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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.
71

Die karakterisering van die reukmerkvloeistof van die Bengaalse tier, Panthera Tigris Tigris

Viviers, Marlize Z. 03 1900 (has links)
Thesis (MSc (Botany and Zoology))--University of Stellenbosch, 2006. / Although the Bengal tiger, Panthera tigris tigris, appears on the IUCN Red Data List for endangered animals, very little information is available in the literature on the components of this animal's marking fluid. Scent marking is the main form of communication in all cat species. In some species, including the Bengal tiger, the liquid used for spraying is not pure urine, but is mixed with scent gland secretions. The objective of this study was to characterise the volatile components in the marking fluid of the Bengal tiger to achieve a better understanding of the semiochemical communication of this animal. The marking fluid of the tiger was characterised through the use of analytical techniques, such as gaschromatography, low resolution gas chromatography - mass spectrometry and retention time comparison. Homologous series of alkanes, alcohols, aldehydes, methyl ketones, carboxylic acids, γ- and δ-lactones, amides and lactams, as well as esters and nitrogen containing compounds, were identified. Of these identified compounds the unbranched alkanes, saturated alcohols, aldehydes, branched methyl ketones, saturated carboxylic acids and γ- and δ- lactones are commonly found in mammalian secretions. Compounds that aren't as common in their secretions are the methyl ketones, branched carboxylic acids, dimethyl esters of dicarboxylic acids and amides. The marking fluid contains a phthalic acid ester. Phthalic acid esters are used in the polymer industry and are nowadays found almost everywhere in nature. It is known that these pollutants have endocrine disrupting properties. The heat, humidity and wet conditions that are characteristic of the Bengal tiger's natural habitat makes it necessary for the tiger to make use of a fixative to prolong the life of the semiochemical message. The compounds and the concentrations in which these compounds are present in the urine and the lipid fraction of the marking fluid of the tiger was determined and compared to assess the fixative role of the lipids. This study has provided evidence that the lipid material has a greater affinity for the volatile organic constituents of the marking fluid and that it can therefore extend the lifetime of a semiochemical message left by the tiger.
72

Investigation into the semiochemical communication involved in neonatal offspring recognition in sheep

