BASC Science Matters - March/April

[Conor O'Gorman]

BASC monitors scientific journals, environmental, policy and political alerts for the results of studies of relevance to shooting and conservation. Click the link below for a selection of papers published in March/April 2024.

https://basc.org.uk/science-matters/

For a review of two recent studies, where our efforts can help, around waterfowl migration, influence of changing climate, and avian flu risks please click the link below.

https://basc.org.uk/citizen-science-at-the-forefront-of-new-research/

Edited May 7 by Conor O'Gorman

[Konor]

Are there any papers published on lead shot toxicity and its impact on inland non wetland quarry species? I was hoping for a study indicating the extent of the threat as it exists in the UK today. Perhaps the one which you base your fear of “the lead shot minefields for the poor wee partridges to eat and die” I’m assuming that was a quote you used from the relevant scientific paper’s abstract .

Joking aside Conor I'm just questioning the degree to which your posts are personal opinion and to what extent they reflect BASC policy. Science matters but are you basing your opinions on verifiable scientific study or arguably baseless emotive rhetoric and to what extent do BASC support the opinions you hold? 

Edited May 8 by Konor
Addition

[Old farrier]

I’d be interested in a scientific paper about the intake of lead by plants from the soil 

is there one available? 
 

or even one on the damage that lead does to flora and fauna 

[Conor O'Gorman]

11 hours ago, Konor said:

Are there any papers published on lead shot toxicity and its impact on inland non wetland quarry species? I was hoping for a study indicating the extent of the threat as it exists in the UK today. Perhaps the one which you base your fear of “the lead shot minefields for the poor wee partridges to eat and die” I’m assuming that was a quote you used from the relevant scientific paper’s abstract .

Joking aside Conor I'm just questioning the degree to which your posts are personal opinion and to what extent they reflect BASC policy. Science matters but are you basing your opinions on verifiable scientific study or arguably baseless emotive rhetoric and to what extent do BASC support the opinions you hold? 

A British grey partridge study published almost 20 years ago showed that grey partridge (adults and chicks) ingest lead shot in their gizzard.

That study is amongst many listed on the GWCT website https://www.gwct.org.uk/advisory/lead-ammunition/effects-of-lead-on-wildlife-and-wildfowl/ and they are but the tip of the iceberg on impacts of various wildfowl and other species eating lead shot as grit (the evidence goes back 100 years) in wetlands and terrestrial environments across Europe and worldwide.

Going back to that British study, grey partridge chicks were found to be eating lead shot - some with up to 14 pieces of lead shot in their gizzard - and grinding them up into their bloodstream. Here are two extracts from the paper:

"The measured incidence of lead shot in gizzards considerably underestimates the annual exposure because the shot is retained in the gizzard only for a relatively short period of time. The average erosion of lead in the grey partridge chicks, 55%, is remarkable given that the chicks were aged only 2–3 weeks (18 days) and had presumably not ingested the lead on their first day".

"It is remarkable that between 1968 and 1978, two chicks sampled from separate broods on the Sussex Downs had, within 3 weeks of hatching, ingested 13 and 14 lead shot. Moreover, the erosion of the individual shot suggests that they were ingested within a short discrete period of time. Somewhat similarly, a grey partridge in Denmark in 1976 had ingested 34 lead shot (Clausen and Wolstrup 1979), a grey partridge in Wiltshire in 1966, 26 (this study)".

Potts, G.R. (2005). Incidence of ingested lead gunshot in wild grey partridges (Perdix perdix) from the UK. European Journal of Wildlife Research, 51:31–34.
https://link.springer.com/article/10.1007/s10344-004-0071-y  

Food for thought, and for those wee wild grey partridge chicks, lead minefields indeed.

Whether in wetland or on dry land when birds ingest lead shot it grinds in their acidic gizzards and toxic lead salts are absorbed into the blood stream and find their way into the tissues of vital organs and bone causing sub-lethal or lethal effects depending on the species and how much lead shot that species of bird eats. 

A study of red grouse in Scottish and Yorkshire moors published almost 15 years ago found that when high levels of lead were found in the bones of grouse the source was lead shot using lead isotope analysis, with the authors recommending mitigation measures including the use of non-lead shot on grouse moors to reduce exposure risks. 

