Kea are an inquisitive species which have evolved to take advantage of any opportunities that present themselves within their environment. This adaptation has been crucial to their survival, however in a human altered landscape it is now resulting in kea mortalities through ingestion of foreign materials inclusive of highly toxic lead products. Lead has been commonly used in buildings throughout the South Island, in the form of roofing nailheads and flashing. It is naturally sweet, soft and malleable - an irresistable combination for juvenile kea in particular.
How lead affects animals
Lead is a highly toxic. It has wide ranging effects on multiple body systems (Pain, 2003) and is known to affect neurological development and survivorship in animals (McLelland, unpub). Lead toxicosis presents in the following ways;
Death can result from secondary infection, starvation, predation or misadventure” (McLelland, unpublished draft, 2007).
Are kea affected?
Recent research on lead toxicity in Mt Cook kea by McLelland, has found that of 38 live kea tested all were found to have detectable blood lead levels, 26 considered dangerously high. Additional analysis of 15 dead kea (sent to
Research conducted by Clio Reid of Victoria University (2008) has confirmed that the natural curiosity of kea which has enabled the species to adapt to its extreme environment, may increase its propensity to poisoning through ingestion of lead – ie. the more investigative behaviours identified in a bird the higher its blood lead levels were likely to be.
Curiosity in kea is an important evolutionary adaptation. Removal of these birds from the population (through death by lead poisoning) could effectively decrease the species long-term survival by reducing essential survival traits within the wider population.
Where is the lead located and how much is there in the environment?
The amount of lead in a form dangerous to kea is potentially enormous. A large number of Department of Conservation huts and out-buildings, skifield complexes, high country farms, old mining areas and private alpine dwellings are riddled with lead nailheads and flashings. A recent NZ Royal Society study carried out by Jules Robson found that wherever buildings containing lead in them in kea habitat are located, kea have or continue to access the lead from them. The amount of lead accessible to kea is therefore considered extensive and it is located across the species range.
The results of recent research on affect of lead toxicity on wild kea populations show a significant and potentially widespread impact throughout the species range. Continued monitoring of the effect of this on kea populations may help to quantify the impact but will not solve the problem.
As such, and as an immediate solution to lead toxicity in wild kea, it is recommended that lead products be removed from buildings throughout the kea range and replaced with alternative products unattractive to kea. This recommendation is supported by Department of Conservation and advised by the 1995 Kea Advocacy Strategy.
If you or your organisation are able to help us remove lead from the keas environment and replace them with more envrionmentally friendly products, please contact us at the Trust (contact details in the side menu).
For information on the Trusts involvement with lead toxicity research carried out by Clio Reid of Victoria University, please read below and visit our Kea Research Projects - Associated Projects page for a detailed account of the research expedition.
Juvenile kea chewing lead nail heads (Mt Cook) Photo: Corey Mosen 2008
For all those kea that have been tested for evidence of lead poisoning, many more will have gone un-noticed. It is now a fact that kea in areas of human habitation are being exposed to and have access to often high levels of lead in their environment!
How you can help save kea from lead poisoning!
It is also important to remember that lead toxicity can also affect keas ability to negotiate hazards in the environment so to help keep kea safe in your area:
And remember, if you find any dead or injured kea please contact us on 0274249594 for information on what to do.
Photo credit: Vicky Nall