Transcript NGOET Grey Partridge Presentation

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NGO Educational Trust
and the individuals and organisations who have provided the component
images.
It should not be reproduced in part or as a whole without
their permission.
© National Gamekeepers’ Organisation Educational Trust, April 2013
The NGO Educational Trust are particularly indebted to
the Game & Wildlife Conservation Trust (G&WCT) for providing much of the
material contained in this presentation and also
Stephen Tapper and Dick Potts for their help and advice throughout this project.
The Trust also wish to thank:
- Jacques Hicter for allowing us to use and include his DVD
Perdreaux et Quintaux (Partridges and Yields).
- The British Ecological Society for allowing us to reproduce three
research papers published in the Journal of Applied Ecology
We also wish to thank David Mason for providing
the majority of the photographs used in this
presentation.
The Grey Partridge has evolved in the temperate grassland ecosystems of the Asian
Steppes in the Northern Hemisphere.
Man’s early development in agriculture, especially the clearing of woodland and early
growth of cereal crops created even more and new favourable habitat and brought
about a further increase in numbers
Back to the 1930s, when corn was cut with a reaper
...and sheaths of corn stacked in stooks to ripen before threshing
Throughout Europe, Asia and North
America (where it was introduced) the
Grey Partridge was a prolific species and
was the most numerous bird on many
arable farms.
In the 20th century it became an iconic
image of rural Britain with ‘coveys’ of
partridge to be seen in most fields.
In the years following the second world
war there was a dramatic decline in Grey
Partridge numbers, not only in Britain but
across its full range.
This was due to:
- a reduction in predator control due to
the number of gamekeepers serving and
killed during World War 2
- the modernisation and development of
intensive farming practice involving the
extensive use of pesticides, particularly
herbicides.
This decline was first noticed, recorded and reported by the shooting
organisations. The Grey Partridge was a prolific and popular game bird highly
regarded as an exciting quarry species and much prized for its delectable
flavour. Over 2 million were shot annually in the UK between the wars and
some 25 million shot annually across Europe. At that time it was the most
important lowland game bird.
Analysis of game bags on major shooting estates enabled a graphical
representation of its decline in Britain.
Similar declines were recorded across Northern Europe.
WWI
WWII
10
Bag per 100 hectares
8
6
4
2
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
It is estimated that there were more
than 1 million breeding pairs in
Britain prior to the second World
War and this population has now
reduced to 65,000 pairs.
It is also estimated that in 1953
there were 110 million pairs in the
world which had reduced to 25
million by 1985.
Meadow Brown
Tortoiseshell
Peacock
The Grey Partridge decline is clearly a world phenomenon but
nowhere is it more significant than in England.
Our focus is on Grey Partridge but it also poses the question as to the
effect of the same factors on a wide range of other wildlife species,
such as butterflies, sharing the same habitat.
Is this an indication that all is not well in the British countryside?
Not surprisingly it was game biologists, most notably Dr. G.R. Potts, who
were the first to scientifically investigate and demonstrate the reasons for
this decline.
Much of this early research in Britain was
carried out at:• ICI Game Research Station at Fordingbridge
• then the Game Conservancy Trust, now
the Game & Wildlife Conservation Trust
currently based at Burgate Manor,
Fordingbridge
Game biologists were the first to show the consequences
of herbicide use for farmland birds. Early work by
Dr. D. Middleton, the first director of the Game Research
Association funded by Eley, included studies on the % of
birds surviving from hatching to adulthood.
Doug Middleton
 The Grey Partridge is now one of the most intensively
studied birds in Britain.
 A summary of partridge research projects is included on the
disk & the NGO ET website
 Three of the most important research papers are also
included on the disk & the NGO ET website
G.R.Potts’ book ‘The Partridge’,
Pesticides, Predation and Conservation
published by Collins in 1986 was, and
still is, regarded as the complete,
authoritative gospel
Professor Jon Hutton is a member of the monitoring group of the United Nations
Environment Programme based at Cambridge and he is also Chair of the
Sustainable Use Specialist Group. Their role is to evaluate the values of Biodiversity
and put authoritative biodiversity knowledge at the centre of decision making.
He has pointed out that:




