The next step is to collect data for analyses that add value to the fieldwork. In order
to plan how best to collect data, it is important to access the analysis software in
advance.
For example, the most sensitive tests require data to be collected systematically,
in ways that make it easy to identify how long individuals survived, when they dis-
persed and how they used different areas. For testing whether performance relates
to areas used by the animals, it will also be important to analyze location data. This
too requires systematic data collection, in ways that are indicated by the software.
Indeed, location analysis software should be used when starting the pilot phase of
a project, to develop efficient field methods. Map data may also be needed to estim-
ate the habitats available to different individuals. Software for survival analyses
helps to estimate how many tags will be needed to show significant differences,
which means using a computer before buying radio equipment. This is further
explained below and in manuals (White and Garrott 1990; Kenward 2001).
However, it is always best to consult a statistician before starting the work.
6.4 Approaches
6.4.1Pilot studies
Harris et al.(1990) noted the importance of a pilot study when collecting location
data. Before embarking on extensive work, it is wise to check techniques for
capture, tagging, and data collection. Can the animals be marked without bias?
Tagging nestlings is likely to minimize bias compared with trapping techniques
that may select poor quality individuals. Tests for tag impacts can start with simple
behavioral comparison with untagged birds, ideally in captivity and remembering
that animals may always require a day or two to adjust to handling and tagging.
How large a sample can be monitored in the field? That will depend on how easy it
is to check individuals and move between them, which will improve with practice.
A pilot study helps the pessimist to be more ambitious in a main study, and the
optimist to avoid over-ambitious planning.
A pilot study should also address the issue of how often to monitor animals,
typically by deliberate over-sampling so that analyses can define a minimum-
effort protocol. That may mean that initial tracking is continuous, recording the
location and time each time a bird feeds or flies, developing field skills to avoid
disturbance and gaining behavioral insights that aid later work. This showed,
for instance, that released naïve hawks were likely to survive once they had made
2–3 kills (Kenward et al. 1981). Continuous monitoring also reveals when ani-
mals are likely to be active, so that foraging observations can be planned for those
times. Activity data can also be recorded by automated logging, for instance while
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