Adventures with Woodpeckers
On 12th March 2012, in a traditional orchard complex on the western flanks of the Malvern Hills, I
had an avian encounter that most British birdwatchers can nowadays only dream about. As I entered
one of the orchards to start some survey work I immediately heard a Lesser Spotted Woodpecker
drumming. A few minutes later the original bird plus another were drumming against each other. A
little after that, the first bird started calling so I decided to track it down and bingo I flushed it from
the roadside hedge just a few metres in front of me. The next two hours of survey work were
punctuated by birds drumming regularly, with definitely two and more likely three drummers
involved.
Having finished the survey I sat down to check through my field notes and a bird immediately started
drumming close by. Determined to get some good views I sat and waited but despite it drumming
regularly I couldn't see it. It then started calling (I always think that they sound like demented
Kestrels) and then I found it - high up (12m.) on a dead, vertical hybrid poplar stem. This stem had
within the space of perhaps 3m - a Green Woodpecker nest hole, 2 Great Spotted Woodpecker nest
holes and a Lesser Spotted Woodpecker nest hole! What followed was fascinating. For ten minutes or
so I watched the bird alternately drumming and then pecking systematically around the dead stem. At
first I thought that it was feeding but I became convinced that actually it was nest prospecting - testing
the wood for a suitable place to excavate. Suddenly three Great Spotted Woodpeckers started chasing
each other very noisily around the stand of trees. I was surprised that the Lesser Spotted just carried
on unconcernedly, but as soon as a single Great Spotted returned and started drumming and calling
the Lesser Spotted froze. The Great Spotted then flew in to the dead stem and landed in exactly the
same spot which the Lesser Spotted promptly vacated as soon as it saw the larger bird approaching.
The Lesser Spotted then flew high up into the canopy and started feeding like a tit, hanging upside
down and gleaning from the narrowest branches (perhaps 20 m. up). The Great Spotted meanwhile
just sat motionless for around five minutes, the Lesser Spotted then flew off (relinquishing possession
of the potential nest site?); the Great Spotted then sat motionless for another five minutes (claiming
possession?) and then also flew off.
Remarkable as this encounter was we are still fortunate to host a small population of these delightful
but elusive birds on the flanks of the Malvern Hills and more widely throughout Herefordshire.
What follows is a resume of what we know about the biology of this species and some thoughts on
why it still clings on in this part of the world.
The Lesser Spotted Woodpecker is a UK Biodiversity Action Plan Species and since 2009 has been a
UK Red List species also. The latest (2009) population estimate is 1000-2000 pairs. It seems likely
that now, in 2014, the population may be nearer or even below the lower estimate.
Its winter and summer distribution is almost identical. There has been an accelerating contraction in
range since 1980, with an 11% decline up to the second bird atlas in 1988-91 and a further 34% to the
latest 2007-11 atlas. Losses have been most pronounced in East Anglia and North and West England
whilst the West Midlands and adjacent Welsh Marches are now one of few remaining strongholds.
There are now very few sites in the UK where it can be reliably seen and indeed it is now too scarce
to be monitored by national schemes such as the BBS. As a consequence it can now suffer from nest
disturbance by photographers. In Herefordshire however it has one of highest relative abundances and
unlike other areas with high abundance, such as the South-East, its range and population is not
declining as rapidly.
Habitat preference studies have been undertaken in Austria, Belgium, France, Germany, Sweden,
Switzerland and the UK. It favours traditional orchards, old growth deciduous forest with large
quantities of dead wood and riparian deciduous woodland around ponds and flowing water with
decaying riparian timber. Studies have shown that wet woodlands are selected for high densities of
dead trees rather than wetness per se. It has an enormous home range for such a small bird. Solitary
during the winter, its home range then can be as much 700 ha. This declines to around 20 ha in the
pre-breeding period, 100 ha in the late spring and 45 ha when nesting. It is single brooded and usually
excavates a new hole every year high up in soft substrates. Trees used preferentially appear to be
alder, birch, fruit trees, poplar and willow. Aspen is used widely in continental Europe. Whilst oak is
used it is exploited only rarely in proportion to its availability.
The annual survival rate of adults is high at 0.59, male survival is usually higher then female and most
adult mortality is in the breeding season. It has very high mate fidelity and very high year on year
fidelity to its breeding territory.
In contrast to adult survival rate it has a low productivity for such a small bird. It is single brooded
with a mean first egg date of 29th April. Mean clutch size is five eggs; incubation lasts 11 days with a
further 20 days to fledging. Breeding success in the UK is currently very low with nest survival only
52% due to high levels of chick starvation rather than nest predation. This compares with rates of 80%
in Sweden, 74% in Germany and 83% in the UK before the late 1980s. Daily nest survival rate is
positively related to rates of provisioning by the adults. Provisioning rates and chick survival rates are
negatively correlated with rainfall. Nest predation by Great Spotted Woodpeckers is recorded but is
not the main cause of nest failure. Similarly, aggressive interactions with Great Spotted Woodpeckers
are common but are unrelated to nesting success.
The commonest cause of nest failure is starvation after the disappearance of one adult – usually the
female which often abandons the nest at the late chick stage. This female abandonment is thought to
be due to a small but significant proportion of polyandrous birds which in turn is driven by an excess
of males in the population due to their higher survival rates. In continental Europe males simply
increase their provisioning rate in response to the departure of the female. In the UK however they are
unable to do this. Food availability appears therefore to be limiting the population. Lesser Spotted
Woodpecker chicks are fed almost exclusively on Lepidoptera larvae. Coinciding with the decline in
Lesser Spotted Woodpeckers has been a well documented widespread decline in common moth
species, so it seems likely that food availability is limiting the population.
In the winter and in the pre-breeding season adults feed predominantly on saproxylic invertebrate
larvae. It is known that birds which hold good territories in the pre-breeding season nest earlier and
produce more young.
Why then are these charismatic little birds still apparently doing well on the Malvern Hills? The
answer surely lies in the quality of the landscape and its historical and ecological connectivity.
The bocage landscape of Colwall and Mathon remains largely intact. It is a landscape of mixed, but
predominantly pastoral, farming interspersed with small ancient semi-natural woodlands, wooded
streams and ponds, large numbers of traditional orchards and remnants of wood pasture and all still
connected by relatively diverse hedgerows. Compared with surrounding parishes much of the area
remains relatively untouched by pesticides and artificial fertilisers. Moth species diversity is very high
and presumably numbers have held up better than over much of lowland UK.
The orchards, along with the ponds which are often flanked with mature willows and poplars, provide
a large resource of potential nest sites.
Geographical connectivity is very high. Inspection of satellite photography shows that it is possible
for a Lesser Spotted Woodpecker to move around for mile after mile and never have to be more than a
few meters from a tree. The area once formed a major part of the Bishop of Hereford’s hunting chase
and there is still a substantial legacy of large open grown veteran trees with their associated fauna.
The first orchard recorded in Colwall was documented in 1537 and is still an orchard today. Many
orchards mapped by the Ordnance Survey First Edition are still extant. Orchard trees of course
assume veteran features at a much younger age than larger trees such as oak. This continuity of wood
decay habitats has resulted in Colwall’s orchards supporting one of the richest saproxylic invertebrate
faunas yet recorded in England. Winter and pre-breeding food supplies for Lesser Spotted
Woodpeckers may well be close to optimal.
However given the enormous home range of these birds it is clear that the population is likely to be
small. If ever a species required action to maintain high quality habitat at a landscape scale then this is
surely it. It is perhaps no coincidence that much of Colwall and Mathon lie within the Malvern Hills
AONB.