The Australian fur seal (Arctocephalus pusillus doriferus) population has displayed a relatively slow rate of recovery since being hunted by commercial sealers during the early 19th century. Despite this, population abundance doubled in the past 2 – 3 decades, indicating that the population growth rate has recently increased. Yet, the factors influencing the population’s dynamics are poorly understood, primarily because basic demographic rates are unknown. / Female age, survival, fecundity, breeding and physiology were studied at Kanowna Island, Bass Strait, Australia, between 2003 – 2006 by conducting censuses and captures (n = 294). Mark-recapture estimates of pup production were used to validate direct pup counts, allowing a 9-year dataset to be used for calculation of the population growth rate (2.2% p.a.) and investigation of environmental influences on reproductive success. Annual pup production (x = 3108) was synchronous, with 90% of births occurring within 28 days of the median birth date of 23 November. Births occurred earlier in years when pup production and female body condition were high and these factors were correlated with local oceanographic indicators, suggesting that reproductive success is constrained by environmentally-mediated nutritional stress. / Pregnancy was assessed by blood plasma progesterone radioimmunoassay and the pupping status of the same females was observed during breeding season. Despite high mid-gestation pregnancy rates (x = 84%), the birth rate was lower than in other fur seals (x = 53%), suggesting that late-term abortion is common. Lactating females were less likely to pup, indicating that nutrition may be insufficient to support concurrent lactation and gestation. / Age and morphometric data were used to construct body growth, age structure and survivorship models. Adult female survival rates were similar to those of other fur seals (x = 88.5%). A life table was constructed and its age-specific survival and fecundity rates used in a Leslie-matrix model to project the population growth rate (2.2% p.a.) and determine the relative influence of each parameter. The abundance of female non-pups was 6 times greater than that of female pups, which is approximately 50% higher than previous conversion factors used to extrapolate population abundance from pup censuses in Australian fur seals. However, if the non-pup sex ratios of other otariids are considered, the pup:population conversion factor is 4.5. / Compared to a study performed before the recent population increase, the modern population displays similar body growth and fecundity rates but higher survival rates. This suggests that recent population growth resulted from a relaxation of hunting and/or predation mortality rather than from increased food availability. The low population growth rate is attributed to a low birth rate associated with nutritional stress, yet despite this, body growth occurs rapidly. Such characteristics are typical of sea lions rather than fur seals, perhaps because Australian fur seals employ the typical sea lion strategy of using benthic foraging to exploit a continental shelf habitat. The effect of ecological niche on population dynamics in the Otariidae is discussed.

Dyer Island is thought to host one of the most abundant populations of white sharks on the planet; this is often credited to the large (55 – 60,000) Cape fur seal colony at Geyser Rock. Yet relatively little work has ever been produced from the area. This may be attributed to the harshness in its location as a study site, exposed to wind and swell from west to east which limits research periods. This study accounts for over 220 hrs of manual tracking at Dyer Island with a further 68 added from the inshore shallow areas of the bay. Sharks focused their movements and habitat use to reefs or channels that allowed access to Cape fur seals. Movement- Based Kernel Estimates (MKDE) were used to compute home range estimates for shark movements through and around the heterogeneous structures of Dyer Island and Geyser Rock. Inshore two core areas were revealed, one being the major reef system at Joubertsdam and the other at a kelp reef where the tracked shark had fed on a Cape fur seal. At Dyer Island one core area was identified in a narrow channel, ‘Shark Alley’, here a second tracked shark foraged for entire days within meters of rafting Cape fur seals. Rate of Movement (ROM) and Linearity (LI) of tracks were low during daytime and movements were focused around areas such as Shark Alley or other areas close to the seal colony before moving into deeper water or distant reefs with higher rates of ROM and LI at night. If moonlight was strong foraging would take place to the south of Geyser Rock but with higher ROM and LI than observed during the day. Foraging patterns in this study contrast studies from other sites in South Africa and home range and activity areas were comparatively much smaller than observed in Mossel Bay. It has been established that several known white sharks forage at Dyer Island and the other studied aggregation sites, such differences in foraging would suggest that they are able to adapt their foraging behaviour to suit the environment they are in; making them site specific in their foraging ecology. Both satellite and acoustic telemetry are revealing aggregation hotspots of white sharks in South Africa. It is important that such information is used to assist the recovery of the species which has been protected since 1991, yet is rarely considered in planning of coastal developments. / Dissertation (MSc)--University of Pretoria, 2012. / Zoology and Entomology / MSc / Unrestricted

