Many animals socially learn, but very few do so through teaching, where an individual modifies its behaviour in order to facilitate learning for another individual. Teaching behaviour is costly, but can confer numerous advantages, such as high fidelity transmission of information or an increase in the rate of social learning. In many putative cases of teaching, it is not known whether the pupil learns from the modified behaviour. This thesis addresses this issue in three cases of potential teaching behaviour. In particular, it investigates whether the role of food transfers in wild golden lion tamarins is to teach which foods are good to eat (Chapter 5). There was little evidence that novel foods were transferred more than familiar foods, and this was not due to the juveniles attempting to obtain novel foods more than familiar ones, or by adults discarding novel foods more than familiar ones. Transfers were however more successful when donors had previously ingested the food type transferred. Successful food transfers also had a positive correlation with foraging choices once juveniles were older, suggesting they learned from food transfers. In golden lion tamarins, this thesis also examined whether juveniles learned from food-offering calls which substrates were good to forage on (Chapter 6). Juveniles that experienced playback of food-offering calls ate more on a novel substrate, than juveniles that did not experience those playbacks, both immediately as the calls were being played, and in the long term, six months after the playbacks. This suggests that juveniles learned from the playbacks. Finally, this thesis attempted to replicate previous findings showing that hens modify their behaviour when chicks feed from seemingly unpalatable food, and explored whether chicks learned what food to eat based on the maternal display (Chapter 7). The experiment failed to find evidence for teaching behaviour, but results were not inconsistent with previous findings. Moreover, there was little evidence that chicks learned from their mother, quite to the contrary, hens seemed to acquire their foraging decisions based on their chicks' choices.

Anecdotal reports, flipper tag returns, satellite migration paths, and above-water and net surveys have identified an important foraging area for sea turtles in the Robinson Point area, 12 kilometers southwest of Belize City. Visual observations confirmed that sea turtles were actively foraging at Robinson Point. Sixteen 30 minute visual observations from stationary and drifting boats made 132 sea turtle sightings from October 2007 through January 2008, with a maximum of 40 sightings made in one survey. In-water capture methodology tested the traditional turtle net, which captured 14 turtles in 63 sets for a success rate of only 22%. There were 11 green turtles captured during the migratory months from April through October, and three hawksbill turtles were captured during non-migratory months, November through March, indicating that both species were resident at Robinson Point. No loggerheads, adult males, or juvenile turtles were captured, but anecdotal reports confirmed presence. Size range for captured hawksbills was between 63.7 - 80.4 cm SCLnn and between 70.9 - 91.5 cm SCLnn for green turtles. There were two recaptured turtles. One was a nesting hawksbill tagged in Mexico in 2008 and recaptured at Robinson Point in 2009, and the other was a sub adult hawksbill that was captured at Robinson Point in 2008 and recaptured in 2013 in Nicaragua. There was a small growth of fibropapilloma on one green turtle. Habitat surveys suggest benthic communities are more diverse than previously described consisting of prey items sought by sea turtles. Geomorphology of the Robinson Point area is equally diverse and provides shelter for resident turtles. Proposed boundaries for a turtle conservation zone at Robinson Point and an internesting zone to protect turtles at Belize premier hawksbill nesting beach at Gales Point, are linked to existing protected areas, and would facilitate protection of sea turtles not only in Belize, but also throughout the Caribbean.

