A first general approach (Table 2-15) shows that groups of puku were larger in Kasanka NP than in Kafue Region. Maximum and average of observed group sizes were much larger in Kasanka NP. When comparing different survey periods in Kasanka NP (Table 2-15, Figure 2-22 A), the largest group size was recorded in November 2010. But generally, more large groups were encountered in July, resulting in a mean group size being larger. These differences were not significant (KS-test: p=0.382, N=534). In Kafue Region (Figure 2-22 B), the distribution of group sizes was similar in PPKR and Kafue NP but not significant (KS-test:
p=0.999, N=154). Although the largest group size was recorded in Kafue NP, group sizes in PPKR were slightly larger, as also shown by the mean values (Table 2-15). In the cool dry season, larger group sizes were observed in Kasanka NP than in Kafue Region (Figure 2-22 C).
When considering the mean value in July in Kasanka NP it was almost double the mean values in Kafue Region. These differences between the study regions concerning the observed group sizes were significant (KS-test: N=349, p=0.018).
Table 2-15: Statistics about the observed group sizes of puku (Kobus vardonii) in the study regions
study region Kasanka NP Kafue NP
PPKR Kafue NP
survey period July 2009 November 2010 July/August 2010 August 2010 mean value (± SE) 10.47 (± 0.95) 8.21 (± 0.67) 5.93 (± 0.68) 5.74 (± 0.67)
minimum value 1 1 1 1
maximum value 104 169 25 37
modal value 1 1 1 1
Generally, small group sizes of 1 to 5 animals were observed most often in all study regions and during all survey periods and made up 50% or more of the sighted groups (Figure 2-23). Modal value was 1 in all study regions. Single puku made up more than 20% of the encountered groups; in Kasanka NP single puku were observed at 18%. Other group sizes were encountered in generally less than 10% of the sightings; only in Kafue NP, groups of two puku were observed in about 17% of the sightings. Large group sizes of more than 25 puku were observed only once in Kafue Region. These large group sizes were observed in both July and November in Kasanka NP and made up about 14% and 10% of the sighted groups, respectively. Speaking about the amounts of puku observed in the specific group sizes, the image is different: Less than 5% of all puku observed along the transect lines in each study region and survey period were encountered as single animals. In Kafue Region, most of the puku, more than 78% in the subregions, were encountered in groups of up to 15 animals. Less than 50% of the puku in Kasanka NP were encountered in the respective
groups of up to 15 animals in the survey periods. Contrarily, 41% and 25% of the puku were encountered in group sizes with more than 25 animals.
Groups of puku encountered in the grassland (habitat category 1) showed the tendency of being larger than those in intermediate habitats of woodlands (habitat 2 or 3) (Figure 2-24). This was visible especially from the data collected in the survey carried out in July 2009 in Kasanka NP (Figure 2-24 A), where very large groups were observed in grassland only. Concerning group sizes observed in Kafue NP (Figure 2-24 D), the median value was higher in grassland than in the other habitat types. Differences were only significant for Kafue NP (KW-test: N=78, p=0.002) but not for the other surveys (July 2009: KW-test: N=204, p=0.093; November: KW-test: N=330, p=0.335; PPKR: KW-test: N=67, p=0.919).
A B
C
Figure 2-22: Boxplot comparing group sizes of puku (Kobus vardonii) in different surveys. They were observed during the surveys in July 2009 and in November 2010 in Kasanka NP (A), in Kafue NP and PPKR in the cool dry season 2010 (B) and in Kasanka NP (survey in July 2009) and Kafue Region (survey from July to August 2010) in the cool dry season (C). Differences are significant comparing Kasanka NP (July 2009) to Kafue Region (see text).
A B
C D
Figure 2-23: Group sizes of puku (Kobus vardonii) shown as the amount of sighted groups and the amount of sighted individuals in the respective groups in different surveys: in the cool dry season (July 2009) (A) and in the hot dry season (November 2010) (B) in Kasanka NP; in PPKR (C) and Kafue NP (D) in the cool dry season 2010.
A B
C D
Figure 2-24: Boxplot comparing group sizes of puku (Kobus vardonii) observed in the different habitat categories during different surveys: during the survey in the cool dry season (July 2009) (A) and in the hot dry season (November 2010) (B) (the largest group in grassland is not shown in the figure) in Kasanka NP, in PPKR (C) and in Kafue NP (D) in the cool dry season 2010. Differences in each case are not significant (see text).
