An influx of Little
Bustards......
Following sightings of single LITTLE
BUSTARDS in Dorset at West Bexington on 18th November (Mike Morse) and in East
Sussex on East Guldeford Levels on 30th December 2014 (Alan Parker), a third
individual was located on New Years Eve in East Yorkshire just NE of
Fraisthorpe, SSW of Bridlington. This beckons the question - do they all derive
from the reintroduction programme ongoing in SW France or are they genuine
immigrants arriving from record high populations in the east?
At first, I was pretty convinced of the
former logic, with the two birds appearing on the South Coast - a direct target
for post-breeding dispersal of French youngsters. However, with the appearance
of two in two days at the classic arrival time of late December, and following a
period of intense cold weather in the east - it may be perhaps best to treat
them as natural arrivals, particularly as all three show no evidence of rings or
tagging.
This latest bird presumably arrived fresh in
from the North Sea on 31st December 2014, where local birder Kevin Barnard
discovered it close to the beach at around 0850 hours. It soon flushed and flew
inland but a sharp-eyed Tony Dixon soon joined in with the search, having been
phoned by an extremely excited KB, and relocated it with European Golden Plovers
in a grassy field nearby. Jittery as they always are, particularly in an area
frequented by dogwalkers, the GP's were soon off, in turn sparking fright in the
bustard. Desperate to get proof, TD fired off a number of flight shots and in
doing so, lost the bird as it whistled rapidly inland. As luck would have it,
the young Little Bustard was distracted by a large field of Kale and
crash-landed into it, sparking off one of the biggest twitches this side of the
Millenium.
The field was beside the single-track lane
leading to the sea from Fraisthorpe hamlet and owned and managed by Auburn Farm
and was an instant attraction to the vagrant vegetarian. Once pinned down, it
remained on view from late morning until dusk, allowing an estimated 280
birdwatchers to connect before nightfall, representing the first Yorkshire
record since November 1956. As expected, it remained in the same spot in the
field overnight, delighting an estimated 1,200 further observers on New Years
Day 2015. Perhaps due to a strong wind, the bird barely budged a few inches,
deciding to stay low in the Kale, every now and again taking advantage of a few
bugs on the plant leaves. It was about 100 yards in from the lane.
Plates 1-8: first-winter Little Bustard, Auburn Farm Kale Field, Fraisthorpe, East Yorkshire, 31 December 2014 (Tony Dixon)
The Reintroduction
Problem
The Little Bustard has declined rapidly
across European farmland landscapes due to agricultural intensification. In
France, the number of breeding males in agricultural habitats has been reduced
by 92% in 30 years as a result of decreases in insect abundance and nest
destruction during harvesting. As a result, an age and sex-structured stochastic
metapopulation model was formulated for the remaining population in south-west
France and, using actual estimates of demographic rates obtained after 1997, its
extinction risk over the next 30 years was estimated to be very high. Limited
population reinforcement has thus appeared as a potential conservation strategy
for this species in agricultural habitats, while agro-environmental actions have
begun to have an effect on habitat quality at the landscape level. Different
strategies for the reinforcement of fledglings, including the number and
frequency of releases and the number of release localities in relation to four
criteria for choosing the release points, were evaluated in terms of their
effect in reducing the extinction risk of local populations and of the
metapopulation. The reinforcement of 100 fledglings per year for 5 years and
choosing the actual release points using the current abundance were found to be
the optimal choices for reducing the estimated extinction risk of the remaining
little bustard population in south-west France (Vincent Bretagnolle 2005). This
project was propelled into action but found to be extremely difficult to
implement, not least because the number of released young could not be sustained
but that the survival rate of those released was very poor (0.04%). An
estimated 760 Little Bustards were eventually released (2005-2013) but little is
known of the success of the project and to date, the species in SW France
remains precarious at best.
Vagrancy from the
East...
In terms of vagrancy in the UK and elsewhere
in NW Europe, we really must look towards the east for answers. The species has
two widely separated breeding populations. In the east, it occurs in Russia
(25,000+), Georgia (60 non-breeding individuals; Ernest Garcia, 2007),
Kyrgystan, Kazakhstan, where the population is estimated to be 20,000 and
increasing (N. Petkov, 2012), the Ukraine (100-110 individuals; Andryuschenko,
1999), NW China (very few), northern Iran and Turkey (negligable populations).
In the west, its range covers Spain (71-147,000 individuals; Garcia de la Morena
et al, 2006) and Portugal (17,500 displaying males; Ernest Garcia, 2007), with
smaller populations in Italy and France (up to 1,875 displaying males in 2008).
Eastern populations winter from Turkey and the Caucasus to Iran, and east to
China, with Azerbaijan holding the largest population (over 150,000 individuals in
2005-2006 [Gauger 2007, E. García in litt. 2007]) and sightings in the
winter of 2010 report 25,000 and 50,000-70, 000 individuals in Adjinohur valley
and Shirvan National Park respectively (Gauger and Heiß 2010). Western
populations winter in the Mediterranean zone, with the Iberian peninsula holding
the most important wintering quarters (a minimum of 16,429-35,929 and 11,200
individuals in Spain and Portugal, respectively)
(E. García in litt. 2007). The global population (excluding
Kazakhstan) was estimated at a minimum of c.240,000 individuals in the late
1990s (C. Martínez in litt. 1999), but it may be substantially lower
than this, due to the re-evaluation of the size of the Spanish population
(García et al. 2007). Whilst it remains widespread and numerous, in
some parts of its range it has declined dramatically since the 19th century,
leading to extinctions in at least 11 European countries, Algeria, Tunisia and
probably as a breeding bird in Azerbaijan. The species has now disappeared from
mainland Italy, where it occurred in Apulia, and it is presently declining in
France and Spain (V. Bretagnolle in litt. 2007). In Portugal, the
population appears to be stable, and eastern populations are said to have
increased in recent years (E. García
in litt. 2007). The population in the Eurasian steppe belt is thought to
have recovered due to an increase in fallow land during the transition process
of the former Soviet Union (Gauger 2007) (Birdlife 2013)