South African southern right whales (SRWs; Eubalaena australis) have been studied intensively since 1969, and annual aerial surveys between 1971 and 2006 indicate a predominant 6.9% annual population growth rate – a conservation success story after the species’ legal protection from commercial whaling in 1935. However, the prevalence of South African SRW unaccompanied adults (non-calving adults) and cow-calf pairs dropped sharply after 2009 and 2015, respectively. Additionally, the calving interval of many female South African SRWs has shifted from a three-year cycle to a four- or five-year cycle, since 2010, suggesting calving failure. This has resulted in a decrease in the population growth rate from 6.9% between 1971 and 2006, to 6.5% in 2017. SRWs are capital breeders that meet migratory and reproductive costs through seasonal energy intake, leading to strong links between their calving and foraging success. The anomalous trends in the South African SRW population have therefore raised concern about the ecological status of its broad feeding range in the Southern Ocean and ultimately about its continued population recovery. This necessitated investigation firstly into the influence of large-scale global climate drivers, Antarctic winter sea-ice extent and summer ocean productivity on the calving output of the South African SRW population. Auto-regressive integrated moving average models revealed significant model performance improvement through the inclusion of the Oceanic Niño Index (a key measure of El Niño events), the Antarctic Oscillation (the leading mode of atmospheric variability in the Southern Ocean) and chlorophyll a concentrations. The findings indicate that the South African SRW calving output appears closely influenced by not only the species’ life cycle, but also by foraging ground productivity and global climate. Secondly, the foraging strategies of South African SRWs during the 1990s (i.e. a period of high calving rates) and the late 2010s (i.e. a period of low calving rates), were assessed, through the analyses of stable carbon (δ13C) and nitrogen (δ15N) isotope values in SRW skin biopsy samples (n = 122). Results show that South African SRWs underwent a dramatic northward shift in foraging location, as well as a diversification in foraging strategy, between the 1990s and 2010s. Bayesian mixing models suggest that during the 1990s, the population foraged on prey with isotopic values similar to krill from around South Georgia. By contrast, in the 2010s, it is inferred that the population foraged on prey with isotopic values consistent with prey found in the waters of the Subtropical Convergence, Polar Front, and Marion Island. This shift could represent a new strategy to cope with changes in the availability of preferred prey or changes in habitat productivity. However, the co-occurring reproductive declines show that altering foraging strategies may not be sufficient to successfully adapt to a changing ocean. Overall, the results of this dissertation advocate that South African SRWs have recently been affected by environmental change at their foraging grounds, in turn affecting their reproductive success. Their predictive coastal presence and the existing long-term monitoring suggest that the species should be regarded as an indicator species – illustrative of climate change impacts in Southern Ocean ecosystems. / Dissertation (MSc ((Zoology))--University of Pretoria, 2020. / Zoology and Entomology / MSc (Zoology) / Restricted

Coral reefs are one of the world’s most diverse yet heavily impacted marine ecosystems. As a result of many direct and indirect stressors, coral reefs have experienced major degradation over the last several decades. Declines in coral reefs in the Caribbean have been particularly acute and generally associated with the loss of key herbivores and an increase in algae. Herbivorous fishes such as parrotfishes can positively impact coral reefs by removing algae that compete with corals for light and space. However, many parrotfishes are also important coral predators. Predation on corals, known as corallivory, can adversely affect coral growth, reproduction and survivorship. In this time of changing environments and coral reef decline, understanding the context-dependent nature of parrotfish foraging behavior is of critical importance to scientists and managers. Knowledge of the responses of parrotfishes across a range of resource abundance will help scientists and managers better predict the impacts that these herbivores have on benthic communities as both herbivores and corallivores. In Chapter 1, we examined how six different species of coral reef herbivores (i.e. parrotfishes), all of which belong to a single feeding guild but represent a range of dietary specialization, respond to changes in the abundance of preferred food items. We conducted behavioral observations of parrotfishes in two regions of the Greater Caribbean, and compared consumption rates, diet preferences, and foraging territory size in relation to natural variation across sites in preferred resource abundance. We found that the more-specialized parrotfishes increased their dietary specialization, had smaller foraging territories, and increased their feeding rate with increased preferred resource abundance. In contrast, less-specialized species exhibited constant foraging traits regardless of the abundance of their preferred resources. This study suggests that differences in dietary preference, specialization, and subsequent nutritional demand may drive a differential response in foraging behavior by generalists and specialist herbivores to changes in resource abundance. Recognizing that generalists and specialists differ in the degree to which their foraging behaviors are context-dependent can allow researchers to better predict how herbivores shape the structure and function of marine and terrestrial ecosystems. In Chapter 2, we determined if and how corallivory rates and intensity by parrotfishes differ between two regions of the Greater Caribbean that vary in coral and parrotfish community composition and abundance. We found that more species of parrotfishes than previous studies suggest contribute to corallivory. However, corallivory rates and selectivity for coral species by parrotfishes were largely context-dependent, particularly with regards to the relative abundance of preferred corals and diversity of corallivores at a given site. Although we found that corallivory rates decrease with coral cover, it appears that areas of low coral cover may have high corallivory intensity and coral tissue loss, in part due to the relatively high abundance of corallivores in these areas. The impact of high corallivory intensity and tissue loss requires further knowledge regarding the fate of bite scars on corals.This information will help predict the positive and negative consequences of parrotfishes on coral persistence in the Caribbean. Evidence provided in this thesis furthers our understanding of the dual role of parrotfishes as herbivores and corallivores. Additionally, it reveals the implications of changing coral reef habitats on parrotfish behavior and subsequent coral reef health and resilience.

