Behaviour of the black flying fox Pteropus alecto: 1. An ethogram of behaviour, and preliminary characterisation of mother-infant interactions

The black flying fox Pteropus alecto is one of four species of flying fox found on the Australian mainland. Little information exists about the specific behaviour of this species, and no framework for the study of its behaviour has yet been constructed. In the study reported here, two P alecto colonies were observed at two day roosts in South East Queensland, Australia, between 1998-2000. Observations focused on solitary and social actions in general and on mother-infant interactions in some detail and led to the construction of an ethogram that defines each action structurally and functionally, describing accompanying vocalisations where appropriate. Diurnal activity patterns of P. alecto throughout the year consisted predominantly of roosting, grooming and sleeping, and involved little social activity. Social interactions were largely restricted to the seasonal contexts of the birthing/rearing period of October to March and the subsequent courtship/mating season of February to April. In all, 74 behavioural units were defined with the aim of facilitating further research and the implementation of effective conservation strategies for the species.

Behaviour of the black flying fox Pteropus alecto: 2. Territoriality and courtship

Flying foxes are commonly thought of as highly social mammals, yet little is known about the dynamics of their social interactions at a day roost. The aim of the present study was to examine the nature of the seasonal activities of territoriality and courtship amongst wild flying foxes in Australia. Focal observations were conducted at two permanent roosts of black flying foxes Pteropus alecto during periods of peak social interaction in the summers of 1999 and 2000 in urban Brisbane, Queensland. Observations of male territoriality were conducted at dawn and began eight weeks prior to the commencement of mating. The majority of defense bouts (87%) consisted of ritualised pursuit, while 13% of bouts involved physical contact expressed as either wrestling or hooking. One male with an unusually large territory took significantly longer to defend it than other males with less territory to defend. Observations of courtship revealed repetitive courtship sequences, including pre-copulatory approaches by the males, copulation attempts and grooming/resting periods. Thirty-four complete courtship sequences incorporating 135 copulation attempts were recorded over two seasons. Females actively resisted courtship approaches by males, forcing males to display a continuous determination to mate over time where determination can be considered an indicator of 'fitness'. The courtship bout length of females with suckling young was significantly longer ((x) over bar +/- SE; 230.9 +/- 22.16 s) than that of females unencumbered by large pups (158.5 +/- 9.69 s), although the length of copulations within those courtships was not (45.6 +/- 5.19 versus 36.2 +/- 3.43 s).

Collection, seminal characteristics and chilled storage of spermatozoa from three species of free-range flying fox (Pteropus spp.)

This study reports observations on the collection and characteristics of semen from free-range populations of flying fox in Brisbane, Australia. Semen was successfully recovered by electroejaculation from 107 of 115 wild flying foxes (Pteropus alecto, Pteropus poliocephalus and Pteropus scapulatus). A proportion of ejaculates collected from all three species contained seminal vesicle secretions, the incidence of which appeared related to breeding season. Ejaculate volume was small (5-160 mu L), requiring a specialised collection vessel and immediate extension to avoid desiccation. Sperm morphological abnormalities and characteristics are described for the first time. In two species (P. scapulatus and P. alecto), sperm quality varied with breeding season. Dilution in Tris-citratefructose buffer and subsequent incubation (37 degrees C) of Pteropus semen for 2-3 h appeared to have a negative impact on sperm motility and the percentage of sperm with intact plasma membranes and acrosomes and represents a concern for the potential development and use of assisted breeding technology in these species. Preliminary attempts to develop a short-term chilled preservation protocol for flying fox semen revealed that spenn viability (percentage motility and percentage live sperm with intact acrosomes) was significantly reduced after 102 h chilled storage at 5 degrees C; nevertheless, approximately 40% of the spermatozoa were still motile and contained intact acrosomes. Glycerol was neither protective nor detrimental to sperm survival during chilled storage. Microbial flora of the prepuce, urethra and semen of all species were isolated and their antibiotic susceptibility tested. Tetracycline, penicillin, ciprofloxacin, and ceftazidime were the most effective antibiotics in preventing growth of all identified bacteria; however, their effects on sperm survival were not investigated. (c) 2005 Elsevier Inc. All rights reserved.

