| Literature DB >> 34188859 |
Robert S Davis1,2, Richard W Yarnell1, Louise K Gentle1, Antonio Uzal1, William O Mgoola3, Emma L Stone2,4.
Abstract
Effective conservation management requires an understanding of the spatiotemporal dynamics driving large carnivore density and resource partitioning. In African ecosystems, reduced prey populations and the loss of competing guild members, most notably lion (Panthera leo), are expected to increase the levels of competition between remaining carnivores. Consequently, intraguild relationships can be altered, potentially increasing the risk of further population decline. Kasungu National Park (KNP), Malawi, is an example of a conservation area that has experienced large-scale reductions in both carnivore and prey populations, leaving a resident large carnivore guild consisting of only leopard (Panthera pardus) and spotted hyena (Crocuta crocuta). Here, we quantify the spatiotemporal dynamics of these two species and their degree of association, using a combination of co-detection modeling, time-to-event analyses, and temporal activity patterns from camera trap data. The detection of leopard and spotted hyena was significantly associated with the detection of preferred prey and competing carnivores, increasing the likelihood of species interaction. Temporal analyses revealed sex-specific differences in temporal activity, with female leopard activity patterns significantly different to those of spotted hyena and male conspecifics. Heightened risk of interaction with interspecific competitors and male conspecifics may have resulted in female leopards adopting temporal avoidance strategies to facilitate coexistence. Female leopard behavioral adaptations increased overall activity levels and diurnal activity rates, with potential consequences for overall fitness and exposure to sources of mortality. As both species are currently found at low densities in KNP, increased risk of competitive interactions, which infer a reduction in fitness, could have significant implications for large carnivore demographics. The protection of remaining prey populations is necessary to mitigate interspecific competition and avoid further alterations to the large carnivore guild.Entities:
Keywords: activity patterns; camera traps; carnivore ecology; competition; niche segregation; predator dynamics
Year: 2021 PMID: 34188859 PMCID: PMC8216965 DOI: 10.1002/ece3.7620
Source DB: PubMed Journal: Ecol Evol ISSN: 2045-7758 Impact factor: 2.912
FIGURE 1Camera trap locations for surveys conducted in 2016, 2017, and 2018 in Kasungu National Park, Malawi. Inset maps show the area covered within Kasungu National Park and the location of Malawi within sub‐Saharan Africa
Detection covariates, with sampling range and mean, hypothesized to affect the likelihood of detection for leopard and spotted hyena in Kasungu National Park, Malawi
| Covariate | Source | Sampling range (mean) | Hypothesized effect | Supporting evidence |
|---|---|---|---|---|
| Hyena detection | Camera trap |
1 (detection) 0 (nondetection) | − | Swanepoel et al. |
| Leopard detection | Camera trap |
1 (detection) 0 (nondetection) | + | Balme, Miller, et al. |
| Distance to water (km) | GIS |
0.03–10.45 (3.35) | + | Watts & Holekamp, |
| Distance to park border (km) | GIS |
0.78–14.38 (7.99) | − | Woodroffe & Ginsberg, |
| Preferred prey detection | Camera trap |
1 (detection) 0 (nondetection) | + | Höner et al. |
| Habitat type | Observation |
1 (open) 0 (closed) |
− + | Balme et al. |
The hypothesized effect on large carnivore detection is indicated, alongside supporting evidence for the predicted effect.
Effect on leopard detection.
Effect on hyena detection.
Hypothesized effect is based on habitat openness.
List of species detected and yearly and total counts from camera trap surveys between 2016 and 2018 in Kasungu National Park, Malawi
| Order | Scientific name | Common name | 2016 captures | 2017 captures | 2018 captures | Total captures |
|---|---|---|---|---|---|---|
| Carnivora |
| Leopard | 48 | 116 | 115 | 279 |
|
| Spotted hyena | 113 | 148 | 133 | 394 | |
|
| Lion | 0 | 11 | 0 | 11 | |
|
| African wild dog | 0 | 9 | 9 | 18 | |
| Artiodactyla |
| Common duiker | 22 | 42 | 63 | 127 |
|
| Bushbuck | 4 | 7 | 7 | 18 | |
|
| Greater kudu | 1 | 6 | 17 | 24 | |
|
| Warthog | 4 | 9 | 12 | 25 | |
|
| Bushpig | 13 | 48 | 36 | 97 | |
| Lagomorpha |
| Savanna hare | 25 | 110 | 45 | 180 |
| Rodentia |
| Cape porcupine | 24 | 166 | 158 | 348 |
| Primates |
| Yellow baboon | 5 | 23 | 7 | 35 |
Capture totals are provided for all large carnivores recorded and the prey species of leopard and spotted hyena that were chosen for spatiotemporal analyses.
