Wednesday, September 30, 2015

The Importance Of Lead-Free Hunting

Lead Poisoned Bald Eagle from Postville, IA
The paper A Global Update of Lead Poisoning in Terrestrial Birds from Ammunition Sources states that lead poisoning in wildfowl and waders from the ingestion of spent lead gunshot has been extensively studied, documented and reviewed over the last half century. They identify two main routes of ingestion: direct ingestion of lead pellets, which look like grit or small seeds, and secondary poisoning among birds that prey upon or scavenge animals that have been shot: primarily raptors, including eagles, hawks, falcons, and condors. Lead poisoning has been documented in 63 species of birds since 1939, including ravens, pheasants and other game birds, owls, rails, gulls, buzzards, kites, eagles, vultures, condors, falcons, red-tailed hawks, white-throated sparrows, yellow-rumped warblers, and solitary vireos. 

How serious is lead poisoning? It is both is pretty serious and very preventable.  Saving Our Avian Resources has done a lot of advocacy for non-toxic shot and they have wonderful information on their website. A few figures that struck me:
  • A study of causes of mortality in eagles submitted to the National Wildlife Health Center between 1975 and 2013 found that trauma and poisonings (including lead poisoning) were the leading causes of death for bald eagles throughout the study period. 
  • 56% of all eagles admitted to Iowa rehabilitators between 2004 and 2008 had abnormal lead levels in their blood. This ranged from a low of 37.5% in 2004 (with 62.5% of eagles being tested) to a high of 70.0% in 2005 (with 90.0% being tested). 
  • The University of Minnesota’s Raptor Center in St. Paul received 117 lead-poisoned bald eagles during the winter of 2009. In 2012, Dr. Pat Redig co-authored this paper about spent ammunition and lead poisoning in bald eagles.
  • In Canada and the USA, approximately 10–15% of recorded post-fledging mortality in Bald and Golden Eagles was attributed to the ingestion of lead shot from prey animals (Scheuhammer and Norris 1996). Elliott et al. (1992) found that 14% of 294 sick, injured. or dead Bald Eagles in British Columbia (1988 to 1991) were lead-poisoned and an additional 23% sub-clinically exposed.
  • A 2012 study by a team at the University of California at Santa Cruz found that 30 percent of blood samples taken from condors each year showed levels of lead high enough to cause significant health problems and that 20 percent of the free-flying birds required treatment to remove lead. From 1992 to 2012, the cause of death was established for 123 condors in California, Arizona and Baja California, Mexico; lead was responsible for 42 of the mortalities (https://goo.gl/fmK8Ku).
  • While lead poisoning can kill directly, lead toxicity is also a factor in collision deaths and injuries. According to the Raptor Center, about 85% of eagles that come in with collision injuries also have elevated lead levels. This video from the UK shows the effects of lead on a duck's coordination and motor skills: http://youtu.be/KaVr70-2mpc
Where is the lead coming from? Study after study identifies lead shot as the primary source for lead exposure.  In 1991, the US Fish and Wildlife Service banned lead shot in waterfowl hunting, although it can still be used for some other types of hunting, depending on your state's laws and regulations. A survey of ducks on the Mississippi Flyway found that the ban on lead shot reduced lead poisoning deaths of Mississippi Flyway mallards by 64 percent, while overall ingestion of toxic pellets declined by 78 percent over previous levels. By significantly reducing lead shot ingestion in waterfowl, the ban prevented the lead poisoning deaths of approximately 1.4 million ducks in the 1997 fall flight of 90 million ducks. 

Did the ban on lead shot prevent successful waterfowl hunting? No. The total number of geese and ducks harvested nationwide declined steeply beginning in about 1984, but started rising again in roughly 1992, as shown by this chart: http://flyways.us/regulations-and-harvest/harvest-trendsRequiring the use of non-toxic shot did not negatively impact waterfowl hunting, but did prevent ducks, geese, and many other animals from coming into contact with lead shot by ingesting it directly or feeding on lead-poisoned animals or carcasses containing shot. 

Back in 2013, Bob picked up an eagle that died of lead poisoning shortly after he got it. At the time, he said: “I have reached a point regarding these lead poisoned eagles that surprises me.  I do not get hardened and begin acceptance for picking up these sick eagles on the verge of death and clearly in severe pain.  To look at an adult bald eagle gasping for breath and making what can only be described as cries of pain; is something that never gets easy and to think it is clearly preventable.” 

If you hunt or shoot, please use non-toxic shot. It does your prey well, it does you well, and it does the environment well. We aren’t anti-hunting and we aren’t anti-gun, but handling lead-poisoned eagles has made us anti-lead shot!

Looking for loads? Try these links:
Are non-toxic loads effective? Some resources that conclude they are:
Has reducing lead shot helped birds? In addition to this study on waterfowl, a voluntary program in Arizona and Utah appears to be reducing condor deaths in those two states.  We are looking forward to hearing the results from California, which is beginning to phase in a lead shot ban just this year.

Looking for non-toxic advocates or educational materials? Try these links:
Good luck with your lead-free hunt! 

References


1 comment:

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