Syftet med detta examensarbete är att finna exoenzymer från Rhizopus sp, Mucor indicus och Rhizomucor pusillus som kan användas vid förbehandling av organiskt avfall. Syftet är även att finna kolkällor/energikällor som tidigare inte använts inom forskningen i ämnet resursåtervinning vid Högskolan i Borås.För att kunna undersöka vilka kolkällor mikroorganismerna bryter ner odlas dessa upp på agarplattor innehållande minimal-medium samt en specifik kolkälla. Efter fyra dagars inkubering i 30oC studerar man agarplattorna för att se om mikroorganismerna vuxit eller inte. Kan man urskilja tillväxt har de lyckats bryta ner kolkällan samt producera motsvarande exoenzym. Då vissa resultat är oklara odlas mikroorganismerna även i skakflaskor, detta för att se om det är själva agarn i agarplattorna som påverkar mikroorganismernas tillväxt.Resultatet visar att vissa mikroorganismer växer bättre än andra. Detta kan bero på kolkällornas struktur, det vill säga om de är komplicerade eller ej. Studerar man mikroorganismerna var för sig skiljer de sig lite åt. Rhizopus sp växer bäst på galaktan vilket indikerar att den lyckas producera exoenzymet galaktas. Mikroorganismen saknar produktion av exoenzym när den odlas på kolkällorna cellulosa och kitin.Studerar man mikroorganismen Mucor indicus har den bäst tillväxt på galaktan och potatismjöl, vilket indikerar att den producerar exoenzymerna galaktas samt α-amylas. Den kolkällan som ger sämst tillväxt är cellulosa.Rhizomucor pusillus har bäst tillväxt på galaktan samt triglycerider och producerar då exoenzymerna galaktas och lipas. Den lyckas inte bryta ner cellulosa eller kitin och saknar då produktion av exoenzymen cellulas samt kitinas.Både xylan och galaktan testas var för sig för att kunna dra slutsatser om någon produktion av exoenzymet hemicellulas finns. Detta görs eftersom det inte finns tillgång till något rent ämne med hemicellulosa. Xylan testas även endast för exoenzymet xylanas.En av de kolkällorna som gett minst tillväxt för alla de testade mikroorganismerna var cellulosa. För att styrka detta resultat odlas mikroorganismerna upp i skakflaskor, där ingen tillväxt skedde. Den lilla tillväxt som erhölls på agarplattorna tyder på att mikroorganismerna växer med den tillsatta agarn som kolkälla och inte utnyttjar själva kolkällan. Varför mikroorganismerna inte kan tillgodo se sig cellulosa kan bero på att cellulosa har en komplex struktur som gör den svår att bryta ner utan förbehandling.

<p>Odor discrimination ability was tested in four female South African fur seals (<em>Arctocephalus pusillus pusillus</em>) using a food-rewarded two-choice instrumental conditioning paradigm. The seals’ ability to distinguish between members of homologous series of aliphatic ketones (2-butanone to 2-heptanone) and alcohols (1-butanol to 1-heptanol) was assessed. The results showed that three out of four seals successfully discriminated between all of their stimulus combinations in both classes of odorants. One seal succeeded to reach the discrimination criterion with all 2-ketones but failed with all 1-alcohols.</p><p>No significant correlation between odor discrimination performance and structural similarity of the odorants in terms of differences in carbon chain length was found in either of the two chemical classes. Furthermore, it was found that the 2-ketones were significantly better discriminated than the 1-alcohols. The fact that both classes of odorants are known to be present in the natural environment of seals provides a possible explanation as to why most of the seals were able to successfully discriminate between them. The results of the present study support the notion that the sense of smell may play an important role in behavioral contexts such as social communication, foraging and reproductive behavior of fur seals.</p>

Odor discrimination ability was tested in four female South African fur seals (Arctocephalus pusillus pusillus) using a food-rewarded two-choice instrumental conditioning paradigm. The seals’ ability to distinguish between members of homologous series of aliphatic ketones (2-butanone to 2-heptanone) and alcohols (1-butanol to 1-heptanol) was assessed. The results showed that three out of four seals successfully discriminated between all of their stimulus combinations in both classes of odorants. One seal succeeded to reach the discrimination criterion with all 2-ketones but failed with all 1-alcohols. No significant correlation between odor discrimination performance and structural similarity of the odorants in terms of differences in carbon chain length was found in either of the two chemical classes. Furthermore, it was found that the 2-ketones were significantly better discriminated than the 1-alcohols. The fact that both classes of odorants are known to be present in the natural environment of seals provides a possible explanation as to why most of the seals were able to successfully discriminate between them. The results of the present study support the notion that the sense of smell may play an important role in behavioral contexts such as social communication, foraging and reproductive behavior of fur seals.

