50 research outputs found
Setback distances as a conservation tool in wildlife-human interactions : testing their efficacy for birds affected by vehicles on open-coast sandy beaches
In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i) most drivers did not create sizeable buffers between their vehicles and birds; ii) bird disturbance was frequent; and iii) predictors of probability of flushing (escape) were setback distance and vehicle type (buses flushed birds at higher rates than cars). Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m) and vehicle speeds to be slow (< 30 km h-1). Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures), and rely on changes to current driver behaviou
Setback distances as a conservation tool in wildlife-human interactions : testing their efficacy for birds affected by vehicles on open-coast sandy beaches
In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i) most drivers did not create sizeable buffers between their vehicles and birds; ii) bird disturbance was frequent; and iii) predictors of probability of flushing (escape) were setback distance and vehicle type (buses flushed birds at higher rates than cars). Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m) and vehicle speeds to be slow (< 30 km h-1). Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures), and rely on changes to current driver behaviou
Genome-wide study of hair colour in UK Biobank explains most of the SNP heritability
Natural hair colour in Europeans is a complex genetic trait. Here, the authors carry out a genome-wide association study using UK BioBank data, suggesting that in combination with pigmentation genes, variants with roles in hair texture and growth can affect hair colouration or our perception of it
A direct localization of a fast radio burst and its host
Fast radio bursts are astronomical radio flashes of unknown physical nature
with durations of milliseconds. Their dispersive arrival times suggest an
extragalactic origin and imply radio luminosities orders of magnitude larger
than any other kind of known short-duration radio transient. Thus far, all FRBs
have been detected with large single-dish telescopes with arcminute
localizations, and attempts to identify their counterparts (source or host
galaxy) have relied on contemporaneous variability of field sources or the
presence of peculiar field stars or galaxies. These attempts have not resulted
in an unambiguous association with a host or multi-wavelength counterpart. Here
we report the sub-arcsecond localization of FRB 121102, the only known
repeating burst source, using high-time-resolution radio interferometric
observations that directly image the bursts themselves. Our precise
localization reveals that FRB 121102 originates within 100 mas of a faint 180
uJy persistent radio source with a continuum spectrum that is consistent with
non-thermal emission, and a faint (25th magnitude) optical counterpart. The
flux density of the persistent radio source varies by tens of percent on day
timescales, and very long baseline radio interferometry yields an angular size
less than 1.7 mas. Our observations are inconsistent with the fast radio burst
having a Galactic origin or its source being located within a prominent
star-forming galaxy. Instead, the source appears to be co-located with a
low-luminosity active galactic nucleus or a previously unknown type of
extragalactic source. [Truncated] If other fast radio bursts have similarly
faint radio and optical counterparts, our findings imply that direct
sub-arcsecond localizations of FRBs may be the only way to provide reliable
associations.Comment: Nature, published online on 4 Jan 2017, DOI: 10.1038/nature2079