Wild ungulates are considered one of the major drivers for shaping terrestrial ecosystems, which has been developing since the early Cenozoic. Understanding the effects of ungfulates on vegetation is necessary for qualified knowledge how European landscape looked prior to human habitation and how it would look like without human intervention. Further, such understanding is of practical importance as management information necessary for managing abandoned landscapes. While the present-day wild ungulate European fauna does not contain several large grazers like auroch (Bos primigenius) anymore, the landscape has long been affected by them. It thus possesses historical experience of response to large grazers, which has been further maintained by livestock grazing. Importantly, the European landscape is experiencing a steady increase of populations of deer (Cervidae) and wild boar (Sus scrofa) with major effects of vegetation and landscape structure. While the effects of these present-day dominants have been studied mainly in forest habitats, there is a growing evidence that they both promote species diversity of forest understory and, interestingly, preferably feed in open vegetation and thus can affect broader landscape heterogeneity. The main aim of this thesis is therefore to examine effects of...

It is important for the ecological management of wildlife populations in the Czech Republic to know the composition of species in individual habitats. This will allow predictions on the reactions of wildlife based on evolving changes that will occur sooner or later in these habitats due to human activity and natural change of our environment. Camera traps are a powerful tool of the 21st century with which we are able to observe wildlife without major interventions in their lives. With the right experimental design, camera traps allow us to find out details about wildlife life such as their distribution and habitat preferences, population structure, and their behavior. In this work, I used camera traps to determine the species composition of two groups; ungulates and carnivores in different habitats. This thesis analyzes the habitat preferences and hepls to find out to what extent the spatial patterns of occurrence on these two groups are in the monitored habitats over the course of a couple years. Data collection took place from June 2015 to May 2017 in the Central Bohemian Region northeast of Prague. Despite the fact that the area is densely populated and agriculturally exploited, I was able to capture four species of ungulates and nine species of carnivores on a total of 73 camera traps in this...

The capture of neonate ungulates has played an integral role in studies of habitat selection, phenology, survival, and other topics of ecological interest. However, neonates can be difficult for researchers to locate and capture. Neonate ungulates are born in habitats with reduced visibility, frequently spend time in a concealed, prone position, and may display cryptic coloration. In an attempt to improve researchers' likelihood of locating and capturing neonate ungulates, multiple capture methods have been developed. Much remains unknown about biases associated with capture methods and how to further improve capture methods once biases are understood. Our objectives were to determine if opportunistic captures of neonate mule deer (Odocoileus hemionus) bias estimates of litter size (Chapter 1) and to determine when searches for neonate elk (Cervus canadensis) should begin following parturition to maximize likelihood of capture while minimizing disturbance (Chapter 2). To complete our objectives, we analyzed data from 161 litters of mule deer and 55 attempted captures of neonate elk during 2019-2021 in Utah, USA. Estimates of litter size derived from opportunistic captures of mule deer were smaller than estimates derived from movement-based captures or captures completed with the aid of vaginal implant transmitters (VITs). The time elapsed between parturition and when searches were initiated for neonate mule deer did not influence estimates of litter size, but we could only analyze this relationship for VIT-aided captures within approximately 2 days of parturition. Until more data are available, we recommend that estimates of litter size for neonate mule deer be completed using movement-based or VIT-aided captures within approximately 2 days of parturition. When attempting to capture neonate elk, reducing the time elapsed between parturition and when searches were initiated resulted in a decreased search length, decreased distance traveled by the neonate, and increased likelihood of capture. We initiated searches as early as 3.6 hours post-parturition with no evidence of maternal abandonment and probability of capture was near or above 90% when searches were initiated within 10 hours of parturition. We recommend that searches for neonate elk be initiated 3.6-10 hours post-parturition. Future researchers can use utilize our results to perform captures of neonate ungulates that minimize bias, decrease disturbance, increase efficiency, and maximize the likelihood of capture success.