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors
https://pubmed.ncbi.nlm.nih.gov/19264349/ 

As regards BASC's latest position - below an extract from one of the documents BASC submitted to last year's HSE lead ammunition review consultation:

• BASC is opposed to any further regulation on the use of lead ammunition in the UK.
• Regulations are already in place to mitigate risks to wildfowl from the use of lead shot in wetlands.
• There is clear evidence that lead shot poses a risk to a wide range of bird species in terrestrial habitats and a voluntary move away from lead shot for live quarry shooting with shotguns is reducing these risks.
• The shooting sector must be allowed time to develop non-lead shotgun ammunition due to a world shortage of components and the need for manufacturers and assemblers to source new machinery to produce lead shot alternatives and biodegradable wads for all shotgun calibers.
• Lead in game meat is potentially a risk to human health via secondary exposure and government guidance and market forces are managing risks via best practice.
• Lead exposure pathways are not conclusive for livestock, soil, soil organisms, plants, and surface waters; and current legal and regulatory frameworks are in place to manage risks.

https://basc.org.uk/wp-content/uploads/2023/12/BASC-review-of-HSE-Annex-15-opinion.pdf

 

1 hour ago, Old farrier said:

I’d be interested in a scientific paper about the intake of lead by plants from the soil 

is there one available? 
 

or even one on the damage that lead does to flora and fauna 

Do you mean from lead shot or generally?

[Konor]

1 hour ago, Conor O'Gorman said:

A British grey partridge study published almost 20 years ago showed that grey partridge (adults and chicks) ingest lead shot in their gizzard.

That study is amongst many listed on the GWCT website https://www.gwct.org.uk/advisory/lead-ammunition/effects-of-lead-on-wildlife-and-wildfowl/ and they are but the tip of the iceberg on impacts of various wildfowl and other species eating lead shot as grit (the evidence goes back 100 years) in wetlands and terrestrial environments across Europe and worldwide.

Going back to that British study, grey partridge chicks were found to be eating lead shot - some with up to 14 pieces of lead shot in their gizzard - and grinding them up into their bloodstream. Here are two extracts from the paper:

"The measured incidence of lead shot in gizzards considerably underestimates the annual exposure because the shot is retained in the gizzard only for a relatively short period of time. The average erosion of lead in the grey partridge chicks, 55%, is remarkable given that the chicks were aged only 2–3 weeks (18 days) and had presumably not ingested the lead on their first day".

"It is remarkable that between 1968 and 1978, two chicks sampled from separate broods on the Sussex Downs had, within 3 weeks of hatching, ingested 13 and 14 lead shot. Moreover, the erosion of the individual shot suggests that they were ingested within a short discrete period of time. Somewhat similarly, a grey partridge in Denmark in 1976 had ingested 34 lead shot (Clausen and Wolstrup 1979), a grey partridge in Wiltshire in 1966, 26 (this study)".

Potts, G.R. (2005). Incidence of ingested lead gunshot in wild grey partridges (Perdix perdix) from the UK. European Journal of Wildlife Research, 51:31–34.
https://link.springer.com/article/10.1007/s10344-004-0071-y  

Food for thought, and for those wee wild grey partridge chicks, lead minefields indeed.

Whether in wetland or on dry land when birds ingest lead shot it grinds in their acidic gizzards and toxic lead salts are absorbed into the blood stream and find their way into the tissues of vital organs and bone causing sub-lethal or lethal effects depending on the species and how much lead shot that species of bird eats. 

A study of red grouse in Scottish and Yorkshire moors published almost 15 years ago found that when high levels of lead were found in the bones of grouse the source was lead shot using lead isotope analysis, with the authors recommending mitigation measures including the use of non-lead shot on grouse moors to reduce exposure risks. 

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors
https://pubmed.ncbi.nlm.nih.gov/19264349/ 

As regards BASC's latest position - below an extract from one of the documents BASC submitted to last year's HSE lead ammunition review consultation:

• BASC is opposed to any further regulation on the use of lead ammunition in the UK.
• Regulations are already in place to mitigate risks to wildfowl from the use of lead shot in wetlands.
• There is clear evidence that lead shot poses a risk to a wide range of bird species in terrestrial habitats and a voluntary move away from lead shot for live quarry shooting with shotguns is reducing these risks.
• The shooting sector must be allowed time to develop non-lead shotgun ammunition due to a world shortage of components and the need for manufacturers and assemblers to source new machinery to produce lead shot alternatives and biodegradable wads for all shotgun calibers.
• Lead in game meat is potentially a risk to human health via secondary exposure and government guidance and market forces are managing risks via best practice.
• Lead exposure pathways are not conclusive for livestock, soil, soil organisms, plants, and surface waters; and current legal and regulatory frameworks are in place to manage risks.

https://basc.org.uk/wp-content/uploads/2023/12/BASC-review-of-HSE-Annex-15-opinion.pdf

 

Do you mean from lead shot or generally?

