Bird Ecology and Conservation A Handbook of Techniques

Samples should usually not exceed 20 mm



20 mm and there

must be at least 10 times the volume of fixative as there is tissue. Small carcasses can be fixed whole, following opening for processing

Tissues fixed in glutaraldehyde for

As above

Generally as above but only tiny samples are taken. Scanning electron

transmission electronmicroscopy

microscopy (SEM) employs different techniques and is not

(TEM)

considered here

Cytological

As above (histology)

Easy to take, cheap to process (readily done in any veterinary pr

actice

preparations

or in the field), and produce rapid results. Usually consist of touch preparations/impression smears which can give valuable informa

tion

about tissues within a few minutes. The samples must first be blotted onfilter paper in order to remove excess blood

Swabs, organ/tissue samples,

Live birds (superficial lesions, mouth or

Usually comprise swabs (in transport medium if they are t

o be sent

and other specimens for

cloacal swabs, or dead birds but also

elsewhere), portions of tissue, or e

xudates/transudates (Hunter 1

989;

microbiological and other

samples from internal organs)

Scullion 1989). If culture proves impossible for financial or other

investigations

reasons, an impression smear stained with Gram or other stains will often provide some useful information

Tissues for toxicological

Mainly dead birds but some small

Toxic chemicals may have been the cause of dea

th or could have

examination

samples can be taken from live birds,

contributed to the bird’s ill-health, either dir

ectly or by increasing its

for example, blood or muscle biopsies

susceptibility to infectious disea

se. Samples from wild bird casualties can

for certain pesticide analyses, feathers

be taken and stored routinel

y for toxicological analysis

(for heavy metal and other analyses)

Samples for toxicology ar

e usually kept frozen and can be analyzed

at a later date. As with formalin-fixed samples, such specimens should betaken and stored even when there is no immediate prospect of their beinganalyzed