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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.
21

How stimuli by toys affect pigs growth, health and welfare

Södergren, Carin January 2010 (has links)
Pigs do naturally have a high motivation to explore their environment. In a poor environment pigs still display this motivation and when there is no stimulation in the pen, pigs direct their behavior at pen-mates and pen components. Lack of stimulation can lead to decreased welfare and increased stress. This study investigates if extra stimuli by toys would affect pigs growth, health and welfare. Growing pigs (219) were followed during 7 weeks and divided into twenty two pens, eleven with toys and eleven without toys. I found partly support for the prediction that toys would help in a short time perspective but there was no support for the prediction that in a longer run the toys (used in this experiment) would increase pigs welfare. One explanation to this might be the straw that all the pens had (by law in Sweden), which seemed to be the most importuned component for satisfying pigs behavioral needs.
22

Conflict & communication : consequences of female nest confinement in yellow-billed hornbills

Finnie, Michael January 2018 (has links)
The most striking feature of hornbills (Bucerotiformes) is their unusual nesting behaviour. Before laying, a female hornbill enters the nest in a tree cavity. Uniquely among birds, she then seals the nest entrance using her faeces and locally available materials, leaving a narrow gap only 1 cm wide. Through this tiny slit, the female is totally dependent on her mate for between 40 days in the smallest hornbills and up to 130 days in the largest. Once walled in the nest, the female will lay her eggs and shed all of her wing and tail feathers. The male then becomes completely responsible for provisioning his mate and a few weeks later, the chicks. When her feathers have regrown, the female breaks out of the nest, often before the chicks are fully grown. The chicks then reseal the entrance until they too are ready to fledge. This thesis describes attempts to better understand the nesting behaviour of hornbills. The first chapter introduces hornbill ecology and behaviour and highlights their potential as model systems for studying conflict and communication. Chapter 2 describes the methods used to set up a study population of Southern Yellow-Billed Hornbill (Tockus leucomelas) consisting of 47 occupied nest boxes, over 35km2 in the Southern Kalahari Desert, South Africa. Chapter 3 summarises behaviour over three breeding seasons from October 2008 to April 2011. Female feather moult followed a precise staggered pattern, unlike other populations. Widespread filial cannibalism by females of both eggs and chicks was observed for the first time. The possible proximate causes of cannibalism are explored. Egg cannibalism allowed females to recoup some of their energetic investment, while cannibalism of chicks served as an efficient mechanism of brood reduction for nests with low paternal feeding rate. Chapter 4 investigates how females communicate need for nesting materials to males. Females altered the rate and structure of their begging calls when experimentally deprived of nest lining and males in turn delivered more nest materials. Chapter 5 examines the factors that determine how long females remain in the nest. Females with larger broods stayed in the nest longer, irrespective of their own or their chicks’ condition or male feeding rates. This raises questions about the role of mothers in the nest. Chapter 6 addresses this issue, demonstrating that females controlled sibling competition in the nest. Experimental temporary removal of mothers led to increased intrabrood aggression and more uneven food distribution in the brood, with larger chicks taking a greater share. The final chapter draws these findings together and the potential for future research is discussed.
23

The evolution of animal communication systems : questions of function examined through simulation

Noble, Jason January 1998 (has links)
Simulated evolution is used as a tool for investigating the selective pressures that have influenced the design of animal signalling systems. The biological literature on communication is first reviewed: central concepts such as the handicap principle and the view of signalling as manipulation are discussed. The equation of “biological function” with “adaptive value” is then defended, along with a workable definition of communication. Evolutionary simulation models are advocated as a way of testing the coherence of a given theory. Contra some ALife enthusiasts, simulations are not alternate worlds worthy of independent study; in fact they fit naturally into a Quinean picture of scientific knowledge as a web of modifiable propositions. Existing simulation work on the evolution of communication is reviewed: much of it consists of simple proofs of concept that fail to make connections with existing theory. A particular model (MacLennan & Burghardt, 1994) of the evolution of referential communication in a co-operative context is replicated and critiqued in detail. Evolutionary simulations are then presented that cover a range of ecological scenarios; the first is a general model of food- and alarm-calling. In such situations signallers and receivers can have common or conflicting interests; the model allows us to test the idea that a conflict of interests will lead to an arms race of ever more costly signals, whereas common interests will result in signals that are as cheap as possible. The second model is concerned with communication during aggressive interactions. Many animals use signals to settle contests, thus avoiding the costs associated with fighting. Conventional game-theoretic results suggest that the signalling of aggression or of strength will not be evolutionarily stable unless it is physically unfakeable, but some recent models imply that cost-free, arbitrary signals can be reliable indicators of both intent and ability. The simulation, which features continuous-time perception of the opponent’s strategy, is an attempt to settle the question. The third model deals with sexual signalling, i.e., elaborate displays that are designed to persuade members of the opposite sex to mate. The results clarify the question of whether such displays are the pointless result of runaway sexual selection, or whether they function as honest and costly indicators of genetic quality. The models predict the evolution of reliable communication in a surprisingly narrow range of circumstances; a serious gap remains between these predictions and the ethological data. Future directions for simulation work are discussed.
24