The general aspect of the group compositions sighted in the two study regions was similar (Table 2-16). Common observed groups were females, eventually accompanied by juveniles and/or neonates. These groups were especially frequent in PPKR. Adult males can and do accompany females and young puku; this was the second most frequent group composition observed. In Kafue NP, this was the most common group composition encountered. Except for Kafue NP, single adult males made up the most common group form. Single subadult males as well as groups of only subadult males were encountered in Kasanka NP, only. Groups comprising males only were not observed in PPKR at all. Groups of adult males, subadult males and juveniles were not encountered in Kafue Region contrary to Kasanka NP. Group compositions encompassing only juveniles and/or neonates were not observed in Kafue Region. The number of groups whose members could not all be classified
into age and sex classes leading to groups with unknown group composition is higher in Kasanka NP than in Kafue Region. According to Wilcoxon-test, the differences observed were not significant neither within the study areas (Kasanka July 2009 vs. November 2010: N=17, p=0.687; PPKR vs. Kafue NP: N=17, p=0.433) nor between the study areas (Kasanka July 2009 vs. PPKR: N=17, p=0.234; Kasanka July 2009 vs. Kafue NP: N=17, p=0.619).
Table 2-16: Group compositions observed in puku (Kobus vardonii) in Kasanka NP and Kafue Region. The frequency of occurrence [%] refers to all groups whose members could be all determined according to the sex and age classes used in this study. The amount of unclassified groups refers to all groups sighted. Differences between seasons and study regions are not significant (see text). Juv = juveniles, Neo = neonate.
study region Kasanka NP Kafue Region
PPKR Kafue NP survey period
July 2009
November 2010
July/August 2010
August 2010
group composition Frequency of occurrence [%]
males single adult male 24.77 25.84 25.45 20.83
single subadult male 2.75 0.48 0 0
2 or more adult males 8.26 7.18 0 9.72
2 or more subadult males 5.50 1.44 0 0
adult + subadult males (2 or more) 7.34 4.31 1.82 4.17
adult + subadult males (2 or more) +juv 6.42 4.78 0 0
1 adult male + 1 or more juv 3.67 0.48 1.82 5.56
females single adult female 4.59 1.91 5.45 2.78
single adult female + 1 juv/neo 0 1.44 0 1.39
1 adult female + 2 or more juv/neo 0.92 0 1.82 2.78
2 or more females (+ juv/neo) 13.76 20.10 34.55 13.89
juv/neo single juv/neo 0.92 2.87 0 0
2 or more juv/neo 6.42 0 0 0
pairs adult male + adult females 0.92 2.39 0 5.56
adult male + adult females + juv/neo 0.92 0.48 1.82 0
breeding
group 1 adult male + 2 or more females (+juv/neo) 9.17 17.22 23.64 26.39
others other group compositions 3.67 9.09 3.64 6.94
amount of all groups sighted
that could not be classified 46.57 36.67 17.91 7.69
In Kasanka NP, when evaluating about the survey of all transect lines in July 2009, the ratio of females to males was biased towards the males (0.66), considering all males, and only slightly biased to the females, when considering adult males only (Table 2-17). Both values were more biased toward the females in November 2010 and were then similar to the values observed in Kafue NP. Looking closer at the situation along Puku-Loop, the sex ratio was very much biased towards all males in July and especially in August 2009 with 0.82
and 0.57 females to all males, respectively. Considering adult males, the ratio was biased towards females. This was similar in October 2010. Only in November 2010 the sex ratio was biased towards the females when considering all males and only adult males. The ratio of females to juveniles and neonates decreased from July to November, considering all transect lines as well as along Puku-Loop. In both cases the ratio dropped from about 1 to about 4.
In Kafue Region, the ratio of females versus males was biased towards the females (Table 2-17). The ratio of females to all males was 1.52 in Kafue NP and it was more biased to the females in PPKR with 4.12. The ratios were higher if only adult males were considered.
Where there were about 3 young puku per females in PPKR, there were only about 5 young puku per female in Kafue NP, the lowest overall value of this ratio.
