Foraging costs,hunting success and its implications for African wild dog (Lycaon pictus) conservation inside and outside a protected area

When selecting a habitat, animals utilize habitat in which they yield the highest rate of energy. Differences in foraging costs and hunting success are therefore likely to affect habitat choice. In a previous study, we showed that African wild dog (Lycaon pictus) packs with territories inside Hwange National Park (HNP), over the course of several years, moved their territories into the buffer zone outside HNP, where reproductive success was higher but anthropogenic mortality exceeded natality. In this study, based on long‐term radio‐telemetry data from 22 African wild dog packs, we analysed whether differences in foraging costs and hunting success could have contributed to this territorial drift. Taking seasonality and pack size into account, we determined foraging costs (foraging distance and chase distance) and hunting success (successful or failed chase) inside and outside HNP. Although we observed no difference in foraging costs, hunting success was higher outside HNP, which is likely to have contributed to the territorial drift into the buffer zone outside the protected area. This study shows the importance of taking factors affecting hunting success into account in the conservation strategy of African wild dogs.     

Individual,Group, and Environmental Influences on Helping Behavior in a Social Carnivore

Variation in group composition and environment can affect helping behavior in cooperative breeders. Understanding of how group size, traits of individuals within groups, food abundance, and predation risk simultaneously influence helping behavior is limited. We evaluated pup‐guarding behavior in gray wolves (Canis lupus) to assess how differences in individuals, groups, and environment affect helping behavior. We used data from 92 GPS‐collared wolves in North America (2001–2012) to estimate individual pup‐guarding rates. Individuals in groups with low helper‐to‐pup ratios spent more time guarding young than those in groups with more helpers, an indication of load‐lightening. Female helpers guarded more than male helpers, but this relationship weakened as pups grew. Subset analyses including data on helper age and wolf and prey density showed such factors did not significantly influence pup‐guarding rates. We show that characteristics of individuals and groups have strong influences on pup‐guarding behavior in gray wolves, but environmental factors such as food abundance and predation risk from conspecifics were not influential.     

Offspring food allocation by parents and helpers in a cooperative mammal

In cooperatively breeding species, helpers and parents commonlyface two decisions when they find a food item: first, whetherto feed the item to a young group member or to eat it themselves;and second, which offspring to feed. Little is known aboutthe factors that influence these decisions in cooperative mammals,though optimal foraging theory provides a basis for a rangeof predictions. In this article we describe pup feeding behaviorby helpers and parents in a cooperative mongoose, the meerkat(Suricata suricatta). When meerkat pups begin accompanyingthe group, they beg food from older group members, who digup dispersed prey items. As predicted, the probability of aprey item being fed to a pup shows a positive relationship with prey size and a negative relationship with pup distance.Meerkats apparently follow a "feed the nearest pup rule" andare more likely to feed the nearest pup if it is hungry. Hungrierpups beg more and follow older group members more closely.Across all age categories, females feed pups more frequentlythan males, both in terms of the relative frequency of feeds,and the proportion of prey biomass found by each individualthat is fed to pups. Females also feed female pups significantlymore than male pups, while males feed pups of both sexes equally.These sex biases in feeding contributions may result from femalegroup members benefiting more than males from higher pup survival,and in particular higher female pup survival, because femalesare the philopatric sex.     

Behavioral Ecology of Coyotes: Social Organization,Rearing Patterns,Space Use,and Resource Defense

Two groups of coyotes in which genealogical relationships were known were studied in the Grand Teton National Park, outside of Jackson, Wyoming, U.S.A., from 1977–1982. One group, a pack consisting of parents and some non-dispersing and non-breeding offspring, defended a territory and the food (mainly elk carrion) contained within it, especially during winter, and also had helpers at den sites (5 of 6 were males). The other group, a mated resident pair, all of whose young dispersed during the first year of life, did not defend a territory and never had helpers at dens. Delayed dispersal and retention of some offspring as helpers was related to the presence of an abundant, clumped, and defendable winter food resource. Dispersing yearlings suffered higher mortality than did non-dispersing individuals. Litter size was the same for the pack and resident pair; litter size was not significantly correlated with number of adults in the group or with the number or percentage of pups that survived to 5–6 months of age. The presence of pack helpers was not significantly correlated with pup survival, although there was a positive correlation (r^s = +0.37) between the number of adults attending a den(s) and pup survival. Helpers rarely fed pups and their presence had no appreciable effect on juvenile weight. Helpers partook in den-sitting (pup-guarding), but they did not reduce the amount of time that parents spent at den sites. Helpers also actively initiated and took part in territorial and food defense. The proportion of times that pack members initiated defense was inversely related to intruder density (r = –0.94).     