Viviers, Marlize Zaretha 03 1900 (has links)
Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010. / Video 1: Twin-bearing Döhne Merino ewe butting only one of her lambs in typical rejection behavior. Rejection of one twin is not a common phenomenon. (Video by Dr Marlize Viviers) / Video 2: Twin-bearing ewe # 22 accepting alien lamb # 179. The alien lamb wears a jacket her other lamb has been wearing for the preceding 24 hours. The excessive sniffing at the jacket, bleating and looking around show that the ewe is not totally satisfied with the situation. (Video by Dr Marlize Viviers) / Video 3: Ewe # 22 rejecting alien lamb # 179 after removal of the jacket it has worn in the previous video. (Video by Dr Marlize Viviers) / ENGLISH ABSTRACT: Sheep husbandry substantially contributes to South Africa’s economy. Lamb mortality is regarded as a major constraint to sustainable sheep production, and an important factor in lamb survival is the strong ewe–lamb bonding. This is a well-known phenomenon in all sheep races and strong evidence exists that the selective ewe–lamb bond formation has a pheromonal basis, in that the ewe can distinguish her lamb by its unique, familiar smell. Sheep farmers and scientists have examined various methods of making alien lambs acceptable to foster ewes. The survival rate of offspring could be substantially increased if a reliable method could be devised to prevent ewes from rejecting their own lambs or if ewes could be induced to accept alien lambs. A better understanding of the semiochemicals involved in this communication between ewe and offspring could facilitate the development of a method by which ewes can be coaxed into adopting foster lambs. This would positively contribute to efficient sheep production in South Africa. The objective of this study was to characterise the volatile constituents present in the wool and the amniotic fluid collected from the Döhne Merino lambs to achieve a better understanding of the ewe–lamb semiochemical communication. The volatile organic constituents associated with the wool and amniotic fluid were characterised and a total of 133 volatile organic compounds were identified. Several compound classes are represented in these samples and the majority of these compounds have previously been identified in the excretions and secretions of numerous mammalian species. A number of different aspects of ewe–lamb kin recognition were investigated. First, the odour profiles of twin lambs were compared to those of other twins. The results of these analyses revealed that the wool volatiles of twin lambs are qualitatively as well as quantitatively practically identical, but different from those of other lambs in the flock. Second, the change in the odour profiles of lambs was studied over a seven-day period. It was found that the odour profiles of lambs are not fixed, and for as long as a ewe makes use of olfactory recognition as the main mode of identification of her lamb she has to continue learning the odour of her lamb. Third, the amniotic fluid was investigated as a possible source of maternal labels, i.e. as chemical codes consisting of mixtures of compounds in specific quantitative ratios that are imprinted on lambs by their mothers at birth. It was found that the amniotic fluids of first- and second-born lambs are qualitatively and quantitatively different. It is possible that the duration of the lambing birth process could contribute to this change in amniotic fluid composition. Fourth, the role of residual proteins in the dissemination of the semiochemicals involved in ewe– lamb communication was investigated and six proteins were identified as amniotic fluid and wool-associated proteins. Bioassays carried out during the lambing season of 2009 confirmed the role of the odour of the lamb in ewe-lamb recognition, but bioassays carried out with synthetic pheromone formulations gave inconclusive results. / AFRIKAANSE OPSOMMING: Skaapboerdery lewer aansienlike bydrae tot die ekonomie van Suid Afrika, maar lamsterftes is een van die kwellende probleme waarmee kleinveeboere te kampe het. Die eksklusiewe band wat binne die eerste paar uur na 'n lam se geboorte tussen die ooi en haar lam ontwikkel, is die hooffaktor waarvan lammers se oorlewing afhang. Hierdie sterk binding tussen lam en ooi is 'n bekende verskynsel in alle skaap-rasse en dit is bekend dat 'n feromoon wat deur die lam vrygestel word, dit vir die ooi moontlik maak om haar lam aan sy unieke reuk uit te ken. Lamsterftes sou aansienlik verminder kon word as hierdie feromoon geïdentifiseer en gebruik kan word om ooie te verhoed om hulle eie lammers te verwerp en om die aanvaarding van vreemde lammers deur ooie moontlik te maak. Die doel van hierdie studie was die chemiese karakterisering van die vlugtige organiese verbindings aanwesig in die amniotiese vloeistof en wol van Döhne Merino lammers ten einde 'n beter begrip van die semiochemiese kommunikasie tussen ooie en lammers te verkry. In die amniotiese vloeistof is 70 vlugtige organiese verbindings geïdentifiseer. Dieselfde verbindings asook 'n verdere 63 verbindings is in lammerwol geïdentifiseer. Die meerderheid van hierdie verbindings is reeds voorheen in verskeie soogdierafskeidings gevind. Die studie het verskeie interessante aspekte van hierdie semiochemiese kommunikasie aan die lig gebring. Eerstens is daar gevind dat die samestelling van die vlugtige organiese materiaal in die wol van tweelinglammers, oftewel hul reukprofiele, feitlik identies is. Verder verskil die reukprofiele van 'n tweeling van dié van ander tweelinge en enkelinge in die trop. Tweedens is gevind dat die reukprofiel van 'n lam nie by geboorte vasgelê word en so behoue bly nie, maar dat dit geleidelik verander oor ten minste die periode van sewe dae waaroor hierdie verskynsel bestudeer is. Dit noodsaak die ooi om haar geheue met betrekking tot die lam se reuk voortdurend te verfris gedurende die tydperk wat sy hoofsaaklik van haar reuksin gebruik maak om haar lam te herken. Derdens is die amniotiese vloeistof ondersoek as moontlike bron van ‘n sogenaamde moedermerk, waardeur chemiese mengsel van verbindings wat in ‘n spesifieke kwantitatiewe samestelling by geboorte deur die ooi op haar lam agter gelaat word. Ten opsigte van kwalitatiewe en kwantitatiewe samestelling, verskil die vlugtige organiese fraksie van die amniotiese vloeistof van die tweelinglam wat eerste gebore word van die amniotiese vloeistof van die lam wat tweede gebore word. Dit is onwaarskynlik dat amniotiese vloeistowwe wat ten opsigte van hul vlugtige organiese fraksies van mekaar verskil, nagenoeg identiese moedermerke op tweeling lammers sou kon laat. Vierdens is vasgestel dat spore van ses proteïene uit die amniotiese vloeistof op die wol van lammers agtergelaat word. Daar kon ongelukkig nie vasgestel word of hierdie proteïene 'n rol in die vrystelling van semiochemiese inligting speel nie. Gedragstoetse wat tydens die lamseisoen van 2009 uitgevoer is, het bevestig dat die lam se reukprofiel deurslaggewende rol in ooi-lam herkenning speel, maar gedragstoetse wat met sintetiese feromoonmengsels uitgevoer is, het onbesliste resultate opgelewer.
73