22 million recreational hunters spend £16 billion per annum
(shooting, falconry, angling, etc) gives economical value to land and habitats
favourable to wild species which would otherwise be converted to crop lands.
Recreational hunting achieves conservation in situations where there are few
alternatives.
Where it is practiced responsibly in context with good governance recreational
hunting is an important tool for conservation.
Those linking hunting with conservation need to demonstrate what they are
doing and why.
The appearance of much of the British countryside as we know it today has been
largely shaped by hunting, shooting and farming.
It was the ‘recreational shooter’ who first alerted the government to the demise
of the grey partridge and they are the body/group most prepared and
determined to actively seek a solution.
One of the problems in the UK is that few of the government, scientific and
wildlife bodies have as much experience or background knowledge as the
‘hunter’ based organisations. Liaison between both camps is now, thankfully,
beginning to improve.
It is now generally recognised that the future of the Grey Partridge is closely
linked to recreational shooting.
If it was made a protected species or game shooting was banned, then most of
the finance and conservation management linked to field sports, which is
bringing about it’s current recovery, could disappear overnight.
In 1996 the Grey Partridge was identified in Britain as a Biodiversity Action
Plan Species and it was the Game Conservancy Trust (now the Game &
Wildlife Conservation Trust) who were made the ‘lead partner’ by the UK
government.
They are responsible for delivering targets by deadlines
Their role is to carry out research, advise, monitor, advocate and
demonstrate, best practice and get the research into Government’s agrienvironment policy.
The annual National Game Census, which was initiated by the GCT in
1956, monitors a number of species including the Grey Partridge.
Studies in Grey Partridge mortality rate initiated by the GCT looked at
deaths recorded at various stages in life cycle/ year :1 Egg mortality
2 Nesting Hen mortality
3 Chick mortality
4 Shooting mortality
5 Winter mortality
These studies led to insect monitoring
in farmland starting in 1969
Spring pairs/km2
30
Long-term members
20
New members
10
0
1950
1960
1970
1980
1990
2000
2010
The significant peaks in early 50’s, 1960 and mid 70’s are thought to be due to
particularly good weather in Spring and early Summer.
There is an old saying that “a wet Ascot week means a bad year for partridges”
Sussex autumn partridge count - 1970
Shows a family covey
(pair + offspring)
Sussex autumn partridge count - 1994
Shows a family covey
(pair + offspring)
Sussex autumn partridge count - 2008
Shows a family covey
(pair + offspring)
The monitoring of Grey Partridge in this Sussex site is a typical example showing a
progressive decline from 1970 to 1994 and then on to 2008.
However, this site includes a discrete recovery in the east of this region centred on the
Norfolk Estate, Arundel. This recovery demonstrates what can be achieved and is
testament to the hard work and commitment of the Duke of Norfolk and his team. A
summary of this project is included on the disk.
•
The recorded 80% decline in Grey
Partridge is similar in both timing
and rate in several Northern
European countries. The
modernisation of farming spread so
quickly that many of the factors
involved in the decline were
synchronised across much of the
Northern hemisphere.
•
Conclusions from studies in Britain
may well therefore be relevant
elsewhere.
1.
Habitat decline
2.
Decline in Gamekeepers
3.

Reduction in predator control

Habitat and conservation management
Increased use of pesticides and herbicide
Habitat decline; more and more land has been taken into modern intensive farming
with larger fields bringing about loss of hedgerows and hedge banks.
The introduction of new winter wheat varieties led to a prevalence of Autumn seed
drilling. This resulted in a reduction of Winter stubbles and subsequent loss of
Winter food for both partridges and songbirds.
However G&WCT still estimate that there is potential suitable general habitat for
511,000 pairs of Grey Partridge (8x more than we have actually got).

