No description available.

From September 2005 to March 2006 a zoo study was performed with one male and two female rhinos at Orana Wildlife Park in Christchurch. The study had two aims: (1) to assess whether faeces from unfamiliar rhinos carry information that influences the behaviour of adult rhinos in a zoo habitat, and (2) to identify olfactory constituents of the faeces that potentially stimulate the change in behaviour. Faeces samples were collected from seven male, female, and juvenile rhinos residing at Hamilton and Auckland zoos and from one male rhino held in a separate enclosure at Orana Park. From each sample type six individual samples of 2 kg each were collected. The samples were put in plastic bags and kept frozen at -1O℃. As controls, samples from peat, peat with testosterone, and heated faeces were used. An individual thawed sample was presented at a time to the subjects by placing it into the enclosure. Behaviour and positions of the subjects was monitored for 3 h. In addition weather data was collected. Each exposure test of one sample type consisted of at least six observation sessions during which one two-kg dung specimen was presented to the subjects in the Orana Park enclosure. Each session consisted of nine trial periods of 15 min, during which each subject was observed individually and all actions ofthe animal were recorded. There was a strong response of the subjects to faeces from male donors. The bull reacted with increased frequency of spray urinating. The bull habituated to the faecal stimulus within about an hour. Other strongly affected behaviour categories of all subjects included smelling the ground, scanning, and walking. The distance between the subjects and frequency of synchronous behaviour of the subjects was affected by various samples to a lesser degree. Correlation of faecal compounds with territorial behaviour activities and chemical analysis identified possible signalling compounds such as esters of low molecular weight fatty acids (propanoic, butanoic, and pentanoic acids) and perhaps testosterone and terpenoids. Even simulated control samples consisting of peat impregnated with testosterone initiated some response. Overall, faecal scent marks were found to stimulate multifaceted behavioural effects of captive white rhinoceros. Chemical analyses of faeces identified new olfactory components not previously attributed to male faeces, and which could act as male signalling compounds.

No description available.

Suspension-feeding bivalves produce biodeposits (faeces and pseudofaeces) that have much higher sinking velocities than their constituent particles. Consequently they cause sedimentation of material that might otherwise not be deposited. The benthic remineralisation of biodeposits increases sediment oxygen demand and nutrient regeneration, thus enhancing the benthic-pelagic coupling of nearshore ecosystems. In New Zealand the mussel Perna canaliculus has a high natural abundance and is also intensively cultured. This thesis examines the dispersal and remineralisation characteristics of mussel P. canaliculus biodeposits and the impacts of sedimentation from a mussel farm in the Firth of Thames on sediment biogeochemistry by combining laboratory, field and modelling studies. Dispersal characteristics were examined in the laboratory by measuring sinking velocities and erosion thresholds of biodeposits produced by mussels of a wide size range fed three experimental diets. The results show that biodeposit dispersal is a function of mussel diet and size and thus could differ significantly between locations and seasons. Estimates of dispersal distances based on these results demonstrated that the initial dispersal of biodeposits produced by cultured mussels is not far. Depending on the hydrodynamic conditions, secondary dispersal via resuspension potentially plays a more important role in the dispersal of biodeposits from mussel farms than initial dispersal and almost certainly serves as the major means of transport of biodeposits from natural mussel beds. Biodeposit mineralisation was studied by incubating coastal sediments with added biodeposits and measuring oxygen and nutrient fluxes as well as sediment characteristics over an 11 d period. Sediment oxygen consumption and ammonium release increased immediately after biodeposit addition and remained elevated compared to control cores without additions for the incubation period. A biodeposit decay rate (0.16 d-1) was calculated by fitting a first-order G model to the observed increase in oxygen consumption. This rate is 1 - 2 orders of magnitude higher than published decay rates of coastal sediments without organic enrichment or plant material. Nutrient fluxes during the incubation period illustrated that biodeposit remineralisation alters the stoichiometry of the nutrients released from the sediments which may potentially be more significant than the changes of the individual fluxes. To determine the impact of a mussel farm in the Firth of Thames I measured sediment oxygen and nutrient fluxes by deploying benthic chambers, sediment characteristics by collecting sediment cores and sedimentation rates by deploying sediment traps in four seasons. Oxygen consumption and sediment nutrient release rates were generally higher under the farm compared to a reference site, demonstrating the typical response to increased organic input. Unusually low nitrogen release rates measured in summer may indicate enhanced denitrification under the farm. A simple budget demonstrated the importance of benthic nutrient regeneration in maintaining primary production in this region and that mussel culture can lead to a redistribution of nutrients. This study showed that site-specific hydrodynamic and biogeochemical conditions have to be taken into account when planning new mussel farms to prevent excessive modifications of nutrient dynamics. Results of the laboratory and field studies conducted in this thesis were used to parameterise, calibrate and validate models of mussel biodeposit dispersal and remineralisation. A particle tracking model showed that the maximum initial dispersal of faecal pellets from the mussel farm is approximately 300 m and that pellets can be transported several times this distance via resuspension. The remineralisation model was able to simulate the increased nitrogen fluxes from the sediments well and highlighted the need for thorough calibration and parameterisation of the model. This thesis contributed to the current understanding of the ecosystem impacts of mussel culture and provided numerical models and model parameters that will assist in the assessment of mussel culture sustainability and the contribution of mussels to the nutrient cycling in nearshore ecosystems.