Chemiese kommunikasie van die Suid-Afrikaanse gordelakkedisse

Louw, Stefan 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The sungazer, Cordylus giganteus, is an endangered lizard species belonging to the family Cordylidae. It has been speculated that the function of semiochemical communication is performed by two types of skin glands, the femoral glands and the generation glands, which are also found in this family of lizards. Other skin glands and also the cloacal glands are further possible sources of semiochemicals. The investigation of these potential sources of chemical messages in C. giganteus, served as a starting point towards a better understanding of the chemical communication of lizard species belonging to the family Cordylidae. In continuation of this study the femoral gland secretion of the Cape girdled lizard, C. cordylus, was also investigated. Gas chromatography, low resolution GC-MS, GC-HR-MS, MO-TMS derivatisation and retention time comparison were used as analytical techniques in the chemical characterization of the femoral and generation gland secretions of C. giganteus and the femoral gland secretion of C. cordylus. Some compounds were not identified because of their low concentration in the secretions and/or mass spectra could not be obtained for pure compounds because of co-elution with other compounds. Compounds identified in the femoral gland secretion include the following: Carboxylic acids - saturated and unsaturated Alcohols Ketones Aldehydes - saturated and unsaturated Esters - saturated and unsaturated Hydrocarbons - saturated and unsaturated Nitriles Amides - saturated and unsaturated y-Lactones Squalene u-Tocopherol Steroids Quantitative analysis of the femoral and generation gland secretions of a number of sungazers indicated distinct differences between the secretions of males and females (in the case of the femoral gland secretions), but no apparent trend could be found in the differences between the femoral and generation gland secretions of individual lizards of the same gender. Qualitative seasonal differences were however observed in the femoral gland secretions of all individuals of C giganteus. / AFRIKAANSE OPSOMMING: Die ouvolk, Cordylus giganteus, is 'n bedreigde akkedisspesie van die familie Cordilidae. Daar is gespekuleer dat twee soorte velkliere wat by hierdie familie akkedisse voorkom, naamlik die femorale- en generasiekliere, betrokke is by semiochemiese kommunikasie van hierdie diere. Ander velkliere, asook die kliere in die akkedisse se kloaka, is ook potensiele bronne van semiochemiese verbindings. Die bestudering van hierdie potensiele bronne van chemiese boodskappe by C. giganteus is as 'n beginpunt gebruik om die semiochemiese kommunikasie van die akkedisse van die familie Cordilidae beter te verstaan. Ter uitbreiding van hierdie studie is die femorale klierafskeiding van die Kaapse gordelakkedis, C. cordylus, ook ondersoek. Die femorale en generasieklierafskeidings van C. giganteus en die femorale klierafskeidings van C. cordylus is chemies gekarakteriseer deur van analitiese tegnieke, naamlik gaschromatografie, lae resolusie GC-MS, GC-HR-MS, MO- TMS derivatisering en retensietydvergelyking, gebruik te maak. Talle verbindings is nie geidentifiseer nie omdat hulle in 'n baie lae konsentrasie in die afskeidings voorkom, en/of saam met ander komponente elueer, wat veroorsaak dat daar nie massaspektra vir hierdie suiwer komponente verkry kon word nie. Verbindingstipes wat in die afskeidings voorkom, sluit die volgende in: Karboksielsure - versadig en onversadig Alkohole Ketone Aldehiede - versadig en onversadig Esters - versadig en onversadig Koolwaterstowwe - versadig en onversadig Nitriele Amiede - versadig en onversadig y-Laktone Skwaleen a-Tocopherol Steroiede Kwantitatiewe analises van die femorale en generasieklierafskeidings van verskeie ouvolk akkedisse het getoon dat daar duidelike kwantitatiewe verskille tussen die afskeidings van mannetjies en wyfies is (in die geval van die femorale klierafskeidings), maar dat daar geen duidelike patroon in die verskille tussen die femorale en generasieklierafskeidings van individuele akkedisse van dieselfde geslag is rue. Daar is kwalitatiewe seisoenale verskille tussen die femorale klierafskeidings van individue van C. giganteus gevind.
74

