Sixteen adult male and 8 adult female post moult mallards were
equipped with radio transmitters, in a two year study (1977-6AHY-M
and 4AHY-F; 1978-10AHY-M and 4AHY-F). Field-feeding was monitored at
a lure crop and on adjacent grain fields. Ninety-two percent of the
mallards radio-equipped were recorded at a field-feeding site at least
once with 71% recorded field-feeding within one week. There was no
significant difference in field-feeding activity between males and
females.
In the morning during periods of rain, mallards field-fed 0.55h
longer, arriving 0.30h later and departing 0.9h later than mallards
field-feeding during clear weather. The morning field-feeding period
was longer in duration than the evening foeld-feeding period.
Light intensity was the dominant climatological variable contributing
to the arrival of mallards in the morning during periods of no rain
(multiple R2=68.1%) and rain (R2=69.5%). Light appeared to act as an
initiating cue for morning feeding activity. A high correlation existed
between duration of stay during periods of no rain (r=0.815) and rain
(r=0.860) suggesting that mallards remained longer at a field-feeding
site in the morning by departing later, not arriving earlier.
Light intensity was also the dominant climatological variable
contributing to the arrival of mallards in the evening amongst those
mallards which field-feed in both the morning and evening (R2=78.1%)
and those which field-fed in the evening only (R2=63.3%). In addition,
light intensity was the only contributing factor in the evening for all
mallards departing a field-feeding site (R2=72.7%). Mallards were
never recorded field-feeding longer than 15 minutes after there was
non measurable light...
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/4406 |
| Date | 31 September 1983 |
| Creators | Ball, Garth |
| Contributors | Not available, Not available |
| Source Sets | University of Manitoba Canada |
| Language | en_US |
| Detected Language | English |
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