The gene mcr-1 conferring resistance to last-line antibiotic colistin has been reported globally. Here, we describe the first detection of plasmid-mediated colistin resistance in Russian wildlife, an isolate of Escherichia coli sequence type 2280 from a black kite (Milvus migrans) scavenging raptor. Whole-genome sequencing and plasmid transferability experiments revealed that mcr-1.1 was located on conjugative IncI2 plasmid pDR164 (59891 bp). Migratory black kites may contribute to the global spread of mobile colistin resistance.

SummaryCollisions with power lines represent an important mortality factor for Great Bustards Otis tarda throughout the distribution range of the species. This study evaluates the success of two conservation measures implemented in the West-Pannonian distribution range to reduce the number of power line collision casualties: (1) extensive underground cabling of 43.1 km power lines, and (2) marking of 89.7 km power lines starting in 2005 and 2006, respectively. The mortality rate of Great Bustards in our study area (covering 686.5 km 2 ) decreased significantly between 2002 and 2011, predominantly caused by reduced mortality due to power line collisions. Univariate tests indicate that underground cabling and power line marking significantly decreased power line collision casualties. Generalised linear models (GLMs) highlighted the prominent effect of underground cabling. Our results indicate that five years after underground cabling and marking of power lines within core areas of the West-Pannonian distribution range of the Great Bustard, the population already benefited through a significantly decreased mortality rate. Both conservation measures most likely contributed strongly to the rapid recovery of the West-Pannonian Great Bustard population observed within the last decade.

SummaryFlight directions of Great Bustards Otis tarda after take-off were used to analyse effects of power lines on spatial movements of this highly endangered bird species. Data on flight directions came from Great Bustard observations conducted in eastern Austria (northern and eastern parts of Lower Austria, northern part of Burgenland), western Slovakia and western Hungary. Flight directions were determined by a constructed line connecting take-off site and the bird's position after a flown distance of 100 m. Up to a distance of 800 m from the nearest power line, mean flight direction of Great Bustards after take-off deviated significantly from a random distribution. The mean flight direction angles clearly indicate that take-off flight routes point away from power lines at an angle of approximately 180°. Furthermore, flight directions of bustards still deviated from a random distribution in two 200-m distance bands much further away from power lines (. 1,200-1,400 m, . 1,400-1,600 m), possibly suggesting that even at larger distances from power lines flight directions might still be affected by such artificial linear landscape structures. With increasing distance to nearest power lines, mean vector length r values of flight paths decrease significantly, while circular standard deviations S values increase significantly. Very similar results were achieved independently if all data were pooled or analysed separately for individual study areas for which the number of flight observations was large enough to conduct reliable analyses. Our study reports a strong effect of power lines on the flight behaviour of Great Bustards, at least up to a distance of 800 m, perhaps even up to 1,600 m. Although this may significantly reduce the risk of collision with power lines it most likely has severe consequences for the spatial movements of birds within the entire landscape and between potentially suitable breeding and foraging habitats.

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Understanding intrinsic and extrinsic influences of movement behavior in migratory species, with the potential to recommend management actions for species of conservation concern, requires data from across the species' range. For some raptor species, such as the red kite (Milvus milvus; kite), existing data focus on breeding populations or movements en route to wintering areas without considering movements within the wintering areas. Here, we contribute to filling this knowledge gap by investigating landscape-level associations of kites in their southwestern European winter ranges between 2015 and 2020. We also explore aspects of the migration process in terms of geographical patterns in the location of over-wintering grounds, including time spent and distances traveled within them. We predicted that space use in overwintering areas would be linked to the proportional amount of open, lowland, or urban land cover they contain at the landscape level. Specifically, we tested whether winter range sizes (95% kernel density estimator [KDE] home ranges and 50% KDE core areas) would be smaller in areas with greater proportional open and urban land cover within kite ranges. Controlling for the effects of age and sex, we compared results in 3 over-wintering regions: the Iberian Peninsula, Italy, and the Pyrenean region of southern France. We tracked 36 kites by global positioning system-global system for mobile communications (GPS-GSM) telemetry over 70 individual winters between 2015 and 2020. Kites wintering in the Pyrenees had