Olfactory communicatiaon : chemical characterization of the interdigital secretion of the black wildebeest, Connochaetes gnou

Slade, Desmond 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The black wildebeest, Connochaetes gnou, is a terriorial animal and although it is not generally accepted, it is believed that it defines its territory by scent marking, using interdigital and preorbital secretions, faeces, and urine. The aim of this study was to characterize the chemical constituents of the interdigital secretion. Due to the complexity of the secretion, only one hundred and ten of the approximately 350 compounds could be determined with known techniques. Gas chromatography, low resolution GC-MS and retention-time comparison were the main analytical techniques used. Classes of compounds identified in the interdigital secretion include the following: • Hydrocarbons - Aliphatic (saturated and unsaturated) and aromatic • Alcohols - Aliphatic (saturated, unsaturated, cyclic and diols) • Phenols and Phenylalkanols • Aldehydes - Aliphatic (saturated and unsaturated) and aromatic • Ketones - Aliphatic (saturated, unsaturated, cyclic and diketones) and aromatic • Hydroxy ketones - Aliphatic and cyclic • Carboxylic acids - Aliphatic (saturated, unsaturated and cyclic) and aromatic • An anhydride • Esters - Methyl esters, ethyl and higher esters, unsaturated esters and aromatic esters • Lactams • A steroid Only small qualitative and quantitative differences were found between the male and female interdigital secretions. / AFRIKAANSE OPSOMMING: Die swartwildebees, Connochaetes gnou, is 'n territoriale dier en alhoewel dit nie algemeen aanvaar word nie, word vermoed dat hierdie bokke hul gebied afbaken met behulp van interdigitale en preorbitale afskeidings, en deur faeces en urine. Die doel van hierdie studie was om die chemiese samestelling van die interdigitale afskeiding te karakteriseer. As gevolg van die kompleksiteit van die afskeiding, kon slegs eenhonderd-en-tien van die ongeveer 350 verbindings met bekende bestaande tegnieke geïdentifiseer word. Gaschromatografie, lae resolusie GC-MS en retensietyd-vergelyking was die belangrikste analitiese tegnieke wat gebruik is. Klasse van verbindings wat bepaal is, sluit die volgende in: • Koolwaterstowwe - Alifaties (versadig en onversadig) en aromaties • Alkohole - Alifaties (versadig, onversadig, siklies en diole) • Fenole en Fenielalkanole • Aldehiede - Alifaties (versadig en onversadig) en aromaties • Ketone - Alifaties (versadig, onversadig, siklies en diketone) en aromaties • Hidroksiketone - Alifaties en siklies • Karboksielsure - Alifaties (versadig, onversadig en siklies) en aromaties • 'n Anhidried • Esters - Metiel esters, etiel en hoër esters, onversadigde esters en aromatiese esters • Laktame • 'n Steroïed Slegs klein kwalitatiewe en kwantitatiewe verskille is gevind tussen die bul en koei interdigitale afskeidings.
75

The role of micro-organisms in the production of semiochemicals in the interdigital secretion of the bontebok, Damaliscus pygargus pygargus