Thank you Conor. 

In all the studies of the presence of lead shot in the gizzards of inland birds such as the partridge you mentioned are there figures for the mortality rate due to lead shot exposure? Were the studies carried out so far  carried out on what could reasonably be considered heavily shot over areas? 

In one of the studies cited I note a 1.2 %carriage rate in the partridge population studied  and a 4.5% carriage rate in those found dead yet no figures actual or estimated to determine the impact of lead shot exposure on mortality rate, do such figures exist. Are the only figures available then the carriage rate of lead shot in partridge but no data to support an increased mortality rate due to lead shot exposure? 

 

Edited May 8 by Konor
Clarification and addition

[Conor O'Gorman]

43 minutes ago, Konor said:

Thank you Conor. 

In all the studies of the presence of lead shot in the gizzards of inland birds such as the partridge you mentioned are there figures for the mortality rate due to lead shot exposure? Were the studies carried out so far  carried out on what could reasonably be considered heavily shot over areas? 

 

 

There are various estimates based on modelling - and its not specifically about terrestrial birds in terrestrial habitats, its about wildfowl and other bird species in terrestrial habitats, if that makes sense.  Typically we are talking about estimated mortality rates of 1-10% due to lead shot ingestion depending on the species.

There are a collection of papers up to 2019 here (and each paper links to many more papers):

https://link.springer.com/journal/13280/volumes-and-issues/48-9

The introduction to this 2019 volume of peer reviewed papers states:

Impacts of lead ammunition on species and ecosystems have been addressed directly or indirectly in multiple international Multilateral Environmental Agreements. Globally, lead gunshot has been subject to legislative and other forms of regulation in many countries over the last 40 years, especially for the protection of wildfowl and their wetland habitats. However, few countries have regulated lead gunshot outside wetland habitats or lead in rifle ammunition (California now being the exception).

It is evident that (1) the problem exists and requires action, (2) it is well documented, (3) lead-free ammunition is available, (4) the social constituencies responsible are identified, and (5) the solutions are apparent. Nevertheless, action at international and national levels is either lacking or progress is slow. The question is: why is this? Major lobby organizations actively oppose attempts to ban, or even restrict, the use of lead-based ammunition, either out of commercial interests or because it is viewed as an unjustified intervention, which fundamentally affects the right to hunt and is therefore construed as anti-hunting. Hunters are well-organized at national and international levels, and are represented effectively by industry and wealthy, politically influential groups, including heads of state and royalty, which potentially restricts the level of debate. Indeed, the public can be surprisingly unaware of the problems, and decision-makers fail to act appropriately in the complex and diverse interplay between socio-political and economic interests, especially where the debate may often be dominated by false or anecdotal information.

We believe that the most constructive way to reduce the use of lead ammunition is through continued and persistent documentation of the problems, clear presentation of solutions and more effective outreach at all levels. Clearly, the foundation for this should be sound science. The evidence for the impact of lead from hunting ammunition on wildlife and ecosystems is overwhelming (Arnemo et al. 2016). However, it is often widely scattered and poorly synthesized. A series of scientific publications to improve organization of the existing knowledge would greatly improve our ability to support informed debate and provide the evidence base to international and national decision makers, the press, stakeholders, and the public.

In the last decade, two major compilations of scientific research were published as proceedings from international conferences (Watson et al. 2009; Delahay and Spray 2015). Both are valuable sources of background evidence for the problems and provide tools to manage the problems associated with dispersal of lead from hunting ammunition in the natural environment. This Ambio Special Issue “Lead in ammunition: Persistent problems and solutions” represents a third step to inform further discussion. This Special Issue will contribute significantly to better defining the problems and solutions associated with lead ammunition in the environment and reducing the adverse impacts of lead on species and ecosystems.

This Special Issue has relied upon the work of very many people. We thank the authors for contributing their research results and original data and the many reviewers for ensuring the scientific quality of the submissions. Many institutions and persons provided significant support to the production of this collection of papers, including grants from the 15. Juni Fonden (Denmark) to produce the Special Issue, and the Aarhus University DCE - Danish Centre For Environment And Energy for the costs of printing and distribution. We thank our colleague members of the Project Group, Dr. Debbie Pain, Dr. Ruth Cromie, Dr. Jon Arnemo, and Dr. Rafael Mateo, for supporting the initial idea of this publication and for prompt feedback on consultations during the whole production process. Finally, we thank the Editor in Chief of Ambio, Dr. Bo Söderström, and his staff for ensuring the production and publication of the final edition.