The energetics of lactation in cooperatively breeding meerkats Suricata suricatta

Species may become obligate cooperative breeders when parents are unable to raise their offspring unassisted. We measured the daily energy expenditure of mothers, helpers and offspring during peak lactation in cooperatively breeding meerkats Suricata suricatta using the doubly labelled water technique. Lactating mothers expended more energy per day than allo-lactating subordinate females, non-lactating females or suckling offspring. Metabolizable energy intakes of lactating mothers were calculated from isotope-based estimates of offspring milk energy intake, and were not significantly different from the previously suggested maximal limit for mammals. Allo-lactating females were the only category of animals that lost weight during the period of study, probably because they spent more time babysitting than non-lactating females. Daily energy expenditure (DEE) of lactating mothers increased with litter size but decreased with the number of helpers. Calculations show that for every 10 helpers, even in the absence of allo-lactators, mothers are able to reduce their DEE during peak lactation by an amount equivalent to the energy cost of one pup. These results indicate that helpers have beneficial energetic consequences for lactating mothers in an obligate cooperatively breeding mammal.     

Breeding success in cooperative meerkats: effects of helper number and maternal state

Studies of cooperatively breeding birds and mammals generallyconcentrate on the effects that helpers have on the number ofreproductive attempts females have per year or on the numberand size of offspring that survive from hatching/weaning toindependence. However, helpers may also influence breeding successbefore hatching or weaning. In the present study, we used anultrasound imager to determine litter sizes close to birth,and multivariate statistics to investigate whether helpers influencefemale fecundity, offspring survival to weaning, and offspringsize at weaning in cooperative meerkats, Suricata suricatta.We found that the number of helpers in a group was correlatedwith the number of litters that females delivered each year,probably because females in large groups gave birth earlierand had shorter interbirth intervals. In addition, althoughpup survival between birth and weaning was primarily influencedby maternal dominance status, helper number may also have asignificant positive effect. By contrast, we found no evidenceto suggest that helpers have a direct effect on either littersizes at birth or pup weights at weaning, which were both significantlyinfluenced by maternal weight at conception. However, becausedifferences in maternal weight were associated with differencesin helper number, helpers have the potential to influence maternalfecundity and offspring size within reproductive attempts indirectly.These results suggest that future studies may need to considerdirect and indirect helper effects on female fecundity and investmentbefore assessing helper effects on reproductive success in societiesof cooperatively breeding vertebrates.     

Assessing trophy hunting in South Africa by comparing hunting and exporting databases

Trophy hunting constitutes a major part of the global wildlife tourism industry and is connected through the export of kills to international wildlife trade. Inconsistencies between kills and exports can contribute to identifying illegal trophy hunting that constitutes a major threat to biodiversity conservation. This paper quantitatively analyses to what extent the data of trophy hunting kills and of trophy exports are consistent using the example of South Africa. Data was extracted from two different sources for the year 2018. These sources were trade data reported under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and its Trade Database on the export of trophy items from South Africa, which is compared with the South African Professional Hunting statistics (SAPHs) containing trophy kills information for each species and the country of origin of the hunter. The data of trophy hunting kills and data of trophy hunting export was found to differ to varying degrees across the countries contributing to trophy hunting and CITES-listed trophy-hunted species. We found that both databases report hunting of the same 28 threatened taxa. On the other hand, the same data reports that hunters of 64 nationalities participated in a total of 4,726 trophy kills, while only 3,131 hunting trophy items were exported from South Africa, to 37 countries as final destinations. Among the possible reasons for the discrepancies found, we suggest that the time required to taxidermize trophy specimens may delay the items being addressed to their final destination, in addition to the dual citizenship of some hunters that should also have some influence on our results, as well as the important commercial destination of Brussels Airport. The USA show the highest absolute number of trophy hunters, followed by Spain, but Denmark is the highest driver per capita. Therefore, greater participation of these countries in conservation policies for endangered species is necessary. Additionally, a more detailed differentiation of the term “trophy” to more specific terms such as claws, skins, skulls, etc. may improve reporting systems to easier identify illegal activities related to hunting.     