Scott, Gary Terri 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Bontebok, Damaliscus pygargus pygargus, formerly classified as D. dorcas dorcas, are territorial animals with interdigital glands between the toes of the forelegs. Males regularly defecate on dung heaps, on which they often lie, to communicate with other members of their species. They also communicate by means of visual displays, scent marking and occasionally with scraping or pawing of dung heaps. It is assumed that scent marking with the interdigital secretion serves to define territories frequented by these antelope. These glands secrete a complex mixture of volatile and non-volatile compounds and the volatile compounds in the secretion serve as a chemical signal for other bontebok. It has been suggested that the interdigital secretion is not produced in its final composition by the interdigital gland alone, but that microbial activity is responsible for many of the compounds present in the secretion. In general, many compounds can be attributed to the by-products of microbial hydrolysis of triglycerides, a common characteristic of sebum. It is well documented that micro-organisms inhabit the deep recesses of sebaceous glands and the presence of micro-organisms has been found to be consistent in all antelope exocrine glandular areas. This study involved the chemical characterisation of the volatile metabolites produced in vitro by micro-organisms from the interdigital cavity of the bontebok. Various comparative studies were made, one of which was comparison of the metabolites produced by the individual microbial species as well as the total community of bacteria incubated in different media. A comparison of the compounds identified in the interdigital secretion and the metabolites produced by the micro-organisms in the different media was also made. The volatile metabolite extracts of the individual bacterial species and of the total community were chemically characterised by low-resolution gas chromatography-mass spectroscopy. Classes of compounds identified from the volatile metabolite extracts include: • Acids - Aliphatic (saturated and unsaturated) • Alcohols - Aliphatic (saturated and unsaturated) • Aldehydes - Aliphatic (saturated and unsaturated) • Aromatic compounds • Ketones - Aliphatic (saturated and unsaturated) • Pyrazines • Dimethyldisulphide • Squalene and cholesterol Several qualitative differences were found between the compounds identified in the volatile metabolite extracts of the micro-organisms when incubated in tryptic soy broth (TSB) and minimal salt medium (MSM). In particular, when the microbes were incubated in TSB medium a number of pyrazines were found that were not present when utilising MSM as a medium. Additional qualitative differences were found between the compounds identified in the metabolite extracts of the individual bacterial species and the total community of bacteria, when incubated in both TSB and MSM media. A comparison of the interdigital secretion and the metabolite extracts of the microbial communities incubated in TSB and MSM revealed that many compounds produced in MSM corresponded to the compounds identified in the interdigital secretion. These corresponding compounds were found to be saturated and unsaturated acids, aldehydes and squalene. Furthermore, there was only one corresponding compound in the case of TSB as medium. / AFRIKAANSE OPSOMMING: Die bontebok, Damaliscus pygargus pygargus, voorheen geklassifiseer as D. dorcas dorcas, is 'n territoriale dier met interdigitale kliere tussen die kloutjies van die voorpote. Ramme ontlas gereeld op mishope, waarop hulle dikwels lê, om met ander lede van die spesie te kommunikeer. Hulle kommunikeer ook deur middel van visuele seine, reukmerking en soms deur mishope met die voorpote te kap of te skraap. Reukmerking met die interdigitale afskeiding dien klaarblyklik om gebiede wat deur hierdie diere bewoon word, af te baken. Die interdigitale kliere skei 'n komplekse mengsel van vlugtige en nie-vlugtige verbindings af en die vlugtige verbindings dien as chemiese sein vir ander bontebokke. Die vermoede bestaan dat die interdigitale klier nie alleen verantwoordelik is vir die finale samestelling van die interdigitale afskeiding nie, maar dat mikrobiese aktiwiteit bydra tot die produksie van baie van die verbindings wat in die afskeiding aanwesig is. Sekere verbindings kan in die algemeen toegeskryf word aan die vorming van die neweprodukte van mikrobiese hidrolise van trigliseriede, 'n algemene eienskap van sebum. Dit is bekend dat die diep holtes van vetkliere 'n goeie teelaarde is vir mikroorganismes en daar is gevind dat mikroorganismes feitlik deurgaans voorkom in alle anteloop eksokriene klierareas. Hierdie studie behels die chemiese karakterisering van die vlugtige metaboliete wat in vitro deur mikroorganismes van die interdigitale klierholte van die bontebok geproduseer word. Verskeie vergelykende studies is uitgevoer waarvan een die vergelyking was van die metaboliete wat deur die individuele mikrobiese spesies sowel as die totale gemeenskap van bakterieë geproduseer word tydens inkubasie in verskillende media. Vergelyking van die verbindings wat in die interdigitale afskeiding geïdentifiseer is met die metaboliete wat in verskillende media geproduseer is, het ook deel van die studie uitgemaak. Die vlugtige metaboliet ekstrakte van die individuele bakteriese spesies en van die totale gemeenskap is chemies gekarakteriseer deur middel van laeresolusie gaschromatografie-massaspektrometrie. Die volgende groepe verbindings is onder andere in die vlugtige metaboliet ekstrakte geïdentifiseer: • Sure - Alifaties (versadig en onversadig) • Alkohole - Alifaties (versadig en onversadig) • Aldehiede - Alifaties (versadig en onversadig) • Aromatiese verbindings • Ketone - Alifaties (versadig en onversadig) • Pirasiene • Dimetieldisulfied • Skwaleen en cholesterol Verskeie kwalitatiewe verskille is gevind tussen die verbindings wat geïdentifiseer is in die vlugtige metaboliet ekstrakte van die mikroorganismes onderskeidelik in TSB medium en MSM geïnkubeer. Opvallend was byvoorbeeld die voorkoms van pirasiene in gevalle waar mikroorganismes in TSB medium geïnkubeer is, terwyl hierdie groep verbindings afwesig was wanneer MSM gebruik is. Onderlinge kwalitatiewe verskille is ook gevind tussen die verbindings wat geïdentifiseer is in die metaboliet ekstrakte van die individuele bakteriese spesies en die totale gemeenskap van bakterieë, wanneer in TSB medium sowel as in MSM geïnkubeer is. Vergelyking van die verbindings in die interdigitale afskeiding en in die metaboliet ekstrakte van die mikrobiese gemeenskappe, het getoon dat 'n aantal verbindings wat in MSM geproduseer is, ooreenstem met verbindings wat in die interdigitale afskeiding geïdentifiseer is. Daar is gevind dat hierdie verbindings versadigde en onversadigde sure en aldehiede en skwaleen is. Met TSB as medium was daar slegs een ooreenstemmende verbinding.
76