[Conor O'Gorman]

55 minutes ago, Konor said:

Were the studies carried out so far  carried out on what could reasonably be considered heavily shot over areas? 

Shooting pressure and therefore density of available lead shot on the ground will be hugely variable across the studies. I think some site specific studies will have measured shot density but the species population modelling studies will not have taken specific account of that as far as I know.

[Konor]

1 hour ago, Conor O'Gorman said:

There are various estimates based on modelling - and its not specifically about terrestrial birds in terrestrial habitats, its about wildfowl and other bird species in terrestrial habitats, if that makes sense.  Typically we are talking about estimated mortality rates of 1-10% due to lead shot ingestion depending on the species.

There are a collection of papers up to 2019 here (and each paper links to many more papers):

https://link.springer.com/journal/13280/volumes-and-issues/48-9

The introduction to this 2019 volume of peer reviewed papers states:

Impacts of lead ammunition on species and ecosystems have been addressed directly or indirectly in multiple international Multilateral Environmental Agreements. Globally, lead gunshot has been subject to legislative and other forms of regulation in many countries over the last 40 years, especially for the protection of wildfowl and their wetland habitats. However, few countries have regulated lead gunshot outside wetland habitats or lead in rifle ammunition (California now being the exception).

It is evident that (1) the problem exists and requires action, (2) it is well documented, (3) lead-free ammunition is available, (4) the social constituencies responsible are identified, and (5) the solutions are apparent. Nevertheless, action at international and national levels is either lacking or progress is slow. The question is: why is this? Major lobby organizations actively oppose attempts to ban, or even restrict, the use of lead-based ammunition, either out of commercial interests or because it is viewed as an unjustified intervention, which fundamentally affects the right to hunt and is therefore construed as anti-hunting. Hunters are well-organized at national and international levels, and are represented effectively by industry and wealthy, politically influential groups, including heads of state and royalty, which potentially restricts the level of debate. Indeed, the public can be surprisingly unaware of the problems, and decision-makers fail to act appropriately in the complex and diverse interplay between socio-political and economic interests, especially where the debate may often be dominated by false or anecdotal information.

We believe that the most constructive way to reduce the use of lead ammunition is through continued and persistent documentation of the problems, clear presentation of solutions and more effective outreach at all levels. Clearly, the foundation for this should be sound science. The evidence for the impact of lead from hunting ammunition on wildlife and ecosystems is overwhelming (Arnemo et al. 2016). However, it is often widely scattered and poorly synthesized. A series of scientific publications to improve organization of the existing knowledge would greatly improve our ability to support informed debate and provide the evidence base to international and national decision makers, the press, stakeholders, and the public.

In the last decade, two major compilations of scientific research were published as proceedings from international conferences (Watson et al. 2009; Delahay and Spray 2015). Both are valuable sources of background evidence for the problems and provide tools to manage the problems associated with dispersal of lead from hunting ammunition in the natural environment. This Ambio Special Issue “Lead in ammunition: Persistent problems and solutions” represents a third step to inform further discussion. This Special Issue will contribute significantly to better defining the problems and solutions associated with lead ammunition in the environment and reducing the adverse impacts of lead on species and ecosystems.

This Special Issue has relied upon the work of very many people. We thank the authors for contributing their research results and original data and the many reviewers for ensuring the scientific quality of the submissions. Many institutions and persons provided significant support to the production of this collection of papers, including grants from the 15. Juni Fonden (Denmark) to produce the Special Issue, and the Aarhus University DCE - Danish Centre For Environment And Energy for the costs of printing and distribution. We thank our colleague members of the Project Group, Dr. Debbie Pain, Dr. Ruth Cromie, Dr. Jon Arnemo, and Dr. Rafael Mateo, for supporting the initial idea of this publication and for prompt feedback on consultations during the whole production process. Finally, we thank the Editor in Chief of Ambio, Dr. Bo Söderström, and his staff for ensuring the production and publication of the final edition.

The actual carriage rate in partridge studied was 1.2% yet the estimates for mortality runs up to 10% is this due to the increased susceptibity of wildfowl which are included in the higher estimates of lead shot associated mortality. 

[Gordon R]

• Quote

  The shooting sector must be allowed time to develop non-lead shotgun ammunition due to a world shortage of components and the need for manufacturers and assemblers to source new machinery to produce lead shot alternatives and biodegradable wads for all shotgun calibers.

