77 research outputs found

    The colour of paternity: extra-pair paternity in the wild Gouldian finch does not appear to be driven by genetic incompatibility between morphs.

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    In socially monogamous species, individuals can use extra-pair paternity and offspring sex allocation as adaptive strategies to ameliorate costs of genetic incompatibility with their partner. Previous studies on domesticated Gouldian finches (Erythrura gouldiae) demonstrated a genetic incompatibility between head colour morphs, the effects of which are more severe in female offspring. Domesticated females use differential sex allocation, and extra-pair paternity with males of compatible head colour, to reduce fitness costs associated with incompatibility in mixed-morph pairings. However, laboratory studies are an oversimplification of the complex ecological factors experienced in the wild, and may only reflect the biology of a domesticated species. This study aimed to examine the patterns of parentage and sex-ratio bias with respect to colour pairing combinations in a wild population of the Gouldian finch. We utilized a novel PCR assay that allowed us to genotype the morph of offspring before the morph phenotype develops, and to explore bias in morph paternity and selection at the nest. Contrary to previous findings in the laboratory, we found no effect of pairing combinations on patterns of extra-pair paternity, offspring sex ratio, or selection on morphs in nestlings. In the wild, the effect of morph incompatibility is likely much smaller, or absent, than was observed in the domesticated birds. Furthermore, the previously studied domesticated population is genetically differentiated from the wild population, consistent with the effects of domestication. It is possible that the domestication process fostered the emergence (or enhancement) of incompatibility between colour morphs previously demonstrated in the laboratory. This article is protected by copyright. All rights reserved

    Planning for success: Why conservation programs need a strategic program for recovering species

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    A substantial amount of money has been spent globally on threatened species management. While the number of threatened species continues to increase, we would expect to observe a portion of those receiving active management to respond positively and recover over time. Management of these recovering species requires a different approach to those which are declining. In particular, recovering species may require active monitoring as the primary management activity, once the threats causing their initial decline have been managed such that populations are stable or increasing. When prioritizing funding actions to improve species persistence (in particular with species prioritization approaches such as cost‐effectiveness rankings), we demonstrate that monitoring species to track their continued improvement would only occur in the (unlikely) scenario of comprehensive program funding. We provide one easily implemented solution to this - the establishment of a separately funded transitional management stream within which recovering or recovered species are prioritized for monitoring from a dedicated monitoring budget. We present a set of criteria to assess recovering species eligible for this management arrangement and demonstrate the successful application of this approach in New South Wales, Australia in the Saving our Species program

    Cognition in a changing world: Red-headed Gouldian finches enter spatially unfamiliar habitats more readily than do black-headed birds

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    Human activities are increasingly confronting animals with unfamiliar environmental conditions. For example, habitat change and loss often lead to habitat fragmentation, which can create barriers of unsuitable and unfamiliar habitat affecting animal movements and survival. When confronted with habitat changes, animals’ cognitive abilities play an important, but often neglected part in dealing with such change. Animals must decide whether to approach and investigate novel habitats (spatial neophilia) or whether to avoid them (spatial neophobia) due to potential danger. For species with strict habitat preferences, such as the Gouldian finch (Erythrura gouldiae), which is an open habitat specialist, understanding these novelty responses may be especially important for predicting responses to habitat changes. The Gouldian finch is a polymorphic species, with primarily red or black head colors, which are linked to differing behavioral phenotypes, including novelty reactions. Here we investigate responses to novel habitats (open, dense) in the Gouldian finch, manipulating the color composition of same-sex pairs. Two experiments, each consisting of novel open and novel dense habitat, tested birds in opposite head color combinations in the two experiments. We measured the number of approaches birds made (demonstrating conflict between approach and avoidance), and their entry latency to novel habitats. Gouldian finches showed more approach attempts (stronger approach-avoidance conflict) towards the dense as compared to the open habitat, confirming their open habitat preferences. Black-headed birds also hesitated longer to enter the dense habitat as compared to the open habitat, particularly in experiment 1, appearing less neophilic than red-headed birds, which showed similar entry latencies into both habitat types. This is surprising as black-headed birds were more neophilic in other contexts. Moreover, there was some indication that pairings including at least one black-headed bird had a stronger approach-avoidance conflict than pairings of pure red-headed birds. Results suggest that the black-headed birds use a cognitive strategy typical for residents, whereas red-headed birds use a cognitive strategy known for migrants/nomads, which may cognitively complement each other. However, as 70% of the population in the wild are black-headed, the spatial wariness we document could be widespread, which may negatively affect population persistence as habitats change

