Lead shot ingestion in birds

[Conor O'Gorman]

I promised in another thread on firearms licensing (that was rapidly deviating off topic) to start a new thread on research into lead shot ingestion in birds. I will start with grey partridge and move onto research for other bird species.

Grey partridge

Incidence of ingested lead gunshot in wild grey partridges (Perdix perdix) from the UK

https://www.researchgate.net/publication/225816496_Incidence_of_ingested_lead_gunshot_in_wild_grey_partridges_Perdix_perdix_from_the_UK

From 1947 to 1992, successive pathologists at The Game Conservancy Trust carried out 1,318 post-mortems on adult wild grey partridges found dead in the UK. During a study of chick food from 1968 to 1978 on the Sussex Downs, the gizzards of 29 wild chicks aged up to 6 weeks were also examined. This paper reports the incidence of lead gunshot ingestion in these two groups of birds. On the assumption that there is no temporal bias, the incidence of lead poisoning increased from 1947–1958 to 1963–1992. During 1963–1992, the incidence of lead gunshot ingestion was 4.5 +/- 1.0% in adults and 6.9 +/- 4.7% in chicks

Dead chicks with up to 26 pieces of lead shot in their gizzard were amongst the data sets, and it was typical to find that the lead shot found had been eroded in half. Most of these chicks were in the first few weeks of life. 

The author also notes:

"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 B, Wolstrup C 1979 Lead poisoning in Game from Denmark. Dan Rev Game Biol 11:1–22], a grey partridge in Wiltshire in 1966, 26 (this study)."

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

This research modelled lead shot ingestion and pesticide poisons combined in grey partridge, and asserted that this may have decreased the equilibrium size of the already declining grey partridge population by almost 20% (not including possible hatching effects).

 

[Konor]

When presenting this information are you doing so on behalf of BASC or is this a personal post ?

[scarecrow243]

i don't believe that lead shot does not get passed thru just like grit that birds eat to help grind down seeds etc

[Conor O'Gorman]

41 minutes ago, Konor said:

When presenting this information are you doing so on behalf of BASC or is this a personal post ?

I don't really compartmentalise what I post on this forum in my mind like that, I have been posting on here since 2008, but the feedback on this thread, like that just now from scarecrow243, may help give me a steer for a briefing I am doing for the BASC website on the evidence around lead shot ingestion by birds.

[Old farrier]

Sadly most of the links are historical not really relevant to non migratory game birds with a expected lifespan of 2 years here’s a chart from some of the data to save members reading a manuscript with no mention of the impact habitat loss has on the population 

[Konor]

3 minutes ago, Conor O'Gorman said:

I don't really compartmentalise what I post on this forum in my mind like that, I have been posting on here since 2008, but the feedback on this thread, like that just now from scarecrow243, may help give me a steer for a briefing I am doing for the BASC website on the evidence around lead shot ingestion by birds.

I ask partially because I’d like it clarified whether you consider that your posting of studies now over 30 years old and some going back over 75 years have much relevance to present day shooting circumstances . When the lead ammunition group reported to DEFRA in 2016 the then Secretary of State Liz Truss concluded that there were no grounds for banning lead ammunition stating that “ the report did not show that the impacts of lead ammunition were significant enough to justify changing current policy “ Have there been any studies post 2016 that contradict those findings ? 
 Can I also ask if this thread is part of a personal crusade by yourself to support the abolition of lead shot use inland completely or an indication that BASC proposes supporting further legislation on lead shot contrary to its present stance. BASC policy and your own personal opinion if they differ should ideally be expressed separately in order to avoid confusion or the impression that your personal opinion dictates BASC policy.

[Konor]

29 minutes ago, Old farrier said:

Sadly most of the links are historical not really relevant to non migratory game birds with a expected lifespan of 2 years here’s a chart from some of the data to save members reading a manuscript with no mention of the impact habitat loss has on the population 

It would appear that the loss of partridge numbers to lead shot pale into insignificance when compared with the other losses shown I would have thought not significant enough to contradict the findings of DEFRA in 2016. Are these the only figures available to quantify partridge death attributed to lead shot use.