  Where do smaller bore shooters stand if manufacturers say that it isn't economic to develop biodegradable wads for all shotgun calibres?

[Conor O'Gorman]

18 minutes ago, Konor said:

The actual carriage rate in partridge studied was 1.2% yet the estimates for mortality runs up to 10% is this due to the increased susceptibity of wildfowl which are included in the higher estimates of lead shot associated mortality. 

I don't know about relative susceptibilities between species, or research into that, just that seed eating birds are susceptible due to what happens in the gizzard when they eat lead shot mistaking it for grit. I think the following British review from 1960 will be of interest to some, given that this thread is in the wildfowling section of PW.

https://wildfowl.wwt.org.uk/index.php/wildfowl/article/download/129/129

 

11 minutes ago, Gordon R said:

• Where do smaller bore shooters stand if manufacturers say that it isn't economic to develop biodegradable wads for all shotgun calibres?

It's a personal choice, people can continue using what works best for them. In Terry Behan's recent podcast I think he mentioned that 28 bore and .410 cartridges in steel with bio wads were on the horizon. 

[Rewulf]

1 hour ago, Conor O'Gorman said:

However, few countries have regulated lead gunshot outside wetland habitats or lead in rifle ammunition (California now being the exception).

California being a well know 'anti gun' state, might have something to do with that ?

 

2 hours ago, Conor O'Gorman said:

There is clear evidence that lead shot poses a risk to a wide range of bird species in terrestrial habitats and a voluntary move away from lead shot for live quarry shooting with shotguns is reducing these risks.

There is clear evidence that death or injury from lead shot ingestion is a drop in the ocean compared to environment loss, predation, and hunting.
The RSPB studies claim an 'estimated' 30-60,000 wild birds a year die from lead shot ingestion.
Compare that to the 50 million birds released every year for game shooting, which are either killed by the guns, predated on, or simply run over by cars.
50 million birds a year killed by domestic cats.
An unknown number , but likely 10s of millions by fox, raptor and badger ?
Poisoned by chemicals or simply starve to death, again 10s of millions ?

Like I say a drop in the ocean, 99.99 % of wild bird deaths occur without any lead shot ingestion, but we dont want to study that, we want to study lead, and how toxic it is to wild birds.
1700 people die on the UKs roads every year, we dont ban cars, because that figure isnt high enough to justify it.
The agenda isnt lead, its gun ownership.

[Conor O'Gorman]

2 minutes ago, Rewulf said:

California being a well know 'anti gun' state, might have something to do with that ?

 

There is clear evidence that death or injury from lead shot ingestion is a drop in the ocean compared to environment loss, predation, and hunting.
The RSPB studies claim an 'estimated' 30-60,000 wild birds a year die from lead shot ingestion.
Compare that to the 50 million birds released every year for game shooting, which are either killed by the guns, predated on, or simply run over by cars.
50 million birds a year killed by domestic cats.
An unknown number , but likely 10s of millions by fox, raptor and badger ?
Poisoned by chemicals or simply starve to death, again 10s of millions ?

Like I say a drop in the ocean, 99.99 % of wild bird deaths occur without any lead shot ingestion, but we dont want to study that, we want to study lead, and how toxic it is to wild birds.
1700 people die on the UKs roads every year, we dont ban cars, because that figure isnt high enough to justify it.
The agenda isnt lead, its gun ownership.

I don't have a view on California, perhaps you are right that it's anti-guns or perhaps its over zealous use of environmental regulations. I think the NRA is challenging some of the regulations. As to the wider points, scientists are studying all sorts of things and sometimes policies follow and sometimes they don't. When it comes to mortality figures at population level its always going to be an estimate - whether its estimated number of birds dying of lead poisoning or estimated number of birds killed by cats etc. As regards cats there are increasing calls for mitigation measures to reduce the risks to birds. SongBird Survival have commissioned much research in this area. Here is a recent article about the use of bells.

https://www.telegraph.co.uk/news/2024/05/05/cats-wear-bells-stop-them-killing-birds/

 

[Rewulf]

4 minutes ago, Conor O'Gorman said:

I don't have a view on California, perhaps you are right that it's anti-guns or perhaps its over zealous use of environmental regulations. I think the NRA is challenging some of the regulations. As to the wider points, scientists are studying all sorts of things and sometimes policies follow and sometimes they don't. When it comes to mortality figures at population level its always going to be an estimate - whether its estimated number of birds dying of lead poisoning or estimated number of birds killed by cats etc. As regards cats there are increasing calls for mitigation measures to reduce the risks to birds. SongBird Survival have commissioned much research in this area. Here is a recent article about the use of bells.

https://www.telegraph.co.uk/news/2024/05/05/cats-wear-bells-stop-them-killing-birds/

 

Thank you 

[Konor]

44 minutes ago, Conor O'Gorman said:

don't know about relative susceptibilities between species, or research into that, just that seed eating birds are susceptible due to what happens in the gizzard when they eat lead shot mistaking it for grit. 

