Bats as bushmeat in Madagascar

Bats are eaten by people throughout Madagascar and although the larger species like Pteropus rufus, Eidolon dupreanum, Rousettus madagascariensis and Hipposideros commersoni are preferred, small insectivorous bats are also eaten. The national hunting season for bats is widely ignored and both unsuitable hunting practices and high offtake represent a serious threat to bat populations in some areas. Bat bushmeat may be an important source of protein for Malagasy people during periods of food shortage but in general there are few data on the socioeconomic and cultural importance of bats. Fruit bats produce a single offspring per year and are therefore susceptible to over - hunting. Nevertheless, large roosts offer the possibility of community managed harvests to secure the colony and provide a source of meat but further research is needed before this can be considered. Roost sites also present the best focus for conservation and greater effort is needed to control hunting using existing legislation and flexible community - based solutions that are sensitive to the local context. The threat of pathogen transfer from bats to people is of growing concern as more bat species are identified as vectors of emergent viral diseases

Three flying fox (Pteropodidae: Pteropus rufus) roosts, three conservation challenges in southeastern Madagascar

We visited three roosts of the Madagascar flying fox Pteropus rufus in December 2005 in the Anosy Region. Colony size was 900 at Berenty Private Reserve, 412 at Amborabao and 54 at Sainte Luce, based on single counts at each site. Hunting at the roost is prohibited at Berenty but P. rufus is trapped at night in the area surrounding the reserve, where it feeds on sisal. At Amborabao, the bats roost in a sacred forest and hunting is forbidden. At Sainte Luce, the forest is highly degraded and the bats are hunted frequently, despite efforts to engage the local community in forest conservation. Questionnaires with people living near the roosts revealed the flying foxes were regarded as pests of litchis in Amborabao and Sainte Luce. Berenty is the only site where tourists are able to observe roosting P. rufus. The role of sacred forests and local taboos (fady) is very relevant for P. rufus conservation and might be the only practical mechanism in sites where legislation on hunting and land use is not being enforced

A conservation assessment of Rousettus madagascariensis (G. Grandidier, 1928, Pteropodidae) roosts in eastern Madagascar

We visited four cave roosts of the near threatened, and endemic, fruit bat Rousettus madagascariensis over a five year period and found major threats to the bats from hunting and deforestation. The conservation of this species is particularly challenging because it is legally hunted inside its cave roosts. Although provisional protected area status was obtained for two sites with community support, hunting continued. R. madagascariensis roosts were associated with humid forest and the loss of vegetation around caves rendered them unsuitable for the bats at two abandoned sites. A few individual hunters can have a rapid and destructive impact on R. madagascariensis roosts and future initiatives in this area should involve working with hunters to develop realistic solutions to reduce hunting. These efforts need to be supported by habitat protection measures.RÉSUMÉL’espèce de chauve - souris frugivore Quasi Menacée Rousettus madagascariensis est endémique à Madagascar. Nous avons étudié quatre gîtes dans des grottes où cette espèce a établi des dortoirs diurnes en procédant à des visites multiples au cours d’une période de cinq ans et avons trouvé que la chasse et la déforestation constituaient les principales menaces pesant sur R. madagascariensis. La conservation de cette espèce est particulièrement difficile dans la mesure où la chasse dans ses dortoirs ou gîtes est permise. Bien que les deux sites abritant l’espèce bénéficient du statut de Nouvelle Aire Protégée avec le soutien de la communauté locale, la chasse ne cesse de s’intensifier. Les gîtes de R. madagascariensis sont associés à la forêt humide, de sorte que la disparition de la végétation arborée autour de deux de ces gîtes les a rendus impropres à héberger R. madagascariensis qui a fini par les abandonner. La disparition de la végétation arborée autour du gîte pourrait être à l’origine d’un changement de microclimat à l’intérieur de la grotte qui constitue le gîte diurne. Les activités de certains chasseurs peuvent aussi avoir un impact destructif rapide sur les gîtes de R. madagascariensis et des initiatives à mener conjointement avec les chasseurs sont nécessaires pour élaborer des mesures réalistes afin de réduire la chasse. De tels efforts doivent être étendus et appuyés par des mesures de protection de l’habitat car plusieurs autres gîtes pourraient exister dans les forêts du versant est de Madagascar et subir les mêmes pressions anthropiques. Des recherches récentes ont également montré que l’histoire naturelle de R. madagascariensis est étroitement liée à la forêt naturelle, de sorte que la perte de la biodiversité de la forêt naturelle malgache menace les plantes dont se nourrit cette espèce ainsi que l’équilibre de l’ensemble de l’écosystème dont elle dépend