Optimum Land = 36,000 km2 (yellow)

Sub-optimum land = 42,000 km2 (green)

Present UK population is 65,000 pairs

There is a habitat potential of 511,000 pairs.
This poses the question why the current population is so low; the current
population is 65,000 pairs whereas the estimated habitat potential is 511,000.
This shows that habitat may be important but is not the most significant
factor.
• Providing “year round” food for grey partridge
• Late winter and spring cover
• Nesting cover
• Accessible, insect rich habitat for brood rearing
Nesting cover
Grey Partridge favour nest sites in grass margins adjacent to
hedgerows on banks
Old dead tussocky grass
It is the previous year’s uncut dead grass that provides
the best nesting sites
Accessible, insect rich habitat next to nesting cover
This could be further improved by
providing protection from aerial strikes.
The margin flora is unaffected by cropping rotation
The headland loss is of little economic significance because this is an area
of traditionally poor crop yield and is better utilised for conservation.
A 6-metre strip all round a field provides territory for a greater number of
partridge pairs than the same area in a single block
A colourful public relations brood rearing mix!
However, a 6-metre margin of unsprayed and unfertilised stubble
is more important to the Grey Partridge chicks
Over winter food & cover-stubbles
Un-harvested Conservation Headlands
This looks good and in the absence of other cover can provide useful shelter
from raptors immediately after harvest. However the large single flush of
food attracts vermin, particularly rats.
Biennial cover crops such as Kale
This can provide vital cover for pairs in Spring
Kale mixes
Kale provides good cover and when mixed with different varieties of quinoa,
which ripen in sequence, achieves continuous natural food over a greater
period of time.
Post harvest auto-cast Kale
The following June it looks like this
Gamekeepers continuously experiment to get the most beneficial margin habitat
including annually renewing half and leaving half to provide cover. Kale provides
good cover but another option is 3 metres of chicory, both reduce sparrow hawk
strikes, and then a further 3 metres of wild flower mix sown amongst cereal as a
brood mixture providing seeds and insects. The food hopper provides overwinter and spring feeding.
Provide round the year cover that offers:
1. Protection from predators - especially in
late winter & spring
2. Nesting areas
3. Accessible, insect rich areas
For further information go to www.gwct.org.uk
The 25,000 employed in 1911 has shrunk by 80%
Traditionally it was one keeper per thousand acres
>1.6
0.8 - 1.6
0.4 - 0.8
0.2 - 0.4
1911
0.1 - 0.2
<0.1
Gamekeepers per 1000 hectares
1981
Stoat
Rat
Weasel
The fox is the most serious predator, followed by
the stoat, rat and weasel.
Different predators tend to be more destructive
at different times of the year
Fox
It was always said that to avoid foxes coveys fly out
into the middle of fields to ‘jug up’ for the night – thus
leaving no scent trail leading to them
Carrion Crow
Magpie
The Grey Partridge has a number of winged predators.
Amongst these two the carrion crow is the most serious
followed by the magpie.
Intra-guild predation, in which higher level predators control middle or lower level predators
within a food web, is a factor which is reducing in many countries. Historically the red fox
population would have been held in check by a number of natural predators.
Intra-guild predation on the red fox
Top predator
Numbers reduction/
interference on fox
Authority
Gamekeeper
83%
Tapper et al. (1996)
Coyote
86%
Sovada et al. (1995)
Lynx
41%
Helldin et al. (2006)
Wolf
36% coyote
Berger & Gese (2007)
Golden eagle
Ξ13% diet
Korpimaki & Nordström (2004)
However the wolf, lynx, coyote and golden eagles are no longer present in many countries. It
is now a crucial role of the gamekeeper to attempt to restore and keep the balance
particularly in the British countryside.
Tools of the trade
1
1. Rifle and scope
2. Shotgun
3. Larsen trap
4. Spring traps used in a tunnel
2
3
5. Approved snares
4
5
A rolling landscape of arable, sheep grazing and military training
North
Collingbourne
1 Km
Arable
Grass
Tidworth
Milston
Bulford
The 25,000 keepers employed in 1911 have reduced by 80% leading to
a reduction in predator control
In the Salisbury Plain Experiment Grey Partridge numbers on large
plots of land were monitored over a 3 year test period. A plot of
keepered land with good predator control was compared to a plot
with no predator control.
At the end of 3 years the predator control variable for the 2 plots was
reversed for a further 3 year period.
1984 The Baseline Year
53 Adult males 32
233 Total birds 213
22 Bag
65
Covey – size related
Single male (hen killed?)
Adult pair with no offspring
(eggs eaten or no
chicks survived)
No control 1987 Predation control
30 Adult males 57
79 Total birds 318
1 Bag
27
Covey – size related
Single male (hen killed?)
Adult pair with no offspring
(eggs eaten or no
chicks survived)
Predation control 1990 No control
49 Adult males 29
