Search results for "FALC"
showing 10 items of 200 documents
Asymmetrical interspecific communication of predatory threat in mixed-species colonies of lesser kestrels (Falco naumanni) and jackdaws (Corvus moned…
2019
Sympatric species derive benefits by attending to information conveyed by heterospecifics. Our previous finding of reduced vigilance among jackdaws and lesser kestrels residing in mixed-species colonies suggested a reliance on interspecific communication of information regarding predatory threats. To test for interspecific communication of threat, we first determined whether jackdaw and lesser kestrel call structure varied with perceived threat. In this call production phase of our study, free-living birds in mixed-species colonies were presented with models representing a potential nest predator (European magpie) or with non-threatening stimuli (wood pigeon or wooden dowel) in proximity to…
Arctic avian predators synchronise their spring migration with the northern progression of snowmelt
2020
AbstractMigratory species display a range of migration patterns between irruptive (facultative) to regular (obligate), as a response to different predictability of resources. In the Arctic, snow directly influences resource availability. The causes and consequences of different migration patterns of migratory species as a response to the snow conditions remains however unexplored. Birds migrating to the Arctic are expected to follow the spring snowmelt to optimise their arrival time and select for snow-free areas to maximise prey encounter en-route. Based on large-scale movement data, we compared the migration patterns of three top predator species of the tundra in relation to the spatio-te…
Current and future suitability of wintering grounds for a long-distance migratory raptor
2017
Conservation of migratory species faces the challenge of understanding the ecological requirements of individuals living in two geographically separated regions. In some cases, the entire population of widely distributed species congregates at relatively small wintering areas and hence, these areas become a priority for the species’ conservation. Satellite telemetry allows fine tracking of animal movements and distribution in those less known, often remote areas. Through integrating satellite and GPS data from five separated populations comprising most of the breeding range, we created a wide habitat suitability model for the Eleonora’s falcon on its wintering grounds in Madagascar. On this…
Predator presence may benefit: kestrels protect curlew nests against nest predators.
1994
We studied whether the presence of breeding kestrels (Falco tinnunculus) affected nest predation and breeding habitat selection of curlews (Numenius arquata) on an open flat farmland area in western Finland. We searched for nests of curlews from an area of 6 km2 during 1985–1993. For each nest found, we recorded the fate of the nest, and the distance to the nearest kestrel nest and to the nearest perch. We measured the impact of breeding kestrels on nest predation by constructing artificial curlew nests in the vicinity of ten kestrel nests in 1993. Curlew nests were closer to kestrel nests than expected from random distribution, eventhough kestrels fed on average 5.5% of curlew chick produc…
Social phenotype extended to communities: Expanded multilevel social selection analysis reveals fitness consequences of interspecific interactions
2015
In social species, fitness consequences are associated with both individual and social phenotypes. Social selection analysis has quantified the contribution of conspecific social traits to individual fitness. There has been no attempt, however, to apply a social selection approach to quantify the fitness implications of heterospecific social phenotypes. Here, we propose a novel social selection based approach integrating the role of all social interactions at the community level. We extended multilevel selection analysis by including a term accounting for the group phenotype of heterospecifics. We analyzed nest activity as a model social trait common to two species, the lesser kestrel (Falc…
Climate determinants of breeding and wintering ranges of lesser kestrels in Italy and predicted impacts of climate change
2017
Climate warming would theoretically create conditions for the breeding range expansion of pseudo-steppe Mediterranean and long-distance migrant species and provide the possibility for these to overwinter in the same breeding areas. However, contemporary changes in rainfall regimes might have negative effects on the climate suitability and in turn, shrink species potential range. The lesser kestrel Falco naumanni is highly sensitive to rainfall oscillations and has recently extended its Italian breeding range towards northern latitudes and increasing its wintering records. We modelled the effects of temperature and rainfall on current and future climate suitability for lesser kestrels in bot…
Lesser kestrel diet and agricultural intensification in the Mediterranean: An unexpected win-win solution?
2018
Abstract Farmland bird species have suffered dramatic declines in recent decades, especially in Mediterranean areas. The intensification of agricultural practices has led to reduced invertebrate prey, which represent the bulk of the diet of many farmland birds. In this study, we investigated the spatial and temporal variation in the diet of the lesser kestrel (Falco naumanni) during the breeding season, monitored over a five-year period between 2006 and 2013 in the Gela Plain (Sicily). Our aim was to understand whether, and to what extent, farming practices affected the reproductive outputs of this predominantly insectivore bird in order to find a profitable compromise between conservation …
Barrier crossings and winds shape daily travel schedules and speeds of a flight generalist
2021
External factors such as geography and weather strongly affect bird migration influencing daily travel schedules and flight speeds. For strictly thermal-soaring migrants, weather explains most seasonal and regional differences in speed. Flight generalists, which alternate between soaring and flapping flight, are expected to be less dependent on weather, and daily travel schedules are likely to be strongly influenced by geography and internal factors such as sex. We GPS-tracked the migration of 70 lesser kestrels (Falco naumanni) to estimate the relative importance of external factors (wind, geography), internal factors (sex) and season, and the extent to which they explain variation in trav…
Development of Novel Peptide-Based Michael Acceptors Targeting Rhodesain and Falcipain-2 for the Treatment of Neglected Tropical Diseases (NTDs)
2017
This paper describes the development of a class of peptide-based inhibitors as novel antitrypanosomal and antimalarial agents. The inhibitors are based on a characteristic peptide sequence for the inhibition of the cysteine proteases rhodesain of Trypanosoma brucei rhodesiense and falcipain-2 of Plasmodium falciparum. We exploited the reactivity of novel unsaturated electrophilic functions such as vinyl-sulfones, -ketones, -esters, and -nitriles. The Michael acceptors inhibited both rhodesain and falcipain-2, at nanomolar and micromolar levels, respectively. In particular, the vinyl ketone 3b has emerged as a potent rhodesain inhibitor (k2nd = 67 × 106 M-1 min-1), endowed with a picomolar b…
Biosynthesis of heme O in intraerythrocytic stages of Plasmodium falciparum and potential inhibitors of this pathway
2019
A number of antimalarial drugs interfere with the electron transport chain and heme-related reactions; however, the biosynthesis of heme derivatives in Plasmodium parasites has not been fully elucidated. Here, we characterized the steps that lead to the farnesylation of heme. After the identification of a gene encoding heme O synthase, we identified heme O synthesis in blood stage parasites through the incorporation of radioactive precursors. The presence of heme O synthesis in intraerythrocytic stages of Plasmodium falciparum was confirmed by mass spectrometry. Inabenfide and uniconazole–P appeared to interfere in heme synthesis, accordingly, parasite growth was also affected by the additi…