Table 2-17: Ratio of female puku (Kobus vardonii) versus all males (adult males and subadult males), adult males and versus juveniles and neonates in the study regions, for Kasanka NP in July 2009 and November 2010 and a more detailed look to the transect line Puku-Loop during all four surveys.
ratio amount[%]
females:
study area survey all males adult males juveniles and
neonates unclassified
Kasanka NP July 2009 0.66 1.06 1.13 68.20
November 2011 1.46 1.95 4.01 48.12
Kafue Region PPKR 4.12 6.35 3.31 10.47
Kafue NP 1.52 1.63 5.24 2.29
Puku-Loop July 2009 0.82 1.49 1.11 61.33
August 2009 0.57 1.19 1.42 38.76
October 2010 0.86 1.50 2.18 44.33
November 2010 1.37 1.86 3.65 50.79
In Kafue Region, two neonates were encountered in Kafue NP (Table 2-18). In Kasanka NP, neonate puku were encountered in different numbers and thus amounts during all surveys. Generally in Kasanka NP, but also along Puku-Loop, the highest number and the highest amount of neonates was encountered in July 2009. For Puku-Loop, numbers and the respective amounts of neonates were low in August and October. They increased in November, but were lower than in July 2009; this applies for Puku-Loop as well as entire Kasanka NP. While the amount of juvenile puku (Table 2-18) was about the same, about 20%, in PPKR and in Kasanka NP in July, the amount of juveniles was about half that value in Kafue NP. In Kasanka NP, the amount of juveniles decreased to about half values from July to November visible in the overall observation as well as along Puku-Loop only.
The amount of puku that could not be classified according to sex or age classes was much higher in Kasanka NP than in Kafue Region. While in Kafue Region the amount of unclassified puku did not exceed 11%, in Kasanka NP it did not fall below 48% for the survey of all transect lines or 38% along Puku-Loop, respectively.
Table 2-18: Number of observed neonate puku (Kobus vardonii) during the surveys in Kafue Region and for different survey in different seasons in Kasanka NP.
neonates juveniles
study area survey observed number amount of all classified puku [%]
Kafue Region PPKR 2 0.55 19.01
Kafue NP 0 0 10.32
Kasanka NP July 2009 46 3.71 22.20
November 2010 33 1.77 11.12
Puku-Loop July 2009 40 3.93 25.02
August 2009 6 0.34 20.00
October 2010 7 0.55 16.97
November 2010 26 2.41 11.29
In Kasanka NP, puku were observed in mixed groups with sitatunga and bushbuck, only. In 2009, during the two surveys along the transect lines, only one sighting resulted in a mixed group of puku and sitatunga along Fibwe. In 2010, during the two surveys along the transect lines, mixed groups were observed on 21 occasions along Puku-Loop only. Thus, in 6% of the sighted puku groups, another bovid species occurred in the same group. Puku were observed with sitatunga or bushbuck, on two occasions a group of puku, sitatunga and bushbuck was sighted. Puku were observed with sitatunga for another 17 times and with bushbuck on another two occasions. Mixed groups of puku and sitatunga contained 1 to 42 puku (mean 15.58 puku) and 1 to 4 sitatunga (mean 2.21).
In Kafue Region, groups of two bovid species were observed at 29 occasions – once a group composed of 3 bovid species (puku, impala and waterbuck) was sighted. 17 of the mixed groups were observed in Kafue-NP and 12 in PPKR. Mixed groups of puku and impala were observed most often. Regarding other antelopes, puku were seen together once with waterbuck and with bushbuck. Additionally, impala were observed two times with kudu.
Concerning the amount of observed groups, in 21% of the sighted puku groups, another bovid species was observed in the same group, in 15% of the sighted puku groups this group was complemented by one or more impala. The mean group size of mixed groups of puku and impala was 17 animals, ranging from 2 to 71 animals. Mixed groups of puku and impala had very different amounts of both species (Figure 2-25): the amount of puku ranged from 1
to 20 animals (mean: 6.06 puku), the amount of impala from 1 to 67 animals (mean 10.91 impala). The number of puku and the number of impala in one mixed group did not correlate (Spearman-Correlation: r=-0.013, p=0.955, N=22). A number of 9 of the 22 groups of puku and impala were observed along Hippo.
Figure 2-25: Scatter Plot showing the numbers of puku (Kobus vardonii) and impala (Aepyceros melampus) in mixed groups of these bovid species.