399 Total birds 128
105 Bag
25
Covey – size related
Single male (hen killed?)
Adult pair with no offspring
(eggs eaten or no
chicks survived)
Conclusions
• Predation control
– Increased the production of young grey partridge
– August numbers improved 75% annually
– Over 3 years this resulted in a 3.5 fold change
– Breeding stocks, measured in spring, increased by 35% p.a.
– Over 3 years resulted in a 2.6 fold change
Gamekeepers would also be involved in reducing disturbance to breeding partridge, the
maintenance of favourable habitat, particularly game crops.
Also provision of supplementary feeding
particularly in Winter.
In Spring many pairs nest close to these
feed sites. This may reduce the size of
territory resulting in pairs nesting closer
together.
These activities also benefit a wide range
of other species
The G&WCT and the NGO believe that wise use of the British countryside rather than
protectionism is the most constructive route forward.
The development and increased use of Pesticides in
an attempt to increase human food production
following World War II seems to have been the main
trigger that started the Grey Partridge decline.
Pesticides, especially herbicides which came into use
20 years earlier than insecticides, break the chick
food chain
In fact both insecticides and herbicides inhibit insect
populations and diversity
Red-Leg Partridge and chicks
Grey Partridge and chicks
The use of pesticides breaks the chick food chain. This is so crucial for the Grey Partridge
because the chicks are solely dependant on a plentiful supply of suitable insect species for the
first 10 days after hatching before they start to eat seeds. It is interesting that Red Leg partridge
chicks start on seeds after only 3 days.
• Farmers must make a profit
• Spraying is linked to yield
• Be selective with the insecticides and herbicides you choose
Herbicides for selective control of grass weeds in cereal headlands?
Avena spp. (wild oats):
tri-allate
diclofop-methyl
difenzoquat
flamprop-m-isopropyl
Alopecurus mysuroides (blackgrass):
tri-allate
diclofop-methyl
HOE 7113-01H
Elymus repens (couch):
glyphosate
What is clear is that improvements made to chemicals used in modern farming over
the past few decades have not brought about the dramatic recovery in Grey
Partridge numbers seen in some other species.
This may seem surprising because the Grey Partridge’s potential to ‘bounce back’,
with brood size numbering up to 14, is enormous. This is because the new chemicals
used are not themselves mortally toxic to the Grey Partridge or its chicks but it is
that their use in modern farming methodology still has the same significant effect of
breaking the crucial early chick nutrition. It will also impact on interaction within the
local food web.
What is now becoming clear is that other species, such as birds like skylarks and corn
buntings, are affected by these same factors.
It would appear that we are not dealing with a contact toxin, a lethal dose for chicks
or even an accumulative toxin. Whatever new chemicals are developed and used, if
they are effective as herbicides and/or insecticides, they are still collectively likely to
break the chick’s food chain.
Because the timing of their application is critical to the crop it may well also
unfortunately be equally critically timed to the life cycle of the Grey Partridge i.e.
the first 10 days after the chicks hatch.
Reduced and selective pesticide use in response to actual crop problems rather
than their use as a blanket preventative safeguard may also be beneficial.
Selective timing of the reduced use of such agro-chemicals, if achievable, may yet
be a critical long term deciding factor in ensuring the future of the Grey Partridge.
The availability of insect food is crucial.
It could be improved by use of one or other of the entry-level
stewardship options :
 Low input conservation headlands to increase insects
 Plant Wild Bird seed mixture
 Don’t use summer insecticides on headlands
Click here to view a
short YouTube video
Animal proteins from insects needed for fledging
Chicks raised with and without insects
One solution is to create spray free conservation headlands, by not spraying a 6metre border around the crop
It is difficult to get farmers to agree not to spray headlands due to the belief
that there is re-infestation by both weeds and insect pests
Conservation headland trials in Norfolk
Two similar adjacent blocks of land, with no conservation headlands, were
chosen for a comparative study. The chick survival percentage was
established for the period 1968 – 2003 on both sites.
In the period 2004 – 2008 Block A was left without conservation headlands
but on Block B conservation headlands were established and maintained.
Block A
(no conservation headlands)
Block B
(conservation headlands
introduced after 2003)
1968-2003
29%
31%
2004-2008
27%
53%
The improvement in survival amounted to an additional 3.6 chicks per brood
Does it work for another game species?
Yes it does – and also for song birds
Pheasant
Linnet
Prickly Poppy
Corn Marigold
Field Mouse
Other benefits to wildlife