The quantitative relationship between the urinary excretion of <I>TBA</I> and the uptake of <I>PPA </I>and <I>CHCA</I> was examined by continuous intraruminal infusion of <I>PPA</I> (8, 16 or 24 mmol/d) either alone or with <I>CHCA </I>(8 or 16 mmol/d) in sheep nourished by intragastric infusions of all nutrients. The daily excretion of <I>TBA</I> was linearly correlated (<I>r</I> 0.99, <I>P</I><0.001) with the amounts of <I>PPA</I> and <I>CHCA</I> infused. The urinary recovery of infused <I>PPA</I> and <I>CHCA</I> as <I>TBA</I> was 0.79 (<I>s.e.</I> 0.01). Recovery of infused <I>SA</I> (8 mmol/d) as urinary total salicylic acid (<I>TSA</I>) was 0.89 (<I>SD</I> 0.08). Both <I>TBA</I> and <I>TSA</I> excretions were found to be exclusively of exogenous origin, with negligible faecal excretion. It is concluded that urinary <I>TBA</I> is a potential estimator of <I>PPA + CHCA</I> absorption from the digestive tract. <I>SA</I> may have potential as a marker of urine volume. The relationship between urinary excretion of <I>TBA</I> and forage intake was assessed with steers fed different amounts of fresh herbage from pastures comprising oat, rye, vetch and lucerne. Herbage samples collected daily were incubated <I>in vitro</I> with buffered rumen fluid for 48 h. The <I>PPA</I> production per unit of herbage <I>DM</I> incubated was fitted to the exponential function of time <I>Y </I>= <I>a +</I> [<I>b</I>. (1 - <I>e</I>^-<I>c.l</I>)]. Regression analysis showed that the <I>TBA:</I>creatine concentration ratio was a good explanatory variable (<I>r</I>²0.92-095; <I>P</I><0.001) of herbage intake. <I>TBA</I>:creatinine concentration ratio divided by the product <I>b.c</I>, both constants from the fitted curves of <I>PPA</I> production of herbage cultures, was another good index (<I>r</I>² up to 0.98). It is concluded that a method for the prediction of herbage intake for grazing animals based on <I>TBA</I> excretion in urine seems promising.

From September 2005 to March 2006 a zoo study was performed with one male and two female rhinos at Orana Wildlife Park in Christchurch. The study had two aims: (1) to assess whether faeces from unfamiliar rhinos carry information that influences the behaviour of adult rhinos in a zoo habitat, and (2) to identify olfactory constituents of the faeces that potentially stimulate the change in behaviour. Faeces samples were collected from seven male, female, and juvenile rhinos residing at Hamilton and Auckland zoos and from one male rhino held in a separate enclosure at Orana Park. From each sample type six individual samples of 2 kg each were collected. The samples were put in plastic bags and kept frozen at -1O℃. As controls, samples from peat, peat with testosterone, and heated faeces were used. An individual thawed sample was presented at a time to the subjects by placing it into the enclosure. Behaviour and positions of the subjects was monitored for 3 h. In addition weather data was collected. Each exposure test of one sample type consisted of at least six observation sessions during which one two-kg dung specimen was presented to the subjects in the Orana Park enclosure. Each session consisted of nine trial periods of 15 min, during which each subject was observed individually and all actions ofthe animal were recorded. There was a strong response of the subjects to faeces from male donors. The bull reacted with increased frequency of spray urinating. The bull habituated to the faecal stimulus within about an hour. Other strongly affected behaviour categories of all subjects included smelling the ground, scanning, and walking. The distance between the subjects and frequency of synchronous behaviour of the subjects was affected by various samples to a lesser degree. Correlation of faecal compounds with territorial behaviour activities and chemical analysis identified possible signalling compounds such as esters of low molecular weight fatty acids (propanoic, butanoic, and pentanoic acids) and perhaps testosterone and terpenoids. Even simulated control samples consisting of peat impregnated with testosterone initiated some response. Overall, faecal scent marks were found to stimulate multifaceted behavioural effects of captive white rhinoceros. Chemical analyses of faeces identified new olfactory components not previously attributed to male faeces, and which could act as male signalling compounds.

