No description available.

Eighteen prairie rattlesnakes (Crotalus viridis viridis) were tracked using radio-telemetry and 82 snakes were PIT-tagged over a 2-year period in Lethbridge, AB to determine population size, movement patterns, and habitat utilization, and to predict fragmentation effects on the species within an urban locale. Population size was estimated using closed population models at 374 snakes (295 adults) and open population models at 204 snakes (161 adults), greater than an estimate of <50 adults in 2003 (Ernst, 2003) and 2006 (Ernst & Quinlan, 2006). Mean home range sizes, based on 95% minimum convex polygon analysis, differed significantly between years (31.51 ha in 2005, 3.72 ha in 2006). Calculated movement parameters, such as mean distance moved per day, total distance moved over the course of the active season, and frequency of movement varied between years and individuals. Greater-than-expected (under hypotheses of even habitat choice) utilization was observed in habitat types located within coulee and flood plain areas, with apparent preference towards unbroken parcels of grassland or cottonwoods, whereas less-than-predicted utilization of agricultural habitat type was observed. Fragmentation effects on prairie rattlesnake movement and occurrence were examined through modeling and were found to coincide with observed species’ locations, suggesting that prairie rattlesnakes are undergoing modification of movement patterns to avoid highly concentrated human density or use. Influence of weather on the use of vegetative ground cover was observed, as it was accessed more by prairie rattlesnakes at higher temperatures. Recommendations towards future management of the prairie rattlesnake population in Lethbridge are given, including protection of the Bridge View Drive site and inclusion of varied habitat types and terrain when planning habitat and wildlife corridors. Management decisions that ensure remaining habitat parcels and connective areas near rattlesnake foraging or movement corridors are also advocated. Identification of future research focuses include studies on juvenile survivorship, genetic structure, and vehicle-related mortality. / xii, 83 leaves : col. ill., col. maps ; 29 cm

Pygmy tarsiers (Tarsius pumilus) of Central Sulawesi, Indonesia are the only species of tarsier known to live exclusively at high altitudes. This study was the first to locate and observe multiple groups of this elusive primate. This research tested the hypothesis that variation in pygmy tarsier behavior and morphology correlates with measurable ecological differences that occur along an altitudinal gradient. As a response to decreased resources at higher altitudes and the associated effects on foraging competition and energy intake, pygmy tarsiers were predicted to exhibit lower population density, smaller group sizes, larger home ranges, and reduced sexually selected traits compared to lowland tarsiers. Six groups containing a total of 22 individuals were observed. Pygmy tarsiers were only found between 2000 and 2300 m, indicating allopatric separation from lowland tarsiers. As expected, the observed pygmy tarsiers lived at a lower density than lowland tarsier species, in association with decreased resources at higher altitudes. The estimated population density of pygmy tarsiers was 92 individuals per 100 ha, with 25 groups per 100 ha. However, contrary to expectation, home range sizes were not significantly larger than lowland tarsier home ranges, and average NPL was smaller than those of lowland tarsiers. The average home range size for the observed pygmy tarsiers was 2.0 ha, and the average nightly path length (NPL) was 365.36 m. Pygmy tarsiers exhibited a nonrandom, clumped distribution near forest edges. While insect abundance and biomass were found to decrease as altitude increased, insect abundance and biomass was higher along anthropogenic edges. Thus, tarsiers within the study area may mitigate the decreased availability of insects at high altitudes by remaining close to forest edges, which in turn may be related to smaller than expected home range sizes. Further, estimates of pygmy tarsier abundance may be inflated because of increased insect abundance along anthropogenic edges. Contrary to the prediction for smaller group sizes as a response to feeding competition, the observed pygmy tarsiers lived in relatively large groups with multiple adult males. However, in support of the prediction for energetic constraints on body proportions, the observed pygmy tarsiers did not exhibit sexually selected traits. The pygmy tarsiers exhibited low sexual dimorphism and small relative testes mass, a trend opposite from lowland tarsier species, which may indicate a constraint on the development of those traits. Considered together, these results suggest that the observed pygmy tarsiers have adapted to life in an environment with limited resources. Future studies should explore the possible contributing effects of seasonality and topography.

No description available.

