H.H. de Iongh

Seagrass distribution and seasonal biomass changes in relation to dugong grazing in the Moluccas, East Indonesia

Abstract Seagrass distribution and seasonal changes in biomass and total organic C were studied in relation to dugong grazing, in intertidal meadows dominated by Halodule uninervis (Forsskal) Ascherson between December 1990 and December 1992 in Nang Bay on the east coast of Ambon. Both below-ground and above-ground biomass of Halodule uninervis significantly increased during the transition period from the dry season to the wet season between February and May. Above-ground biomass of Halodule uninervis decreased significantly during the wet season (between May and August), when low tide occurred in day time, and only slow recovery took place until November. Below-ground biomass remained high until November, resulting in a significant decrease of the ratio of above-ground to below-ground biomass during the period between May and August, and in a ‘sparse’ visible seagrass meadow, with a non-visible high below-ground biomass between August and November. Total organic carbon level in the below-ground plant parts gradually increased between May and August with a peak value in August. Dugong grazing removed 93% of the shoots and 75% of the below-ground biomass of the upper 4 cm deep layer of sediment. Seagrass biomass in freshly grazed feeding tracks was restored to levels of the nearby seagrass bed after 5 months during the onset of the wet season. No significant restoration took place during the dry season. The frequency of dugong grazing showed a strong positive correlation with total organic C level in the below-ground plant parts, indicating that the dugongs preference for the Halodule uninervis seems to be based on a strategy of a high net rate of energy intake.

Resource selection by grazing herbivores on post-fire regrowth in a West African woodland savanna

The preference of grazing herbivores to feed on grass regrowth following savanna fires rather than on unburnt grass swards is widely recognised. However, there is little information on which factors govern patterns of resource selection within burnt areas. In this study, we attempted to disentangle the effects of different habitat and grass sward characteristics on the utilisation of post-fire regrowth by nine species of ungulates in a fire-dominated woodland savanna in north Cameroon. We used resource-selection functions based on logistic regression. Overall, the resource-selection functions identified the time elapsed since burning as the most influential parameter in determining probability of use by ungulates, as most species strongly selected swards that were recently burned. This pattern might be related to nutrient levels in the grass sward. In addition, most species selected areas with high grass cover and avoided grass swards with high amounts of dead stem material. This is likely to increase bite mass and, hence, intake rates. The avoidance of high tree cover by some species may suggest selection for open areas with good visibility and, hence, reduced risk of predation. Body mass seemed to have no effect on differential selection of post-fire regrowth, irrespective of feeding style.

Resource partitioning among African savanna herbivores in North Cameroon: the importance of diet composition, food quality and body mass

The relationship between herbivore diet quality, and diet composition (the range of food plants consumed) and body mass on resource partitioning of herbivores remains the subject of an ongoing scientific debate. In this study we investigated the importance of diet composition and diet quality on resource partitioning among eight species of savanna herbivore in north Cameroon, with different body mass. Dung samples of four to seven wild herbivore and one domesticated species were collected in the field during the dry and wet period. Diet composition was based on microhistological examination of herbivore droppings, epidermis fragments were identified to genus or family level. In addition, the quality of the faecal droppings was determined in terms of phosphorus, nitrogen and fibre concentrations. The results showed that there was no significant correlation between body mass and (differences in) diet composition for wet and dry season. When all species are considered, only significant relationships are found by the Spearman rank correlation analyses during the wet season between body mass and phosphorus and nitrogen, but this relationship did not exist during the dry season. When the analyses focuses on ruminants only (thus leaving out hippo), none of the relationships between body mass and diet quality was significant in either season. During the dry season the proportion of graminoids ranged between 10% (small unidentified herbivore species) to 90% (hippopotamus), during the wet season this proportion ranged from 60% (zebu) to 90% (hippopotamus). All species but zebu had more graminoids in their dung during wet season compared with dry season. However all species but hartebeest had more graminoids old stems in their dung during the dry season, compared with the wet season. The niche breadth for food categories consumed by kob (0.300), hippo (0.090), hartebeest (0.350), roan (0.510) and zebu (0.300) was much greater in the dry season than in the wet season for kob (0.120), hippo (0.020), hartebeest (0.190), roan (0.090) and zebu (0.200). When looking at grass taxa consumed, the niche breadth of kob (0.220), hartebeest (0.140), and roan (0.250) was also greater in the dry season when compared with the wet season for kob (0.050), hartebeest (0.120) and roan (0.120). The opposite was found for zebu and hippo. Comparison of the species’ diet compositions with randomized data showed that dietary overlap between different herbivore species was much higher than what would be expected on the basis of chance, demonstrating surprisingly limited niche separation between species. This offers potential for competition, but it is more likely that the high niche overlap indicates absence of competition, due to low herbivore densities and abundant food resources, permitting species to share non-limiting resources. With increasing herbivore densities and subsequent increasing scarcity of resources, the relationship between diet quality and body mass in combination with increased niche separation is expected to become more visible

The Influence of People’s Practices and Beliefs on Conservation: A Case Study on Human-Carnivore Relationships from the Multiple Use Buffer Zone of the Panna Tiger Reserve, India

Abstract The case presented in this paper is a unique situation of livestock pastoralists, living in the buffer zone of Panna Tiger Reserve in India, displaying unusually high tolerance towards large carnivores in spite offrequent predation incidents. The researchers dissect the case, examine local people’s practices anddraw attentionto factors influencing peoples practices.Through interviews and personal observations the researchers collecteddetailed information on peoples practices and the factors influencing such practices. They collected informationon large carnivores near 29 villages in the buffer zone and looked at factors influencing their presence in theseareas. Their findings reveal the play and working of several social factors that are instrumental in influencingpeoples tolerance and people’s behaviours towards forests and wildlife and recommend that carnivore conservationprojects focusing outside protected areas should critically assess the influence of such aspects on their conservationgoals. And wherever applicable, find ways to innovatively model them into their conservation plans.

