140 research outputs found

    A new female-like morph of juvenile male Levant Sparrowhawk (Accipiter brevipes) – Sexual mimicry to avoid intra-specific predation?

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    In migrant Levant Sparrowhawk (Accipiter brevipes) at Eilat, Israel, we noted that juvenile males had two different morphs – the one described to date in literature; and a second, previously undescribed morph, with femalelike barring on the chest and flanks interspersed with tear-shaped elongated spots, giving an overall female-like appearance. Here we forward the hypothesis that explain the evolutionary consequences for the female-like plumage of juvenile males as that of intra-specific sex mimicry developed to avoid intra-specific predation by the larger females

    Avian Haemosporidian blood parasite infections at a migration hotspot in Eilat, Israel

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    Haemosporidian blood parasites are frequent amongst passerines. Though they often do not cause detectable  consequences to host health, however, their presence or absence and also their prevalence across host  populations may potentially carry meaningful information about the health, stress, body condition and viability of bird individuals or populations. The study of migratory birds captured in Eilat, Israel, allowed us to evaluate the prevalence of blood parasite infections in a wide range of both migrant and resident species in spring (N = 1,950) and autumn (N = 538) of 2004 and 2005. According to blood film microscopy, Haemoproteus spp. and Leucocytozoon spp. were more prevalent in the spring than in the autumn (0.289, 0.082 vs. 0.132, 0.033, respectively), whilst Plasmodium spp. exhibited a slight opposite trend (0.034, 0.056). All other parasites (such as trypanosomes, microfilaria and haemococcidians) were rare. During the spring seasons, prevalences were significantly higher in migrant than in resident species, whilst this difference was only marginally significant in the autumn. Given that Eilat is a migration hotspot for several Palearctic passerine species, the present descriptive study may hopefully serve to set the baseline values for future long-term epidemiological monitoring

    Effects of recreational activity on Acorn Barnacle (Tetraclita squamosa rufotincta) in the Red Sea

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    Environmental recreation is a fast growing industry. However, in many cases the consequences for the environment are ignored. Eilat is just such a case wherein tourism is the mainstay of the city and the Red Sea is the main attraction. Most areas are developed specifically for enhancing tourism and one of the most benign of creatures, that sits permanently on rocks and seashores, is trodden upon regularly is the Acorn Barnacle (Tetraclita squamosa rufotincta). We surveyed 10 sites with the same area for the number of barnacles that were live, dead or deserted. We compared between areas frequented by recreationists, and from which, they were denied access. We found a significantly greater number of individuals, live barnacles, and fewer deserted barnacles in the restricted areas. We conclude that the Acorn Barnacles in the undisturbed areas had significantly greater probability of survival and longevity compared to those exposed to anthropogenic activity

    A review of falconry as a bird control technique with recommendations for use at the Shuttle Landing Facility, John F. Kennedy Space Center, Florida, USA

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    Falconry has been proposed as a method of reducing the bird/aircraftstrike hazard, in addition to current bird control techniques, at the Shuttle Landing Facility (SLF), John F. Kennedy Space Center (KSC), Florida, U.S. Bird control programs using falconry have been employed at a number of military and commercial airfields in the U.S., Canada, and Europe. Most falconry programs have been discontinued. In most situations, falconry did not prove cost effective when compared to alternative bird control techniques. Available literature and documents, as well as several raptor specialists and military personnel, suggest that falconry may be useful only against certain problem species and when other bird control methods have been proven inadequate. Because many of the most commonly used falcons are protected species, acquisition of falcons will complicate their use in bird control programs. Many avian species found at the SLF are federally and state protected or of conservation concern, therefore, environmental impacts may also result from the use of falcons

    Distributed under Creative Commons CC-BY 4.0 OPEN ACCESS Difference on cone size preferences between two coniferous species by Great Spotted Woodpecker (Dendrocopos major)

