Experimentally induced increases in fecundity lead to greater nestling care in blue tits

This is the final version. Available on open access from the Royal Society via the DOI in this recordModels on the evolution of bi-parental care typically assume that maternal investment in offspring production is fixed and predict subsequent contributions to offspring care by the pair are stabilized by partial compensation. While experimental tests of this prediction are supportive, exceptions are commonplace. Using wild blue tits (Cyanistes caeruleus), we provide, to our knowledge, the first investigation into the effects of increasing maternal investment in offspring production for subsequent contributions to nestling provisioning by mothers and male partners. Females that were induced to lay two extra eggs provisioned nestlings 43% more frequently than controls, despite clutch size being made comparable between treatment groups at the onset of incubation. Further, experimental males did not significantly reduce provisioning rates as expected by partial compensation, and if anything contributed slightly (9%) more than controls. Finally, nestlings were significantly heavier in experimental nests compared with controls, suggesting that the 22% average increase in provisioning rates by experimental pairs was beneficial. Our results have potential implications for our understanding of provisioning rules, the maintenance of bi-parental care and the timescale over which current-future life-history trade-offs operate. We recommend greater consideration of female investment at the egg stage to more fully understand the evolutionary dynamics of bi-parental care.NERCRegion Midi-Pyrenee

Influência do aquecimento do substrato e ácido indolbutírico no enraizamento de estacas de mirtilo cvs. Bluegen, poder blue e blue belle.

Este trabalho teve como objetivo avaliar a influência do aquecimento do substrato e uso de concentrações de ácido indolbutírico no enraizamento de estacas das cultivares Bluegen, Powder Blue e Blue Belle. Estacas foram coletadas em 20/01/2005 de plantas a campo com dois anos de idade e levadas para laboratório, onde as mesmas foram seccionadas em comprimento de 6 cm e diâmetro variando entre 4 a 6 mm, deixando 1 par de folhas cortadas ao meio nas estacas. Em seguida, ocorreu a imersão das estacas em bandejas plásticas contendo hipoclorito de sódio a 0,5% por 15 minutos. Após, foram imersas em água destilada por 1 hora e por último foram imersas em solução antioxidante contendo Polyvinylpyrrolidone (PVP) por 1 hora. Após, as estacas foram tratadas com ácido indolbutírico (AIB) em concentrações de 1.000 e 3.000 mg.L-1 e água destilada como testemunha (O mg.L-1). As estacas após serem tratadas com o hormônio foram enraizadas em bandejas de alumínio contendo areia como substrato em ambiente com nebulização intermitente. Metade dos tratamentos foram submetidos a aquecimento do substrato que consistiu na manutenção da temperatura entre 22 e 24 ºC, por meio de aquecimento da água através de resistências elétricas, fazendo com que a água circule por meio de serpentinas de cobre colocadas dentro das bandejas contendo o substrato. O delineamento experimental foi o inteiramente casualizado, com arranjo fatorial 3 x 3 x 2 (cultivares x sem e com concentrações de AIB x sem e com aquecimento do substrato), com 4 repetições, sendo as unidades experimentais formadas por 15 estacas, perfazendo um total de 60 estacas por tratamento. Após 148 dias do início do experimento foi avaliada a porcentagem de estacas enraizadas. O enraizamento das estacas variou de 26,6% até 93,3%. O aquecimento do substrato em estacas da cultivar Bluegen, promoveu maiores percentuais de enraizamento, alcançando os melhores resultados em ausência de AIB, enquanto o aquecimento do substrato não influenciou o aumento do percentual de estacas enraizadas na cultivar Blue Belle. Quanto a cultivar Powder Blue, o aquecimento do substrato proporcionou melhores resultados em porcentagem de estacas enraizadas

Efeito do aquecimento do substrato, ácido indolbutírico e fertilizante orgânico no enraizamento de estacas de mirtilo cv. bluegen.

