The leopard’s (Panthera pardus) broad geographic range, remarkable adaptability, and secretive nature have contributed to a misconception that this species might not be severely threatened across its range. We find that not only are several subspecies and regional populations critically endangered but also the overall range loss is greater than the average for terrestrial large carnivores. To assess the leopard’s status, we compile 6,000 records at 2,500 locations from over 1,300 sources on its historic (post 1750) and current distribution. We map the species across Africa and Asia, delineating areas where the species is confirmed present, is possibly present, is possibly extinct or is almost certainly extinct. The leopard now occupies 25–37% of its historic range, but this obscures important differences between subspecies. Of the nine recognized subspecies, three (P. p. pardus, fusca, and saxicolor) account for 97% of the leopard’s extant range while another three (P. p. orientalis, nimr, and japonensis) have each lost as much as 98% of their historic range. Isolation, small patch sizes, and few remaining patches further threaten the six subspecies that each have less than 100,000 km2 of extant range. Approximately 17% of extant leopard range is protected, although some endangered subspecies have far less. We found that while leopard research was increasing, research effort was primarily on the subspecies with the most remaining range whereas subspecies that are most in need of urgent attention were neglected.
1. For terrestrial carnivores, scat analysis is the technique most often used to determine diets. Various methods of interpreting scat-analysis data exist; however, little is known about how the choice of method affects the results. 2. We reviewed 50 scat-analysis papers to assess the range of methods currently used. Furthermore, we used a large data set from cape fox Vulpes chama and black-backed jackal Canis mesomelas scats to compare 11 scat-analysis methods. Techniques tested included five biomass calculation methods, four frequency of occurrence methods, one method that estimated volume in scats, and another that estimated mass of food items in scats. 3. Frequency of occurrence methods were used in 94% of reviewed papers, and in 50% of papers they were the sole methods used. However, we conclude that frequency of occurrence has the least ecological significance and results can be misleading. Although biomass calculations probably provide the best approximation to true diets, only 23% of reviewed papers used suitable biomass calculation methods when models were available for the study species. 4. Analysis of fox and jackal scats showed that there were significant differences among methods when calculating percent diet composition and niche breadth. Additionally, dietary overlap between species differed considerably among the methods (range of R0 = 0.29-0.79). We conclude that the choice of method can have a significant impact on the results of dietary analysis, and can lead to very different conclusions about a species' ecology. 5. The best approximation of the true diet can be obtained by using a biomass calculation model that was developed for the same species, or for a closely related species with a similar food spectrum. When no such model is available, either the volume or mass of diet components in the scats should be used. To document rare food items, frequency of occurrence data could also be given.
Cape foxes (Vulpes chama) and bat‐eared foxes (Otocyon megalotis) are sympatric with black‐backed jackals (Canis mesomelas) over much of southern Africa, although competition with and/or predation by jackals may suppress local populations of both fox species. From 2005 to 2008, we captured, radio‐collared, and monitored 11 cape foxes, 22 bat‐eared foxes, and 15 black‐backed jackals on a game ranch in South Africa to investigate their spatial, habitat, temporal, and dietary resource overlap. Mean annual home‐range sizes were 27.7 km2 for cape foxes, 5.0 km2 for bat‐eared foxes, and 17.8 km2 for jackal family groups. Home ranges overlapped completely between species, although core areas overlapped less (<45%), with cape foxes and jackals overlapping the least (12%). When active, cape foxes, but not bat‐eared foxes, used core areas of jackal groups less than expected. Additionally, both fox species used jackal core areas less than expected for their den sites, suggesting areas outside jackal core areas were used as refuges by foxes. Strong levels of habitat partitioning were not apparent at the study site or home‐range levels, although habitat selection for den sites differed between jackals and cape foxes. Jackals were the most diurnal across seasons, whereas cape foxes were the most nocturnal. Diets overlapped little (R0 = 0.20–0.34) among the canid species, with bat‐eared foxes overlapping the least with the others. Jackals killed at least 5 collared bat‐eared foxes and 1 collared cape fox, indicating potential interference competition, probably for exclusive use of territorial space rather than over shared resources. We conclude that bat‐eared foxes coexisted with jackals primarily by their dietary specialization and group living. Cape foxes coexisted with jackals by exhibiting high levels of spatial, habitat, temporal, and dietary partitioning. Surprisingly, the fox species exhibited positive associations with each other. Our results show the mechanisms that may allow jackals to suppress fox populations, yet also show how foxes, in turn, use different mechanisms to coexist with a dominant canid. © 2012 The Wildlife Society.
