The role of conspecific social information on male mating decisions

Tese de doutoramento, Biologia (Etologia), Universidade de Lisboa, Faculdade de Ciências, 2018Behavioural plasticity occurs when animals adjust their behaviour to current environmental conditions. Research suggests that this ability helps animals cope with changeable environments, especially in the social domain, where social information is highly variable and unpredictable. In this thesis I evaluated the contribution of the complexity of social information to: 1) male mating behaviours, 2) evolution of courtship display, and 3) evolution of dishonest communication. For male mating behaviours, I performed experiments with guppies (Poecilia reticulata). I predicted that males would invest more on mating attempts if they spend more time without mating (chapter 2), and when there was a higher probability of mating success or fertilization success (chapters 3 and 4). I found that time between encounters with females (not time between actual mating opportunities) was determinant to male investment. Moreover, males did not avoid encountering competitors but invested more when they were the first to arrive near females (not the last), and when competing against more attractive males (but only for orange colouration). These evidences support that males produce complex plastic responses in face of diverse social information. For the evolution of courtship display and dishonest communication, my hypothesis was that competitor (bystander) males use the courtship performance of other males as information about their competitive ability, and that displayer males adjust their behaviour accordingly. For this, I performed systematic reviews (chapter 5), where I found that male male courtship display is, indeed, frequently associated with intrasexual competition, suggesting that courtship display has evolved a dual utility: attract females and intimidate competitors. A corollary of this, which I developed in a conceptual study (chapter 6), is that males can display dishonestly to deter competitors. If so, the interference of bystanders in communication systems could have a non-negligent role in the evolution of dishonest signalling

The expansion and establishment of the New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) in the freshwater ecosystems of Madeira Island (NE Atlantic)

This study reports the spread of the New Zealand mud snail Potamopyrgus antipodarum throughout freshwater ecosystems of Madeira Island, located in the NE Atlantic. Potamopyrgus antipodarum was first detected in 2017–2018 in two streams located in the north coast of the island. Since then, we have visually inspected the island's freshwater ecosystems and detected this gastropod in nine other streams. Previous evidence suggests that this species was introduced to Madeira since at least 2017, likely in the northern part. Our findings indicate that P. antipodarum is now well established in the initial invaded locations and has since spread to the south region and upper streams of the island. Although it is difficult to conclusively determine the origin and vector of this introduction, it is plausible to assume that humans and fish may have contributed to its current distribution. Our records represent the first evidence of vast geographical distribution of P. antipodarum on Madeira Island. Madeira seems to be the first invaded oceanic island of Macaronesia and the westernmost European distribution range for this invasive species.info:eu-repo/semantics/publishedVersio

Production, characterization and application of activated carbon from brewer’s spent grain lignin

Different types of activated carbon were prepared by chemical activation of brewer’s spent grain (BSG) lignin using H3PO4 at various acid/lignin ratios (1, 2, or 3 g/g) and carbonization temperatures (300, 450, or 600 °C), according to a 22 full-factorial design. The resulting materials were characterized with regard to their surface area, pore volume, and pore size distribution, and used for detoxification of BSG hemicellulosic hydrolysate (a mixture of sugars, phenolic compounds, metallic ions, among other compounds). BSG carbons presented BET surface areas between 33 and 692 m2/g, and micro- and mesopores with volumes between 0.058 and 0.453 cm3/g. The carbons showed high capacity for adsorption of metallic ions, mainly nickel, iron, chromium, and silicon. The concentration of phenolic compounds and color were also reduced by these sorbents. These results suggest that activated carbons with characteristics similar to those commercially found and high adsorption capacity can be produced from BSG lignin.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Brazil)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

From plates to baits: using a remote video foraging system to study the impact of foraging on fouling non-indigenous species

Marinas are a gateway for the introduction and establishment of non-indigenous species (NIS). In these habitats, competition and predation are crucial determinants for NIS establishment and invasiveness. However, fish trophic preferences and biotic effects inside marinas are poorly known. This study proposes a novel method that combines the deployment of settlement plates to recruit different assemblages, followed by their use as bait in remote underwater video systems. This combined approach, addressed as a remote video foraging system (RVFS), can record fish foraging behaviour, including feeding choices and their impacts on fouling assemblage composition. An experimental RVFS trial carried out in a marina of Madeira Island, Portugal (NE Atlantic), identified the Mediterranean parrotfish, Sparisoma cretense, as the most important fouling grazer in the area. S. cretense behaved as a generalist and increased the heterogeneity of fouling assemblages, which can hamper NIS dominance of the fouling and reduce the pressure of propagules from the marina to the natural environment. The RVFS tool was useful to understand the trophic links between foragers and fouling and has the potential to provide relevant information for the management of NIS introductions, establishment and spread.info:eu-repo/semantics/publishedVersio