Este trabalho teve como objetivo avaliar o efeito do aquecimento do substrato e uso de concentrações de ácido indolbutírico e do fertilizante orgânico HFF turfa fértil® no enraizamento de estacas da cultivar Bluegen. Estacas foram coletadas em 26/01/2005 de plantas a campo com dois anos de idade e levadas para laboratório, onde as mesmas foram seccionadas em comprimento de 8 cm e diâmetro variando entre 4 a 6 mm, deixando 1 par de folhas cortadas ao meio nas estacas. Em seguida, ocorreu a imersão das estacas em bandejas plásticas contendo hipoclorito de sódio a 0,5% por 15 minutos. Após, foram imersas em água destilada por 1 hora e por último foram imersas em solução antioxidante contendo Polyvinylpyrrolidone (PVP) por 1 hora. Após, as estacas foram tratadas com ácido indolbutírico (AIB) em concentrações de SOO e 1.000 mg.L-1 e água destilada como testemunha (O mg.L-1). As estacas após serem tratadas com o hormônio foram enraizadas em bandejas de alumínio contendo areia como substrato em ambiente com nebulização intermitente. Metade dos tratamentos foram submetidos a aquecimento do substrato que consistiu na manutenção da temperatura entre 22 e 24 ºC, por meio de aquecimento da água através de resistências elétricas, fazendo com que a água circule por meio de serpentinas de cobre colocadas dentro das bandejas contendo o substrato. Após 30 dias do início do experimento, foi colocado o fertilizante orgânico HFF turfa fértil® em concentrações de O mL.L-1 e 5 mL.L-1 nas células onde estavam contidas as estacas. O delineamento experimental foi o inteiramente casualizado, com arranjo fatorial 3 x 2 x 2 (sem e com concentrações de AIB x sem e com aquecimento do substrato x sem e com fertilizante orgânico), com 3 repetições, sendo as unidades experimentais formadas por 13 estacas, perfazendo um total de 39 estacas por tratamento. Após 152 dias do início do experimento foi avaliada a porcentagem de estacas enraizadas O enraizamento das estacas variou de 53,8% até 100,0% entre os tratamentos. O aquecimento do substrato em estacas da cultivar Bluegen, promoveu maiores percentuais de enraizamento (84,6% até 100,0%) em comparação com as estacas acondicionadas em substrato sem aquecimento (53,8% até 74,8%), independente do uso de AIB e do fertilizante orgânico

The repeatability of cognitive performance:A meta-analysis

This is the author accepted manuscript. The final version is available from The Royal Society via the DOI in this record.Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we gathered 44 studies on individual performance of 25 species across six animal classes and used meta-analysis to assess whether cognitive performance is repeatable. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeatability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cognition across a range of taxa which, like behaviour, may be associated with fitness outcomes.PKYC is supported by Japan Society for the Promotion of Science (PE1801); JOvH was funded by an ERC consolidator grant (616474). MC and this research was supported by a grant from the Human Frontier Science Program to ASC and JM-F (RGP0006/2015)

Seasonal differences of corticosterone metabolite concentrations and parasite burden in northern bald ibis (Geronticus eremita): The role of affiliative interactions

The reproductive season is energetically costly as revealed by elevated glucocorticoid concentrations, constrained immune functions and an increased risk of infections. Social allies and affiliative interactions may buffer physiological stress responses and thereby alleviate associated effects. In the present study, we investigated the seasonal differences of immune reactive corticosterone metabolite concentrations, endoparasite burden (nematode eggs and coccidian oocysts) and affiliative interactions in northern bald ibis (Geronticus eremita), a critically endangered bird. In total, 43 individually marked focal animals from a freeranging colony were investigated. The analyses included a description of initiated and received affiliative interactions, pair bond status as well as seasonal patterns of hormone and endoparasite levels. During the reproductive season, droppings contained parasite eggs more often and corticosterone metabolite levels were higher as compared to the period after reproduction. The excretion rate of endoparasite products was lower in paired individuals than in unpaired ones, but paired animals exhibited higher corticosterone metabolite concentrations than unpaired individuals. Furthermore, paired individuals initiated affiliative behaviour more frequently than unpaired ones. This suggests that the reproductive season influences the excretion patterns of endoparasite products and corticosterone metabolites and that affiliative interactions between pair partners may positively affect endoparasite burden during periods of elevated glucocorticoid levels. Being embedded in a pair bond may have a positive impact on individual immune system and parasite resistance

Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita)

Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites’ oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species