Understanding how populations are structured and how they use natural and anthropogenic spaces is essential for effective wildlife management. A total of 510 barren-ground (Rangifer tarandus groenlandicus), 176 boreal (R. t. caribou), 11 mountain woodland (R. t. caribou), and 39 island (R. t. groenlandicus x pearyi) caribou were tracked with satellite collars in 1993-2009 in the Northwest Territories, Nunavut, and northern Alberta. Using satellite location data and hierarchical and fuzzy cluster analyses, I verified that Cape Bathurst, Bluenose-West, Bluenose-East, Bathurst, Beverly, Qamanirjuaq, and Lorillard barren-ground subpopulations were robust; the Queen Maude Gulf and Wager Bay barren-ground subpopulations were distinct. Dolphin and Union island caribou formed one population; boreal caribou formed two distinct subpopulations. Females in robust subpopulations were structured by strong annual spatial affiliation; those in distinct subpopulations were spatially independent and structured by migratory connectivity, movement barriers, and/or habitat discontinuity. An east-west cline in annual-range sizes and path lengths supported the subpopulation structure identified for migratory barren-ground caribou. I analyzed satellite location data to determine parturition dates and activity periods for all caribou ecotypes. For parturition dates I found a north-south cline for boreal caribou, west-east cline for migratory barren-ground caribou, and ecotype and subspecies clines for boreal and barren-ground caribou. Based on annual changes in movement rates I identified eight activity periods for boreal and tundra-wintering, 10 for mountain woodland, and 12 for migratory barren-ground caribou. Based distribution and movements, boreal caribou avoided seismic lines during periods when females and calves were most vulnerable to predators or hunters. They crossed fewer seismic lines and travelled faster when they crossed them than expected. Caribou avoided areas ≤400 m from seismic lines where they could space away from them suggesting that they perceive these as risky areas. I defined secure habitats as areas that were >400 m from anthropogenic linear features. Population growth rates were higher in areas where they had access to secure unburned habitat and where most of that was in patches >500 km2. Critical habitat for boreal caribou is a habitat state that provides “security” from predation risk and facilitates the effectiveness of their anti-predator strategies. / Ecology

Objectives To prevent economic problems by high wild boar populations, an effective and biologically based wild boar management has to be established. A lot of wild boar research has been done in the last decades. However, game managers were not able to incorporate this knowledge into the development of effective management strategies. Thus, furthermore studies have to be accomplished to expand wild boar science and management. This thesis, based on a radiotelemetric study in southwestern Mecklenburg–Western Pomerania, presents research results on wild boar space use patterns, dispersal, grouping patterns and divisions. For all these measures I examined the influence of age classes and environmental factors affecting behavioural patterns (e.g. hunting, seasonal resources, seasonal requirements). Finally, I discussed efficiency and amount of hunting pressure of different hunting methods. Results The wild boar groups divided temporarily in 12.3 % of all observed localisations. We defined four types of divisions: short-term local, short-term extensive, long-term extensive and final division. The small home range sizes did not differ between age classes or group types with a slight tendency for larger home ranges of yearlings, especially in summer. The shift of summer home ranges was stronger in yearlings than in adults. Three space use patterns occurred in summer: field sows, commuters and forest sows. Only 15 % of all shot animals were shot outside their mothers’ home range, only one fourth of these “dispersed” animals were females. Males were shot at larger distances than females. Diurnal activity was positively influenced by daytime length, nutritional needs and fewer disturbances. Due to this reasons an impact of hunting was not clearly detectable. Hunting did influence activity and space use only in moderate intensities. Single hunt from hides is the dominating and an efficient hunting method. The sustainable harvest rate was not exhausted. Conclusions The small home ranges and low, male biased, dispersal rates denote strong site fidelity in all age and reproductive classes within female wild boar. The short distances and low dispersal rates, even within males, might be affected by all year round equably distributed high abundance of resources. Changed space use patterns in summer are mainly influenced by changed food availability. Although hunting was often presumed to be responsible for behavioural changes, little direct influences were observed in this study. The results reflect an interaction between habitat types, season, and nutritional needs on most behavioural patterns. Sound nutritional conditions and year-round low hunting pressure might be responsible for similar seasonal