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<br />Zone usage was not uniform. Distribution of contacts for the 10 large bonytail
<br />demonstrated that site fidelity was high and significant (X2 = 697.93, df = 25, P <
<br />0.001). Usage was nil or low in more than half the zones -- no signals were ever
<br />contacted within 7 zones (B, C, D, E, K, Land 0) and only one or two contacts in
<br />each of 8 zones A, F, H, M, N, V, Y and Z (Table 3 and Fig. 2). Five zones had
<br />moderate usage (5 to 15 contacts each; zones G, P, Q, Rand S) and six zones
<br />had high use (19 or more contacts each, up to a maximum of 63; zones I, J, T, U,
<br />W, X). The six highest use zones occurred in three nearest~neighbor pairs
<br />separated by one or more low use zones.
<br />
<br />Generally, once most fish established "residency," those individuals returned
<br />each morning to the same zone, often to the same exact location, within the high
<br />levee (see Fig. 3). A few fish switched from consistent use of one area to
<br />consistent use of another (e.g., Fig. 3, BT666 and BT777).
<br />
<br />Nonetheless, we only had information on the 10 marked fish. Other, unmarked
<br />individuals may have occupied "empty" zones or been present in the same zones
<br />as the marked fish. Habitat differences were not obvious to us, and the high
<br />levee appeared relatively uniform from zones A to Z. We thus assume other
<br />bonytail, perhaps many, occupied interstices within the high levee.
<br />
<br />Perhaps more striking than the consistent high use of certain zones was the
<br />apparent fidelity of individual fish for specific zones. Most fish were found with
<br />much higher frequency in only one or two zones, with occurrences in other zones
<br />being limited to only one or a few observations (Table 3 and Fig. 3). Two or
<br />more fish rarely occupied the same zone at the same time, although different fish
<br />may have occupied the same zone on different occasions.
<br />
<br />Directional Data. There were 2,947 separate recorded bearings; 1,648 and
<br />1,299 observations were made from the high and river levee listening stations,
<br />respectively. A total of 508 of 945 simultaneous paired readings fell within the
<br />800 m listening station radius: 161 (16.1 contact per 15-minute period) during
<br />dusk (1945-1000), 269 (11.2 contacts per period) during mid-hours (2215-0315),
<br />and 78 (7.8 contact per period) during dawn hours (0330-0545). These results
<br />are consistent with the pattern of signal detections observed in the field across all
<br />contacts - most fish made an appearance shortly after sunset during the dusk
<br />period, numbers typically were reduced by one-to-a few during the mid-hours,
<br />and signals representing all remaining individuals disappeared as fish returned to
<br />the high levee.
<br />
<br />,.
<br />
<br />Directional data applied almost exclusively to fish activity during periods of
<br />darkness because marked individuals spent the daylight hours under cover
<br />provided by interstices of the high levee. Number of paired, simultaneous
<br />contacts averaged 50.8 per fish and varied among individuals from 0 to 112
<br />(Table 1). Few contact intersections fell within the pond, and interpretation of
<br />geographic pattern was based only on the general position of signals (e.g.,
<br />
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