Repeatability in the contact calling system of Spix's disc-winged bat (Thyroptera tricolor)

Spix's disc-winged bat (Thyroptera tricolor) forms cohesive groups despite using an extremely ephemeral roost, partly due to the use of two acoustic signals that help individuals locate roost sites and group embers. While the calls that aid in group cohesion are commonly used, some bats rarely or never produce them. Here, we examine whether the differences observed in the contact calling behaviour of T. tricolor are repeatable; that is, whether individual differences are consistent. We recorded contact calls of individuals in the field and rates and patterns of vocalization. To determine whether measured variables were consistent within individuals, we estimated repeatability (R), which compares within-individual to among-individual variance in behavioural traits. Our results show that repeatability for call variables was moderate but significant, and that repeatability was highest for the average number of calls produced (R=0.46–0.49). Our results demonstrate important individual differences in the contact calling behaviour of T. tricolor; we discuss how these could be the result of mechanisms such as frequency-dependent selection that favour groups composed of individuals with diverse vocal strategies. Future work should address whether changes in social environment, specifically group membership and social status, affect vocal behaviour.UCR::Sedes Regionales::Sede del Su

A Simple Iterative Model Accurately Captures Complex Trapline Formation by Bumblebees Across Spatial Scales and Flower Arrangements

PMCID: PMC3591286This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Communally breeding bats use physiological and behavioural adjustments to optimise daily energy expenditure

Small endotherms must change roosting and thermoregulatory behaviour in response to changes in ambient conditions if they are to achieve positive energy balance. In social species, for example many bats, energy expenditure is influenced by environmental conditions, such as ambient temperature, and also by social thermoregulation. Direct measurements of daily fluctuations in metabolic rates in response to ambient and behavioural variables in the field have not been technologically feasible until recently. During different reproductive periods, we investigated the relationships between ambient temperature, group size and energy expenditure in wild maternity colonies of Bechstein’s bats (Myotis bechsteinii). Bats used behavioural and physiological adjustments to regulate energy expenditure. Whether bats maintained normothermia or used torpor, the number of bats in the roosts as well changed with reproductive status and ambient temperature. During pregnancy and lactation, bats remained mostly normothermic and daily group sizes were relatively large, presumably to participate in the energetic benefits of social thermoregulation. In contrast, smaller groups were formed on days when bats used torpor, which occurred mostly during the post-lactation period. Thus, we were able to demonstrate on wild animals under natural conditions the significance of behavioural and physiological flexibility for optimal thermoregulatory behaviour in small endotherms

Torpor on Demand: Heterothermy in the Non-Lemur Primate Galago moholi

Hibernation and daily torpor are energy- and water-saving adaptations employed to survive unfavourable periods mostly in temperate and arctic environments, but also in tropical and arid climates. Heterothermy has been found in a number of mammalian orders, but within the primates so far it seems to be restricted to one family of Malagasy lemurs. As currently there is no evidence of heterothermy of a primate outside of Madagascar, the aim of our study was to investigate whether small primates from mainland Africa are indeed always homeothermic despite pronounced seasonal changes in weather and food availability., which inhabits a highly seasonal habitat with a hot wet-season and a cold dry-season with lower food abundance, was investigated to determine whether it is capable of heterothermy. We measured skin temperature of free-ranging individuals throughout the cool dry season using temperature-sensitive collars as well as metabolic rate in captured individuals. Torpor was employed by 15% of 20 animals. Only one of these animals displayed heterothermy in response to natural availability of food and water, whereas the other animals became torpid without access to food and water. are physiologically capable of employing torpor. However they do not use it as a routine behaviour, but only under adverse conditions. This reluctance is presumably a result of conflicting selective pressures for energy savings versus other ecological and evolutionary forces, such as reproduction or territory defence. Our results support the view that heterothermy in primates evolved before the division of African and Malagasy Strepsirhini, with the possible implication that more primate species than previously thought might still have the potential to call upon this possibility, if the situation necessitates it

Sympatric woodland Myotis bats form tight-knit social groups with exclusive roost home ranges