The sense of smell in marine mammals is traditionally thought to be poor. However, increasing evidence suggests that pinnipeds may use their sense of smell in a variety of behavioral contexts including communication, foraging, food selection, and reproduction. Using a food-rewarded two-choice instrumental conditioning paradigm, I assessed the ability of South African fur seals, Arctocephalus pusillus, to discriminate between 12 enantiomeric odor pairs, that is, between odorants that are identical in structure except for chirality. The fur seals significantly discriminated between eight out of the twelve odor pairs (according to p &lt; 0.05, with carvone, dihydrocarvone, dihydrocarveol, limonene oxide, menthol, beta-citronellol, fenchone, and alpha-pinene), and failed with only four odor pairs (isopulegol, rose oxide, limonene, and camphor). No significant differences in performance were found between the animals (p &gt; 0.05). Cross-species comparisons between the olfactory performance of the fur seals and that of other species previously tested on the same set of odor pairs lend further support to the notion that the relative size of the olfactory bulbs is not a reliable predictor of olfactory discrimination abilities. The results of the present study suggest that sense of smell may play an important and hitherto underestimated role in regulating the behavior of fur seals.

Tree squirrels play an important role in the maintenance of forest ecosystems by functioning as seed and fungal spore dispersers, forest regenerators, and prey for forest predators. The highest species richness for tree squirrels occurs in tropical forests and these species are also the least studied. We conducted distance sampling to estimate population density, measured habitat variables to investigate forest characteristics that influence habitat selection and feeding site selection at three different scales, and conducted observations to obtain knowledge about activity pattern and behavior of Neotropical pygmy squirrels and Amazon red squirrels in the Peruvian Amazon. Density of Neotropical pygmy squirrels was 0.10 and 0.14 individuals/ha for 2009 and 2010. Activity peaked in early morning, squirrels were found mainly in the canopy but never on the ground, and frequency of behaviors differed by time and story level. Neotropical pygmy squirrels used mainly high and low restinga and areas that had more large trees. Squirrels also used species of trees disproportionately to availability. Neotropical pygmy squirrels seem to be associated with features related to mature forests. Amazon red squirrels use mainly high and low restinga and selected Astrocaryum and Attalea palm trees that were taller and larger as foraging sites compared to random locations. Amazon red squirrels used all vertical strata of the forest and the main behaviors observed were travel and forage. Behaviors were similar among time periods but differed in frequency by vertical strata. Although Amazon red squirrels used vegetation communities differently than their availability and selected for tree characteristics, they did not select for site characteristics and this is different from other tree squirrel species. We also conducted surveys during a wet and a dry year to investigate and estimate diversity of diurnal mammals. We assessed the vertical strata of the forest to determine if diversity index varied by story level, and estimated alpha, beta, and gamma diversity. Overall mammal diversity did not differ between wet and dry years. Diversity index differed by story level between years, but was the highest in the canopy for both years. Alpha diversity was higher in the dry year, and gamma and beta diversity were higher in the wet year. Frequency of sightings of species was influenced by time of day and varied by story level. Protection of continuous, mature forests with large canopies has important conservation implications as these areas most likely protect the greatest diversity of mammals while also providing shelter and food for other taxa.

