parameters, respectively, to identify group means that differed significantly. Analyses of covariance were performed to detect whether age, sex, or day were covariates, and no
significant effects were revealed. If there was no significant difference between respec- Ž
. tive seasons among years, data were pooled. Student’s t-test SPSS, 1998 was used to
compare behaviour between pastures within seasons. Interrelationships among activity and foraging parameters were analyzed with non-linear regression. All statistical compu-
Ž .
tations were performed using SPSS Base 8.0 1998 , and p - 0.05 were accepted as significant. Means are reported with standard errors.
3. Results
Ž From nearly identical forage availability in both pastures in spring i.e., commence-
. ment of the growing season , there was an almost threefold increase in L in early
Ž .
summer, compared to approximately 60 in H Table 1 . Despite this seasonal
difference, feeding and bedding patterns were similar between H and L in all seasons. There was no significant difference in diel, nocturnal, and diurnal foraging and bedding
Ž .
between pastures p 0.05 . Pasture differences in the organization of foraging bouts
Fig. 1. Seasonal activity budgets of wapiti hinds at Ministik Research Station, AB. Other refers to any Ž
. behaviours exhibited when not foraging or bedded e.g., standing, social interaction, nursing, movement .
Ž .
Values are meanSE. Within foraging and bedding, seasons that do not share letters differ p- 0.05 .
Ž .
LG s late gestation; PL s peak lactation; LL s late lactation; EG searly gestation .
Ž .
were only significant during summer p - 0.05 , when wapiti grazing L had more bouts of shorter duration. Differences in foraging intensity between pastures were only evident
Ž .
from early summer through autumn p - 0.05 , with H being higher during summer,
and lower in autumn. Finally, there was no significant difference in gains between H and Ž
. L
p 0.05 . Where seasonal differences were not significant, data were pooled. Wapiti showed polyphasic patterns of alternating foraging and bedding throughout
the year, with foraging peaks at dawn and dusk. They usually bedded during the night in all seasons, particularly in the hours immediately after sunset and before sunrise. These
peaks of activity and inactivity demonstrated seasonal and photoperiodic shifts. Ž
. Diel grazing time was lowest in autumn 8.23 0.24 h and peaked in late summer
Ž . Ž
. Ž .
Ž 12.77 0.43 h
p - 0.01 Table 1 . Peak bedding duration in autumn 12.64 0.25,
Ž . Ž .
Ž . Ž .
Fig. 2. Seasonal a foraging and b bedding of wapiti hinds on heavily H and lightly L grazed pasture, in diurnal and nocturnal periods, expressed as percentage of total hours of daylight and darkness, respectively.
Ž .
LG s late gestation; PL s peak lactation; LL s late lactation; EG searly gestation .
Table 2 Ž .
Ž . Seasonal percentage of active time spent foraging for wapiti hinds on heavily H and lightly L grazed
Ž pasture, at Ministik Research Station, AB LG s late gestation; PL s peak lactation; LL s late lactation;
.
a,b,c
Ž . Ž
. EG searly gestation .
Row means that do not share superscripts differ p- 0.01
ANOVA Spring
Summer Autumn
SE Ž
. Ž
. Ž
. Ž
. LG
Early PL Late LL
EG
U UU
U a
a b
c
H 89.2
87.5 98.8
59.7 2.8
c a
c a
L 85.3
70.2 89.2
73.1 1.7
ab a
b c
Total 87.2
78.8 94.0
66.4 1.6
U
Ž .
Ž .
H differs from L p- 0.01 within season t-test .
UU
Ž .
Ž .
H differs from L p- 0.05 within season t-test .
. Ž
. p - 0.001 coincided with the annual foraging nadir Fig. 1 . To accommodate seasonal
variation in daylength, we expressed diurnal and nocturnal behaviours as percentage of total hours of daylight and darkness, respectively. Annual peak of nocturnal bedding in
Ž .
Ž .
autumn 65.1 7.6 corresponded with nocturnal feeding minimum 27.8 6.5 Ž
. Ž
. Fig. 2 . Late summer maximum of diurnal feeding 62.3 5.7 also paralleled the
Ž .
annual low of diurnal bedding 35.2 5.0 . Ž
. Ž Wapiti foraged most of their active time but this varied seasonally p - 0.01
Table .