I accept the case for the restriction of lead shot over wetlands particularly around overshot inland flight ponds.

I'm not convinced that there is a case for the restriction of lead shot inland outwith the areas of flight ponds and I don't feel there is evidence to suggest that full scale lead ban restrictions are proportionate to any as yet unproven damage caused by the use of lead shot  to the population numbers of seed eating birds inland. 

I feel that the overall beneficial impact shooting has inland probably out ways any negative impact. Where it could be shown that there is a measurable negative effect on the environment then those areas should have controls on the use of lead shot enacted and the effect of such controls monitored to prove or disprove the extent of the harm that accompanies the use of lead shot.

 

[Konor]

54 minutes ago, Rewulf said:

There is clear evidence that death or injury from lead shot ingestion is a drop in the ocean compared to environment loss, predation, and hunting.
The RSPB studies claim an 'estimated' 30-60,000 wild birds a year die from lead shot ingestion.
Compare that to the 50 million birds released every year for game shooting, which are either killed by the guns, predated on, or simply run over by cars.
50 million birds a year killed by domestic cats.
An unknown number , but likely 10s of millions by fox, raptor and badger ?
Poisoned by chemicals or simply starve to death, again 10s of millions ?

Like I say a drop in the ocean, 99.99 % of wild bird deaths occur without any lead shot ingestion, but we dont want to study that, we want to study lead, and how toxic it is to wild birds.
1700 people die on the UKs roads every year, we dont ban cars, because that figure isnt high enough to justify it.
The agenda isnt lead, its gun ownership

That's more or less where I was heading Rewulf. Trying to put the as yet undefined numbers of birds lost to lead shot ingestion in a context and also the extent that those numbers really have on the overall population. Population dynamics aren't so straightforward and birds lost to lead ingestion may not be additive ie their death may enable the survival of others so that their effect on population numbers is zero. 

[Conor O'Gorman]

3 minutes ago, Konor said:

I accept the case for the restriction of lead shot over wetlands particularly around overshot inland flight ponds.

I'm not convinced that there is a case for the restriction of lead shot inland outwith the areas of flight ponds and I don't feel there is evidence to suggest that full scale lead ban restrictions are proportionate to any as yet unproven damage caused by the use of lead shot  to the population numbers of seed eating birds inland. 

I feel that the overall beneficial impact shooting has inland probably out ways any negative impact. Where it could be shown that there is a measurable negative effect on the environment then those areas should have controls on the use of lead shot enacted and the effect of such controls monitored to prove or disprove the extent of the harm that accompanies the use of lead shot.

 

The thing is that a lot of the evidence in terrestrial habitats is for wildfowl eating lead shot as grit. So whether its within wetlands or on dry land many wildfowl species are being impacted by eating lead shot. I do understand where you are coming from on proportionality and it would be great to have the detailed research that you point to to help inform policy - but if we are talking about regulations they are often one size fits all solutions. In my experience the evidence can sometimes influence the political decision making but its politics that often determines it. The reason for the wetlands restrictions coming into effect from 1999-2003 across the UK was because the UK signed an international treaty (AEWA). The reason the HSE is proposing further restrictions on lead ammunition is because of Brexit and the need for continued chemicals trade with EU. A lead ammunition ban in the UK was first proposed in a 1983 Royal Commission on Environmental Pollution report. 

[enfieldspares]

2 hours ago, Rewulf said:

1700 people die on the UKs roads every year, we dont ban cars, because that figure isnt high enough to justify it.
The agenda isnt lead, its gun ownership.

This. 

[Old farrier]

5 hours ago, Conor O'Gorman said:

A British grey partridge study published almost 20 years ago showed that grey partridge (adults and chicks) ingest lead shot in their gizzard.

That study is amongst many listed on the GWCT website https://www.gwct.org.uk/advisory/lead-ammunition/effects-of-lead-on-wildlife-and-wildfowl/ and they are but the tip of the iceberg on impacts of various wildfowl and other species eating lead shot as grit (the evidence goes back 100 years) in wetlands and terrestrial environments across Europe and worldwide.