[Conor O'Gorman]

Red grouse

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors

https://www.sciencedirect.com/science/article/abs/pii/S0048969709001570

This research involved investigating various sources of raised lead levels in red grouse, and suggested management options for the three moors include adopting non-toxic shot for all game shooting on the estates, allowing heather vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead.

[Old farrier]

1 hour ago, Konor said:

It would appear that the loss of partridge numbers to lead shot pale into insignificance when compared with the other losses shown I would have thought not significant enough to contradict the findings of DEFRA in 2016. Are these the only figures available to quantify partridge death attributed to lead shot use.

I haven’t been able to find any newer research sadly 

[Konor]

1 minute ago, Old farrier said:

I haven’t been able to find any newer research sadly 

👍

[Stonepark]

1 hour ago, Conor O'Gorman said:

Red grouse

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors

https://www.sciencedirect.com/science/article/abs/pii/S0048969709001570

This research involved investigating various sources of raised lead levels in red grouse, and suggested management options for the three moors include adopting non-toxic shot for all game shooting on the estates, allowing heather vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead.

And the Iron levels, tungsten levels, uranium, aluminium, bismuth levels etc?

This a study on lead and it appears 1 in 20 birds to 1 in 30 birds may be affected from lead  'notionally' from shotgun lead pellets as evidenced but not checked by say under taking silt analysis in the local water supplies to establish if there was any lead in the environment.

The Yorkshire moor where there was extensive lead in the birds was clearly nearly all environmental and not so much shotgun pellets.

Back to my first question, were there any other poisonous heavy metals in the birds? Iron in Scottish moors due to high iron content and acidic streams (everyone has seen the orange burns coming out of some bogs), peat hydrocarbons (natural oil slicks in bog water), etc

Is lead a serious issue (sites being shot for 200 years and only 1 in 30 birds suggests not), or do other factors cause more issues.

If you are just about to be hit with a 40t truck, worrying about a heart murmur being a cause of death is a bit irrelevant.

 

Just whilst on alternatives, China responsible for 80% of tungsten, bismuth etc is limiting exports to the West and especially USA, so that is 2 alternatives gone even more expensive or potentially unobtainable.

With closure of steel mills, no more home produced steel and again have to import at significant cost (not going to be cheap importing steel pellets from China), it can be easily argued that there is not a true replacement for lead and as such we should stick with it.

 

Edited Monday at 21:59 by Stonepark

[enfieldspares]

As I posted elsewhere the recent Rosebank and Jackdaw Oil case requires that any review take account of worldwide climate emissions in the future from any decision and not just the immediate impact of the decision on the local area to it.

Therefore can anyone here who is a BASC member formally request BASC (as I will be doing the CPSA) to require that the recent DEFRA recommendations on lead shot be ruled invalid as they do not take into account the environmental harms of producing steel shot and the environmental harms of transporting it from where is made to the UK nor the environmental harms that require use of plastic wads and/or scrapping of older guns and their replacement with modern made guns.

For I do not think that that has been addressed by DEFRA. I am not a BASC member so can someone here that is formally request them to take legal opinion on the matter and to let us know the answer.

[Vince Green]

I simply don't accept that this is impartial research or even valid research

They examined 29 dead chicks and found .........

Twenty nine! Where did they get them from? They are not exactly lying about all over the place randomly waiting to be found are they. Highly suspicious 

You absolutely  can't base a whole research paper on 29 chick's unless you are trying to make the findings fit the conclusion you have already decided you want.

Edited Tuesday at 15:08 by Vince Green

[Newbie to this]

49 minutes ago, Vince Green said:

You absolutely  can't base a whole research paper on 29 chick's unless you are trying to make the findings fit the conclusion you have already decided you want.

Nail squarely hit on the head!

[Gas seal]

Hi Conor, if a lot of the research is out dated it should be noted that a lot more game birds are released since the research was done, quotes of some thirty million, so a lot more lead pellets are fired , more birds could ingest lead pellets.