Dissertation (PhD)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The use of helicopters has become almost universally accepted as the method of choice in the enumeration of large ungulates in Southern Africa. In most cases decisions affecting management of these populations are made based on a single count result. In all these instances the within technique variance is ignored, often leading to decisions based on type I or type II statistical errors where the within technique variance is misconstrued as the population change. Many studies have investigated the issue of accuracy of counting methods and a few have quoted precision values for various methods. Very few have, however, investigated power and those extant have approached the problem from a prospective point of view and predicted power values. This study has made use of replicated counts from 12 sites of the original 23 in four vegetation types of the then Transvaal Province. The study sites vary in terms of size and all counts were undertaken with an experienced, trained team in which only four observers were used. A comprehensive post hoc analysis of the results of the field surveys shows precision and power to vary widely according to species and vegetation type and concludes that gamecounting results are largely site specific. A decline in observations during the course of four hours of survey is demonstrated and although the exact cause cannot be determined, correction factors have been constructed for two vegetation types. Observers are shown to differ from one another in observation profile during the course of surveys. This study demonstrates, describes and quantifies the existence of several phenomena suspected to exist by experienced game counters, biologists and wildlife managers and makes proposals in terms of improving the data returned from expensive aerial surveys. / AFRIKAANSE OPSOMMING: In Suider-Afrika word die gebruik van 'n helikopter vir die tel van hoefdiere byna algemeen aanvaar as die metode wat voorkeur geniet. In meeste gevalle word besluitnemings rakende die bestuur van hierdie populasies gebaseer op die resultate van 'n enkele telling. In al die gevalle word tegniekverwante afwykings buite rekening gelaat en dit het die gevolg dat bestuursbesluite gebaseer word op tipe I en tipe II statistiese foute, en dit lei weer op hulle beurt dat tegniekverwante afwykings verkeerdelik geïnterpreteer word as die rede vir veranderings in die bevolkings. Verskeie studies het al die feitegeskil omtrent die akkuraatheid van telmetodes ondersoek en sommige het herhaalbaarheidswaardes vir die verskillende metodes aangehaal. Baie min het egter statistiese mag ondersoek en die wat dit wel gedoen het, het prospektiewe magsanalise as uitgangspunt gebruik en statistiese magwaardes voorspelom die probleem aan te spreek. Hierdie studie het gebruik gemaak van herhaalde tellings van 12 gebiede uit die oorspronklike 23 in vier veldtipes geleë in die ou Transvaal Provinsie. Die studiegebiede verskil in groottes. Alle tellings is deur 'n bekwaamde opgeleide span gedoen wat slegs vier waarnemers ingesluit het. 'n Omvattende post hoc analise van die resultate van die veldopnames dui aan dat herhaalbaarheid en statistiese mag baie varieer met betrekking tot spesies en veldtipes en word die gevolgtrekking gemaak dat wildtellingsresultate grootliks gebiedsgebonde is. In Afname in waarnemings gedurende die verloop van In vier uuropname, is waargeneem en alhoewel die ware oorsaak nie vasgestel kan word nie, is korreksiefaktore bereken vir twee veldtipes. Dit blyk dat waarnemers van mekaar verskil het met betrekking tot hul waarnemingsprofiele gedurende die verloop van die opnames. Hierdie studie dui aan, beskryf en kwantifiseer die bestaan van verskeie verskynsels wat vermoedelik bestaan het by ervare wildtelIers, bioloë en wildlewebestuurders en maak voorstelle met betrekking tot die verbetering van data wat tydens duur lugopnames ingesamel word.