Going back to that British study, grey partridge chicks were found to be eating lead shot - some with up to 14 pieces of lead shot in their gizzard - and grinding them up into their bloodstream. Here are two extracts from the paper:

"The measured incidence of lead shot in gizzards considerably underestimates the annual exposure because the shot is retained in the gizzard only for a relatively short period of time. The average erosion of lead in the grey partridge chicks, 55%, is remarkable given that the chicks were aged only 2–3 weeks (18 days) and had presumably not ingested the lead on their first day".

"It is remarkable that between 1968 and 1978, two chicks sampled from separate broods on the Sussex Downs had, within 3 weeks of hatching, ingested 13 and 14 lead shot. Moreover, the erosion of the individual shot suggests that they were ingested within a short discrete period of time. Somewhat similarly, a grey partridge in Denmark in 1976 had ingested 34 lead shot (Clausen and Wolstrup 1979), a grey partridge in Wiltshire in 1966, 26 (this study)".

Potts, G.R. (2005). Incidence of ingested lead gunshot in wild grey partridges (Perdix perdix) from the UK. European Journal of Wildlife Research, 51:31–34.
https://link.springer.com/article/10.1007/s10344-004-0071-y  

Food for thought, and for those wee wild grey partridge chicks, lead minefields indeed.

Whether in wetland or on dry land when birds ingest lead shot it grinds in their acidic gizzards and toxic lead salts are absorbed into the blood stream and find their way into the tissues of vital organs and bone causing sub-lethal or lethal effects depending on the species and how much lead shot that species of bird eats. 

A study of red grouse in Scottish and Yorkshire moors published almost 15 years ago found that when high levels of lead were found in the bones of grouse the source was lead shot using lead isotope analysis, with the authors recommending mitigation measures including the use of non-lead shot on grouse moors to reduce exposure risks. 

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors
https://pubmed.ncbi.nlm.nih.gov/19264349/ 

As regards BASC's latest position - below an extract from one of the documents BASC submitted to last year's HSE lead ammunition review consultation:

• BASC is opposed to any further regulation on the use of lead ammunition in the UK.
• Regulations are already in place to mitigate risks to wildfowl from the use of lead shot in wetlands.
• There is clear evidence that lead shot poses a risk to a wide range of bird species in terrestrial habitats and a voluntary move away from lead shot for live quarry shooting with shotguns is reducing these risks.
• The shooting sector must be allowed time to develop non-lead shotgun ammunition due to a world shortage of components and the need for manufacturers and assemblers to source new machinery to produce lead shot alternatives and biodegradable wads for all shotgun calibers.
• Lead in game meat is potentially a risk to human health via secondary exposure and government guidance and market forces are managing risks via best practice.
• Lead exposure pathways are not conclusive for livestock, soil, soil organisms, plants, and surface waters; and current legal and regulatory frameworks are in place to manage risks.

https://basc.org.uk/wp-content/uploads/2023/12/BASC-review-of-HSE-Annex-15-opinion.pdf

 

Do you mean from lead shot or generally?

From lead shot

could you tell us who conducted the survey 20 years ago and if there has been any further scientific studies 

[enfieldspares]

I've an experiment. Get two cages and provide each with water and suitable food. Put a six partridge chicks in one cage with a feral cat and six partridge chicks in the other cage the bottom of which is "a minefield of lead pellets". I'll bet £10 a chick which die first. Therefore proving, for me, that lead shot is less a risk to partridge chicks than are feral cats. Anything can be proved with science if you set up the test to prove the get the answer you want to the question you've asked. And actually in life the reality is that for ground nesting birds, especially the chick of ground nesting birds, more likely die each June and July from feral cats than from loose lead shot.

Edited May 8 by enfieldspares

[Penelope]

40 minutes ago, enfieldspares said:

This. 

Ever thus, although I feel it's more the killing of stuff than the shooting of things, that is the driver.

[Conor O'Gorman]

56 minutes ago, Old farrier said:

From lead shot

could you tell us who conducted the survey 20 years ago and if there has been any further scientific studies 

To address your first query about lead shot and soil and plant uptake there is no evidence of that and as per BASC's response to the HSE consultation quoted earlier in this thread "Lead exposure pathways are not conclusive for livestock, soil, soil organisms, plants, and surface waters; and current legal and regulatory frameworks are in place to manage risks".

To address your second query on grey partridge, the 2005 research was done by the late Dr. George Richard Potts (as per author title in the paper, Potts, G R) drawing on data from various study sites, including his own study area, who had a lifelong interest in grey partridge ecology and conservation and as the director general for Game Conservancy was responsible for a huge amount of research of importance to shooting. 