home ranges. Group fluctuations, occurrence of sub-groups as well as temporary and final divisions seem to be common behavioural patterns within wild boar groups, depending on age classes, reproduction, and seasonal nutritional supplies. Wild boar groups react flexible on several seasonal internal and extrinsic factors. The omnivore wild boar is enabled easily to adapt to various environments. Its wide eco-ethological plasticity enables the species to colonize new habitats and enlarge its distribution. All over Europe hunting rates seem to be lower than reproduction of wild boar. To reduce populations and thus, damages, supplemental feeding should be reduced and hunting rates have to be increased especially for females, as all age classes of females are highly reproductive. Hunting management is the most important tool for disease and damage control. As all hunting methods caused similar and negligible disturbances in this study, efficiency should get top priority. The combination of different hunting methods is necessary for reduction on comprehensive areas. / Ziele Um ökonomische Probleme durch Schwarzwild zu vermeiden, muss eine effektive und biologisch fundierte Schwarzwildbewirtschaftung etabliert werden. Die Schwarzwildforschung hat sich in den letzten Jahrzehnten stark entwickelt. Trotzdem konnten viele Erkenntnisse nicht in eine effektive Bewirtschaftung umgesetzt werden. Daher sind Untersuchungen zur Erweiterung des Wissens um das Schwarzwild weiterhin wichtig. Diese These, basierend auf einer radiotelemetrischen Studie im südwestlichen Mecklenburg-Vorpommern, präsentiert Ergebnisse zu Raumnutzung, Ausbreitung, Rottenverhalten und –teilungen. Für all diese Verhaltensmuster wurden Einflüsse der Altersklassen und anderer Faktoren wie Bejagung, saisonale Ressourcen und Bedürfnisse untersucht. Abschließend werden Effektivität und Störungseinfluss verschiedener Bejagungsmethoden diskutiert. Ergebnisse In 12,3 % der Lokalisationen waren die Rotten vorübergehend getrennt. Wir haben vier Trennungstypen definiert: kurzzeitig-lokal, kurzzeitig-extensiv, langzeitig-extensiv und final. Die kleinen Streifgebietsgrößen unterschieden sich kaum zwischen Altersklassen und Rottentypen. Überläuferbachen zeigten eine leichte Tendenz zu größeren Sommerstreifgebieten und verlagerten die Sommerstreifgebiete stärker als Familienrotten. Drei Raumnutzungsmuster waren im Sommer offensichtlich: Feldsauen, Pendler und Waldsauen. Lediglich 15 % aller erlegten Tiere wurden außerhalb ihres Mutterstreifgebietes geschossen, nur ein Viertel dieser „abgewanderten“ Tiere waren weiblich. Keiler wurden in größeren Distanzen als Bachen erlegt. Tagaktivität wurde positiv von der Tageslichtlänge, Nahrungsbedarf und geringer Störung beeinflusst. Aufgrund dieser Faktoren war ein Einfluss durch Bejagung nicht klar erkennbar. Bejagung beeinflusste Aktivität und Raumnutzung nur moderat. Die dominierende Jagdart „Einzeljagd auf dem Ansitz“ war durchaus effektiv, dennoch wurde die nachhaltige Zuwachsrate nicht abgeschöpft. Schlüsse Die kleinen Streifgebiete und niedrigen, keilerdominierten Abwanderungsraten deuten eine starke Standorttreue weiblichen Schwarzwildes in allen Altersklassen an. Die niedrige Abwanderung mit gleichzeitig geringen Distanzen, auch bei Keilern, dürfte durch ganzjährig gleichmäßig verteilte besonders günstige Ernährungsbedingungen beeinflusst sein. Unterschiedliche geänderte Raumnutzungsmuster werden vor allem durch unterschiedliche Nahrungsverfügbarkeiten beeinflusst. Obwohl oft Jagddruck als Hauptursache für Verhaltensänderungen angesehen wird, konnten in dieser Untersuchung nur ein geringer Einfluss der Jagd nachgewiesen werden. Die Ergebnisse reflektieren eine Interaktion zwischen Habitattypen, Jahreszeiten und Nahrungsbedarf auf die meisten Verhaltensmuster. Günstige Ernährungsbedingungen und ganzjährig gleichmäßig niedriger Jagddruck könnten für gleich bleibende saisonale Streifgebiete verantwortlich sein. Änderungen in der Rottenstruktur, Auftreten von Teilrotten sowie temporäre und finale Teilungen scheinen normale Verhaltensmuster beim Schwarzwild zu sein, abhängig von Altersklassen, Reproduktion und saisonalem Nahrungsangebot. Schwarzwildrotten reagieren flexibel auf diverse saisonale interne und externe Faktoren. Das omnivoren Schwarzwild ist befähigt, sich schnell an verschiedenste Umwelten anzupassen. Die große öko-ethologische Plastizität ermöglicht es dieser Art neue Lebensräume zu erschließen und sein Verbreitungsgebiet auszudehnen. In ganz Europa scheinen die Jagdstrecken unter der Zuwachsrate des Schwarzwildes zu liegen. Um die Populationen, und damit die Schäden zu reduzieren, müssen Fütterungen reduziert und die Bejagung intensiviert werden. Dieses gilt insbesondere für die Bejagung von weiblichem Schwarzwild, da alle Altersklassen hohe Reproduktionsraten aufweisen. Jagdliche Bewirtschaftung ist das wichtigste Werkzeug zur Bekämpfung von Krankheiten und Wildschäden. Da alle Jagdmethoden in der vorliegenden Studie ähnlich geringe Störungen hervorrufen, sollte die Effektivität in den Vordergrund treten. Die Kombination verschiedener Jagdmethoden und Zusammenarbeit der Jäger ist zwingend erforderlich zur Reduktion der Schwarzwildpopulationen.