Variation in sound production of the blue catfish, Ictalurus furcatus.

Ghahramani, Zachary 06 August 2010 (has links)
The blue catfish, Ictalurus furcatus, is an invasive species introduced to Virginia in 1974 and is the largest catfish in the United States. Like other Ictalurids, they are capable of producing disturbance calls via stridulation of the pectoral spine. These sounds can be made in air and water, and catfish can be preyed upon by both aerial and underwater predators. I characterized these putative distress calls by recording them in air and in the fish’s natural habitat. Sounds exhibited a wide variation in acoustic parameters relative to fish ontogeny: larger fish produced higher amplitude sounds with lower frequency bands. Sweep and pulse duration increased with fish size, but pulse rate and the number of pulses per sweep decreased. Sounds were more robust in water with a 1400 fold increase in sound pressure compared to air. Frequency response was much more peaked underwater with a considerable amount of high frequency absorption. These sounds appear to be better adapted to water, suggesting that their use in air may be inconsequential.
77

Gestural communication in wild chimpanzees

Hobaiter, Catherine January 2012 (has links)
Great ape gesture is an elaborate, flexible system of intentional communication. It has been suggested that human language originated in gesture, thus, the gestural communication of great apes is of great interest for questions on the origin of language. To date, systematic studies of great ape gesture have been limited to restricted captive settings, supplemented by the study of a few specific gestures in wild populations. To address questions about gestural communication from an evolutionary perspective it is necessary to extend the systematic study of gesture into a wild ape population. I therefore undertook a 22-month study of gesture in the wild Sonso chimpanzee community in Budongo, Uganda. Sonso chimpanzees employ a large repertoire of species-typical gestures in intentional communication; a proportion of this repertoire appears to be ape-typical, as would be expected with a biologically given trait. Chimpanzees can acquire new behavioural patterns through imitation; however, this apparently does not represent a significant means of acquiring gestures. Gesturing was employed regularly in an intentional manner from the end of the first year, and was used by chimpanzees of all ages to communicate across a range of contexts, including the evolutionarily urgent context of consortship. Immature chimpanzees used a wide range of gestures, which they combined into rapid sequences. With maturity, use of the repertoire was ‘tuned’ to focus on the most effective gestures, which were then used individually. Despite the evidence for referential pointing in captive chimpanzees, there was little evidence for the regular use of it in wild chimpanzees. Gestures were used to communicate a range of imperative requests that regulated social behaviour. Chimpanzee gestures vary from the ambiguous to the highly specific in meaning; and, while gestures were used flexibly, they tended to be associated with a single dominant meaning.
78