Dead  birds in the countryside won’t be there for long whatever they died of , millions must die every year and never seen, so the chance of finding any would be small. Lead pellets ingested could make eggs infertile. As English partridges breed in the second year l would be looking at the eggs to see if any are addled,  this could be due to any lead ingested, it would be easier to find a nest than any dead birds . 
Regarding the environment could be killing English partridge in my area we had and still have numbers of partridges on farmland and in and around factories and country parks. A lot of the land that they are on is were the chemical factories were , and still working , and tipping on site  for years . No breeding and releasing, feeding, or vermin control.

I have shot many thousands of woodpigeon with steel shot, most went for animal feed or to feed birds of prey, I’ve not had anyone ask for woodpigeon or rabbits shot with lead because they tell me that it would kill their birds. 
 

[Vince Green]

I can remember being told somewhere, possibly Shooting Times, about 50 years ago that it was unwise to eat woodpigeon too frequently because ingested pesticides and herbicides made their meat toxic Many of these pesticides  I would hope have since been banned. You can't help but wonder though.

My pregnant daughter in law tells me that pregnant women are not now supposed to eat certain types of fish because they are contaminated with mercury.

[Conor O'Gorman]

50 minutes ago, Gas seal said:

Hi Conor, if a lot of the research is out dated it should be noted that a lot more game birds are released since the research was done, quotes of some thirty million, so a lot more lead pellets are fired , more birds could ingest lead pellets.

Dead  birds in the countryside won’t be there for long whatever they died of , millions must die every year and never seen, so the chance of finding any would be small. Lead pellets ingested could make eggs infertile. As English partridges breed in the second year l would be looking at the eggs to see if any are addled,  this could be due to any lead ingested, it would be easier to find a nest than any dead birds . 
Regarding the environment could be killing English partridge in my area we had and still have numbers of partridges on farmland and in and around factories and country parks. A lot of the land that they are on is were the chemical factories were , and still working , and tipping on site  for years . No breeding and releasing, feeding, or vermin control.

I have shot many thousands of woodpigeon with steel shot, most went for animal feed or to feed birds of prey, I’ve not had anyone ask for woodpigeon or rabbits shot with lead because they tell me that it would kill their birds. 
 

Thanks, I agree, there is much we have yet to understand as as regards the impact of many factors on wild greys. Research continues...!

[Gas seal]

Hi Vince the last paragraph in this booklet is interesting regarding woodpigeon.

[Conor O'Gorman]

Common pheasant

Lead exposure in ring-necked pheasants on shooting estates in Great Britain.

https://wildlife.onlinelibrary.wiley.com/doi/abs/10.2193/0091-7648(2005)33[583:LEIRPO]2.0.CO;2

The scientists examined 437 ring-necked pheasant gizzards collected from birds shot on 32 shooting estates in Great Britain during spring 1996 and 1997 and during the shooting seasons of 1999-2000 and 2001-2002. They determined wing-bone-lead concentrations in 98 female birds collected in 1997. Gizzard examinations showed an overall ingestion incidence rate of 3.0%. The birds that had lead in their gizzards in 1997 also had high concentrations of lead in their bones. They suggested that game managers on shooting estates should be aware that pheasants are vulnerable to shot ingestion and may need to consider measures to reduce this problem in areas where prevalence is high.

[McSpredder]

On 17/02/2025 at 18:28, Conor O'Gorman said:

Dead chicks with up to 26 pieces of lead shot in their gizzard were amongst the data sets, and it was typical to find that the lead shot found had been eroded in half. Most of these chicks were in the first few weeks of life. 

Where did BASC find that “Dead chicks with up to 26 pieces of lead shot in their gizzard were amongst the data sets” ?   **** Potts reported no more than 14 pellets in any partridge chick.   

