Carbofuran: Toxicity, diagnosing poisoning and rehabilitation of poisoned birds - Carbofuran and Wildlife Poisoning: Global Perspectives and Forensic Approaches - page 30

Figure 2.2 Birds can die so quickly that they are discovered with poisoned ingesta in their mouths

used in malicious poisoning, and may be applied to seed, processed meat, or, a multitude of other
bait material (depending on the intended target). Poisoning may also occur via the ingestion of dead
and/or dying insects, or from ingestion by scavengers of dead and/or dying birds or other vertebrates.
In cases of suspected poisoning, brain samples should be collected to assess AChE activity. If not
analysed immediately, brains (or the whole head) should be frozen as quickly as possible. The con-
tents of the oesophagus, crop and stomach/gizzard (upper gastrointestinal content) should be saved
(in two separate bags). One can be used as the primary sample for residue analysis, the other for
identifi cation of the contents. It may be advisable to keep a sub-sample as well, in case there are legal
proceedings. These should also be frozen to prevent residue degradation.
An accurate history is often very helpful when making a tentative diagnosis of carbofuran poison-
ing, and when directing any residue work. Knowledge regarding any sprays or granules that have
been used in the proximity of the incident is critical - and such questions should always be asked of
anyone reporting the incident. A detailed history is likely to include species present, species affected,
environmental conditions (i.e., recent rainfall), high temperatures (which might have led to sample
reactivation or chemical breakdown). A detailed identifi cation of the upper gastrointestinal con-
tent is also critical when trying to understand the kill; photographs can be helpful. Wobeser (1996)
provides generic guidance on forensic examination techniques, and emphasises the need for clear
reporting, and a carefully maintained chain of custody (so that a case can be presented in a court
of law if needed). Finally, investigators must wear the appropriate protective clothing to minimise
health risks and prevent accidental exposure since the area of the kill could be heavily contaminated.
Investigators must also consider that the need to quickly recover samples may confl ict with normal
allowable re-entry intervals into the area, which could be heavily contaminated from a spill or from
malicious baiting.