Model selection for binomial generalized linear mixed models predicting the likelihood of leopard detection at camera stations in Kasungu National Park, Malawi, across all survey years (2016, 2017, and 2018) during a given 5‐day sampling occasion
| Model |
| AICc | ΔAICc |
| Cum. | Log likelihood |
|---|---|---|---|---|---|---|
| Hyena + prey + water | 6 | 1,120.34 | 0.00 | 0.31 | 0.31 | −554.13 |
| Prey + water | 5 | 1,121.38 | 1.05 | 0.18 | 0.49 | −555.67 |
| Hyena + prey + water + habitat | 7 | 1,121.91 | 1.58 | 0.14 | 0.63 | −553.91 |
| Hyena + prey + water + border | 7 | 1,122.34 | 2.00 | 0.11 | 0.74 | −554.12 |
| Prey + water + habitat | 6 | 1,123.01 | 2.68 | 0.08 | 0.82 | −555.47 |
| Prey + water + border | 6 | 1,123.37 | 3.03 | 0.07 | 0.89 | −555.65 |
| Hyena + prey + water + border + habitat | 8 | 1,123.90 | 3.57 | 0.05 | 0.94 | −553.89 |
| Prey + water + border + habitat | 7 | 1,124.98 | 4.64 | 0.03 | 0.97 | −555.44 |
| Hyena + water | 5 | 1,125.96 | 5.63 | 0.02 | 0.99 | −557.96 |
| Hyena + prey | 5 | 1,126.85 | 6.51 | 0.01 | 1.00 | −558.40 |
Models were ranked according to Akaike weights (W) based on the Akaike information criterion for small samples (AICc), and cumulative model weight is also presented (Cum. W). Models with AICc differences (ΔAICc) < 2 were averaged, and β‐coefficient estimates, with associated standard error (SE±), 85% confidence limits, and summed model weights (Σw), were presented.
Number of parameters in the model.
Indicates parameter had a significant effect on leopard detection as 85% confidence limits exclude zero.
Model selection for binomial generalized linear mixed models predicting the likelihood of hyena detection at camera stations in Kasungu National Park, Malawi, across all survey years (2016, 2017, and 2018) during a given 5‐day sampling occasion
| Model |
| AICc | ΔAICc |
| Cum. | Log likelihood |
|---|---|---|---|---|---|---|
| Prey + leopard | 5 | 1,245.60 | 0.00 | 0.19 | 0.19 | −617.78 |
| Prey | 4 | 1,246.48 | 0.87 | 0.12 | 0.31 | −619.22 |
| Prey + leopard + habitat | 6 | 1,247.08 | 1.47 | 0.09 | 0.40 | −617.50 |
| Prey + leopard + border | 6 | 1,247.35 | 1.75 | 0.08 | 0.48 | −617.64 |
| Prey + leopard + water | 6 | 1,247.50 | 1.89 | 0.07 | 0.55 | −617.71 |
| Prey + habitat | 5 | 1,247.97 | 2.37 | 0.06 | 0.61 | −618.96 |
| Prey + border | 5 | 1,248.18 | 2.58 | 0.05 | 0.66 | −619.07 |
| Prey + water | 5 | 1,248.44 | 2.84 | 0.05 | 0.71 | −619.20 |
| Leopard | 4 | 1,248.75 | 3.14 | 0.04 | 0.75 | −620.36 |
| Prey + leopard + habitat + water | 7 | 1,248.88 | 3.27 | 0.04 | 0.79 | −617.39 |
Models were ranked according to Akaike weights (W i) based on the Akaike information criterion for small samples (ΔAICc), and cumulative model weight is also presented (Cum. W i). Models with AICc differences (ΔAICc) < 2 were averaged, and β‐coefficient estimates, with associated standard error (SE ±) and 85% confidence limits, were presented. Only the ten highest ranking models are presented here.
Number of parameters in the model.
Indicates parameter had a significant effect on hyena detection as 85% confidence limits exclude zero.
FIGURE 2The observed (red) and expected (gray) probability of detecting hyena after a leopard capture in 2017 (a) and 2018 (b), leopard after a prey species capture in 2017 (c) and 2018 (d), and hyena after a prey species capture in 2017 (e) and 2018 (f), at the same sampling site within five days before and after in Kasungu National Park, Malawi. Asterisks (*) above expected distributions, obtained from 1,000 random simulations of capture events for the corresponding species, indicate days for which observed detection rates were significantly different (p < 0.05) to expected values. Sample sizes, from which observed detection probabilities were calculated, are given for each year
Estimates of proportion of time active for large carnivore species in Kasungu National Park, Malawi, estimated from the distribution of camera trapping photographs over the daily cycle
| Species |
| Estimate | SE | 95% CI |
|---|---|---|---|---|
| Leopard (both sexes) | 273 | 0.573 | 0.048 | 0.473–0.659 |
| Leopard (♂) | 77 | 0.459 | 0.056 | 0.312–0.525 |
| Leopard (♀) | 170 | 0.649 | 0.056 | 0.504–0.723 |
| Spotted hyena | 385 | 0.423 | 0.027 | 0.359–0.465 |
N is the number of photographic captures, and estimate is the overall activity with standard error (SE) and 95% confidence intervals (95% CI).
Includes images of leopards that could not be sexed but identified to species level.
FIGURE 3Temporal overlap in activity patterns between (a) spotted hyena and leopard (both sexes); (b) spotted hyena and male leopard; (c) spotted hyena and female leopard; and (d) male and female leopard. Temporal activity patterns are compiled from surveys conducted in Kasungu National Park, Malawi, between 2016 and 2018. Coefficient of overlap (Δ) for each pairwise comparison is displayed, and shaded areas represent temporal overlap
Estimates of difference in activity between large carnivore species in Kasungu National Park, Malawi, from the distribution of camera trapping photographs over the diel activity schedule
| Species interaction | Difference |
|
|
|
|---|---|---|---|---|
| Leopard (both sexes)–spotted hyena | 0.151 | 0.055 | 7.39 | 0.007 |
| Leopard (♂)–leopard (♀) | 0.190 | 0.079 | 5.763 | 0.016 |
| Leopard (♂)–spotted hyena | 0.037 | 0.062 | 0.346 | 0.556 |
| Leopard (♀)–spotted hyena | 0.227 | 0.063 | 13.048 | <0.001 |
Bootstrapped activity patterns, with 10,000 smoothed bootstrap samples, were compared using Wald statistic (W) on a chi‐square distribution with one degree of freedom in order to test for significance (p) at the 5% level.