Who said “it was typical to find that the lead shot found had been eroded in half”?   That statement certainly does not appear in **** Potts’s paper.   Out of the 29 chicks examined, only two were found to have any lead pellets at all in their gizzards (13 in one chick and 14 in the other).   Do BASC scientists consider results from only two individuals to be an adequate basis for deciding what is “typical”?

Potts commented that instances of the two very young chicks in Sussex (13 and 14 pellets), adults partridges in Denmark (34 pellets) and Wiltshire (26 pellets), and a pheasant in Sussex (87 pellets) all occurred in a predominantly arable environment where cultivation removes most of the shot from the soil surface.   

How far does a 2-3 week old chick roam, and what are the chances that it would have found so many pellets in that area?   I don’t know the answers, and apparently nor did **** Potts (he described those instances as remarkable).   My own research experience was not in any way related to gamebirds, but I was always advised that “science makes progress by the careful study of anomalous results”, and it would be disappointing if none of our gamebird experts had the relevant information to hand. 

I wonder whether these situations might have arisen where somebody dropped a paper-cased cartridge, which disintegrated and released hundreds of pellets very close together.    However, that is nothing more than a guess.   What do PW members think?

[Pukka Bundook]

Vince Green up the page asked the questions that were on my mind;  Chicks, "Where did they get them from?"

As in, I was thinking where in h*ll did chicks pick up such concentrations?

Now, if they were hatched  on a sporting clay or regular clay shooting ground maybe,  but I would defy anyone to find any to speak of on average farm land.

Yes, around grouse butts there could be some but grit piles would reduce injestion.

 

[Konor]

8 hours ago, McSpredder said:

Where did BASC find that “Dead chicks with up to 26 pieces of lead shot in their gizzard were amongst the data sets” ?   **** Potts reported no more than 14 pellets in any partridge chick.   

Who said “it was typical to find that the lead shot found had been eroded in half”?   That statement certainly does not appear in **** Potts’s paper.   Out of the 29 chicks examined, only two were found to have any lead pellets at all in their gizzards (13 in one chick and 14 in the other).   Do BASC scientists consider results from only two individuals to be an adequate basis for deciding what is “typical”?

Potts commented that instances of the two very young chicks in Sussex (13 and 14 pellets), adults partridges in Denmark (34 pellets) and Wiltshire (26 pellets), and a pheasant in Sussex (87 pellets) all occurred in a predominantly arable environment where cultivation removes most of the shot from the soil surface.   

How far does a 2-3 week old chick roam, and what are the chances that it would have found so many pellets in that area?   I don’t know the answers, and apparently nor did **** Potts (he described those instances as remarkable).   My own research experience was not in any way related to gamebirds, but I was always advised that “science makes progress by the careful study of anomalous results”, and it would be disappointing if none of our gamebird experts had the relevant information to hand. 

I wonder whether these situations might have arisen where somebody dropped a paper-cased cartridge, which disintegrated and released hundreds of pellets very close together.    However, that is nothing more than a guess.   What do PW members think?

I think that the evidence put forward doesn’t stand up to scrutiny and the low single figure incidence of ingestion has yet to prove any substantial effect that would justify further restrictions of the use of lead shot inland, much the same conclusion as DEFRA arrived at in 2016. No evidence has been tabled since 2016 that would question that decision , if such evidence was available it would be being used to silence any resistance to further restrictions on the use of lead shot. It seems the argument in favour of restricting the use of lead shot is flawed and that any proposed restrictions are agenda driven. If the reasoning behind further restriction is saving the game meat market then the solution is simple ,all shoots supplying that market should supply the ammunition to be used on the day of the shoot and birds supplied to market should be tested to ensure compliance. 
 If those shooting for the table are happy to do so with lead shot then that should continue ,their shot count is minuscule compared to that of commercial shooting so should have equally minuscule impact. The idea that any animal welfare organisation is concerned about the risk to health of shooters supplying their own table with fresh meat doesn’t hold water I would contend that the scale of sports shooting carried out by commercial shoots is the source of their concern. 
 The impact on human health of lead shot consumption cannot be compared to the impact of smoking or alcohol consumption,I’ll take the concerns of any government on the use of lead shot on human heath more seriously when alcohol and cigarettes are banned and the anti lead shot lobby when they can provide evidence that justifies lead shot abolition on the grounds of environmental impact.

