at their smallest during the mating season. The slightly larger size of home ranges in winter suggests that, due to the temperate climate, raccoon dogs do not hibernate in Germany. Males and females formed a long-term (probably lifelong) pair bond. Same-sex neighbours ignored each other and even adjacent males/females showed neither preference nor avoidance. Thus, it can be assumed that the raccoon dog in Central Europe is monogamous without exclusive territories, based on the results of home range overlap analysis and interaction estimations. Habitat composition within home ranges and within the whole study area was almost equal. Although, percentage shares of farmland and meadow was 16.35% smaller and 12.06% higher within the home ranges, respectively. All nine habitat types (farmland, forest, settlement, water, meadows, maize fields, small woods, reeds and hedges) were used opportunistically by raccoon dogs. No significant, recognisable difference for habitat preferences between seasons was detected. Male and female raccoon dog showed equal habitat preference pattern. A comparison of active and inactive locations in different habitats found no remarkable differences. Habitat composition of individual home ranges was used to classify animals. If the percentage of forest within a home range exceeded 50% the individual was classified as a ‘forest type’ raccoon dog. If the percentage of forest habitats within a home range was less than 5%, the share of pastureland was mean 81.82% ± 16.92 SD. Consequently the individual was classified as a ‘agrarian type’ raccoon dog. Neither habitat preference nor habitat selection process differed between the two ‘types’. Habitat use and preference is discussed with relation to the ability of the raccoon dog to expand its range towards Western Europe. Males spent noticeably more time (40.5% of the time ±11.7 SD) alone with the pups than females (16.4% of the time ±8.5 SD). Females had noticeably larger 95% kernel home ranges (98.24 ha ±51.71 SD) than males (14.73 ha ±8.16 SD) and moved much longer daily distances (7,368 m ±2,015 SD) than males (4,094 m ±2,886 SD) in six weeks postpartum. The raccoon dogs being studied left the breeding den in the 6th week after the birth of the pups. In situ video observation showed that the male carried prey to the den to provide the female and the litter with food. A clear division of labour took place among parents during the period in which the pups were nursed: males guarded the litter in the den or in close vicinity of it, while the females foraged to satisfy their increased energy requirements. There were relocations of 59 (43.4%) ear-tagged young raccoon dogs and mean distance from marking point was 13.5 km ±20.1 SD. Dispersal mortality rate was 69.5% among young raccoon dogs. Most animals (55.9%) were recovered nearer than 5 km from the marking point, whereas only 8.5% relocations were recorded further than 50 km from the marking point. There was no difference in the distances of relocations between sexes. Most (53.7%) relocations of ear-tagged young raccoon dogs were in August and September and, only 34.1% were recorded from October to April. Hunting (55 %) and traffic (27 %) were the major mortality factors. Radiocollared young raccoon dogs generally dispersed between July and September. The mean natal home range size (MCP 100%) with and without excursions was 502.6 ha ±66.4 SD (n = 9) and 92.1 ha ±66.4 SD (n = 17), respectively. There were no differences between sexes in the month of dispersal. The direction of travel for dispersing animals appeared to be random, with distances from 0.5 km to 91.2 km. A highly flexible dispersing behaviour is certainly one of the reasons which contribute to the high expansion success of the species.

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