Background: The structuring of wild animal populations can influence population dynamics, disease spread, and information transfer. Social network analysis potentially offers insights into these processes but is rarely, if ever, used to investigate more than one species in a community. We therefore compared the social, temporal and spatial networks of sympatric Myotis bats (M. nattereri (Natterer's bats) and M. daubentonii (Daubenton's bats)), and asked: (1) are there long-lasting social associations within species? (2) do the ranges occupied by roosting social groups overlap within or between species? (3) are M. daubentonii bachelor colonies excluded from roosting in areas used by maternity groups? Results: Using data on 490 ringed M. nattereri and 978 M. daubentonii from 379 colonies, we found that both species formed stable social groups encompassing multiple colonies. M. nattereri formed 11 mixed-sex social groups with few (4.3%) inter-group associations. Approximately half of all M. nattereri were associated with the same individuals when recaptured, with many associations being long-term (>100 days). In contrast, M. daubentonii were sexually segregated; only a quarter of pairs were associated at recapture after a few days, and inter-sex associations were not long-lasting. Social groups of M. nattereri and female M. daubentonii had small roost home ranges (mean 0.2 km2 in each case). Intra-specific overlap was low, but inter-specific overlap was high, suggesting territoriality within but not between species. M. daubentonii bachelor colonies did not appear to be excluded from roosting areas used by females. Conclusions: Our data suggest marked species- and sex-specific patterns of disease and information transmission are likely between bats of the same genus despite sharing a common habitat. The clear partitioning of the woodland amongst social groups, and their apparent reliance on small patches of habitat for roosting, means that localised woodland management may be more important to bat conservation than previously recognised

Do Bat Gantries and Underpasses Help Bats Cross Roads Safely?

Major roads can reduce bat abundance and diversity over considerable distances. To mitigate against these effects and comply with environmental law, many European countries install bridges, gantries or underpasses to make roads permeable and safer to cross. However, through lack of appropriate monitoring, there is little evidence to support their effectiveness. Three underpasses and four bat gantries were investigated in northern England. Echolocation call recordings and observations were used to determine the number of bats using underpasses in preference to crossing the road above, and the height at which bats crossed. At gantries, proximity to the gantry and height of crossing bats were measured. Data were compared to those from adjacent, severed commuting routes that had no crossing structure. At one underpass 96% of bats flew through it in preference to crossing the road. This underpass was located on a pre-construction commuting route that allowed bats to pass without changing flight height or direction. At two underpasses attempts to divert bats from their original commuting routes were unsuccessful and bats crossed the road at the height of passing vehicles. Underpasses have the potential to allow bats to cross roads safely if built on pre-construction commuting routes. Bat gantries were ineffective and used by a very small proportion of bats, even up to nine years after construction. Most bats near gantries crossed roads along severed, pre-construction commuting routes at heights that put them in the path of vehicles. Crossing height was strongly correlated with verge height, suggesting that elevated verges may have some value in mitigation, but increased flight height may be at the cost of reduced permeability. Green bridges should be explored as an alternative form of mitigation. Robust monitoring is essential to assess objectively the case for mitigation and to ensure effective mitigation

Response of a Specialist Bat to the Loss of a Critical Resource

Human activities have negatively impacted many species, particularly those with unique traits that restrict their use of resources and conditions to specific habitats. Unfortunately, few studies have been able to isolate the individual and combined effects of different threats on population persistence in a natural setting, since not all organisms can be associated with discrete habitat features occurring over limited spatial scales. We present the results of a field study that examines the short-term effects of roost loss in a specialist bat using a conspicuous, easily modified resource. We mimicked roost loss in the natural habitat and monitored individuals before and after the perturbation to determine patterns of resource use, spatial movements, and group stability. Our study focused on the disc-winged bat Thyroptera tricolor, a species highly morphologically specialized for roosting in the developing furled leaves of members of the order Zingiberales. We found that the number of species used for roosting increased, that home range size increased (before: mean 0.14±SD 0.08 ha; after: 0.73±0.68 ha), and that mean association indices decreased (before: 0.95±0.10; after: 0.77±0.18) once the roosting habitat was removed. These results demonstrate that the removal of roosting resources is associated with a decrease in roost-site preferences or selectivity, an increase in mobility of individuals, and a decrease in social cohesion. These responses may reduce fitness by potentially increasing energetic expenditure, predator exposure, and a decrease in cooperative interactions. Despite these potential risks, individuals never used roost-sites other than developing furled leaves, suggesting an extreme specialization that could ultimately jeopardize the long-term persistence of this species' local populations