Geoscience Reference
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radiotelemetry is used to monitor movements, behavior, and physiology of
reptiles (Larsen 1987) and occasionally amphibians (Bradford 1984; Smits
1984). For amphibians, the main constraint appears to be related to transmit-
ter size, and as a general rule it is recommended that packages not exceed 10
percent of the body mass of the study animal (Richards et al. 1994). Radio-
telemetry is problematic with many reptiles and amphibians, and snakes in
particular offer challenges because external mounting is not feasible. Consid-
erable effort has been invested in developing an effective method for implant-
ing transmitters in snakes (Weatherhead and Anderka 1984). However, the
value of stomach implants is questioned on the grounds that they may affect
aspects of snake behavior (Fitch and Shirer 1971; Jacob and Painter 1980;
Reinert and Cundall 1982). For instance, stomach-implanted snakes seem to
behave similarly to nonimplanted snakes that have recently ingested food
(Lutterschmidt and Reinert 1990), suggesting that activity patterns of im-
planted snakes are not representative of those of nonimplanted animals. Stom-
ach transmitters also can affect other behaviors or physiological processes, and
it might be that such markers simply are not acceptable in snakes because of
effects on the animal. Alternatively, transmitters can be implanted in snakes
either intraperitoneally or subcutaneously, and these modes of attachment
generally appear to be effective (Weatherhead and Anderka 1984).
Birds
There is more literature about the effects of marking on birds than for other
taxa (table 2.3). Therefore, we provide a sample of recent (i.e., largely post-
1989) references for numerous avian marking techniques, and refer the reader
to recent reviews by Nietfeld et al. (1994) and Calvo and Furness (1992) for
earlier references.
BANDS AND COLLARS Selecting correct band size and material is a very
important step in the marking process because different band materials and
configurations can have different effects on birds. For example, aluminum
butt-end and lock-on bands can cause more injury and reduce the probability
of recovery or recapture of some birds, compared to stainless steel bands (Mey-
ers 1994). Some authors (Hatch and Nisbet 1983a, 1983b; Nisbet and Hatch
1985) recommend use of incoloy (a metal alloy) bands as a substitute for alu-
minum bands because aluminum bands can cause abrasion to legs of some
bird species. Young birds whose legs are still growing can be the most subject
to harmful effects of improperly fitting bands, but one method alleviating such
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