A introdução de espécies exóticas é uma prática que acompanha a história da humanidade, sendo as espécies introduzidas a base da nutrição e economia em vários países. Porém, esse processo contínuo tem levado a uma homogeneização da flora e fauna global. Os ecossistemas aquáticos, que têm recebido menor atenção que os terrestres, têm sofrido perda de diversidade, hibridação, introdução de patógenos, degradação do habitat além da necessidade e alto custo de controle das espécies introduzidas. O desenvolvimento da aqüicultura tem acelerado a introdução de peixes exóticos, que são a base dessa produção em países como o Brasil. Além desta, entre as razões para a introdução citam-se o esporte, a manipulação ecológica com controle de organismos indesejáveis, o melhoramento dos estoques, a ornamentação ou ainda introduções acidentais. No Rio Grande do Sul, nos rios dos Campos de Cima da Serra estão ocorrendo introduções da espécie exótica truta arco- íris (Oncorhynchus mykiss) desde meados da década de 90 como forma de estímulo ao turismo rural. O objetivo dessa prática é a pesca esportiva, que atrai turistas de várias regiões. Porém, os rios da região possuem várias espécies de peixes endêmicas e as conseqüências dessa prática sobre a biota aquática são desconhecidas. O objetivo do presente trabalho é avaliar o efeito da introdução da truta arco-íris sobre o ecossistema de rios de baixa ordem no município de São José dos Ausentes – RS, Brasil. Para tanto foi descrita a biologia da truta arco- íris no novo ambiente, verificando sua alimentação, movimentação, presença e viabilidade da reprodução. A ictiofauna autóctone dos rios com ausência e presença de trutas foi comparada, bem como o efeito da predação sobre a macrofauna bentônica. A ictiofauna foi amostrada com o uso da pesca elétrica, sendo o conteúdo estomacal das trutas avaliado sazonalmente. Três trutas foram marcadas e acompanhadas por ii biotelemetria para determinação da sua área de vida. Um experimento com ninhos artificiais foi conduzido para verificação da sobrevivência de ovos de trutas nas condições dos rios de São José dos Ausentes. O experimento de exclusão de peixes foi feito a fim de avaliar o efeito da predação sobre a macrofauna bentônica, comparando a macrofauna em rios com e sem trutas. Os resultados indicaram que a truta arco- íris tem como alimento principal os invertebrados bentônicos, porém as maiores classes de tamanho incluem peixes em seus alimentos principais. Logo após sua introdução a movimentação é restrita, porém alguns exemplares foram capturados em um rio onde não foi feita introdução dessa espécie. Apesar de baixa, a sobrevivência dos adultos ocorre, assim como a reprodução. A sobrevivência dos ovos também é baixa, porém, uma pós-larva foi encontrada. A ictiofauna autóctone é diferenciada nos rios com presença de truta, apresentando menor riqueza e diversidade e uma tendência a diminuição da biomassa. A macrofauna bentônica também é diferenciada, apesar de não ser possível atribuir essa diferença somente à presença das trutas. / The introduction of exotic species is a practice that accompanies the humanity's history, being the introduced species the base of the nutrition and economy in several countries. Even so, that continuous process has been taking to a homogenization of the global flora and fauna. The aquatic ecosystems, that have been receiving smaller attention than the terrestrial ones, have been suffering diversity loss, hybridization, pathogens introduction, degradation of the habitat and costs of control of the introduced species. The development of aquaculture has been accelerating the introduction of exotic fish, that are the base of that production in countries as Brazil. Among the reasons for the introduction are the sporting fishing, the ecological manipulation with control of undesirable organisms, the improvement of the stocks, the ornamentation or still accidental introductions. In Rio Grande do Sul, in the rivers of Campos de Cima da Serra are occurring introductions of the species exotic rainbow trout (Oncorhynchus mykiss) from middles of the decade of 90 as incentive form to the rural tourism. The objective of that practice is the sporting fishing, which attracts tourists of several areas. Even so, the rivers of the area possess several endemic species of fish and the consequences of that practice on the aquatic biota have been ignored. The objective of the present work is to evaluate the effect of the introduction of the rainbow trout on rivers of low order in the municipal district of São José dos Ausentes - RS, Brazil. Thus the biology of the rainbow trout was described in the new environment, verifying its feeding, movement, presence and viability of reproduction. The autochthonous ictiofauna of the rivers with absence and presence of trouts was compared, as well as the effect of the predation on the benthic macrofauna. The ictiofauna was collected with the use of