Behavioural tactics of breeders in cooperative meerkats

In eusocial invertebrates, queens commonly show morphological and behavioural modifications to their role as the principal breeders in their colonies. With the exception of naked mole-rats, Heterocephalus glaber, morphological modification of breeders has yet to be shown in cooperative vertebrates, but the behaviour of dominant individuals may be modified so as to maximize reproductive success. We studied the cooperative behaviour of dominant and subordinate adults in meerkats, Suricata suricatta, and found that the decision rules governing the contributions of dominant breeders differed from those of subordinate helpers. Dominant breeders contributed less than adult helpers to babysitting and pup feeding, but raised their individual contributions to pup care to a greater extent when helper:pup ratios were low. In contrast to subordinates, dominant breeders did not increase their contributions when they foraged successfully. Finally, while subordinates of both sexes assisted in rearing the young when dominants bred, dominant females contributed little when subordinates attempted to breed, and male helpers (but not females) reduced their contributions to the care of pups. Our results suggest that the division of labour between breeders and helpers in meerkats is intermediate between that of facultatively cooperative species, where parents are principally responsible for rearing young, and that of specialized eusocial species, which show a well-defined division of labour between breeders and workers.     

Subsistence hunting among the Waimiri Atroari Indians in central Amazonia, Brazil

Subsistence hunting among the Waimiri Atroari Indians in central Amazonia, Brazil, was studied from September 1993 to October 1994 to assess the current levels of resource exploitation. Hunting effort, harvesting yields and species composition of the hunt were recorded daily in five villages varying in number of people, location and age of the settlement. The Waimiri Atroari harvested a total of 3004 individuals of 41 species in one year. Lowland tapir (Tapirus terrestris), white-lipped peccary (Tayassu pecari), collared peccary (T. tajacu) and spider monkey (Ateles paniscus) represented 87% of the total yearly game weight. Sex ratios of spider monkeys killed were heavily biased towards females indicating a stronger hunting pressure on those individuals. Harvesting yields was proportional to hunting efforts indicating no evident game depletion in the study period. However, capture per unit of effort was significantly different among villages. Differences in total game mass harvested may be explained by local resource depletion associated with age and size of the settlement. However, this relationship is confounded by the capacity of some villages to exploit distant hunting sites. Data obtained in one village showed that harvest rates were higher in hunting sites located far from settlement indicating game depletion in hunting sites surrounding the village.     

Wolf-pack (Canis lupus) hunting strategies emerge from simple rules in computational simulations

We have produced computational simulations of multi-agent systems in which wolf agents chase prey agents. We show that two simple decentralized rules controlling the movement of each wolf are enough to reproduce the main features of the wolf-pack hunting behavior: tracking the prey, carrying out the pursuit, and encircling the prey until it stops moving. The rules are (1) move towards the prey until a minimum safe distance to the prey is reached, and (2) when close enough to the prey, move away from the other wolves that are close to the safe distance to the prey. The hunting agents are autonomous, interchangeable and indistinguishable; the only information each agent needs is the position of the other agents. Our results suggest that wolf-pack hunting is an emergent collective behavior which does not necessarily rely on the presence of effective communication between the individuals participating in the hunt, and that no hierarchy is needed in the group to achieve the task properly.     

Effect of predation risk, body size, and habitat characteristics on emigration decisions in mallards

Understanding the processes underlying emigrating behavior isfundamental to better understand animal dispersal. Because ofthe difficulties involved in carrying out controlled manipulationof the proximate drivers of emigration over large spatial scales,results from laboratory or small field enclosures suitable forsmall-bodied species remains to be validated in natural habitats.We investigate whether emigration is driven either by intraspecificcompetition or resulted from hunting-risk avoidance and assessedthe effect of phenotypic variation on individual decisions.We made use of a quasi-experimental situation by using huntingrecoveries of mallards (Anas platyrhynchos) released as ducklingsin a fragmented landscape managed for duck hunting. Our resultssuggest an indirect effect of hunting on emigration. Body sizeplays a major role in modulating individual emigrating decisions,with small-bodied individuals emigrating more to escape fromhigh levels of predation pressure while larger bodied individualsbeing more vulnerable to predation.     

Population dynamics of obligate cooperators

Obligate cooperative breeding species demonstrate a high rate of group extinction, which may be due to the existence of a critical number of helpers below which the group cannot subsist. Through a simple model, we study the population dynamics of obligate cooperative breeding species, taking into account the existence of a lower threshold below which the instantaneous growth rate becomes negative. The model successively incorporates (i) a distinction between species that need helpers for reproduction, survival or both, (ii) the existence of a migration rate accounting for dispersal, and (iii) stochastic mortality to simulate the effects of random catastrophic events. Our results suggest that the need for a minimum number of helpers increases the risk of extinction for obligate cooperative breeding species. The constraint imposed by this threshold is higher when helpers are needed for reproduction only or for both reproduction and survival. By driving them below this lower threshold, stochastic mortality of lower amplitude and/or lower frequency than for non-cooperative breeders may be sufficient to cause the extinction of obligate cooperative breeding groups. Migration may have a buffering effect only for groups where immigration is higher than emigration; otherwise (when immigrants from nearby groups are not available) it lowers the difference between actual group size and critical threshold, thereby constituting a higher constraint.     