Wild versus domestic prey in the diet of reintroduced tigers (Panthera tigris) in the livestock-dominated multiple-use forests of Panna Tiger Reserve, India

Grazing livestock in openly accessible areas is a common practice in the multiple-use forests of India; however, its compatibility with the reintroduction of tigers to these areas requires examination. Here, we investigated the diet of tigers in a livestock-dominated multiple-use buffer zone of the Panna Tiger Reserve, India. We hypothesised that the presence of feral cattle, along with open-access grazing practices in multiple-use forests, would increase the incidence of predation on livestock by tigers, even when wild prey are available. We used generalised linear models to test whether predation of livestock versus wild animals was influenced by (1) the sex and age class of tigers, (2) season, and (3) the distance of prey from the core-zone boundary of the reserve. Overall, sub-adult tigers and male tigers killed more livestock than wild prey, even when wild prey was available. In the winter and rainy seasons livestock were killed in higher numbers in the buffer zone than in summers, this may be because of the seasonally changing livestock herding patterns in the area. Further, with increasing distance from the core-zone boundary, all tigers killed more livestock, possibly because livestock were more easily accessible than wild prey. Our results show that open-access and unregulated livestock grazing is not currently compatible with large carnivore conservation in the same landscape. Such practices will lead to an increase in negative tiger-human-livestock interactions. In conclusion, we suggest the need to encourage locals to corral valuable cattle, leaving feral/unwanted livestock for tigers. This simple strategy would benefit both local inhabitants and tiger conservation in the multiple-use forests of India.

Breeding biology and nestling development of the Grasshopper Buzzard

Research into the effect of environmental variables on reproductive success of tropical raptors is often constrained by the lack of information on breeding biology. We provide the first detailed information of the breeding biology and nestling development of the Grasshopper Buzzard Butastur rufipennis, an Afrotropical migratory raptor threatened by extensive land transformation in its breeding range. Breeding coincided with the transition from the dry to the wet season. The mean incubation period was 30 d and mean fledging period 36 d. The breeding period was characterised by rapid establishment of territories and short post-fledging dependency periods related to the onset of migration shortly after breeding. Growth rate of body mass, tarsus, wing and primary feathers were similar between sexes, which showed significant but moderate body mass dimorphism at fledging (♂85–90% of ♀). Second hatchlings were smaller in body mass and structural dimensions compared to similarly-aged first hatchlings and singles of the same sex. Survival of second hatchlings was related to body mass ratio with first hatchlings, whereas brood reduction occurred through food competition and siblicide. We provide ageing formulae and photographic records to facilitate further studies of Grasshopper Buzzard nestling development and reproductive success in the region.

Lion trophy hunting in West Africa: A response to Bouché et al.

1 Wildlife Conservation Research Unit, Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney, United Kingdom, 2 Panthera, New York, New York, United States of America, 3 Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, Minnesota, United States of America, 4 African Protected Areas & Wildlife, Saint Cloud, France, 5 Laboratory of Applied Ecology, University of AbomeyCalavi, Cotonou, Benin, 6 Institute for Environmental Sciences, University of Leiden, Leiden, The Netherlands

A survey of the Bali mynah Leucopsar rothschildi stresemann 1912

Abstract Present knowledge of the distribution of the Bali mynah Leucopsar rothschildi and the results of a survey implemented during March and April 1979 are reviewed. Maximum numbers of Bali mynahs still present in the West Bali nature reserve are estimated not to exceed 200 individuals. Finally some possible measures to prevent extinction are summarised.

New insights into the factors influencing movements and spatial distribution of reintroduced Bengal tigers (Panthera tigris tigris) in the human-dominated buffer zone of Panna Tiger Reserve, India

Abstract The influence of tiger-specific (sex, age group), environmental (seasons, photoperiod) and anthropogenic (human use regimes) factors on the movements and spatial distribution of tigers using the human-dominated buffer zone of the Panna Tiger Reserve, India was studied. Generalised linear mixed models were used to test the significance of the relationships between the covariates influencing tiger presence. We report that tiger-specific factors – age group (generation) and sex – and environmental factors – seasons and day/night – significantly explain the observed variations in tiger use of the human-dominated buffer zone. For instance, second-generation tigers (sub-adults) spent 40% of their time in the human-use areas, compared to 10% spent by first-generation tigers (adult). When in human-use areas, sub-adult tigers approached areas near villages and spent 30% less time in areas close to water than adult tigers. Our study concludes that, in addition to tiger-specific factors, human factors, including livestock practices and peoples’ activities, influence tiger behaviour and their use of shared spaces. These unchecked human practices may lead to increased negative tiger-human interactions and restricts tigers from exploiting the resources in multiple-use areas.

Evaluation of smallholder farming systems in the Western Highlands of Cameroon

Small scale farming systems in the Western Highlands of Cameroon (WHC) are influenced by many factors. Understanding the determinants that influence the system is essential when targeting appropriate intervention strategies for improvement. A field survey was carried out and analysed to understand the forces that drive the farming systems in this area. The impacts of farming practices on farm sustainability were used as indicators to score sustainability. The results revealed that the household characteristics were very similar across the villages while the sustainability differed depending on the intensity of off-farm inputs in the production systems and other socio-economic factors. Sustainability had significant negative relationships with the intensity of land use, off-farm inputs, and sole cropping practice and a positive relationship with the age of the head of the household. The determinants of the system which explained 62.15% of the total variation of sustainability in the study area were grouped to indicate a number of underlying common factors influencing sustainability. The villages of the WHC had much in common and could benefit equally from the same improved technologies and recommendations.