Yuba Net I reports that a San Diego Zoo Institute for Conservation Research paper shows that human behaviors are the cause of most California Condor deaths. 73 percent of known deaths are due to consuming small bits of trash including bottle caps , broken glass, plastic and metal. The top cause is lead poisoning from lead from fragments in ammunition. The paper states:
“The most important mortality factor for the combined free-ranging populations was lead toxicosis … The evidence that the principal source of exposure is lead ammunition is overwhelming and includes the recovery of lead shotgun pellets and bullet fragments from the upper GI tract where lead is readily absorbed and tissue lead isotope signatures that match lead ammunition and not other sources of lead.”
Other causes of death include
- power-line collisions or electrocution.
- zinc poisoning from ingestion of zinc-core pennies
Read more at YubaNet Scientific paper shows California condor still threatened by human activities.
- California condors rebound, with some human help (cbsnews.com)
- Endangered California condors celebrate 15th anniversary since reintroduction into Arizona (yubanet.com)
- Three California Condors Chicks Hatch in Grand Canyon (naturalhistorywanderings.com)