La sénescence de survie est un processus défini comme le déclin progressif des probabilités de survivre en fonction de l'âge, et caractérisé par deux paramètres clés : l'âge de début de sénescence et le taux de sénescence. En dépit de son caractère délétère sur la fitness, la sénescence est observée chez la plupart des êtres vivants et plusieurs théories évolutives de la sénescence ont été proposées pour expliquer ce paradoxe. Chez les mammifères, il existe une grande diversité de patrons de sénescence de survie entre les espèces, mais aussi entre les sexes. En général, les males sénescent plus tôt et plus vite que les femelles, et vivent donc moins longtemps. Un des objectifs de ma thèse fut d'identifier un (des) facteur(s), qui pourraient expliquer cette diversité aussi bien au niveau inter- que intra-spécifique chez les mammifères. Pour ce faire, j'ai utilisé une approche comparative qui corrige pour la phylogénie, et des données démographiques issues de populations captives (base de données Species360). Ma thèse confirme tout d'abord l'idée commune que les mammifères vivent généralement plus longtemps en captivité qu'en milieu sauvage, mais ce bénéfice est plus important pour les espèces ayant un cycle de vie rapide que pour celles ayant un cycle de vie très lent. De plus, l'intensité de la sélection sexuelle explique en partie les différences de patron de sénescence avec, chez les ruminants, les mâles des espèces polygynes commençant leur sénescence plus tôt et vivant moins longtemps que les mâles des espèces monogames. Cette thèse démontre également l'importance de définir précisément la forme et la force des relations allométriques pour éviter toute erreur d'interprétation. Enfin, mes résultats montrent que les pratiques managériales en zoo, plus que l'allocation à la reproduction, influencent le patron de sénescence de deux espèces de Varis. En conclusion, ma thèse a permis de mettre en évidence l'importance d'inclure les concepts de la sélection sexuelle dans le contexte des théories évolutives actuelles. Enfin, l'étude des facteurs ayant une influence sur le patron de sénescence de survie des espèces menacées, que cela soit en captivité ou dans leur milieu naturel, devrait permettre d'obtenir des informations clés pour aider à la conservation de ces espèces / The process of actuarial senescence is defined as the progressive decline of survival per time unit with increasing age and can be characterized by two keys metrics corresponding to the age at the onset of senescence and the rate of senescence. Despite its detrimental effect in terms of fitness, senescence is a nearly ubiquitous process across the tree of life and several evolutionary theories of senescence have been proposed to solve this apparent paradox. Across mammals, a large diversity of actuarial senescence patterns is observed among species, but also between sexes, with males often living shorter than females. One objective of my Ph.D. was to identify factor(s) influencing survival and actuarial senescence at inter- and intra-specific levels using a phylogenetic comparative approach based on demographic data obtained from captive populations (Species360 database). My thesis first confirms the common belief that mammals in zoos generally outlive their wild counterparts, but fast-living species benefit more of captive condition than slow-living species. In addition, I found that sexual selection intensity partly account for the diversity of actuarial senescence patterns with males of polygynous ruminant senescing earlier and living shorter than males of monogamous ruminants. Moreover, I highlight that evolutionary allometry of sexually selected traits need to be determined accurately to avoid any misinterpretation. Finally, my results confirm that management practices in zoos influence actuarial senescence pattern at intra-specific level in two species of Varecia but not the allocation in reproduction. In conclusion, my Ph.D. highlights the importance to include the concept of sexual selection within the evolutionary framework of current theories of senescence. Finally, the study of factors influencing the actuarial senescence patterns of threatened species is likely to provide key information in conservation projects of these species

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Les cervidés, animaux mobiles et herbivores, peuvent influencer les distributions, assemblages et dynamiques d'espèces végétales. L'objectif de cette thèse est d'évaluer le rôle joué par les cervidés sur la composition, stratification et dynamique de la végétation forestière. Le ré-échantillonnage de relevés couplant composition et abroutissement de la flore, implantés en 1976 en Forêt d'Arc-en-Barrois (52) a permis d'identifier (i) des espèces ligneuses préférées (Cornus sp., Rosa arvensis) ou au contraire évitées par les cervidés qui sélectionnent les espèces arbustives et à bois dense et (ii) le niveau trophique et la pression d'abroutissement comme gradients structurant la végétation et déterminant les dynamiques des espèces et des communautés. Nous analysons plus précisément le rôle des cervidés dans la progression spectaculaire de Cynoglossum germanicum, espèce rare, épizoochore et toxique.A partir d'un réseau national d'enclos/exclos suivis sur 10 ans, nous montrons que les cervidés limitent la croissance des arbustes et des espèces compétitrices, ce qui profite à la richesse spécifique de la strate herbacée. La valeur écologique et patrimoniale des espèces en progression est discutée. A l'aide de données de chasse, nous tentons d'isoler les rôles des différentes espèces d'ongulés dans ces dynamiques.Ces résultats exposent la complexité et la diversité des effets des cervidés sur la végétation forestière. Enfin, ce travail met l'accent sur la nécessité des suivis temporels intégrant toutes les composantes de l'écosystème forestier pour mieux appréhender les changements en cours. / This thesis aims at assessing the impacts of deer on forest vegetation composition, stratification and dynamics.We resampled a network of relevés coupling vegetation and browsing surveys, settled in 1976 in the national forest of Arc-en-Barrois. We identified (i) ligneous species that are either preferred (Cornus sp., Rosa arvensis) or avoided by deer, which tend to select shrubs species with dense wood and (ii) trophic level and browsing pressure as gradients that determine plant communities structures and dynamics. Then, we highlight the roles of deer in the spectacular expansion of Cynoglossum germanicum, a rare, epizoochorous and toxic species. According to a national network of exclosures, monitored for over 10 years, we show that deer limit shrubs and competing species growth, which in turn benefits to the herbaceous species richness probably through an increased light availability. Ecological and patrimonial value of the benefitting species is discussed. Using hunting statistics, we try to isolate the role of the various ungulate species in these dynamics.These results provide evidence for the diversity and complexity of deer impacts on forest vegetation. Finally, we demonstrate the need for long term monitoring programs, including all the forest ecosystem components so that we could better appreciate the forces driving the current changes