Algunas plagas causan daños importantes en productos y granos almacenados, lo cual conlleva consecuentemente a pérdidas de producción y calidad en estos productos.Las principales plagas del arroz almacenado en España son, Sitophilus oryzae L. (Coleoptera Curculionidae), Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae), y Cryptolestes pusillus Schönherr (Coleoptera: Cucujidae). Las dos primeras son plagas primarias que atacan directamente el grano y resultan bastante destructivas debido a que sus larvas se alimentan y desarrollan dentro de él. C.pusillus es, sin embargo, una plaga secundaria que se beneficia de granos que ya están dañados y rotos.Actualmente, el uso de fumigantes e insecticidas de síntesis sigue siendo el principal método de lucha para controlar las plagas de almacén, si bien recientemente (dadas las continuas restricciones al uso de agroquímicos) existe un gran interés en la utilización de otras alternativas tales como el control biológico, el almacenamiento a bajas temperaturas, o los tratamientos con calor entre otros.Igualmente muchos productos obtenidos principalmente de plantas y que derivan del metabolismo secundario de las mismas ofrecen una fuente de bioinsecticidas que podrían representar una alternativa ecológica frente a los insecticidas de síntesis ya que su uso masivo e indiscriminado ha ocasionado problemas tales como la aparición de resistencias en determinadas especies de insectos frente a diferentes materias activas, desequilibrios ecológicos y problemas medioambientales sin olvidar el riesgo que entrañan para la salud humana.Con este trabajo se ha pretendido estudiar la actividad plaguicida de los aceites esenciales extraídos de tres plantas: Coriandrum sativum L. (Umbelliferae), Carum carvii L. (Umbelliferae) y Ocimum basilicum L. (Labiatae) y su posterior fraccionamiento para identificar dentro de estos aceites los compuestos químicos responsables de esta actividad insecticida sobre tres plagas de almacén de arroz (S. oryzae, R.dominica y C.pusillus).Del estudio de estos monoterpenoides, linalol, S-carvona y estragol resultaron tener una alta actividad insecticida sobre estas plagas. Sin embargo el E-anetol fue más selectivo para R.dominica y C.pusillus, así como el limoneno, &#947;-terpineno, geraniol y eucaliptol sólo resultaron activos frente a C.pusillus.Algunos monoterpenoides podrían actuar de sinergistas potenciando la actividad de otros, como podría ser el caso del alcanfor, acetato de geranilo y E-anetol con linalol en R.dominica y C.pusillus, o el caso del metoxicinamaldehido, p-anisaldehido y linalol que pueden tener efecto sinergista sobre el estragol.Este trabajo también abarcó el estudio de un posible modo de acción de estos monoterpenoides, la inhibición de la acetilcolinesterasa, para alcanzar un mayor entendimiento del comportamiento de estas sustancias en el interior del insecto.Así se pudo observar como la mayoría de monoterpenoides estudiados inhibían en cierta medida esta enzima, siendo fenchona, S-carvona y linalol los monoterpenoides que mayor inhibición originaron.Del mismo modo se observó como fenchona, &#947;-terpineno, geraniol y linalol inhibían competitivamente la acetilcolinesterasa, mientras que S-carvona, estragol y alcanfor producían una inhibición mixta para esta enzima.Sin embargo no se observó inhibición de la acetilcolinesterasa por parte del E-anetol a las concentraciones de monoterpenoides ensayadas.Para completar este trabajo se examinó de igual forma la capacidad que tenían estos bioinsecticidas de generar resistencia en estas tres plagas así como el mecanismo de resistencia implicado en el desarrollo de este proceso. Para ello se fueron seleccionando las poblaciones de insectos mediante la aplicación de los diferentes monoterpenoides a dosis crecientes durante 7 generaciones. De este modo se pudo calcular el factor de resistencia en cada una de las plagas y para cada uno de los monoterpenoides comparando las concentraciones letales 50 de las poblaciones seleccionadas con las poblaciones iniciales (sensibles).A continuación se analizaron tres posibles sistemas de detoxificación enzimáticos gracias al uso de sinergistas para estudiar el mecanismo de resistencia que podría estar involucrado.De tal forma se observó como estos monoterpenoides inducían lentamente resistencias resultando ventajosos en un futuro para el control de estas plagas.Esta Tesis ha englobado un estudio íntegro y profundo de estos insecticidas ecológicos desde la extracción de los aceites esenciales, seguido de la identificación de compuestos puros (CG-EM) con actividad insecticida junto con el estudio de un modo de acción de estos insecticidas, la selección de resistencia en las poblaciones de insectos y los posibles mecanismos de resistencia que pudieran estar implicados en este proceso. / Some pests cause serious damage to stored grains and stored products and consequently production and quality losses in these products.The rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), the lesser grain borer, Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae) and Cryptolestes pusillus Schönherr (Coleoptera: Cucujidae) were the main damaging pests found in stored rice in Spain.S.oryzae and R.dominica are primary pests attacking directly the intact grain and are quite destructive because their larvi feed and develop inside the grain whereas C.pusillus is a secondary pest which benefits from grains previously damaged.At the