Ž .
2 . Foraging intensity increased in late summer 94.0 5.0 and declined in autumn Ž
. Ž .
66.4 8.2 p - 0.001 .
Ž . Ž
. Foraging bouts were longest in late summer 99.5 20.3 min
p - 0.01 , followed Ž
. Ž . Ž
. by a sharp decline in autumn 59.9 11.1 min
p - 0.001 Table 1 . Number of bouts
Fig. 3. Seasonal duration of foraging bouts for wapiti on heavily and lightly grazed pasture in relation to Ž
number of daily bouts, from spring to late summer at Ministik Research Station, AB y s10.8 x q173.6,
2
. p- 0.01, R s 0.88 .
Ž .
Ž .
per day were highest in spring 9.7 1.2 and early summer 10.2 2.2 , and fewest in Ž
. Ž
. Ž . Ž
. late summer 7.0 0.8 and autumn 7.3 0.6
p - 0.01 Table 1 .
Ž .
Foraging bout duration min increased with the number of foraging bouts from Ž
2
. Ž .
spring through late summer y s 10.8 x q 173.6, p - 0.01, R s 0.88 Fig. 3 . Forag-
Ž .
ing bouts in autumn did not demonstrate this relationship p 0.05 . Ž
. BRs were highest in late summer 61.9 1.6 bitesrmin and lowest in autumn
Ž . Ž
. Ž .
37.2 1.5 bitesrmin p - 0.001
Table 1 . There was no significant variation Ž
. between H and L in any season
p 0.05 so data were pooled. BS and feeding patch Ž
. phytomass showed similar seasonal patterns in both pastures
Table 1 . Because
Ž .
Ž . Fig. 4. Seasonal foraging rates bitesrmin of wapiti on heavily and lightly grazed pasture in relation to a
Ž .
Ž . Ž
2
. ŽŽ .
bite size mg
and b
feeding patch phytomass g DMrm , at Ministik Research Station, AB
a
y0 .0011 x 2
Ž .
2
. y s 59.5e
, p- 0.01, R s 0.64; b y s 25.1q5548r x, p- 0.05, R s 0.36 .
differences were not significant, data from H and L pastures were pooled. Annual Ž
2
. maxima occurred in early summer BS: 280 28 mg, FPP: 451 68 g DMrm , and
Ž
2
. Ž .
minima in spring BS: 127 14 mg, FPP: 223 21 g DMrm p - 0.01 .
Ž .
Ž . Ž
y0 .0011 x
BRs bitesrmin declined exponentially with BS mg y s 59.5e
, p - 0.01,
2
. Ž
2
. Ž R s 0.64 and inversely with increasing FPP g DMrm
y s 25.1 q 5548rx, p -
2
. Ž .
0.05, R s 0.36 Fig. 4 . Regression of BS against FPP revealed a significant positive
Ž .
Ž .
association p - 0.001 . When regressed against forage availability kg DMrha , strong Ž
. Ž
2
. linear relationships were observed for BS mg
y s 97.7 q 0.05 x, p - 0.05, R s 0.46 Ž
2
. Ž
2
. Ž .
and FPP g DMrm y s 74.5 q 0.11 x, p - 0.001, R s 0.91
Fig. 5 .
Ž . Ž
. Ž .
Ž
2
. Fig. 5. Seasonal a bite size mg and b feeding patch phytomass g DMrm
for wapiti on heavily and Ž
. ŽŽ .
lightly grazed pasture, in relation to forage availability kg DMrha , at Ministik Research Station, AB a
2
Ž .
2
. y s97.7q0.05 x, p- 0.05, R s 0.46; b y s 74.5q0.11 x, p- 0.001, R s 0.91 .
Ž
0.75
. Hinds gained weight, except during spring y2.9 0.8 grkg
. Gains peaked in
0.75
Ž .
early summer at 12.5 1.4 grkg p - 0.001 , whereas hinds maintained weight
Ž
0.75
. Ž
0.75
. Ž .
stasis in late summer 0.3 0.8 grkg and autumn 0.6 1.2 grkg
p 0.05 .
4. Discussion