Costs of cooperative behaviour in suricates (Suricata suricatta).

Functional interpretations of helping behaviour suggest that it has evolved because helpers increase their direct or indirect fitness by helping. However, recent critiques have suggested that helping may be an unselected extension of normal parental behaviour, pointing to evidence that all mature individuals commonly respond to begging young (whether they are parents, relatives or non-relatives) as well as to the lack of evidence that cooperative activities have appreciable costs to helpers. Here we provide an example of one form of cooperative behaviour that is seldom performed by parents and has substantial energetic costs to helpers. In the cooperative mongoose, Suricata suricatta, non-breeding adults commonly babysit young pups at the natal burrow for a day at a time, foregoing feeding for 24 hours. Parents rarely contribute to babysitting, and babysitting has substantial energetic costs to helpers. Members of small groups compensate for the reduced number of participants by babysitting more frequently, and neither the proportion of time that babysitters are present nor the survival of litters vary with group size.     

Kin selection, not group augmentation, predicts helping in an obligate cooperatively breeding bird

Kin selection theory has been the central model for understanding the evolution of cooperative breeding, where non-breeders help bear the cost of rearing young. Recently, the dominance of this idea has been questioned; particularly in obligate cooperative breeders where breeding without help is uncommon and seldom successful. In such systems, the direct benefits gained through augmenting current group size have been hypothesized to provide a tractable alternative (or addition) to kin selection. However, clear empirical tests of the opposing predictions are lacking. Here, we provide convincing evidence to suggest that kin selection and not group augmentation accounts for decisions of whether, where and how often to help in an obligate cooperative breeder, the chestnut-crowned babbler (Pomatostomus ruficeps). We found no evidence that group members base helping decisions on the size of breeding units available in their social group, despite both correlational and experimental data showing substantial variation in the degree to which helpers affect productivity in units of different size. By contrast, 98 per cent of group members with kin present helped, 100 per cent directed their care towards the most related brood in the social group, and those rearing half/full-sibs helped approximately three times harder than those rearing less/non-related broods. We conclude that kin selection plays a central role in the maintenance of cooperative breeding in this species, despite the apparent importance of living in large groups.     

Toxigenic Corynebacterium ulcerans isolated from a hunting dog and its diphtheria toxin antibody titer

Toxigenic Corynebacterium ulcerans is a zoonotic pathogen that produces diphtheria toxin and causes a diphtheria‐like illness in humans. The organism is known to infect and circulate among dogs, which can then transmit it to humans. Furthermore, previous studies have found that C. ulcerans is carried by wild animals, including game animals. In the present study, we tested hunting and companion dogs for the presence of toxigenic C. ulcerans and succeeded in isolating the bacterium from a hunting dog. Moreover, several hunting dogs had serum diphtheria antitoxin titers that were higher than the titers required for protection in humans, suggesting a history of exposure to toxigenic Corynebacterium strains. Notably, ribotyping, pulsed‐field gel electrophoresis and tox gene sequencing demonstrated that the isolate from the hunting dog clustered with previously characterized C. ulcerans strains isolated from wild animals, as opposed to groups of isolates from humans and companion dogs. Interestingly, the wild animal cluster also contains an isolate from an outdoor breeding dog, which could have formed a bridge between isolates from wild animals and those from companion dogs. The results presented herein provide insight into the mechanism by which the zoonotic pathogen C. ulcerans circulates among wild animals, hunting and companion dogs, and humans.     