In nature, pollinators must navigate fields of resources presenting a variety of features, differing in shape, size, colour, etc. Foraging on a flower by flower basis is slow and maladaptive. Instead foragers must be able to differentiate between rewarding and unrewarding floral species while also generalizing learned information between flowers of the same species. The ability to categorize stimuli occurs on several levels of abstraction, laid out by Herrnstein (1990). In order to categorize objects, animals must first be able differentiate between them without memorizing each stimulus separately. Consequently, objects can be grouped by physical characteristics through perceptual categorization, or, on a more abstract scale, by the function they serve to the animal. This thesis explores the bees’ ability to categorize flowers, following the levels of categorization to answer two questions: Can bees form categories? And how abstract can their categorization become? There has been limited investigation previously in categorization in bees, and no research done on invertebrates addresses categorization beyond physical features. The bees’ ability to form categories was evaluated with four experiments of preference: 1) similar-but-different judgements; 2) perceptual categorization; 3) simple and mediated generalization; and 4) functional relevance. Results show firstly that bees can generalize characteristics within flower species, but also differentiate individual flowers. Secondly, bees can form perceptual categories, and while they rely on physical floral features for categorization, bees also demonstrated preliminary abilities for functional generalization as well. These results provide an explanation to natural foraging techniques adopted by the bees. The adaptive nature of categorization allows foragers to find resources more efficiently and better prepare in changing environments.

Orientador: Elza Maria Guimarães Santos / Resumo: A limitação de pólen é um dos fatores que mais afeta a produção de frutos e sementes de muitas populações naturais. Cerca de 60% das angiospermas apresentam baixo sucesso reprodutivo decorrente da transferência ineficiente dos grãos de pólen pelos polinizadores. Assim, o objetivo geral desse estudo foi avaliar diversos aspectos ligados à limitação de pólen em Zeyheria montana (Bignoniaceae), uma espécie ornitófila e autoincompatível. Ao longo do período de florescimento, com ampla variação do anúncio floral, nós avaliamos o efeito do padrão de forrageamento dos polinizadores dentro e entre plantas sobre o sucesso reprodutivo das mesmas. Avaliamos também as estratégias de forrageamento empregadas por cada espécie de polinizador e o efeito do roubo de néctar sobre a produção de frutos. Além disso, estimamos o tamanho do genoma das plantas com a finalidade de avaliar se havia variações intrapopulacional no nível de ploidia que pudessem estar associadas ao baixo sucesso reprodutivo. Em geral, nós demonstramos que a baixa qualidade do pólen transferido pelos polinizadores é o principal fator limitante do sucesso reprodutivo de Z. montana. Esse efeito ocorre principalmente no pico do florescimento, quando o anúncio floral é mais intenso, e os polinizadores tendem visitar um maior número de flores sequenciais dentro da mesma planta transferindo pólen incompatível. Além disso, o padrão de movimento entre plantas também não se mostrou eficiente, visto que os polinizadores frequentemen... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Pollen limitation is one of the factors that most affects the fruits and seeds production of many natural populations. Around 60% of angiosperms have low reproductive success due to inefficient pollen grains transfer among flowers by pollinators. Thus, the general goal of this study was to evaluate several aspects related to pollen limitation in Zeyheria montana (Bignoniaceae), an ornithophilous and self-incompatible species. Throughout the flowering period, with wide variation in floral display, we evaluated the effect of the pollinators’ foraging pattern within and between plants on their reproductive success. We also evaluated the foraging strategies employed by each pollinator species and the effect of nectar robbing on fruit production. In addition, we estimated the plants’ genome size in order to evaluate whether there were intrapopulation variations in the ploidy level that could be associated with the low reproductive success. In general, we demonstrated that the low pollen quality transferred by pollinators is the main limiting factor of the reproductive success. This effect occurs mainly at the flowering peak, when the floral display is more intense, and pollinators tend to visit a larger number of sequential flowers within the plant transferring incompatible pollen. In addition, the movement pattern between plants also was not efficient, since pollinators often visited nearby plants that possibly were more related. Although some hummingbirds species alternate their... (Complete abstract click electronic access below) / Doutor

2 ABSTRACT The degree of spatial activity, especially the home-range size, is one of the basic biolog- ical characteristics of animals and whether it has enough resources is crucial for the survival and reproduction of the individual. Therefore, it is not surprising that many studies trying to make clear the effect of various ecological and morphological variables and explain the varia- bility of space activities. Bats are a group of mammals, for which until recently, existed only few information about their spatial activity. However, due to the miniaturization of technology and the use of radiotelemetry amount of information rapidly increasing. The aim of this study was to assemble the most complete information about the home- range size and foraging distance of bats and analyze the effect of variables that can influence the spatial activity. From published papers I collected data on 106 species representing 8 fami- lies. The influence of 6 variables (weight, wing loading, aspect ratio, food specialization, colony size, primary productivity of environment) on home-range size and average foraging distance of bat was analysed by phylogenetic regression (PGLS). The best predictor of the home-range size is the primary productivity of the environment, food specialization and body size. The best explanation of...

