Bird Ecology and Conservation A Handbook of Techniques

Interpretation of findings| 199

8.6 Interpretation of findings

When investigating dying or dead birds, remember that a “diagnosis” is not nec-
essarily the objective. As was explained earlier, the proximate cause of death may
not be the most important finding, but the endogenous or exogenous factors,
thatcontributedto the bird’s demise. Apparently background findings of, for
example, parasitism or inactive gonads may also be of relevance, especially when
monitoring the health of an avian population.
Care must, therefore, be taken over terminology. A “diagnosis” is one thing,
the “cause of death” another. All findings need to be interpreted in the context of

1

Gross post-

mortem

examination

(see text)

2

Tissues/

swabs for

microbiology

taken direct

to laboratory

or using

swabs +/–

transport

medium

Toxicology

3

Tissues for

cytology—

impression

smears/

touch

preparations

on micro-

scope slides

Tissues or

portions of

organs frozen

at – 20 °C

(preferably

–70°C)

Virology

4

Tissues for

histology in

10%

buffered

formalin

DNA studies

5

Tissues for

transmission

electron-

microscopy

in glutaralde-

hyde (+/–

tissues for

scanning

electron-

microscopy)

Tissues in

ethanol for

DNA finger

printing and

mitochondrial

DNA

6

Other

samples, if

available, for

example,

heart blood

for smears,

serum; bone

marrow for

smears; gut

contents for

toxicology

Remains of

carcass for

chemical

analysis,

skeletal

studies or

deposition

in a Reference

Collection

Dead Bird

Fresh or chilled whole carcass Frozen carcass (usually

following examinations

1, 2, 3 and 4. sometimes

5 and 6 on a fresh carcass)

Sample taking during postmortemexamination of birds.