the electric fishing, being the stomacal content of the trouts evaluated seasonally. Three trouts were marked and accompanied by biotelemetry for determination of its life iv area. An experiment with artificial nests was driven for verification of the survival of eggs of trouts in the conditions of the rivers of São José dos Ausentes. The experiment of exclusion of fish was made in order to evaluate the effect of the predation on the benthic macrofauna, comparing the macrofauna in rivers with and without trouts. The results indicated that the rainbow trout has as main food benthic invertebrates, even so, in larger size classes it include fishes as main food. After its introduction the movement is restricted, even so trout s were found in a river where they were not introduced. Although low, have survival, as well as reproduction. The survival of the eggs is low, but it is happening in Silveira River, a post larvae being found. The autochthonous ictiofauna is differentiated in the rivers with trout presence, presenting smaller richness and diversity. The benthic macrofauna is also differentiated, in spite of not being possible to attribute that difference only to the presence of trouts.

Very little is known about the spatio-temporal ecology of the rusty-spotted genet, Genetta maculata. With this study I aimed to describe the activity patterns, resting site use and spatial ecology of G. maculata in Telperion Nature Reserve. I particularly looked at the activity profile and the activity period. I wanted to determine the spatial distribution of resting sites, the number of sites used per individual as well as the index of resting site reuse. I also calculated the distance between resting sites on consecutive days and tested for differences between sexes and seasons. I determined the size of home ranges, as well as that of core areas and compared space use between sexes and seasons as well as vegetation types. A total of six males and nine females were trapped, radio-collared and tracked during continuous night and daytime sessions between September 2015 and August 2016. Rusty-spotted genets were primarily nocturnal (nocturnality index: 0.84) and therefore made use of the darkness for cover when hunting. Overall, male effective activity duration (586 ± 172 min) was greater than for females (564 ± 175 min) possibly because they search for females to mate with as well as due to their larger body size. Seasonal changes in activity were evident – specifically in winter – and were probably a function of both food availability and temperature. Areas with a denser vegetation structure seemed to be more suitable for rusty-spotted genet resting sites. Neither the number of resting sites nor the reuse rate of these resting sites differed between sexes or seasons. The inter-resting site distance on consecutive days was higher for males (938 ± 848 m) than females (707 ± 661 m). This was possibly caused by males travelling larger distances when searching for females to mate with. The inter-resting site distance was higher during autumn, likely due to the decrease in food availability, which made it necessary for genets to increase their hunting efforts. However, a similar increase in hunting effort was not evident during winter as genets decreased their overall activity, possibly in order to avoid colder temperatures. No sexual or seasonal differences in home range size were found. This was attributed to a well-spread and consistent availability of food sources. Core areas only covered on average 7% of the total individual home range which further supports the hypothesis that food was readily available. Both intra- and intersexual home range overlaps were recorded. This was not unusual for carnivores and due to a combination of reproductive and social actions. Home ranges mainly included bushveld vegetation (78%) rather than grassland as these areas provided better cover and likely more abundant food sources. As this was the first exhaustive study of its kind on this species over a full annual cycle, the information gathered is important for the development of conservation strategies for this species, but also for other Genetta species in the rest of Africa. / College of Agriculture and Environmental Sciences / M. Sc. (Environmental Science)