Habitat location and selection by the Sargassum crab Portunus sayi: the role of sensory cues

Unknown Date (has links)
The Sargassum community consists of a unique and idverse assemblage of fauna critical to pelagic food chains. Associated organisms presumably have adaptations to assist in finding Sargassum. This study investigated cues used for habitat location and selection by the Sargassum crab, Portunus sayi. Chemical detection trials were conducted with a two-chamber choice apparatus with Sargassum spp. and Thalassia testudinum as source odors. Visual detection trials (devoid of chemical cues) and habitat selection trials were conducted in which crabs were given a choice of habitats. Results showed that P. sayi respoded to chemical odors from Sargassum spp. Crabs visually located habitats but did not visually distinguish between different habitats. In habitat selection trials, crabs selected Sargassum spp. over artificial Sargassum and T. testudinum. These results suggest that crabs isolated from Sargassum likely use chemoreception from longer distances ; within visual proximity of a potential patch, crabs use both chemical and visual information. / by Lorin E. West. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
79

A memória de um gesto comunicativa humano no cão doméstico (Canis familiaris) / Memory of a communicative human gesture in the domestic dog (Canis familiaris)

Brandão, Maria Mascarenhas 14 May 2012 (has links)
São diversos os estudos sobre a compreensão de dicas comunicativas humanas pelo cão. Em todos eles, a verificação da compreensão do sinal é realizada imediatamente após a emissão do mesmo. A nossa pesquisa busca refletir sobre os processos de memória envolvidos na operação de designação-busca do objeto escondido pelo cão, tendo como objetivo investigar a memória operacional dos cães para um sinal comunicativo humano. Comparamos a retenção de informações para duas condições: quando o cão tinha contato visual direto com o objeto-alvo (não-comunicativa) e quando recebia a informação a respeito da localização do alvo por um sinal comunicativo humano (comunicativa). Num primeiro experimento, quisemos saber como a retenção das informações era afetada em função do intervalo de tempo decorrido para as duas condições. Em outro, também para as duas condições, como a retenção da informação, em um mesmo intervalo de tempo, era afetada em função de diferentes tipos de distração. Para tanto, utilizamos nos dois experimentos uma tarefa de busca pelo objeto escondido, em que o cão recebia a informação sobre a localização de um alimento desejado em uma de duas caixas, esperava por um intervalo retido atrás de um anteparo (barreira visual) e depois era liberado e poderia aproximar-se de uma das caixas. Na condição indicação gestual (comunicativa), a informação era dada pelo experimentador em um gesto de apontar proximal momentâneo. Na condição observação, o cão podia ver o alimento disponível em uma de duas caixas após a colocação do anteparo as caixas eram giradas e o cão perdia a visão do objeto. No Experimento I, os sujeitos recebiam a informação e eram liberados para responder após intervalos de 5, 60 ou 240 segundos. Os resultados indicaram uma tendência à significância nas respostas dos sujeitos no intervalo de 60 segundos, favorecendo a condição indicação gestual. No experimento II, os sujeitos eram testados no mesmo intervalo de retenção (60 segundos), mas variavam as situações de distração entre as tentativas: distração por comando (comunicativa) ou por deslocamento (não-comunicativa), além de uma tentativa controle (sem distração). Os resultados indicam que as distrações não tiveram efeitos significativos para nenhuma das condições. De maneira geral, podemos concluir que a informação transmitida por um gesto comunicativo humano (o apontar do local onde está escondido alimento) pode ser conservada na memória e que ela tem um trajeto mnemônico semelhante a outros constatados no estudo da cognição de cães / There are many studies regarding the comprehension of human cues by dogs. In all of them, the comprehension of the cue is verified immediately after its emission. Our research intends to reflect over the memory processes involved in the operation of designation-search of a hidden object by the dog, with the objective of investigating the dogs operational memory for a communicative human sign. We compared the informations retention under two conditions: when the dog had direct visual contact with the target-object (non-communicative situation) and when it received information regarding the targets location through a human communicative sign (communicative situation). In the first experiment, we wanted to know how the informations retention was affected based on the elapsed time for the two conditions. In another experiment, for the same two conditions, we wanted to know how the informations retention, under only one latency period, was affected based on different types of distraction. To do so, we utilized in both experiments a object search task, in which the dog received information regarding the location of a desired piece of food in one of two boxes. The dog was retained for a certain latency period, recluse behind a screen (visual barrier), and then was released and could approach one of the boxes. Under the gestural indication condition (communicative situation), information was given by the experimenter, using a proximal momentary pointing gesture. Under the observation condition, the dog could see the piece of food available in one of two boxes which were turned after the screen was placed, making the dog lose sight of the object. In Experiment I, the subjects received information and were released to respond after a time frame of 5, 60 or 240 seconds. The results indicate a tendency of a difference in the performance of dogs in the 60 seconds-latency period, favoring the gestural indication condition. In Experiment II, the subjects were tested under the same retention latency period (60 seconds), but the distraction situations vary between the attempts: command distraction (communicative situation) or dislocation distraction (non-communicative), besides a control situation (without distraction). The results point that the distractions had no significant effects for neither the conditions. In general, we can conclude that the transmitted information through a human communicative gesture (pointing the location where the food is hidden) can be conserved in the dogs memory and that it has a mnemonic path similar to others found in studies of the dogs cognition
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A complexidade do repertório acústico das capivaras (Hydrochoerus hydrochaeris) / The complexity of capybaras acoustic repertoire (Hydrochoerus hydrochaeris)

