What killed bearded vulture Palanfré?

Palanfré, a captive-bred female bearded vulture released as part of our Alpine reintroduction project in 2004 was found dead beneath power lines earlier this year. Now, the comprehensive post-mortem analysis done reveals that multiple factors have led to her death. 

 

Reintroducing bearded vultures in the Alps

Palanfré, a captive-bred female, was released into the wild back in 2004 in the Alpi Marittime Natural Park in north-west Italy, and over the last 14 years was regularly observed in the skies above the park.  Palanfré was part of our programme to reintroduce the species back to the Alps since the last animal was shot in 1913. 

 

Death of Palanfré

It was with great sadness that Palanfré was found dead near a medium voltage power line earlier this year in the municipality of Novalesa, not far from the border with France. The results of the post-mortem of Palanfré, done at the University of Turin, recently made available, show that bleeding in the lungs and body cavity was the primary cause of death due to her possible collision with the power line.

 

Results of post-mortem

Firstly, an X-ray revealed that Palanfré had been shot by shotgun pellets, probably from a long distance, several months previously. Shotgun pellets were found in the wings and legs of the bird with a malformed bone in the right wing suggesting that this might have caused a break that had subsequently fused out of position. Sadly, it is still common for bearded vultures to be shot at in Europe, and although birds such as Palanfré can survive the initial shooting incident, many sustain injuries which eventually contribute to their death.  

 

 

Secondly, the chemicals brodifacoum, bromadiolone and difenacoum, commonly used poisons to control rodent populations across Europe, were found in the tissue samples from Palanfré. These poisons have an anticoagulant effect preventing the blood from clotting and when ingested by predators and scavengers often cause their death through internal bleeding. The analysis done in Turin stated that it is possible that the ingestion of these toxins promoted the bleeding which led to Palanfré’s death.  

 

Thirdly, the parasite Toxoplosma gondii was detected in tissue samples from Palanfré. This parasite is relatively common in wild and domestic animals (especially domestic cats), usually as a result of consuming infected meat, and has been detected previously in vultures and other scavenging birds. Although the parasite can cause toxoplasmosis in birds, a disease which affects the central nervous system and can cause blindness, the impact of the presence of the parasite on Palanfré’s health could not be verified.. 

 

Finally, the presence of lead residues in Palanfré’s bones, tissues and organs indicated that the bird had ingested lead at some point, possibly derived from hunting ammunition, which is common among vultures and other avian scavengers. Although the lead levels did not indicate recent acute intoxication, they could also have contributed to Palanfré’s death through toxic effects on the central nervous system that are widely recognised and frequently encountered in avian scavengers.      

 

In conclusion, the team who carried out the post-mortem suggested that although internal bleeding was the main cause of death, possibly due to collision with the overhead power line, the bleeding was likely to have been made worse by the anticoagulant effects of the rodenticides. It is also possible that the inhibiting effects of lead and the T. gondii parasite might have worked together to cause Palanfré to collide with the overhead cables. 

 

This case illustrates the many challenges that bearded vultures must overcome to survive in the wild, and that mortality factors are often complex and inter-linked. 

  

The VCF would like to thank the Turin University of Veterinary, Parco regionale Api Cozie and Parco Nazionale dello Stelvio. for this comprehensive investigation.    

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