We radio-tracked 10 coyotes (Canis latrans) from April 1996 to March 1998 on Fort Riley Military Reservation, Kansas, to compare movements, habitat use, and survival between resident (breeders and pack associates) and transient coyotes. Home ranges of resident coyotes were mutually exclusive, whereas those of transient coyotes overlapped the home ranges of other coyotes. Excursions from home ranges were made by all resident pack associates but not by resident breeders. Grassland habitats were used more than expected by resident coyotes but less than expected by transients. Woodlands and cultivated lands were used more than expected by transients. Transient coyotes used areas between the home ranges of resident family groups. Annual survival rates were higher for resident than for transient coyotes. Avoidance of resident coyotes by transient coyotes may explain differences in space and habitat use by coyotes.
To investigate the role of black‐backed jackals (Canis mesomelas) as predators, we studied diet, prey selection, and predation impact of jackals on 2 game ranches in South Africa that differed in ungulate diversity and biomass. Results showed that large (>15 kg) ungulate species dominated jackal diets throughout the year on both the less diverse (range of ingested biomass across seasons = 39–78%) and more diverse (26–69%) game ranch. Other important food items included medium‐sized mammals (1–3 kg; 1–26%) and fruit (2–69%), whereas small mammals comprised 3–11% of ingested biomass across seasons on both sites. Jackals were not random in consumption of ungulates, and consumption patterns suggested jackals actively hunted certain species rather than consumed them as carrion. During ungulate birthing periods, jackals consumed almost exclusively those ungulate species that were hiders (i.e., fawns were hidden in tall vegetation away from herd) regardless of ungulate densities, suggesting that primarily fawns were preyed upon. Among hiders, there was a negative relationship (P = 0.01) between body size and percent of population consumed by jackals, indicating smaller species were more susceptible than larger species to jackal predation. Consequently, springbok (Antidorcas marsupialis) were always selected over other ungulate species on both sites, and this species was the most impacted by jackal predation. In contrast, ungulate species that were followers (i.e., fawns immediately followed mothers within protection of the herd) were scarcely or not at all consumed by jackals, regardless of body size or density. Medium‐sized mammals were selectively consumed over ungulates, and there was a negative relationship (P < 0.01) between consumption of berries and ungulates, indicating alternative food resources influenced consumption of ungulates on our study sites. Our results will help wildlife managers in Africa identify ungulate species susceptible to jackal predation, and can be used to develop management strategies for reducing jackal predation in areas where it is problematic.
Several nonlethal methods have been developed to determine the stomach contents of fish, including gastroscopes, tubes, stomach suction, stomach flushing, emetics, forceps, and chronic fistulas. By reviewing the literature on this subject, we found that the effectiveness (ability to remove all stomach contents) of the different methods depends on size, age, species of fish, and the size of the food items in the stomach. Overall, various methods of stomach flushing were the most effective method of recovering stomach items from a variety of fishes. Mechanized pressure appeared to be the most efficient method of stomach flushing for most large fishes. The use of syringes allowed stomach flushing to be performed on most young and small fishes. The use of tubes and stomach suctions, much simpler and less expensive methods than stomach flushing, were nearly as effective for some fishes such as black bass (Micropterus spp.) and salmonids.
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