Thesis (M. Sc.) Uppsala : Sveriges lantbruksuniv., 2007.

A capivara é uma espécie da fauna silvestre que se favoreceu da situação de conversão de áreas florestais para fins agropecuários, tornando-se bastante comum. Tal superpopulação causa conflitos, especialmente em virtude de prejuízos agrícolas e riscos de transmissão de doenças. Entretanto, a espécie apresenta grande potencial zootécnico e econômico, sendo que, aparentemente, o sistema produtivo mais sustentável seria o extensivo. Para fornecer subsídios técnicos a este sistema, torna-se necessário o monitoramento das populações. Um dos métodos mais utilizados para populações de capivaras é o de contagem direta dos animais, utilizada usualmente em ambientes mais abertos, porém pouco eficiente em locais de vegetação mais fechada e para populações mais arredias. O que se buscou testar neste trabalho foi um método de monitoramento alternativo à contagem direta. O trabalho foi realizado em sete áreas, sendo quatro com populações fechadas e três abertas. Semanalmente foram contadas as fezes depositadas durante esse período numa área amostral, contados diretamente os animais e levantados dados sobre flutuação real das populações fechadas. A obtenção de um índice de abundância através da contagem de fezes apresentou um coeficiente de regressão linear melhor que a contagem direta, em comparação com a flutuação real da população, obtida em ambientes fechados. Porém, nenhum dos métodos apresentou resultados satisfatórios que refletissem, no índice, as alterações ocorridas na população. A contagem de fezes mostrou-se satisfatória para separar em faixas de número de indivíduos as diferentes populações e também na aplicação da estimativa populacional baseada na técnica de Índice-manipulação-índice. O trabalho levanta inúmeras questões a respeito da intensidade amostral, de possíveis estudos quanto ao uso do habitat e do grau de confiabilidade dos monitoramentos baseados em contagens diretas. / The capybara is a wild species that would be favored by the conversion of the forest areas to farmlands, becoming abundant. Such overpopulation causes conflicts, especially due to agricultural damages and risks of transmission of illnesses. However, this species presents a great potential in both aspects: zootechnical and economical. As a result, apparently, the most sustainable productive system would be the extensive one. In order to supply technical subsidies to this system, surveying of populations become necessary. One of the survey methods most used in capybara populations is the direct counting that is usually adopted in ecosystems predominantly herbaceous. However, this methodology relies in some problems. It presents low efficiency in dense forested areas as well as in dealing with fearful capybara individuals. Thus, we proposed in this study a surveying method as an alternative to the direct counting one. The work was done on seven areas (four with closed populations and three open). Weekly, the individuals had been counted, as well as the feces deposited in the period on a sample area, besides getting the real data with respect to fluctuation of the closed populations. The attainment of an index of abundance through the feces counting presented a coefficient of linear regression better that the direct counting, in comparison with the real fluctuation of the population, gotten in closed environments. However, none of the methods presented satisfactory results that they reflected, in the index, the occurred alterations in the population. The feces counting revealed satisfactory to also separate in bands of number of individuals the different populations and in the application to estimate populations based in the technique of Index-manipulation-index. The work raises innumerable questions about the sampling intensity, possible studies about the home range use and the degree of trustworthiness of the surveys based on direct countings.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.

Licentiatavhandling (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2007. / Härtill 3 uppsatser.