Seabirds are often used as indicator species for changes in marine ecosystems due to the species visibility and sensitivity to changing conditions, such as changes in prey abundance. They often reside in habitats affected by anthropogenic impacts such as large-scale fisheries and pollution. Understanding the connection between seabirds and their surrounding environment can give us important insight about the ecology of the ocean and how anthropogenic pressures affects it. Studying feeding habits, and foraging behavior especially, is useful for understanding seabird´s responses to changing environments. Feeding studies are commonly used in seabird monitoring and requires a lot of time and resources. Monitoring of seabirds are also logistically challenging, and the risk of disturbing bird colonies must be considered. It can be especially complicated when studying cliff nesting seabirds such as the common murre, Uria aalge, the study species for this thesis. Photography as a method for monitoring seabirds may limit the need of people on site, hence minimize disturbance and save time and resources. This study provides insight in whether it is a viable option to use photography instead of on-site field studies when monitoring sea birds. This was accomplished by installing cameras and monitor a feeding study at Stora Karlsö, Sweden, parallel with performing the usual monitoring in the field. This thesis makes it clear that a camera study very well could replace the field study without any larger concerns, although, improvements need to be considered if the study is to maintain a high quality and for results to be reliable.

This thesis reports on the number of individuals in Macrotermes natalensis (Hav.) colonies, their biomass and food consumption in the northern Kruger National Park (KNP). The ecology of M. natalensis is largely undocumented despite the abundance of colonies in southern African savannas. New approaches to mound excavation, sub-sampling and data management are introduced. Via the intracolonial demography of colonies the contribution of each caste in number or proportion is determined. Using this information in combination with body mass and mound density data, biomass per unit area has been computed indicating the importance of this termite in synecology. The measurement of food consumption gives further insight as to how much litter is removed, fragmented and redistributed as nutrients in the ecosystem. Mounds were completely excavated, termites collected by means of vacuuming, and colony size estimated by sub-sampling. It was estimated that, on average, small mounds contain more than 5 000, medium mounds more than 45 000, and large mounds more than 200 000 individual termites. A highly significant relationship between total number of individuals (N ) and mound height (h ) was found, given by lnN = 7.893 + 1.093h (r = 0.92). The proportion of soldiers was found to change as colonies grew larger. In order to derive biomass estimates, a statistical bootstrap procedure was carried out using three databases: body mass, colony population sizes and mound density. Live biomass for small, medium and large mounds was found to be 0.17, 1.40 and 4.16 kg. Dry/wet body mass ratios were established for workers (23.7 %), major soldiers (20.3 %), minor soldiers (35.3 %), nymphs (17.1 %), king (35.4 %) and queen (20.8 %). Average live and dry biomass was calculated to be 0.51 kg/ha (0.051 g/m2) and 0.11 kg/ha (0.011 g/m2). Geology, geomorphology, elevation, local relief, soil patterns and annual rainfall were the abiotic factors shown to be most influential in determining termite biomass, either directly or indirectly. Termite biomass is high in undulating areas where the elevation is 250-400 m, where granitic and rhyolitic soils occur, and where annual rainfall is high (650-700 mm) in the context of the region. Major workers fetch woody litter outside the nest through ingestion into the section of the crop and gizzard. Gut contents were dried, weighed, ashed and reweighed. The ash mainly represents soil particles. The ash-free mass of food that is consumed during a single foraging trip by a foraging individual is 0.166 ± 0.009 mg (CI). Frequency of foraging trips between the mound and food source was observed using translucent tubing. The annual food consumption is given by the formula 365mnp/t , where m = individual mass of ashed crop-gizzard contents, n = number of foraging major workers, p = daily foraging period, and t = individual time spent between nest and food source. Food consumption of this termite in the northern KNP is calculated to be 20.2 kg/ha/yr. It is shown that termites are primary decomposers and contribute to litter fragmentation and the recycling of nutrients into the soil. This thesis gives greater insight into aspects such as colony development, biomass investment and resource utilization of M. natalensis in the northern KNP. / Dissertation (PhD)--University of Pretoria, 2003. / Zoology and Entomology / unrestricted