Searching for the critically endangered European eel in oceanic islands: a pioneer study in the freshwater systems of Madeira, Macaronesia

1. The globally threatened European eel (Anguilla anguilla) is the only freshwater fish native to Macaronesia. Despite being a keystone species to freshwater habitats, little is known about its population, environmental associations and conservation requirements in oceanic islands. 2. The density and geographical-related factors influencing the distribution of A. anguilla in the subtropical Archipelago of Madeira (Portugal) were examined. Data on the species occurrence was initially collected using an online survey addressed to citizens. Eels were then sampled through electrofishing in 31 sampling sites along 11 streams on Madeira Island, and eel-habitat associations were investigated using LMMs and GLMMs. One stream was also sampled in Porto Santo Island. 3. The presence of A. anguilla was confirmed in the two islands of the archipelago with streams (Madeira and Porto Santo). Eels are distributed throughout Madeira Island, being more abundant – particularly small size individual– at lower altitudes (mostly below 150 m). The number of weirs was an important predictor of eel density, suggesting that these flood-control structures limit their upstream migration. 4. This study represents a pioneer sampling effort of the European eel in Madeira and results provide much-needed baseline information on the species distribution and related environmental factors in oceanic islands. While most eel research has historically focused on mainland habitats where dams pose a significant threat to eel habitats, our study underscores the critical importance of addressing smaller, often overlooked barriers that may also cause habitat fragmentation. 5. The European eel is a panmictic species, thus, the conservation of the Macaronesian subpopulations can have substantial benefits for its global recovery. A comprehensive investigation of the impact of man-made obstacles on eel habitat is still needed. Similarly, other common threats such as interactions with non-indigenous species and infection by Anguillicola crassus should be a research priority in future studies

Stone-stacking as a looming threat to rock-dwelling biodiversity

Non peer reviewe

Interferências sexuais nos cavalos de Sorraia da Coudelaria de Alter

Tese de mestrado em Ecologia e Gestão Ambiental, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2007Embora existam referências a interferências sexuais (interrupção da cópula por outra fêmea) em equídeos, nenhum trabalho em cavalos sobre este tema foi publicado e anteriores resultados não foram conclusivos. Por isso, este estudo pretendia averiguar quais as causas, funções e o impacto deste comportamento numa raça autóctone portuguesa, considerada em risco crítico de extinção. Para tal foram realizadas observações de uma subpopulação de cavalos de Sorraia presente na Coudelaria de Alter, constituída por 16 éguas e 1 macho. A anteceder a análise das interferências sexuais, foi determinada a posição de dominância de cada indivíduo e as preferências sexuais do macho. Como esperado a hierarquia era aproximadamente linear e o macho, por representar um novo membro no grupo, apresentou uma posição de dominância inferior. Embora o grau hierárquico estivesse correlacionado com a idade, os resultados sugerem que o tempo de residência é o principal factor da posição individual de dominância. As tentativas de acasalamento foram dirigidas preferencialmente a éguas com quem o vínculo ao garanhão era mais forte. No entanto, o nível de selecção sexual do macho era baixo e a idade e grau hierárquico das éguas não influenciaram as investidas sexuais, possivelmente devido à inexperiência do garanhão. As interferências sexuais ocorreram em 30% das tentativas de acasalamento observadas e apresentaram uma elevada taxa de sucesso na sua interrupção. Em geral a égua interferente era dominante, com elevado parentesco à fêmea do casal e a interferência consistia, predominantemente, em comportamentos agonísticos. Quando a interferente se encontrava sexualmente receptiva raramente ameaçava o macho e viceversa. A maioria das interacções dirigidas à égua do casal era realizada por uma fêmea em estro. Das hipóteses analisadas as que melhor se enquadram nos resultados são: dominância em relação ao macho e competição sexual entre éguas aparentadasAlthough there are references to sexual interferences (copulation interruption by other female) in equines, no work in horses about this issue as been published and the previous results have not been conclusive. For that reason, this study aimed to investigate what were the causes, functions and impact of this behaviour on an autochthonous Portuguese breed, considered to be at critical risk of extinction. Therefore, observations where made to a sub-population of Sorraia horses present in Coudelaria de Alter, composed of 16 mares and 1 stallion. Anticipating the analysis of the sexual interferences, both the position of dominance of each individual and the male sexual preferences were determined. As expected, the hierarchy was approximately linear and the male, once it constituted a new member on the group, presented a lower dominance position. Although the hierarchical degree was correlated with age, the results suggest that residence time is the main factor for the individual dominance position. Mating attempts were mainly directed to mares with which the stallion had a greater bond. However, the level of ale sexual selection was low and the mare's age and hierarchical degree didn't influence sexual attempt, possibly due to the stallion's inexperience. The sexual interferences occurred in 30% of the observed mating attempts and presented a high level of success in its interruption. In general, the interferer mare was dominant, with a high kinship to the female of the couple and the interference itself consisted, predominantly, in agonistic behaviours. When the interferer was sexually receptive, it rarely threatened the male and vice-versa. The majority of interactions directed to the mare of the couple were done by an oestrus female. The investigated hypotheses that better fit in the results are: dominance in relation to the male and sexual competition between related mare