Duck hunter activity,success, and satisfaction on public hunting areas

Because hunting disturbance can influence local distribution of ducks and their availability to hunters, managers often limit access to hunting areas to improve hunting success and satisfaction. Few studies have quantified the effectiveness of public area access restrictions on duck hunter activity, harvest, or hunters' satisfaction with their hunting experience. We used a cross-over design over 6 consecutive hunting seasons (2008–2009 through 2013–2014) on State Wildlife Areas (SWAs) in northeastern Colorado, USA, to compare the effects of restricted hunting access regulations and regulations without these restrictions on duck hunter activity, harvest success, harvest levels, and satisfaction. We also considered effects of SWA types, duck abundance, temperature, precipitation, use of equipment by duck hunting parties, and, for hunter satisfaction, hunting success, hunting parties' satisfaction with ducks seen, habitat conditions, crowding from other hunters, and SWA regulations. The number of days when duck hunters had access to restricted properties was about half that on unrestricted properties, and unrestricted properties were used by about twice as many duck hunting parties, but the mean number of hunting parties per available hunting day and mean party size were similar under the 2 types of regulations. Most (56%) duck hunting parties did not bag any ducks; hunting success (harvest of ≥1 duck by a hunting party) was best explained by a model that included a regulation type × hunting season interaction, a SWA type × month interaction, hunter density the previous day, an index of hunter investment (number of decoys used and whether dogs and calls were used), and temperature. Successful hunting parties harvested 1.92 ± 1.60 (SD) ducks/hunter/day (range = 0.1–7.0); the best model predicting the number of ducks harvested per hunter in successful parties included a regulation type × hunting season interaction, a SWA type × month interaction, hunter density the previous day, an index of hunter investment, temperature, and precipitation. Overall satisfaction of duck hunting parties with a day's hunt averaged 3.62 ± 1.20 based on a rank scale of 1 (very unsatisfied) to 5 (very satisfied), and was best explained by a model that included hunting party success; hunter investment; temperature; and satisfaction with duck numbers, habitat conditions, hunting regulations, and crowding. While greatly reducing days available for hunting, access restrictions were associated with improved chances of hunting parties successfully harvesting ≥1 duck in 5 of 6 hunting seasons, and substantially greater numbers of ducks harvested by hunters in successful parties in 1 of 6 hunting seasons. Restrictions did not have a strong direct effect on hunting parties' satisfaction with a day's hunt. Uncontrolled factors, including weather and use of equipment by hunters, had important influences on hunter success, harvest, and satisfaction. Managers should carefully assess hunting activity, hunter expectations and desires, and hunting area characteristics when considering access restrictions on public hunting areas.     

The impact of tourist hunting on large mammals in Tanzania: an initial assessment

In Tanzania, where tourist hunting is employed as a conservation tool for habitat protection, information on population sizes and hunting offtake was used to assess the impact of tourist hunting on mammal densities. In general, tourist hunting pressure was unrelated to local population sizes, but for most species, animals were removed at a level of less than 10% of the local population size, suggesting that over-exploitation was unlikely. Eland, however, and perhaps small antelope, bushbuck, kudu and reedbuck were hunted at levels which may be unsustainable in the long term. Analyses also identified areas of Tanzania with high levels of tourist hunting pressure, showed that, in certain areas, species with small population sizes such as eland could be declining as a result of tourist hunting, and suggested that current levels of lion and leopard offtake are too high. These findings, although preliminary, allow recommendations to be put forward for changing hunting quotas for certain species in particular areas of Tanzania.     

Subsistence hunting and conservation issues in the game reserve of Gile, Mozambique

Ethnozoological research was conducted to gather information on the hunting activities and their relevance for the subsistence of local people in 8 villages around the game reserve of Gile, Mozambique. Two series of data were gathered by questionnaires to: (a) 510 householders from eight villages located in the outskirts of the Reserve; (b) 10 hunters from the village of Gile, the main centre of the study area. Several hunting techniques were recorded: spears, nets, traps (including gin-traps) and wildfires, while the use of guns did not appear relevant. The importance of subsistence hunting for local people was underlined by the high percentage of respondents who declared that they usually conduct this activity and sell bushmeat. The proportion of hunters per village was related to the village size but not to its geographical location of villages and the household composition. A positive relationship existed between the proportion of hunters, crop production and fishing activities, indicating that hunting is part of an integrated system of subsistence activities. Most animals harvested were mammals (89.5%, of which 46.7% were ungulates) and most were captured within the Reserve (96%). A higher percentage of animals was sold (56%), representing a relevant income source for the villagers. Small animals were mainly captured by traps during solitary hunting, medium-sized animals in collective net hunting; larger prey were captured by gin-traps adopted by both solitary and collective hunting. In the diet of the local people wild animals represented a higher protein source than domestic animals.     

Ka'apor ritual hunting

Several investigators cite population control, frequent settlement relocation, trekking, expansion of diet breadth, and food taboos as strategic responses to game depletion by indigenous populations living in interfluvial zones of lowland South America. The Ka'apor Indians of the interfluvial forest of northern Maranhão, Brazil, employ other means of optimizing hunting efficiency, partly based on ritual. Menstruating women, pubescent girls, and parents of newborns can consume meat only of the tortoise (Gochelone denticulata), the first prey species to be hunted out of an area. Tortoise capture requires, on average, one full day of hunting. This means that the full potential of hunting pressure does not materialize near the settlement. Meat productivity is unusually high even near old settlements. I argue that ritual tortoise hunting helps to regulate environmental utilization, to maintain a sustained yield of meat protein, and to expand the catchment area gradually.