How fishing cats Prionailurus viverrinus Bennett, 1833 fish: describing a felid’s strategy to hunt aquatic prey

The fishing cat’s persistence in a ‘semi-aquatic niche’ suggests the evolution of a successful hunting strategy. We describe it for the first time by analysing 197 camera-trap video-clips, collected from a participatory-science initiative, within an ethogram framework. The cats spent ∼52% of the time sitting and waiting for prey (fishes) to come nearer and took limited attempts to hunt (3.89%) in deeper waters (in which the upper portions of the cat’s body were submerged), where its hunting success was found to be 42.86%. In shallow waters, it adopted a predominantly active mode of hunting (∼96%) to flush out prey.

Ethnozoological study of the wild pig (Sus spp.) hunting among Sundanese in Upper Citarum Watershed area, West Java, Indonesia

Mulyanto D, Abdoellah OS, Iskandar J, Gunawan B. 2021. Ethnozoological study of the wild pig (Sus spp.) hunting among Sundanese in Upper Citarum Watershed area, West Java, Indonesia. Biodiversitas 22: 4930-4939. In the past, wild pigs had a high population in the rural ecosystem of West Java. However, the population of wild pigs, particularly Javan warty pig, decreases due to forest destructions and intensive hunting. This study aimed to elucidate the local knowledge on wild pigs, the mode of hunting, and diverse aspects of wild pig hunting. We conducted qualitative methods with ethnozoological approach, including participant observation and in-depth interview. The results showed that based on the local people the wild pig can be divided into four “races”, while based on zoology, two species of wild pig are documented in Java. During hunts all members get specific key roles. Thus, hunting success is increased by division of labor. Hunting wild pigs played an important role in socio-economic and cultural function for the village community. Due to intensive hunting of wild pigs, the population of these animals, particularly the Javan warty pig are decreased, and consequently the socio-economy of this animal in rural ecosystem may decrease ot even disappear.

The hunter and the hunted—A 3D analysis of predator-prey interactions between three-spined sticklebacks (Gasterosteus aculeatus) and larvae of different prey fishes

Predator-prey interactions play a key life history role, as animals cope with changing predation risk and opportunities to hunt prey. It has recently been shown that the hunting success of sticklebacks (Gasterosteus aculeatus) targeting fish larvae is dependent on both the size of the prey and the prior exposure of its species to stickleback predation. The purpose of the current study was to identify the behavioural predator-prey interactions explaining the success or failure of sticklebacks hunting larvae of three potential prey species [roach (Rutilus rutilus), perch (Perca fluviatilis) and whitefish (Coregonus wartmannii)] in a 3D environment. Trials were carried out for each prey species at four different size classes in a standardised laboratory setup and were recorded using a slow motion, stereo camera setup. 75 predator-prey interactions including both failed and successful hunts were subject to the analysis. 3D track analysis indicated that sticklebacks applied different strategies. Prey with less complex predator escape responses, i.e. whitefish larvae, were hunted using a direct but stealthy approach ending in a lunge, while the behaviourally more complex roach and perch larvae were hunted with a faster approach. A multivariate logistic regression identified that slow average speed and acceleration of the prey in the initial stages of the hunt increased the probability of stickleback success. Furthermore, predators adjusted their swimming direction more often when hunting larger whitefish compared to smaller whitefish. The results suggest that appropriate and adequately timed avoidance behaviours, which vary between prey species and ontogenetic stages, significantly increase the chances of outmanoeuvring and escaping stickleback predation. Small whitefish larvae can reach similar levels of swimming performance compared to older conspecifics, but display ineffective anti-predator behaviours, resulting in higher hunting success for sticklebacks. Thus, the development of appropriate anti-predator behaviours depending on size appears to be the crucial factor to escaping predation.

Population control by means of organised hunting effort: Experiences from a voluntary goose hunting arrangement

Implementing management objectives may be challenging when decisions are made at different scales than where they are supposed to be carried out. In this study we present a situation where local goose hunting arrangements respond to objectives in an international management plan for pink-footed geese (Anser brachyrhynchus) and a local wish to reduce goose numbers as means to reduce grazing damage on farmland. A unique ten-year dataset provides an evaluation of the efficiency of voluntary actions at a local scale for implementing a policy of population control of geese, and general lessons are drawn for collaboration and co-production of knowledge for adaptive management. The study demonstrates how both the hunters and geese adapt in a situation where increasing the harvest of geese is the main objective. Introducing hunting-free days and safe foraging areas significantly increased goose numbers in the study area, with a corresponding increase in hunting success in terms of number of harvested geese. The geese’s behavioural response to hunting also triggered the hunters to adapt accordingly by optimal timing and placement in the landscape. Based on the results of the present study we suggest a framework for local implementation of management actions. Bringing end-users on board, facilitates processes and strengthens the achievements, as they represent the actors where implementation occurs. Specifically, our findings demonstrate how optimal goose hunting can be practiced by the use of an adaptive framework with active stakeholder participation.

