Academic literature on the topic 'Pteropus spp'

Roosting colonies of Pteropus spp. at Myeik and Nyaung-zin in Myanmar’s Tanintharyi Region were surveyed between March and October 2016. Flying Foxes from 12 roost sites in Myeik town are considered to represent the taxon Pteropus hypomelanus geminorum based on the collection of a single specimen, which is the first record of the taxon from a mainland location. Further information was gathered from local people concerning the ecology and seasonal migration of Flying Fox colonies at the coastal village of Shaw-Taw-Maw and on the small island of The-byu. Data are presented on the roost tree species selected by Pteropus colonies and local threats to the bats and their habitat.

Population estimation and monitoring is a fundamental component in the conservation management of any species. For species such as flying-foxes (Pteropus spp.) population estimation is complicated by the large number of animals involved, their mobility and the conditions under which counts are conducted. Because count results are used in the determination of management requirements, they are the focus of much critical attention. Despite this, while measures of the precision of fly-out counts of Pteropus spp. have been published, measures of their accuracy have not. In this paper we present an assessment of the accuracy and precision of observer counts of dusk fly-outs by comparing recordings of observers’ counts with a video of the same fly-out. Observer’s counts were significantly related to the video-count (rs = 0.69, P < 0.0001), with the average observer’s count underestimating the video-count by 14.7% (± 25, s.d.) of the video-count. Observers’ errors increased with the rate at which flying-foxes left the camp and with the width of the fly-out stream. These results suggest that while observers’ errors are inherent in dusk fly-out counts, these errors are manageable and relatively predictable. Other sources of error are likely to have a greater impact on the final population estimate at both camp and regional scales.

AbstractGlobally, island bats are vulnerable to subsistence hunting, with widespread population declines, local extirpations and extinctions. Bats are important to the ecological functioning of remote oceanic islands, and thus the sustainable management of hunting of flying foxes Pteropus spp. is a conservation priority in the Pacific. In Solomon Islands people hunt flying foxes for bushmeat and their canine teeth, which are used as traditional currency. The value of teeth potentially increases hunting pressure on species of Pteropus. We interviewed 197 people on Makira Island to determine the nature of this use and how it may influence flying-fox populations. We asked questions to gather information about hunting practices, the value of canine teeth, utilization of traditional currency, and population trends of Pteropus. Flying-fox teeth remain highly valued on Makira. It is primarily the teeth of P. tonganus that are used rather than those of the smaller P. cognatus. Although flying foxes are not targeted solely for their teeth, this added value seemingly drives hunters to focus on P. tonganus. Hunting varied across five regions of Makira and high hunting pressure corresponded with perceived rarity of P. tonganus. Regions with low hunting pressure may be opportune locations to initiate flying-fox conservation on Makira.

Seminal characteristics are described in six Pteropus species including the critically endangered P. rodricensis. Spermic ejaculates (~40 μL) were collected using electro-ejaculation on 406 of 413 attempts. All flying-fox species had mean percentages of acrosome- and plasma-membrane (PM)-intact spermatozoa of >66% and >73%, respectively; the predominant sperm abnormalities found across all species were damaged, folded or missing acrosomes, bent midpieces and coiled tails. Seminal pH ranged from a low of 7.5 in P. giganteus to a high of 8.2 in P. alecto with the other species in between. Electro-ejaculates recovered in short succession from P. alecto revealed no differences in sperm quality, allowing spermatozoa to be utilised for multi-treatment experiments that evaluated the effects of transportation, incubation temperature and in vitro physico-chemical environments on acrosome and PM integrity. Pteropus alecto spermatozoa were successfully held at ~27°C and 37°C for up to 6 h before a reduction in PM integrity (P = 0.003) was observed. Acrosome and PM integrity decreased (P < 0.000) when P. alecto spermatozoa were incubated at 37°C for 30 min in a Tris–citrate buffer of pH 9.0 but remained stable at pH 5.0 to 8.0. Pteropus alecto mean (± s.e.m.) seminal osmolality was 307.0 ± 2.5 mOsm kg–1; nevertheless, spermatozoa were tolerant of media ranging from 160 to 1190 mOsm kg–1 but exposure to media of ≤160 mOsm kg–1 resulted in increased acrosome damage (P < 0.000).