    Análise técnica e econômica do equipamento Stump Harvester

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    Orientador: Prof. Dr. Ricardo Anselmo MalinovskiMonografia (graduação) - Universidade Federal do Paraná,Setor de Ciências Agrárias, Curso de Engenharia Florestal.Resumo: As atividades de colheita florestal comumente geram uma grande quantidade de resíduos em plantios florestais de Pinus spp. e Eucalyptus spp, prejudicando as operações silviculturais. Dentre todos os tipos de resíduos florestais, os tocos constituem um grande dificultador das operações de implantação florestal como subsolagem, fertilização, plantio e manutenção. A redução da qualidade das operações pode levar à uma redução na área de efetivo plantio, reduzindo o número de árvores plantadas por hectare e subutilizando o sítio. Diante disso, buscam-se alternativas para remoção e aproveitamento de resíduos florestais. Quanto a remoção de tocos, uma alternativa atual é o equipamento stump harvester que consiste em um implemento específico para a remoção de tocos montado em uma escavadeira hidráulica. Diante disso, o presente trabalho avaliou técnica e economicamente o equipamento stump harvester para a reforma e realinhamento de plantios de Pinus taeda e Eucalyptus dunnii em uma empresa florestal do norte de Santa Catarina. Foram avaliados a produtividade, custos, receitas e indicadores econômicos no intuito de avaliar a viabilidade do investimento no equipamento. Como resultado de produtividade obteve-se uma média de 3,88 e 3,19 tocos/min para o Pinus taeda e Eucalyptus dunnii, respectivamente. O custo de remoção foi calculado em 1.521,47 R/haparaoPinustaedae1.778,72R/ha para o Pinus taeda e 1.778,72 R/ha para o Eucalyptus dunnii. Foram estimadas diversas situações de aumento de receitas com a utilização do equipamento. Quando utilizado somente para fins de reforma e realinhamento o uso do equipamento é inviável a uma taxa mínima de atratividade de 10%. Recomenda-se, entretanto, a quantificação e qualificação do material extraído para a produção de biomassa, pois, segundo literatura especializada, existe um grande potencial energético nesse material

    Synchronised provisioning at the nest: parental coordination over care in a socially monogamous species

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    Bi-parental care is very common in birds, occurring in over 90% of species, and is expected to evolve whenever the benefits of enhanced offspring survival exceed the costs to both parents of providing care. In altricial species, where the nestlings are entirely dependent on the parents for providing food until fledging, reproductive success is related to the capacity of the parents to provision the offspring at the nest. The degree to which parents synchronise their visits to the nest is rarely considered by studies of bi-parental care, and yet may be an important component of parental care, affecting the outcome of the reproductive attempt, and the dynamics of sexual conflict between the parents. Here we studied this aspect of parental care in the long-tailed finch (Poephila acuticauda), a socially monogamous estrildid finch. We monitored parental nest visit rates and the degree of parental visit synchrony, and assessed their effects on reproductive success (e.g., brood size, number of offspring fledged and nestling growth).The frequency of nest visits in a day was low in this species (<1 visit/h), but there was a high level of synchrony by the two partners with 73% of visits made together. There was a correlation between the proportion of visits that were made by the pair together and the size of the brood at hatching, although it was not related to the number of fledglings a pair produced, or the quality of those offspring. We suggest that nest visit synchrony may primarily be driven by the benefit of parents being together whilst foraging away from the nest, or may reduce nest predation by reducing the level of activity around the nest throughout the day

