Search results for " zoology"

Towards a tractable working hypothesis for deimatic displays

2016

Age, condition and dominance-related sexual ornament size before and during the breeding season in the black grouse Lyrurus tetrix

2018

Male ornaments function as honest cues of male quality in many species and are subject to intra- and intersexual selection. These ornaments are generally studied during peak expression, however their size outside the breeding season may determine ultimate ornament size and costliness, and as such reproductive success. We investigated whether male black grouse Lyrurus tetrix eye comb size was related to age, condition and measures of male dominance before and during the breeding season. Total combined eye comb size began to increase ~70 d before the start of the breeding season. Adult males (aged ≥ 2 yr old) had consistently larger eye combs than younger males (1 yr old) both before and duri…

Morphology, Genetics and Biology of Pterochloroides persicae Cholodkovsky (Hemiptera: Lachninae) and Their Effect on Pauesia antennata Mukerji (Hymen…

2021

Pauesia antennata Mukerji is a specific parasitoid of the brown peach aphid Pterochloroides persicae Cholodkovsky which causes severe damage on almond and peach in Tunisia. To control this pest, P. antennata was collected from Iran, introduced to Tunisia in 2011 and some of their biological parameters were studied in laboratory conditions. Therefore, in orchard, aphid population and sites/zones of Tunisia and aphid behaviour impact on the parasitoid have not been studied. Morphometric measurements, molecular analysis of P. persicae specimens collected from two Tunisian sites [(Akouda-Sousse (Site 1), Sfax (Site 2)] were studied and compared and aphid behaviour versus P. antennata was follow…

Environmental Fluctuations Drive Species' Competitive Success in Experimental Invasions

2020

Climate change is presumed to increase both the number and frequency of fluctuations in environmental conditions. Fluctuations can affect the ecological and evolutionary processes that make species more successful competitors. For example, fluctuating conditions can create selection pressures for traits that are profitable in adaptation to fast climate change. On an ecological timescale, environmental fluctuations can facilitate species competitive success by reducing other species’ population sizes. Climate change could then enhance species invasions into new areas if fluctuation-adapted invaders displace their native competitors in chancing environments. We tested experimentally whether f…

Pactola kuschelisp. nov. (Coleoptera: Curculionidae), a potential cause for the decline of the threatened New Caledonian conifer,Agathis montanade La…

2016

Agathis montana is a conifer endemic to New Caledonia and one of the most threatened (Critically Endangered) plant species of this area. The exact causes of its decline are still unknown. The authors describe the characteristics of A. montana, the history and methodology of population monitoring, and possible factors causing the decline and habitat degradation. In 2014, some twigs showing symptoms suggesting attack by wood-boring insects were collected. From these, imagines of an unknown weevil species belonging to the genus Pactola Pascoe (Eugnomini) were reared. The new species is described as Pactola kuscheli Mazur sp. nov. Colour photographs of the dorsal habitus, line drawings of taxon…

Comparative analysis of abundance–occupancy relationships for species at risk at both broad taxonomic and spatial scales

2015

The abundance–occupancy relationship is one of the most well-examined relationships in ecology. At the species level, a positive association has been widely documented. However, until recently, research on the nature of this relationship at broad taxonomic and spatial scales has been limited. Here, we perform a comparative analysis of 12 taxonomic groups across a large spatial scale (Canada), using data on Canadian species at risk: amphibians, arthropods, birds, freshwater fishes, lichens, marine fishes, marine mammals, molluscs, mosses, reptiles, terrestrial mammals, and vascular plants. We find a significantly positive relationship in all taxonomic groups with the exception of freshwater…

The mechanistic basis of demographic Allee effects: The search for mates

2017

In Focus: Berec, L., Kremer, A.M., Bernhauverova, V., & Drake, J.M. (2017). Density-dependent selection on mate-finding Allee effects. Journal of Animal Ecology, 87, 24-35. https://doi.org/10.1111/1365-2656.12662 In Focus: Shaw, A.K., Kokko, H., & Neubert, M.G. (2017). Details of mate finding drive dynamics of sex structured invasions. Journal of Animal Ecology, 87, 36-46. https://doi.org/10.1111/1365-2656.12658 Lowered population growth ability at low abundances is called the demographic Allee effect. The difficulty of finding mates in a sparse population is the best documented pathway through which a demographic Allee effect might arise. The articles in focus here aim to establish the mec…

Individual level consistency and correlations of fish spatial behaviour assessed from aquatic animal telemetry

2017

The potential for populations to undergo adaptive evolution depends on individual variation in traits under selection and how multiple traits are correlated. While fitness relates to the performance of animals in the wild, most of the research on evolutionary potential of behavioural traits has used captive or mesocosm settings, especially with aquatic organisms. We investigated the individual level consistency (personalities) and correlations (behavioural syndromes) of fitness-related behavioural traits displayed by a harvested marine fish in the natural environment, and the potential of such individual level behaviour to constrain adaptive evolution. For this, we acoustically tracked 303 …

Density dependence of infanticide and recognition of pup sex in male bank voles

2010

[Infanticide — the killing of conspecific young — is a common phenomenon in many invertebrate and vertebrate species, particularly common in rodents. It can increase juvenile mortality and, thus, affect population growth. Male infanticide is explained by adaptive hypotheses based on sexual selection. Removing future competitors for mating opportunities would require recognition of pup sex and directing infanticide against male pups. We studied whether the sex of a pup and population density affect male bank voles' ( Myodes glareolus ) aggressive behaviour towards conspecific pups. Population density increased aggressiveness. Against our predictions, male bank voles from high density populat…

Is Mating Alone Enough to Inhibit Infanticide in Male Bank Voles?

2010

Infanticide, the killing of conspecific young, is commonly recognized as an adaptive behavioural strategy enhancing the fitness of the perpetrator. Infanticide is supposed to be inhibited in several male rodent species after mating with a time lag to the time when perpetrators own offspring would be born. This is because males with no parental care do not recognize their own offspring. It has been suggested that copulation alone is enough to inhibit infanticidal behaviour in male rodents. Infanticidal behaviour occurs in more than 50% of male bank voles (Myodes glareolus), and offspring loss because of infanticide may have a great effect on breeding success and population recruitment. In a …