Influence of spatial and temporal dynamics of agricultural practices on the lesser kestrel

1. European agriculture is facing dramatic changes that are likely to have marked impacts on farmland biodiversity. There is an urgent need to develop land management strategies compatible with the conservation of biodiversity.2. We applied a spatially explicit behaviour-based model to assess how farmland management and the pattern of events across the annual farming calendar influences the foraging decisions of lesser kestrels Falco naumanni in a cereal steppe landscape. Moreover, we simulated the most likely scenarios of future agricultural changes to predict its impacts on lesser kestrel breeding success. Lesser kestrels have been the subject of serious conservation concern and constitute a good model species to judge impacts on farmland species more widely.3. Our results show that the location of cereal and fallow patches within a 2-km radius of a kestrel colony influences the total food supply delivered to the nestlings, explaining the differences in breeding success between years and colonies. Furthermore, the particular sequence in which patches are harvested by farmers is also predicted to influence offspring survival.4. Agricultural intensification, simulated by increasing the proportion of cereal fields, is predicted to negatively influence breeding success. However, the field harvesting sequence can play an important role in alleviating the effects of the increased percentage of cereal, as demonstrated by the higher breeding success obtained when harvesting starts from patches farthest from the colonies. The replacement of cereal cultivation by low-intensity grazed fallows would not be detrimental for kestrels.5. Synthesis and applications. Our results highlight the effectiveness of behaviour-based models to evaluate the interacting effect of spatial and temporal dynamics of agricultural landscapes and predict the response of populations to environmental change. To optimize food availability for lesser kestrels, land managers should implement long rotational schemes with < 60% of the area under extensive cereal cultivation in a 2-km radius around colonies. Harvesting should start in the cereal patches farthest from colonies. Ideally, the predominant land use around colonies should be fallows. These outcomes illustrate how behaviour-based models can be applied to identify specific management recommendations that would improve the effectiveness of agri-environmental schemes, the most accepted tool for maintaining farmland landscapes

Pengaruh Kompensasi Terhadap Kinerja Karyawan pada Koperasi Jaya Abadi

Human resources have a major role in an organization or company. All aspects related to human resources in the end also affect performance, especially in relation to employee performance, in this study the authors focus on Employee Compensation and Performance. This study aims to determine empirically the effect of compensation on employee performance at the Jaya Abadi Cooperative. This study uses a population and a sample of 30 employees as respondents. The data collection technique used an online questionnaire with a google form that was sent to the respondents. The data obtained were analyzed using simple linear regression analysis. The results obtained indicate a real and significant effect of compensation variables on employee performance.Sumber daya manusia memiliki peran yang utama dalam sebuah organisasi atau perusahaan. Semua aspek yang berkaitan dengan sumber daya manusia pada akhirnya juga mempengaruhi kinerja terutama kaitannya dengan kinerja karyawan, dalam penelitian ini penulis fokus pada Kompensasi dan Kinerja Karyawan. Penelitian ini bertujuan untuk mengetahui secara empiris pengaruh kompensasi terhadap kinerja karyawan pada Koperasi Jaya Abadi. Penelitian ini menggunakan populasi dan sampel sebanyak 30 karyawan yang dijadikan sebagai responden. Teknik pengumpulan data menggunakan kuesioner online dengan google form yang dkirimkan kepada responden. Data yang diperoleh dianalisis dengan menggunakan analisis regresi linier sederhana. Hasil penelitian yang diperoleh menunjukkan adanya pengaruh yang nyata dan signifikan variabel kompensasi terhadap kinerja karyawan

Body size, assortative mating and divorce rates in a little-known skua taxon, the Falkland Skua Stercorarius antarcticus antarcticus

Several studies have attempted to identify the selective pressures leading to reversed size dimorphism (RSD), a characteristic of skuas and of a wide range of bird species with a raptorial lifestyle. One of the prevailing hypotheses posits that females in species of aggressive and well-armed males should select males that are smaller than themselves, to avoid injuries during pair formation and mating. This hypothesis predicts assortative mating by size in such species, and in previous research, this was confrmed to occur in two skua species. This study presents, for the frst time, biometric data for Falkland Skuas Stercorarius antarcticus antarcticus based on large sample sizes. Despite the clear RSD, we found no assortative mating by size, which could be related to the low divorce rates and few opportunities for mate selection in this population. Our results highlight the need for further work to fnd an explanatory hypothesis for the evolution and maintenance of reversed size dimorphism in skuas.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

Within an between-year winter-site fidelity of Chiffchaffs Phylloscopus collybita

Current knowledge concerning between-year winter site fidelity in passerines suggests there might be important inter-specific and regional variations in recurrence rates (the proportion of birds recaptured in years subsequent to marking). However, there are virtually no studies reporting low recurrence rates that show this not to be simply the result of low recapture probabilities. This problem can be particularly acute for partly nomadic and mostly non-territorial species in their winter quarters. The present study shows that, in spite of the apparently nomadic behaviour of wintering Chiffchaffs Phylloscopus collybita, some individuals can become temporarily sedentary. Temporarily sedentary Chiffchaffs have very small linear home-ranges (ca. 200m) and their calculated recapture probability (by re-sighting of colour-ringed birds) is high. In spite of that, recurrence rate of temporarily sedentary birds is very low, suggesting that the majority of the surviving individuals are not site faithful. This is in contrast to what has been found in several detailed studies in other Sylviidae and also Parulidae involving mostly territorial birds. The type of approach developed here should be used in other studies before any comparisons and generalisations involving winter-site fidelity results are attempted

Provenance does matter: links between winter trophic segregation and the migratory origins of European robins

Amongst migratory species, it is common to find individuals from different populations or geographical origins sharing staging or wintering areas. Given their differing life histories, ecological theory would predict that the different groups of individuals should exhibit some level of niche segregation. This has rarely been investigated because of the difficulty in assigning migrating individuals to breeding areas. Here, we start by documenting a broad geographical gradient of hydrogen isotopes (δ2H) in robin Erithacus rubecula feathers across Europe. We then use δ2H, as well as wing-tip shape, as surrogates for broad migratory origin of birds wintering in Iberia, to investigate the ecological segregation of populations. Wintering robins of different sexes, ages and body sizes are known to segregate between habitats in Iberia. This has been attributed to the despotic exclusion of inferior competitors from the best patches by dominant individuals. We find no segregation between habitats in relation to δ2H in feathers, or to wing-tip shape, which suggests that no major asymmetries in competitive ability exist between migrant robins of different origins. Trophic level (inferred from nitrogen isotopes in blood) correlated both with δ2H in feathers and with wing-tip shape, showing that individuals from different geographic origins display a degree of ecological segregation in shared winter quarters. Isotopic mixing models indicate that wintering birds originating from more northerly populations consume more invertebrates. Our multi-scale study suggests that trophic-niche segregation may result from specializations (arising in the population-specific breeding areas) that are transported by the migrants into the shared wintering grounds