Hedge Brown
Predatory Beetle
Wildflowers
Butterflies
Small mammals
Predatory beetles
There are clearly a number of issues involved in the Grey Partridge decline
and it may well be a quite complex interaction of factors.
Previously present factors may well have become more significant as the
decline reached critical thresholds.
Some think that factors such as predation by protected species inhibit any
national recovery from the low population count that currently exist in many
areas.
While everyone is pleased to see a recovery in the population of rare and
protected species the decision makers need to recognise that if these
species are predators there is an ecological price to pay.
Marsh Harrier
Hen Harrier
Red Kite
While such species benefit from this protection and their
populations increase beyond natural limits they start to impact on
the vulnerable prey species.
Buzzard
Badger
Goshawk on
Pheasant
Goshawk
Freshly Killed Grey
Partridge
Sparrowhawk
It is possible that a national Grey Partridge
recovery may be handicapped by current
increased populations of their natural
predators.
Start
Predator
Control
DECREASING POPULATION
Increased
hen mortality
&egg loss
Yes
Yes
Herbicide
Use
Reduced
chick survival
No
Increased
chick survival
Autumn
Count
Shooting policy
dependant on
Autumn count
No
Increased
Winter loss
• Predation loss depends on
Decreased
hen mortality
&egg loss
Spring Cover
+
Feed Hoppers
Number
Shot
Yes
Reduced
Winter loss
Winter
Loss
INCREASING POPULATION
No
Breeding
Stock
control of nest predators
• Chick survival depends on
herbicides and insecticides
• Winter loss depends on
hedgerows, spring cover and
feed hoppers
The Game & Wildlife Conservation Trust have put forward a protocol to save
the Grey Partridge as a national species.
It is based on an improvement in the number of controllable factors and has
been put into practice at its test site at Royston.
1.
Provide good Winter and Spring cover crops for shelter, hiding places
and food.
2.
Supplementary winter feeding strategically placed hoppers near cover
crops and nesting sites. Also select and strategically plant insect rich
habitat.
3.
Good nesting sites –hedgerows and beetle banks- particularly those
close to supplementary feeding sites.
4.
Chick survival is increased by moderated use of selected herbicides and
insecticides and provision of 6-metre unsprayed field margins
5.
6.
Intensive Traditional Gamekeeping to provide:

habitat maintenance- high level of liaison with landowners and/or tenant
farmers for the considerations listed in 14 are essential but expensive
consequences of the decision making necessary to give Grey Partridge
population numbers any chance of recovery

predator control- also expensive and time consuming requiring an experienced,
skilled person to target identified species