The role of intrasexual competition on the evolution of male-male courtship display:a systematic review

BackgroundEvidence of male-male courtship display is widespread across the animal kingdom. Yet, its function and evolutionary origin remain unclear. Here, we hypothesise that male-male courtship display evolved in response to selection pressure exerted by intrasexual competition during male-female courtship interactions. Intrasexual competition can be caused by bystander male pressure through eavesdropping and exploiting on displayer male’s courtship interactions with females. This bystander pressure can lead to an audience effect by the displayer, who will change their courtship behaviour in the presence of bystanders and display directly towards them, even in the absence of females, as an intimidation strategy. In species where this selection pressure has taken place, we predict that the male courtship display will have a dual function: attract females and deter competitors. Therefore, we expected to find more evidence of bystander-related behaviours in species for which male-male courtship display is linked to intrasexual competition compared to species for which other explanatory hypotheses are more plausible (e.g., mistaken identity or courtship practice).MethodologyWe conducted two systematic reviews to test this hypothesis. First, we conducted a search for studies of species with courtship display between males and of the hypotheses provided to explain this behaviour. Our goal was to identify the species with male-male courtship display and evidence of intrasexual competition. Second, among the species with male-male courtship display, we searched for evidence of bystander-related behaviours, i.e., articles referring to eavesdropping, exploitation, and audience effect during male-female courtship interactions. Our goal was to test whether species with intrasexual competition are also more likely to show bystander-related behaviours.ResultsAlthough most studies reporting male courtship display towards other males do not suggest any explanatory hypothesis for this behaviour, the intrasexual competition hypothesis was largely mentioned and supported by some studies reviewed. Additionally, there is more evidence of eavesdropping and of all three bystander-related behaviours combined in species for which the intrasexual competition hypothesis was suggested.ConclusionsOverall, our review supports the hypothesis that intrasexual competition can play a key role in male courtship display evolution, namely that male-male courtship display may have evolved as a secondary function of male-female courtship interactions via bystander male pressure. However, our review also shows that despite the increasing interest in same-sex sexual behaviours, and male-male courtship display in particular, most studies were found to be merely descriptive, and the hypotheses they suggested to explain courtship display between males mostly speculative. This highlights an important gap in the literature. To clarify both the evolution and the function of male-male courtship display, this behaviour needs to be empirically studied more often. Our review can help advancing this research area, as it makes the 20 species with male-male courtship display for which the intrasexual competition hypothesis was suggested excellent candidates for empirical research.</p

Giant cell arteritis presenting as multiple ischaemic strokes: a successful case of endovascular treatment

Giant cell arteritis (GCA) may manifest with aggressive intracranial stenosis resistant to medical therapy, and patients may develop refractory neurologic deficits and cerebral infarcts, making GCA a life-threatening condition. We report the case of a 68-year-old woman recently diagnosed with GCA, medicated with prednisolone 60 mg daily. Two weeks later, the patient was admitted to our Stroke Unit after a sudden episode of global aphasia. Magnetic resonance angiography showed two recent ischaemic lesions, besides an erythrocyte sedimentation rate of 17 mm/hour. A cerebral angiography revealed bilateral stenosis and dilation in the petrous, cavernous and supraclinoid segments of internal carotid arteries (ICA). The patient was started on intravenous methylprednisolone pulses (250 mg daily for five days). Computed tomography (CT) angiography and Doppler ultrasound showed severe vascular disease affecting multiple territories, without significant intracranial involvement. The hypothesis of GCA with extracranial vasculitic involvement was considered as the aetiology of ischaemic cerebral infarctions in multiple territories and, given the severity of the disease, it was decided to add tocilizumab. Despite this, the patient evolved with significant worsening neurological deficits and a CT scan confirmed the presence of new vascular events. Endovascular treatment (EVT) with balloon angioplasty was conducted on both ICAs, with improved calibre and downstream filling. After that, the patient presented sustained clinical improvement, without recurrence of any ischaemic events at the one-year follow-up. This clinical case stands out for the importance of EVT as an effective therapy in patients with medically refractory GCA with symptomatic intracranial stenosis, improving their prognosis