Behavioural adjustments of lion (Panthera leo) in response to risk of human-caused mortality

Cotterill, Alayne January 2013 (has links)
Fear of predation can have a major impact on the behaviour of prey species. Despite recent codifying of the concept of the ecology of fear, there has been relatively little focus on how these ideas apply to large carnivore species which, although not prey sensu stricto, may experience fear as a result of threats from humans. This thesis argues that large mammalian carnivores are subject to a Landscape of Fear similar to that described for prey species, and will respond behaviourally to fear of human-caused mortality. The idea of a "Landscape of Coexistence" is introduced to denote the perceived risk from humans and associated behavioural responses that can be overlain on spatio-temporally heterogeneous landscapes. Literature on the ecology of fear for large mammalian carnivores and, as there is a dearth of such literature, the current theory on the ecology of fear for other guilds is reviewed, and how this might inform large carnivore behaviour in a Landscape of Coexistence is explored. Behavioural effects of human-caused mortality risk are revealed for lions living in a human dominated landscape (Laikipia County, Kenya), specifically how lions adjust their movement patterns, habitat use and foraging tactics when in proximity to humans. It is argued that these behavioural adjustments represent a trade-off between maximising fitness enhancing activities and minimising the risk of human-caused mortality, thus need to be taken into consideration along with the lethal effects of humans when explaining the density, distribution and behaviour of lions throughout much of their remaining range. Although fear is generic, 'human-caused mortality risk' represents a distinct and very important sub-set of the ecology of fear for the carnivore guild. The existence of a Landscape of Coexistence has implications for understanding their foraging ecology, and ultimately their population dynamics and role in the ecosystem, and is therefore, important for the conservation of large carnivores throughout large parts of their remaining ranges.
25

Population and behavioral ecology of water monitor lizard (Varanus salvator)

Ahmad, A. Unknown Date (has links)
No description available.
26

Innovative environmental enrichment method for Pallas cat (<em>Felis manul)</em>

Rioldi, Emmanuela January 2010 (has links)
<p>Due to the expansion of the human population we are an increasing threat to all wild animals. They are driven to exist in smaller areas and in the worst case scenario extinction. Zoos are being encouraged to improve the animal’s physical and social surroundings. Environmental enrichment is a term used for such improvements. In this behavioural study, the enrichment introduced to two Pallas cats (<em>Felis manul</em>) at Parken Zoo in Eskilstuna, Sweden, consisted of a fishing rod and a clothes peg with a dead mouse or chick attached. The intention was to see if the feeding enrichment could increase activity levels and how the cats were using their enclosure. The enclosure was divided into seven zones which have a varying degree of opportunities for the animals to climb, hide and rest above ground level. The environmental enrichment effects on the Pallas cats´ behaviour, activity levels and use of the enclosure were measured and recorded using instantaneous scan sampling, and the mean value was calculated for each individual. The behavioural and enclosure results proved that enrichment benefits the cats activity levels. The behaviours that showed a variation when presented with enrichment were: walking, climbing, grooming, aggressive behaviour, out of sight behaviour, crouching position, sitting and standing still.  The results showed that the cats preferred the zones in the enclosure that offered a larger view of the nearby enclosures. This study shows that providing captive felids with inexpensive, easy to administer enrichment objects can have profound effects on activity behaviours and their enclosure.</p><p> </p>
27

Olfactory-Related Behaviors in Captive Chimpanzees (Pan troglodytes)