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    ABSTRACT The number of species that specialize in pre-dispersal seed predation is relatively small. Examples of specialized pre-dispersal seed predators adapted to feeding on closed cones include vertebrate species like Crossbills, Squirrels, Nutcrackers and Woodpeckers. Seed predation selects against certain phenotypic features of cones and favors another phenotypic features. In this study, we document preferences of the Great Spotted Woodpecker (Dendrocopos major) for specific traits in the cones of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris). We found that the Great Spotted Woodpecker prefers to feed on medium sized Norway spruce cones. The results suggest a disruptive selection that favors the extreme cone lengths in Norway spruce. In Scots pine, the woodpeckers avoided cones with large apophyses. Further, the selectivity for the specific characteristics of the cones is probably related to the configuration of the anvil, a place at which woodpeckers extract seeds from the cones. We think that the Great Spotted Woodpecker preferences in relation to the morphological characteristics of cones are a key to the design of the anvil in order to maximize the use of it as a tool for processing cones of both the Norway spruce and the Scots pine

    NQO1 Binds and Supports SIRT1 Function

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    Silent information regulator 2-related enzyme 1 (SIRT1) is an NAD+-dependent class III deacetylase and a key component of the cellular metabolic sensing pathway. The requirement of NAD+ for SIRT1 activity led us to assume that NQO1, an NADH oxidoreductase producing NAD+, regulates SIRT1 activity. We show here that SIRT1 is capable of increasing NQO1 (NAD(P)H Dehydrogenase Quinone 1) transcription and protein levels. NQO1 physically interacts with SIRT1 but not with an enzymatically dead SIRT1 H363Y mutant. The interaction of NQO1 with SIRT1 is markedly increased under mitochondrial inhibition. Interestingly, under this condition the nuclear pool of NQO1 is elevated. Depletion of NQO1 compromises the role of SIRT1 in inducing transcription of several target genes and eliminates the protective role of SIRT1 following mitochondrial inhibition. Our results suggest that SIRT1 and NQO1 form a regulatory loop where SIRT1 regulates NQO1 expression and NQO1 binds and mediates the protective role of SIRT1 during mitochondrial stress. The interplay between an NADH oxidoreductase enzyme and an NAD+ dependent deacetylase may act as a rheostat in sensing mitochondrial stress

    Adjusting risk-taking to the annual cycle of long-distance migratory birds

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    International audienceLife-history theory predicts that current behaviour affects future reproduction, implying that animals should optimise their escape strategies to reflect fitness costs and benefits of premature escape. Both costs and benefits of escape may change temporally with important consequences for the evolution of escape strategies. Moreover, escape strategies of species may differ according to their positions on slow-fast pace of life gradients. We studied risk-taking in long-distance migratory animals, waders (Charadriiformes), during the annual cycle, i.e., breeding in Europe, stopover in the Middle East and wintering in tropical Africa. Phylogenetically informed comparative analyses revealed that risk-taking (measured as flight initiation distance, FID) changed significantly over the year, being lowest during breeding and peaking at stopover sites. Similarly, relationships between risk-taking and life-history traits changed among stages of the annual cycle. While risk-taking significantly decreased with increasing body mass during breeding, risk-taking-body mass relationship became marginally significant in winter and disappeared during migration. The positive trend of risk-taking along slow-fast pace of life gradient measured as adult survival was only found during breeding. The season-dependent relationships between risk-taking and life history traits suggest that migrating animals respond to fluctuating environments by adopting behavioural plasticity

    The first Neanderthal remains from an open-air Middle Palaeolithic site in the Levant

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    The late Middle Palaeolithic (MP) settlement patterns in the Levant included the repeated use of caves and open landscape sites. The fossil record shows that two types of hominins occupied the region during this period - Neandertals and Homo sapiens. Until recently, diagnostic fossil remains were found only at cave sites. Because the two populations in this region left similar material cultural remains, it was impossible to attribute any open-air site to either species. In this study, we present newly discovered fossil remains from intact archaeological layers of the open-air site 'Ein Qashish, in northern Israel. The hominin remains represent three individuals: EQH1, a nondiagnostic skull fragment; EQH2, an upper right third molar (RM3); and EQH3, lower limb bones of a young Neandertal male. EQH2 and EQH3 constitute the first diagnostic anatomical remains of Neandertals at an open-air site in the Levant. The optically stimulated luminescence ages suggest that Neandertals repeatedly visited 'Ein Qashish between 70 and 60 ka. The discovery of Neandertals at open-air sites during the late MP reinforces the view that Neandertals were a resilient population in the Levant shortly before Upper Palaeolithic Homo sapiens populated the region
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