present time, organic synthetic pesticides are still the main method to control stored grain pests, however, recently (due to restriction in agrochemicals use) there is a great interest in using other altenatives such as biological control, storage at low-temperatures, or heat treatment.Likewise, many products obtained mainly from plants and derived from secondary metabolism have insecticidal activity against insects, such as monoterpenoids, which present a broad variety of bioinsecticide products which could turn out to be an ecologic alternative to synthetic pesticides since the majority of alternative products are not harmful for the human healthy and they become less environmentally damaging, exhibiting a low impact on the environment.In addition, it cannot be ignored the different difficulties related to resistance due to several active compounds from organic pesticides found in some species of insects.With this work, we have considered remarkable to study the insecticide activity of essential oils extracted from three plants: Coriandrum sativum L. (Umbelliferae), Carum carvii L. (Umbelliferae) and Ocimum basilicum L. (Labiatae) and carry out a bioassay-guided fractionation of their essential oils to identify which compounds were responsible for the volatile toxicity shown on three stored rice pests (S. oryzae, R. dominica and C. pusillus).Linalool, S-carvone and estragole turned out to have a high insecticide activity on these pests. Nevertheless E-anetol was more selective to R. dominica and C. pusillus, being only active on C. pusillus limonene, &#947;-terpinene, geraniol and eucalyptol.Some monoterpenoids were found as synergists, increasing the activity of the other ones, like for instance, camphor, geranyl acetate and E-anethole with linalool in R.dominica and C.pusillus or metoxycinnamaldehyde, p-anysaldehyde and linalool which could activate to estragole.In this work, the inhibition of acetylcholinesterase as a posible mode of action was studied as well, to reach a clear understanding about the action of these products inside the insects.The majority of monoterpenoids inhibited the enzyme acetylcholinesterase being fenchone, S-carvone and linalool the monoterpenoids that produced a higher inhibition.Furthermore, it was observed how fenchone, &#947;-terpinene, geraniol and linalool showed a competitive inhibition whereas S-carvone, estragole and camphor produced a mixed inhibition for this enzyme. However the enzyme acetylcholinesterase was not inhibited by E-anethole.To finish up this work, the selection for monoterpenoid resistance on these pests as well as the metabolic mechanisms implicated was studied.The resistant strains were selected from susceptible insect populations and survivors were reared separately for each monoterpenoid and successive generations were treated with higher concentrations. These populations were selected until seven times.As a result we could calculate the resistance factor on each pest (comparing lethal concentration 50 values of susceptible and resistant strains).Next, three enzymatic systems detoxifying these monoterpenoids were analysed to study the metabolic mechanism implicated.In this way we could realize that all monoterpenoids induced resistance slowly, concluding that these pesticides will be appropriated to control these pests in the future.This Thesis has concerned a study in depth about ecological insecticides from extraction of essential oils, identification of compounds (GC-MS) with insecticide activity, mode of action and study of resistance and mechanism of insecticide resistance involved in this process.

[For the Abstract, please see the PDF files below, namely "front.pdf"] CONTENTS. Chapter 1 Introduction. Chapter 2 Gross and microscopic visceral anatomy of the male Cape fur seal with reference to organ size and growth. Chapter 3 Age determination and growth in the male Cape fur seal: part one, external body. Chapter 4 Age determination and growth in the male Cape fur seal: part two, skull. Chapter 5 Age determination and growth in the male Cape fur seal: part three, baculum. Chapter 6 Suture age as an indicator of physiological age in the male Cape fur seal. Chapter 7 Sexual dimorphism in the adult Cape fur seal: standard body length and skull morphology. Chapter 8 Reproduction in the male Cape fur seal: age at puberty and annual cycle of the testis. Chapter 9 Diet and foraging behaviour of the Cape fur seal. Chapter 10(a) The Impact of the fur seal industry on the distribution and abundance of Cape fur seals. Chapter 10(b) South African Airforce wildlife rescue: Cape fur seal pups washed from Black Rocks, Algoa Bay, during heavy seas, December 1976. Chapter 11(a) Operational interactions between Cape fur seals and fisheries: part one, trawl fishing. Chapter 11(b) Operational interactions between Cape fur seals and fisheries: part two, squid jigging and line fishing. Chapter 11(c) Operational interactions between Cape fur seals and fisheries: part three, entanglement in man-made debris. Chapter 12 Concentrations of heavy metals (Cd, Cu, Pb, Ni & Zn) and organochlorine contaminants (PCBs, DDT, DDE & DDD) in the blubber of Cape fur seals. Chapter 13 Endoparasites of the Cape fur seal. Chapter 14(a) Preliminary investigations of shark predation on Cape fur seals. Chapter 14(b) Aggressive behaviour of an adult male Cape fur seal towards a great white shark Carcharodon carcharias. Chapter 15 Conclusions and future directions.