Elina, Lundholm January 2011 (has links)
Primates have traditionally been considered having a poor sense of smell compared to other orders of mammals, like carnivores, due to reduced olfactory structures of the primate brain. This thought, however, is slowly changing. There are now a range of studies showing that primates do use their sense of smell, for example in chemical communication. However, few studies have been carried out on olfactory-related behaviors in Great Apes. The aim of this study was to assess the occurrence of olfactory-related behaviors in captive chimpanzees (Pan troglodytes). The results do not only show that chimpanzees use their sense of smell, but also a behavioral difference between male and female chimpanzees. There was a significant difference between male to female smelling of the anogenitals and male to male smelling of the anogenitals (p = 0.0001) and also a difference between the occurrences of males and females touching an object with the hand and then smelling at the hand (p = 0. 0007). There was a significant difference between male and female frequency of smelling at an object (p = 0.001) and a significant difference between the occurrences of male and female smelling at foods and liquids (p = 0.003). There were no observations of chimpanzees performing a scent-marking behavior. These results suggest that chimpanzees use their sense of smell, from investigating new objects to the inspection of food and other chimpanzees. It would be interesting in future studies to study the difference between male and female frequency of olfactory-related behaviors.
28

Operant conditioning in a self controlling test with a reinforcement delay in Pygmy Hippos (Hexaprotodon liberiensis)

Nauman, Laila January 2010 (has links)
The curiosity whether or not animals have the characteristics of long term planning skills is fairly new. Some researchers agree that certain species have a form of episodic-like memory, in the terms of where, when and what. But the most difficult thing is to find out if these species have an aim for the future which involves what some call mental time travel. This study is a part of the discussion if the tests in long term planning and foresight can be explained by associative learning and the ability of self control in highly trained animals. Many self control and delay tasks have been conducted with laboratory animals such as rats, pigeons, monkeys and apes. Here we made a self control test with a reinforcement delay in pygmy hippos (Hexaprotodon liberiensis), an endangered species (listed as vulnerable at Cites, 2000), to extend the test among species. Also for trying to find out more about their cognitive skills, so we can better fulfil their needs in captivity. In this study, the female succeeded in 71,1 % (27 out of 38 trials) of the opportunities and the male in 84,2 % (32 out of 38 trials). To our knowledge this is the first study of learning and cognition in Pygmy hippos.
29

Innovative environmental enrichment method for Pallas cat (Felis manul)

Rioldi, Emmanuela January 2010 (has links)
Due to the expansion of the human population we are an increasing threat to all wild animals. They are driven to exist in smaller areas and in the worst case scenario extinction. Zoos are being encouraged to improve the animal’s physical and social surroundings. Environmental enrichment is a term used for such improvements. In this behavioural study, the enrichment introduced to two Pallas cats (Felis manul) at Parken Zoo in Eskilstuna, Sweden, consisted of a fishing rod and a clothes peg with a dead mouse or chick attached. The intention was to see if the feeding enrichment could increase activity levels and how the cats were using their enclosure. The enclosure was divided into seven zones which have a varying degree of opportunities for the animals to climb, hide and rest above ground level. The environmental enrichment effects on the Pallas cats´ behaviour, activity levels and use of the enclosure were measured and recorded using instantaneous scan sampling, and the mean value was calculated for each individual. The behavioural and enclosure results proved that enrichment benefits the cats activity levels. The behaviours that showed a variation when presented with enrichment were: walking, climbing, grooming, aggressive behaviour, out of sight behaviour, crouching position, sitting and standing still.  The results showed that the cats preferred the zones in the enclosure that offered a larger view of the nearby enclosures. This study shows that providing captive felids with inexpensive, easy to administer enrichment objects can have profound effects on activity behaviours and their enclosure.
30

Exposing the elusive: Franklin’s ground squirrel (Poliocitellus franklinii) demography, nest relocation, and dam response to ectoparasitism

Pero, Ellen 26 August 2015 (has links)
Franklin’s ground squirrels (Poliocitellus franklinii; FGS) are increasingly considered of conservation concern throughout much of their range, yet little is known about this species as compared to their congeners. The main objectives of this thesis were to (1) collate and summarize demographic and life-history data to present an up-to-date account of population characteristics for a FGS population near Delta Marsh, Manitoba, (2) document nest movements wherein female FGS relocate their nests and litter during the energetically demanding lactation period and to investigate proximate factors mediating movements, including intraspecific interaction, ectoparasite burden, and nest habitat associations, and, (3) investigate the influence of ectoparasite infestation on dam and litter attributes. Dams consistently relocated litters during lactation in response to conspecific nest discovery, ectoparasite pressure and habitat type. Relocations may compensate for major costs of ectoparasitism, as beyond the frequency of relocation, only litter sex ratio was influenced by ectoparasite burden in this study. / October 2015

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