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / A área de vida pode ser definida como o espaço físico necessário para um animal desempenhar as atividades essenciais para sua sobrevivência, desenvolvimento e reprodução. O conhecimento sobre área de vida é essencial para a compreensão dos processos que regem o uso do espaço e a organização social em populações animais. Neste estudo, investigamos aspectos das áreas de vida do lagarto saxícola, endêmico da Caatinga, Tropidurus semitaeniatus, avaliando possíveis variações intersexuais, ontogenéticas e sazonais nos tamanhos das áreas de vida, bem como elementos da organização social da espécie. A área de estudo consistiu em uma área típica de Caatinga stricto sensu, localizada no município de Pentecoste - Ceará. Realizamos coletas em dois afloramentos rochosos, nos quais demarcamos pontos de referência a cada cinco metros. Coletamos os lagartos residentes nestes afloramentos, registrando, para cada indivíduo, o sexo e o tamanho rostro-cloacal (mm), e posteriormente, identificando-o com marcação única. Vistoriamos cada afloramento durante 20 dias em cada estação (chuvosa e seca), respectivamente em junho e dezembro de 2011, realizando recapturas visuais e coletando registros de posições espaciais de cada indivíduo. Estimamos as áreas de vida pelo método do Polígono Convexo Mínimo, para os indivíduos recapturados pelo menos seis vezes. Obtivemos 56 áreas de vida, das quais 10 foram de machos, 20 de fêmeas e 26 de jovens. Não existiu relação entre os tamanhos das áreas de vida e os comprimentos rostro-cloacais dos indivíduos. Não houve diferenças sexuais, ontogenéticas ou sazonais nos tamanhos das áreas de vida. Contudo, o espaçamento entre as áreas de vida foi menor durante a estação chuvosa e a maioria das sobreposições entre áreas de vida também ocorreu neste período. Ao todo, registramos 81 sobreposições de áreas de vida, sendo estas mais frequentes entre fêmeas e jovens e menos frequentes entre pares de machos. A proporção da área de vida total sobreposta com outro indivíduo foi maior entre pares de fêmeas e menor entre pares de machos. Os machos estiveram associados em média com 1,5 fêmeas, possuindo de zero a sete áreas de vida de fêmeas sobrepostas com suas áreas de vida. O número de áreas de vida de fêmeas sobrepostas às áreas de vida de machos esteve positivamente associado ao tamanho dos machos. Por outro lado, não houve associação entre o número de áreas de vida de fêmeas sobrepostas às áreas de vida de machos e os tamanhos das áreas de vida dos machos correspondentes. Em suma, à luz do conhecimento acumulado sobre a história natural do organismo de estudo, acreditamos que sua extrema especificidade por ambientes rochosos e a disponibilidade limitada de habitats adequados à ocupação constituem fatores preponderantes na determinação dos padrões singulares de uso do espaço e organização social em T. semitaeniatus. / The home range may be defined as the physical space required for an animal to perform the essential activities for its survival, development and reproduction. The knowledge on home range is essential to understanding the processes that govern the use of space and the social organization in animal populations. Herein, we investigated home range aspects of the saxicolous lizard, endemic from Caatinga, Tropidurus semitaeniatus, evaluating possible intersexual, ontogenetic and seasonal variations in home range size, as well as elements of the social organization of the species. The study area was a typical Caatinga stricto sensu area, located in Pentecoste municipality - Ceará. We performed sampling at two rocky outcrops, where we defined reference marks each five meters. We collect the lizards living in these outcrops, recording for each individual, the sex and snout-vent length (mm), and subsequently, identifying it with unique marking code. We scanned each outcrop for 20 days in each season (rainy and dry), respectively on June and December 2011, performing visual recaptures and collecting records of spatial positions of each individual. We estimated the home range size by Minimum Polygon Convex method, for individuals recaptured at least six times. We obtained 56 home range areas, of which 10 males, 20 females and 26 juveniles. There was no relationship between home range size and snout-vent length of individuals. There were no sexual, ontogenetic or seasonal differences in home range size. However, the spacing between home range areas was lowest during the rainy season and the most of the home range overlaps also occurred in this period. Overall, we recorded 81 home range overlaps, which were more frequent between females and juveniles and less frequent among pairs of males. The proportion of the total home range overlapped with another individual was highest among pairs of females and lowest among pairs of males. Males were associated on average with 1.5 females, having from zero to seven females home range overlapped with their own home ranges. The number of female home ranges overlapped with male ones was positively associated with the body size of males. Moreover, there was no association between the number of female home ranges overlapped with male ones and the home range size of the corresponding males. In conclusion, in the light of accumulated knowledge about the natural history of the studied organism, we believe that their extreme specificity to the rocky environments and restricted availability of suitable habitats for its occupation are important factors in determining patterns of use of space and social organization in T. semitaeniatus