    Response behaviour of native lizards and invading wall lizard to interspecific scent: implications for invasion success

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    The human-assisted movement of species beyond their native range facilitates novel interactions between invaders and native species that can determine whether an introduced species becomes invasive and the nature of any consequences for native communities. Avoiding costly interactions through recognition and avoidance can be compromised by the naïvety of native species to novel invaders and vice versa. We tested this hypothesis using the common wall lizard, Podarcis muralis, and the native lizard species with which it may now interact in Britain (common lizard, Zootoca vivipara, sand lizard, Lacerta agilis) and on Vancouver Island (northern alligator lizard, Elgaria coerulea) by exploring species' responses (tongue flicks, avoidance behaviour) to heterospecific scent cues in controlled experiments. The tongue flick response of P. muralis depended on the different species’ scent, with significantly more tongue flicks directed to E. coerulea scent than the other species and the control. This recognition did not result in any other behavioural response in P. muralis (i.e. attraction, aggression, avoidance). Lacerta agilis showed a strong recognition response to P. muralis scent, with more tongue flicks occurring close to the treatment stimuli than the control and aggressive behaviour directed towards the scent source. Conversely, Z. vivipara spent less time near P. muralis scent cues than the control but its tongue flick rate was higher towards this scent in this reduced time, consistent with an avoidance response. There was no evidence of E. coerulea recognition of P. muralis scent in terms of tongue flicks or time spent near the stimuli, although the native species did show a preference for P. muralis-scented refuges. Our results suggest a variable response of native species to the scent of P. muralis, from an avoidance response by Z. vivipara that mirrors patterns of exclusion observed in the field to direct aggression observed in L. agilis and an ambiguous reaction from E. coerulea which may reflect a diminished response to a cue with a low associated cost. These results have significant implications for the invasive success and potential impacts of introduced P. muralis populations on native lizards

    Genetics and evidence for balancing selection of a sex-linked colour polymorphism in a songbird

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    Colour polymorphisms play a key role in sexual selection and speciation, yet the mechanisms that generate and maintain them are not fully understood. Here, we use genomic and transcriptomic tools to identify the precise genetic architecture and evolutionary history of a sex-linked colour polymorphism in the Gouldian finch Erythrura gouldiae that is also accompanied by remarkable differences in behaviour and physiology. We find that differences in colour are associated with an ~72-kbp region of the Z chromosome in a putative regulatory region for follistatin, an antagonist of the TGF-β superfamily genes. The region is highly differentiated between morphs, unlike the rest of the genome, yet we find no evidence that an inversion is involved in maintaining the distinct haplotypes. Coalescent simulations confirm that there is elevated nucleotide diversity and an excess of intermediate frequency alleles at this locus. We conclude that this pleiotropic colour polymorphism is most probably maintained by balancing selection

    Competition for resources mediated by intrinsic social dominance in sympatric finches

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    Gouldian Erythrura gouldiae and Long-tailed Finches Poephila acuticauda are morphologically and ecologically similar sympatric species, for which social dominance relationships are likely to determine access to critical limiting resources. Building on previous research showing that Long-tailed Finches dominate competition for nest-sites, I staged dyadic contests for food between the two species in captivity in order to test social dominance dynamics under controlled conditions. Long-tailed Finches were likely to dominate interactions with Gouldian Finches and expressed higher levels of aggression while competing for access to food. These results suggest a stable dominance relationship between the two species which could be affecting Gouldian Finches' access to food resources in the wild, potentially constraining their ability to recover from recent population declines.5 page(s

    Provisioning habitat with custom-designed nest-boxes increases reproductive success in an endangered finch

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    Manipulating resource availability to assess the strength and effects of resource limitation on an animal population is relatively straightforward, and thus, common in the scientific literature. Resource quality, however, is rarely manipulated, as this r
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