Suzuki, Cintia Tomoe 18 February 2016 (has links)
A capivara é uma espécie altamente social que vive em grupos multi-macho e multi-fêmea hierarquicamente organizados. Um rico repertório de comportamentos, incluindo o acústico, regula as interações sociais e organiza a vida em sociedade. Para investigar o repertório acústico da espécie realizamos o levantamento e a descrição categorizada das vocalizações. Os sinais acústicos foram registrados a partir de uma população de vida livre habitante do campus da USP de Ribeirão Preto e um grupo de capivaras do Bosque e Zoológico Municipal Fábio Barreto, em Ribeirão Preto. Nossos resultados mostram a existência de dez sinais acústicos, alguns deles com 3 a 4 variantes, o uso de um sistema de combinação de notas, e a presença de efeitos não-lineares em sinais relacionados a estados internos alterados como no grito de agonia emitido durante a contenção. Os resultados encontrados apontam para uma riqueza maior e mais variada de chamados já descritos na literatura revelando um repertório acústico comparável com o descrito para o mocó (Kerodon rupestris), o preá (Cavia aperea) e outros caviomorfos. O registro de outros níveis de organização de notas e a presença de elementos não-lineares também enriquecem o sistema de comunicação da espécie e demostram a sua complexidade. Nossos resultados vêm trazer contribuições de forma a complementar a descrição do repertório da espécie que se mostrou maior e mais complexa / The capybara is a highly social species that lives in hierarchically organized multi-male/multi-female groups. A rich behavioral repertoire, including acoustic signalization, mediates social interactions and life in society. To investigate the acoustic repertoire of this species we conducted a survey and categorization of calls. The acoustic signals were registered from a population living free local campus of USP in Ribeirão Preto and of a captive group (Bosque e Zoológico Municipal Fábio Barreto) in the municipality of Ribeirão Preto. Our results show the existence of ten different acoustic signals, some of them subdivided in 3 to 4 variant, and the use of note composition from two different types, and non-linearity in distress signals, as those produced by under containment individuals. The results point to a larger and more varied richness of calls already described in the literature showing an acoustic repertoire comparable to that described for the mocó (Kerodon rupestris) , the guinea pig (Cavia aperea) and other caviomorph . The registry of other levels of organization of notes and the presence of non - linear elements also enrich the communication system of the species and demonstrate its complexity. Our results come bring contributions to complement the description of the repertoire of the species that was larger and more complex

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