Detaljhandeln har under en längre tid gjort en förflyttning från fysiska butiker till internetbaserad handel, så kallad e-handel. Sedan år 2020 har e-handeln ökat med 60 procent som följd av coronapandemin. Denna utveckling beror på att nya konsumenter har börjat handla via internet och att redan befintliga e-handelskunder har ökat inköpen, vilket medför att många idag är mer vana vid att handla online.  Det finns många olika typer av e-handelssidor. Den största andelen riktas direkt till konsumenter. Många webbplatser inom e-handeln har idag ett stort utbud av produkter, vilket leder till informationstunga menyer. Det ställer större krav på navigationsstrukturen och hittbarheten, då det påverkar användarnas upplevelse av interaktionen med systemet. Eftersom användare har olika strategier för att nå informationsmålen behöver e-handelssidor vara uppbyggda baserat på kunskapen om kategorisering av produkter och etiketter. Det måste också finnas förståelse för användarnas beteendemönster kring navigeringsstrategier, så att systemet hjälper användare att nå informationsmålen och ger en positiv användarupplevelse. Syftet med denna studie var att skapa kunskap och förståelse kring vilka faktorer inom e-handelns globala och lokala navigation, avseende UX och hittbarhet, som påverkar konsumenters användarupplevelse. Tidigare forskning påvisar att det kritiska designproblemet inte är att förse användare med så mycket information som möjligt utan att lättare kunna hitta rätt information. Hur människor navigerar på webben för att uppfylla informationsbehov är ofta genom att på kort tid erhålla så mycket väsentlig information som möjligt. Det förklarar i huvudsak varför de inte planlöst scrollar och klickar på länkar. Undersökningsmetoderna som har tillämpats i denna studie var kvalitativa användartester som observerades, följt av en SUS-utvärdering och kompletterande kvalitativa semistrukturerade intervjuer. Användarstudien genomfördes vid ett datainsamlingstillfälle och metoderna ansågs lämpade för att ta reda på användarnas subjektiva erfarenheter, upplevelser, attityder och uppfattningar. Det kunde konstateras genom studien att olika faktorer påverkar användarupplevelsen både positivt och negativt. Det är individuellt hur användare navigerar på webbplatsen, tolkar etiketter samt vilka produkter de förväntas hitta under viss kategorisering. Ett generellt beteende kunde även påvisas gällande navigeringsstrategier, tolkning av etiketter och förväntningar på produkters placeringar som ofta grundades i en igenkänningsfaktor baserad på tidigare erfarenheter. / Retail has for a long time gone from physical stores to internet-based trade. In addition, e-commerce has expanded by 60 percent since 2020 as a result of the Corona pandemic. This development is partly due to the fact that new consumers have switched to shopping online, existing e-commerce customers have increased spending and that the habit of shopping online has increased. Today, there are many different types of e-commerce sites. The largest share is aimed directly at consumers. Many Websites in e-commerce today have a wide range of products, which leads to information-heavy menus. This requires greater demands on the navigation structure and findability as it affects the user experience of interacting with the system. Because users have different strategies for achieving their information goals, e-commerce Websites must be built based on the knowledge of categorizing products and labels. There must also be an understanding of users' behavioral patterns in their navigation strategies, so that the system helps to achieve the users information goals and provides a positive user experience. The purpose of this study was to examine the factors in e-commerce's global and local navigation, regarding UX and findability that affect consumers' experience. Previous research shows that the critical design problem is not to gather as much information as possible but rather finding the right information. The way people navigate the web to meet their information needs are often by obtaining as much essential information as possible in a short period of time. This mainly explains why they do not scroll and click on links aimlessly. The survey methods applied in this study were qualitative user tests that were observed, followed by a system usability scale (SUS), and supplementary qualitative semi-structured interviews. The user study was conducted at one data collection occasion and the methods were considered suitable to find out the users' subjective experiences, attitudes and perceptions. It could be ascertained through the study that various factors affect the user experience both positively and negatively. It is individual how the user navigates the website, interprets labels and which products they expect to find under a certain categorization. A general behavior could also be demonstrated regarding navigation strategies, interpretation of labels and expectations of product placement, which were often based on a recognition factor based on previous experience.