[Conor O'Gorman]

14 hours ago, McSpredder said:

Where did BASC find that “Dead chicks with up to 26 pieces of lead shot in their gizzard were amongst the data sets” ?   **** Potts reported no more than 14 pellets in any partridge chick.   

Who said “it was typical to find that the lead shot found had been eroded in half”?   That statement certainly does not appear in **** Potts’s paper.   Out of the 29 chicks examined, only two were found to have any lead pellets at all in their gizzards (13 in one chick and 14 in the other).   Do BASC scientists consider results from only two individuals to be an adequate basis for deciding what is “typical”?

Potts commented that instances of the two very young chicks in Sussex (13 and 14 pellets), adults partridges in Denmark (34 pellets) and Wiltshire (26 pellets), and a pheasant in Sussex (87 pellets) all occurred in a predominantly arable environment where cultivation removes most of the shot from the soil surface.   

How far does a 2-3 week old chick roam, and what are the chances that it would have found so many pellets in that area?   I don’t know the answers, and apparently nor did **** Potts (he described those instances as remarkable).   My own research experience was not in any way related to gamebirds, but I was always advised that “science makes progress by the careful study of anomalous results”, and it would be disappointing if none of our gamebird experts had the relevant information to hand. 

I wonder whether these situations might have arisen where somebody dropped a paper-cased cartridge, which disintegrated and released hundreds of pellets very close together.    However, that is nothing more than a guess.   What do PW members think?

The word 'typical' is mine. The exact text in the paper:

"The weights of individual lead shot in the chick gizzards showed a rapid rate of erosion, indicating a short retention time in the gizzard, as also reported for adult waterfowl and game birds" 

and:

"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) and a pheasant on the Sussex Downs in 1970, 87 (Beer 1988). All these cases occurred in a predominantly arable environment where cultivation removes most of the shot from the soil surface (Esslinger and Klimstra 1983). 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. The erosion in the chick gizzards is consistent with lead shot loss in adult mallard (Bellrose 1959); mourning dove (Zenaida macroura) and bobwhite quail (Colinus virginianus) (McConnel 1968) and willow grouse (Lagopus lagopus) (Gjerstad and Hanssen (1984). It follows that the gizzards of some living partridges that contain no lead shot at the time of sampling will probably have contained shot previously."

[Conor O'Gorman]

Also the Danish grey partridge that was reported as having ingested 34 lead shot in the Potts paper is from a very detailed report on lead poisoning in various Danish birds, that is available to read online from the link below, and the results are stark, and that is from 50 years ago!

https://dce2.au.dk/pub/vbs/DRGB11_2.pdf

 

[Conor O'Gorman]

17 hours ago, Conor O'Gorman said:

Common pheasant

Lead exposure in ring-necked pheasants on shooting estates in Great Britain.

https://wildlife.onlinelibrary.wiley.com/doi/abs/10.2193/0091-7648(2005)33[583:LEIRPO]2.0.CO;2

The scientists examined 437 ring-necked pheasant gizzards collected from birds shot on 32 shooting estates in Great Britain during spring 1996 and 1997 and during the shooting seasons of 1999-2000 and 2001-2002. They determined wing-bone-lead concentrations in 98 female birds collected in 1997. Gizzard examinations showed an overall ingestion incidence rate of 3.0%. The birds that had lead in their gizzards in 1997 also had high concentrations of lead in their bones. They suggested that game managers on shooting estates should be aware that pheasants are vulnerable to shot ingestion and may need to consider measures to reduce this problem in areas where prevalence is high.

Also from UK:

Calvert H (1876) Pheasants poisoned by swallowing shot. Field 47:18

Beer JV (1988) Diseases of gamebirds and wildfowl. Game Conservancy Ltd, Fordingbridge.
(refs a pheasant having ingested 87 pieces of lead shot)