As for other studies the following 2016 paper drew on data for various studies to model grey partridge population level impacts from lead shot:

Can Ingestion of Lead Shot and Poisons Change Population Trends of Three European Birds: Grey Partridge, Common Buzzard, and Red Kite?
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0147189 

Look at the references section in the above paper for the other studies from Europe. There are also other grey partridge studies in USA and Canada.

 

Edited May 8 by Conor O'Gorman

[Rewulf]

35 minutes ago, Conor O'Gorman said:

Can Ingestion of Lead Shot and Poisons Change Population Trends of Three European Birds: Grey Partridge, Common Buzzard, and Red Kite?
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0147189 

Look at the references section in the above paper for the other studies from Europe. There are also other grey partridge studies in USA and Canada.

Im going to pick one of the birds mentioned in that paper, the common buzzard.
This graph appears to show them in decline.

Yet its widely accepted that buzzards are doing very well at the moment, and are very 'common'
This graph shows them doing OK to good.

 

So which graph is correct , or is the one in your supplied paper out of date ?
All I can say is in my area of the Vale of Belvoir, there are wall to wall buzzards, all trying to carve out territory, along with many other BOP that we are often told are endangered.
The reason being , all the shooting that goes on in these areas, and the ready source of dead things for them to eat.

[Conor O'Gorman]

3 hours ago, Rewulf said:

Im going to pick one of the birds mentioned in that paper, the common buzzard.
This graph appears to show them in decline.

Yet its widely accepted that buzzards are doing very well at the moment, and are very 'common'
This graph shows them doing OK to good.

 

So which graph is correct , or is the one in your supplied paper out of date ?
All I can say is in my area of the Vale of Belvoir, there are wall to wall buzzards, all trying to carve out territory, along with many other BOP that we are often told are endangered.
The reason being , all the shooting that goes on in these areas, and the ready source of dead things for them to eat.

That buzzard graph is about density dependence and per capita growth rates I think, ie. as pop density goes up that is more competition for resources and pop growth rates slow down. Only so many wild birds will naturally fit into the same acreage I guess. Same downward slope graph for grey partridge in that paper and most other species that would be measured in that way. The relevance of the graphs to the paper I am unsure of. The point of linking to the paper was to answer @Old farrierrequest for more studies on grey partridge and ingestion of lead shot - which are referenced in that paper.

Ingestion of lead shot by grey partridge is primary exposure to lead. 

Buzzards eating dead birds or mammals shot with lead ammunition is secondary exposure to lead. 

The buzzard population is indeed growing in the UK albeit with a recent dip. See trend here:

https://data.bto.org/trends_explorer/?species=Buzzard 

The speculated reasons for the population recovery are various, the following article summarises it well enough I think.

https://www.birdspot.co.uk/a-little-bird/focus/the-ups-and-downs-of-the-uk-buzzard-population  

Some would argue that that the pop increase would be even greater were it not for secondary exposure from lead ammunition.

https://www.cam.ac.uk/stories/raptorsuppression 

In BASC's response to last year's second HSE lead ammunition consultation the Association looked at the HSE presented evidence for mortality and sub-lethal effects from secondary exposure and the HSE suggestion that a secondary exposure pathway exists for predatory and scavenging birds from lead shot and lead rifle ammunition used for live quarry shooting. BASC concluded in its response to the HSE that there is no conclusive evidence which links lead ammunition as a cause of lead poisoning via secondary exposure to predatory and scavenging birds. 
 

[Old farrier]

There has been a lot of changes to farming practices since the survey sadly not to the benefit of the English partridge 

the changes to the countryside have probably had a bigger impact on the population of them than anything else along with the right to roam brigade and there dogs 

strict predator control habitat creation suitable for them to nest and feed their young no disturbance in the breeding season in areas free from pesticides are some of the key factors in getting the population to increase 

 

[Conor O'Gorman]

23 minutes ago, Old farrier said:

There has been a lot of changes to farming practices since the survey sadly not to the benefit of the English partridge 

the changes to the countryside have probably had a bigger impact on the population of them than anything else along with the right to roam brigade and there dogs 

strict predator control habitat creation suitable for them to nest and feed their young no disturbance in the breeding season in areas free from pesticides are some of the key factors in getting the population to increase 

 

I think it would help us to know what 'survey' you are referencing?  

Also, you asked me for "a scientific paper about the intake of lead by plants from the soil" and I took the time to reply. You might perhaps acknowledge that?