Relative demographic susceptibility does not explain the extinction chronology of Sahul's megafauna

The causes of Sahul's megafauna extinctions remain uncertain, although several interacting factors were likely responsible. To examine the relative support for hypotheses regarding plausible ecological mechanisms underlying these extinctions, we constructed the first stochastic, age-structured models for 13 extinct megafauna species from five functional/taxonomic groups, as well as eight extant species within these groups for comparison. Perturbing specific demographic rates individually, we tested which species were more demographically susceptible to extinction, and then compared these relative sensitivities to the fossil-derived extinction chronology. Our models show that the macropodiformes were the least demographically susceptible to extinction, followed by carnivores, monotremes, vombatiform herbivores, and large birds. Five of the eight extant species were as or more susceptible than the extinct species. There was no clear relationship between extinction susceptibility and the extinction chronology for any perturbation scenario, while body mass and generation length explained much of the variation in relative risk. Our results reveal that the actual mechanisms leading to the observed extinction chronology were unlikely related to variation in demographic susceptibility per se, but were possibly driven instead by finer-scale variation in climate change and/or human prey choice and relative hunting success.

First report of intraspecific variation in wing translucency for a Neotropical bat species

Although most variation regarding bat colouration has been recorded for fur, there have also been a few bat species for which intraspecific variation in wing translucency has been reported. However, all records are from the Paleotropics, with no cases reported for any bat species in the Neotropics. Here we describe the first case of intraspecific variation in wing translucency for a Neotropical bat species, the lesser ghost bat (Diclidurus scutatus). Two individuals captured hundreds of kilometres away from each other in the Brazilian Amazon forest showed distinct patterns in relation to the degree of their wing translucency. While one individual in the North‐eastern Amazon forest had fully translucent wings, the other in the Southern Amazon had whitish opaque wings. We propose three hypotheses to explain this variation, which are related to differences in: (1) light conditions and camouflage in the roost; (2) thermoregulation requirements; and (3) habitat structure relationship with hunting success

Large winter falcons and their Rock Pigeon (Columba livia) prey at an urban grain terminal in Edmonton, Alberta: an update

In winter, Gyrfalcon (Falco rusticolus) and Prairie Falcon (Falco mexicanus) frequent a 96-year-old grain terminal, in Edmonton, Alberta, hunting Rock Pigeon (Columba livia). This phenomenon was reviewed shortly after it was first noticed by others in 1998 and, since then, we have observed hunting success and methods of Gyrfalcons and Prairie Falcons that were similar but not identical to earlier observations, with success rates of 21.0% and 10.6%, respectively, compared with 10.6% and 26.0% earlier. The most frequently observed hunting strategy for both species was a repeated upward attack on swirling Rock Pigeon flocks, resulting in success rates of 10.7% and 11.4%, respectively. Notably, 50% of downward dive hunts made by Gyrfalcon were successful, although only eight hunts using this method were recorded. The falcons were mildly selective with respect to pigeon colour morphs, with an apparent preference for pied colouration. Contrary to previous interpretations, Rock Pigeon do not appear to eat spilled grain on the building to any great extent; instead, the terminal may simply provide abundant roosting sites, which attain surface temperatures roughly 10°C warmer than ambient on sunny days and at temperatures below −20°C when the building is warmed internally.

Relative demographic susceptibility does not explain the extinction chronology of Sahul’s megafauna

The causes of Sahul’s megafauna extinctions remain uncertain, although multiple, interacting factors were likely responsible. To test hypotheses regarding plausible ecological mechanisms underlying these extinctions, we constructed the first stochastic, age-structured models for 13 extinct megafauna species from five functional/taxonomic groups, as well as 8 extant species within these groups for comparison. Perturbing specific demographic rates individually, we tested which species were more demographically susceptible to extinction, and then compared these relative sensitivities to the fossil-derived extinction chronology. Here we show that the macropodiformes were the most resilient to extinction, followed by carnivores, monotremes, vombatiform herbivores, and large birds. Five of the eight extant species were as or more susceptible than were the extinct species. There was no clear relationship between extinction susceptibility and the extinction chronology for any perturbation scenario, but body mass and generation length explained much of the variation in relative risk. Our models reveal that the actual mechanisms leading to extinction were unlikely related to variation in demographic susceptibility per se, but were driven instead by finer-scale variation in climate change and/or human prey choice and relative hunting success.