Throughout their world distribution, fruit bats (Chiroptera: Pteropodidae) play an extremely important role in forest ecology through seed dispersal and pollination. However, the recognition of their role in maintaining forest ecological diversity has been largely overshadowed by the fact that fruit bats are known to cause damage to a wide variety of cultivated fruits and, as a result, significant effort is undertaken to control fruit bat numbers in areas where crop damage frequently occurs. In Australia, fruit bats of the genus Pteropus (or flying foxes) are well known for their role in destroying valuable fruit crops, particularly along the east coast from Cairns to Sydney. Historical evidence suggests that flying foxes have been culled as an orchard pest in large numbers for the past 80 years. Uncontrolled culling both on-farm and in roosts coupled with extensive habitat destruction in the past century, has resulted in noticeable declines both in flying fox distribution and local population numbers. In New South Wales, flying foxes have been 'protected' under the National Parks and Wildlife Act (1974) since 1986. From that time, fruitgrowers have been required to obtain a licence (referred to as an occupier's licence) from the National Parks and Wildlife Service (NPWS) to cull flying foxes causing damage to fruit crops. However, despite the 'protected' status of the species, flying foxes continue to be culled in large numbers as an orchard pest. An examination of the management of flying foxes in NSW, has shown that, between 1986-1992, fifteen NSW National Parks and Wildlife Service Districts issued a combined total of 616 occupier's licences to shoot flying foxes with an total allocation of over 240,000 animals. In addition, most flying foxes are culled when the female is carrying her young under wing or when the young remain in the camp but continue to be dependent on her return for survival. Further evidence on the extent of culling includes a widely distributed fruitgrower survey with responses indicating that as few as 50% of the fruitgrowers shooting flying foxes in NSW obtain the required licence from the National Parks and Wildlife Service. While the NPWS has undertaken research into the role of flying foxes in seed dispersal and pollination, management effort largely continues to focus on resolving conflicts between fruitgrowers and flying foxes primarily by issuing culling permits to fruitgrowers. At present, there is no NPWS policy on the management of flying foxes in NSW to guide the administration of the permit system. As a result, the process of issuing permits for flying foxes is largely inconsistent between NPWS Districts. The absence of comprehensive goals and objectives for the management of flying foxes has resulted in the current situation where large numbers of flying foxes are being culled both legally and illegally in the absence of any data on the impacts of unknown culling levels on local flying fox populations. The NPWS has a statutory obligation to manage flying foxes consistent with the 'protected' status of the species in NSW and several well known principles of wildlife management. However, current management of flying foxes in indicates that the Service may be in violation of the requirement to 'protect' and 'conserve' flying foxes as required under the National Parks and Wildlife Act (1974). This study recommends that licences issued to fruitgrowers to cull flying foxes be discontinued immediately and that adequate enforcement be engaged to reduce illegal shooting. This action should continue until such time that research on flying fox populations is able to demonstrate that the culling of flying foxes will not lead populations into decline. Furthermore, management effort should focus on the development of alternative strategies to reduce crop damage by flying foxes and provide incentives for growers to utilize existing control strategies such as netting.

Temperature preference, behavioral tolerance, and physiological tolerances were determined for locally captured, invasive juvenile lionfish at four different acclimation temperatures (13°C, 20°C, 25 °C and 32°C). Temperature preferences and avoidance temperatures were evaluated using an automated shuttlebox system that presents subject-driven temperature stimuli to subjects, who control the temperature with their movement throughout the tank for 12 hours. Subjects are tracked by a computer system, with data output approximately every second. Acute preference was calculated from the archived data as the mean temperature that the fish occupied during the first two hours of dynamic experimentation. Acute preference measurements were used to determine final temperature preferendum and avoidance temperatures were used to determine behavioral tolerance. Critical thermal methodology (CTM) determined the CTmin and CTmax of the lionfish with loss of equilibrium (LOE) as the endpoint. It is assumed that beyond this temperature, the fish would be unable to survive. Temperature was increased or decreased by 0.33°C per minute until the end point was reached. Thermal tolerance polygons provide a visual representation of the lower and upper thermal avoidance temperatures, delineating the thermal range of the species. Their CTmin and CTmax (acclimated to 25°C) were compared experimentally with two other Florida reef fish species (Cephalopholis cruentata and Lutjanus apodus). Acute preferences of juvenile invasive lionfish showed a final preferendum at 28.7 ± 1°C, but with no significant difference between acclimation temperatures. The thermal tolerance polygon of invasive lionfish shows a strong correlation between CTM and acclimation temperature, with the highest CTmax at 39.5°C and the lowest CTmin at 9.5°C. The thermal polygon, preference, and avoidance data describes the thermal niche of the lionfish. Lionfish CTM (24.61°C) is narrower than those of C. cruentata (25.25°C) and L. apodus (26.87°C).

Predator satiation and prey-size preference were determined for locally caught lionfish, schoolmaster, and graysby, all co-occurring predatory fishes in the Florida coral reef ecosystem. Individuals were evaluated by exposing them to wild-caught killifish over a gradient of four size classes (20 mm to 60 mm, in 10 mm increments). Preference trials extended over a 2 hr time period and were filmed to determine the order in which each prey item was consumed. Satiation was evaluated by exposing the predators to an equal number of excess prey items for 24 hrs and evaluating consumed prey weight. Lionfish and schoolmaster showed a significant preference for the smallest size class (20-30 mm) while the graysby preferred the largest (50-60 mm) and smallest equally. Graysby were shown to consume the least amount of food per gram by biomass (0.034g/gram predator-1) while lionfish consumed the most (0.079g/gram predator-1). A significant difference was also found between consumption rates of lionfish and schoolmaster (0.053g/gram predator-1). If consumption is compared by length between species, lionfish ( = 0.051g/mm predator-1) and schoolmaster ( = 0.061g/mm predator-1) consumption was not significantly different. These results suggest that lionfish success may stem from its ability to target prey sizes not preferred by the graysby while able to outcompete schoolmaster for the same prey size class. However, if the lionfish is compared on an individual level to schoolmaster by individual or length, consumption is similar, suggesting lionfish consumption is not significantly greater on the reef than the native species on an individual basis.