The particularly well keepered Royston project loses 40% of sitting hens but
without intensive game keeping it could be 80% or higher
Census numbers, at critical phases, help to monitor the status of the Grey Partridge
within the Biodiversity Action Plan
7.
Control the practice of Grey Partridge shooting - limit to harvesting
the surplus. Until stocks recover don’t shoot grey partridges
1.
Only those conserving good stocks
(more than 20 per 250 acres)
should consider shooting
2.
Never shoot greys after December
3.
Never shoot partridges that are in
pairs
4.
Take precautions not to shoot
greys when shooting redleg
partridges
Grey partridge pairs – Spring 2002
2.9 pairs / sq. km
20 Pairs total
Grey partridge pairs – Spring 2007
2007
18.4 pairs / sq.km
184 pairs total
Spring pairs at Royston
Spring pairs / 100 ha
20
01
Predicted 31
Actual
19
15
07
185
184
10
5
Demonstration area
Reference area
0
2002
2003
2004
2005
Year
2006
2007
Target
Number of game birds counted in autumn (Birds / sq.km)
Grey partridge
Red-legged partridge
Pheasant
Number
Density
Young: Old
Ratio
Density
Young: Old
Ratio
2001
7.6
0.6
15.7
0.3
66
2002
28.8
3.0
18.5
1.1
353
2003
39.1
2.9
43.9
2.2
432
2004
53.4
2.8
43.9
1.2
537
2005
60.8
1.9
58.4
0.9
612
2006
87.8
2.6
77.5
1.5
522
Autumn
Number of brown hares counted in winter
Hares
Year
Demo
Ref
Spring 2002
39
63
Winter 2002
94
83
Winter 2003
159
57
Winter 2004
179
75
Winter 2005
185
93
Winter 2006
216
137
Songbirds at Royston
Song Thrush
Greenfinch
Chaffinch
Goldfinch
Jacques Hicter, a shooting farmer from northern France, has
also achieved remarkable results from a total commitment to
the future of the Grey Partridge, the balance of natural
ecology and modern farming methodology.
His activities feature in a DVD, sponsored
by Syngenta, which is included on the
disk and can be viewed on the
NGO ET YouTube Channel.
Click here to view now
The graph shows the population recorded at Jacques Hicter’s two farms,
situated 20kms apart. He has achieved similar success at both sites.
pairs per 100ha
100
80
60
The sharp decline in
2007 and 2008 is
almost certainly due
to adverse weather
conditions
40
20
0
1980
1990
2000
2010
The overall impression in 2008 is that a Grey Partridge recovery will be hard
earned. There is unlikely to be any short term spectacular bounce back. The
G&WCT have identified a number of key factors in the original demise which
may all need to be countered and they have produced recommendations in a
recovery document. Even in the G&WCT project areas where a recovery is in
progress it has not yet been demonstrated that a similar recovery is possible
on a wide range of other soil types or that the population will stand
even a controlled shooting strategy.
What has been demonstrated by the G&WCT at Royston, Jacques Hicter in
Northern France and more recently the “Norfolk Estate Project”, is that with
passion and complete commitment to the future of the Grey Partridge a
local/discrete recovery can be achieved.
However those are very intensive and expensive projects and, at present,
there seems little evidence that a general species recovery is possible
without similar support. The government stewardship scheme, as far as
the Grey Partridge is concerned, is probably no more than a small step in
the right direction.
Dick Potts believes it will be impossible to achieve recovery targets
without the crucial role of the gamekeeper.
•
•
Jacques Hicter video – Perdreaux et Quintaux (Partridges and Yields)
G&WCT
– Conserving the Grey Partridge
– Insect population graphs (1970 – 2005)
– How to identify grey partridges
– Chick food favourites
– Environmental Stewardship: Making the most for grey partridges
– Late winter and spring feeding of pheasants and partridges
– Providing nesting cover for wild grey partridges
– Providing brood-rearing cover for wild grey partridges
– Providing winter cover and food for wild grey partridges
– Restoring wild grey partridges to your farm
– Using predation control to increase wild grey partridge numbers
– Summary of research projects
•
British Ecological Society published research papers
– Pesticide Use on Cereals and the Survival of Grey Partridge Chicks: A Field Experiment
Author(s): M. R. W. Rands
– Effect of Hedgerow Characteristics on Partridge Breeding Densities Author(s): M. R. W. Rands
– The Effect of an Experimental Reduction in Predation Pressure on the Breeding Success and
Population Density of Grey Partridges Perdix perdix Author(s): S. C. Tapper, G. R. Potts, M. H.
Brockless
Dick Potts – Norfolk Estate Project review
•
For further information regarding any aspects of this
presentation please contact:
Brian Hayes
NGO Educational Trust
PO Box 3360
Stourbridge
West Midlands
DY7 5YG
: 01384 221308
[email protected]
www.gamekeeperstrust.org.uk