Chromosome banding patterns of four species of bats, with special reference to a case of X-autosome translocation

The karyotypes of 4 species of bats, Artibeus lituratus (Phyllostomatidae), Pipistrellus pipistrellus (Vespertilionidae), Pteropus alecto and P. giganteus (Pteropodidae), were studied after several banding techniques. For A. lituratus, in which an X-autosome translocation was observed, an analysis of the replication pattern in the rearranged chromosome was also made after BrdU incorporation.

Novel paramyxoviruses in Australian flying-fox populations support host–virus co-evolution

Understanding the diversity of henipaviruses and related viruses is important in determining the viral ecology within flying-fox populations and assessing the potential threat posed by these agents. This study sought to identify the abundance and diversity of previously unknown paramyxoviruses (UPVs) in Australian flying-fox species (Pteropus alecto, Pteropus scapulatus, Pteropus poliocephalus and Pteropus conspicillatus) and in the Christmas Island species Pteropus melanotus natalis. Using a degenerative reverse transcription-PCR specific for the L gene of known species of the genus Henipavirus and two closely related paramyxovirus genera Respirovirus and Morbillivirus, we identified an abundance and diversity of previously UPVs, with a representative 31 UPVs clustering in eight distinct groups (100 UPVs/495 samples). No new henipaviruses were identified. The findings were consistent with a hypothesis of co-evolution of paramyxoviruses and their flying-fox hosts. Quantification of the degree of co-speciation between host and virus (beyond the scope of this study) would strengthen this hypothesis.

On the intrinsic capacity for increase of Australian flying-foxes (Pteropus spp., Megachiroptera)

In the reproductive biology of organisms, a continuum exists from "highly reproductive species" at one end to "survivor species" at the other end. Among other factors, the position of a species along this continuum affects its sensitivity to human exploitation and its vulnerability to extinction. Flying foxes are long-lived, seasonal breeders, with a rigid, well-defined breeding season that is largely or wholly genetically determined. Unlike opportunistic, highly reproductive species, such as rabbits or mice, female flying foxes are unable to produce viable young before their second or third year of life, and are then capable of producing just one young per year. Such a breeding strategy will be successful only if flying-foxes are long-lived and suffer naturally low mortality rates. In this paper, we assess the vulnerability of flying foxes to extinction, using basic parameters of reproduction observed in the wild, and in captive breeding colonies of P. poliocephalus, P. alecto and P. scapulatus, and survival rates that are likely to apply to Australian conditions. Our models show explicitly that flying-fox populations have a very low capacity for increase, even under the most ideal conditions. The implications of our models are discussed in reference to the long-term management and conservation needs of Australian flying foxes. We conclude that current death-rates of flying-foxes in NSW and Queensland fruit orchards are putting state populations at serious risk.

Neuro-angiostrongylosis in wild Black and Grey-headed flying foxes (Pteropus spp)

Objective To identify nematodes seen in histological sections of brains of flying foxes (fruit bats) and describe the associated clinical disease and pathology. Proceedures Gross and histological examination of brains from 86 free-living flying foxes with neurological disease was done as part of an ongoing surveillance program for Australian bat lyssavirus. Worms were recovered, or if seen in histological sections, extracted by maceration of half the brain and identified by microscopic examination. Histological archives were also reviewed. Results There was histological evidence of angiostrongylosis in 16 of 86 recently submitted flying foxes with neurological disease and in one archival case from 1992. In 10 flying foxes, worms were definitively identified as Angiostrongylus cantonensis fifth-stage larvae. A worm fragment and third stage larvae were identified as Angiostrongylus sp, presumably A cantonensis, in a further three cases. The clinical picture was dominated by paresis, particularly of the hind-limbs, and depression, with flying foxes surviving up to 22 days in the care of wildlife volunteers. Brains containing fifth-stage larvae showed a moderate to severe eosinophilic and granulomatous meningoencephalitis (n = 14), whereas there was virtually no inflammation of the brains of bats which died when infected with only smaller, third-stage larvae (n = 3). There was no histological evidence of pulmonary involvement. Conclusion This is the first report of the recovery and identification of A cantonensis from free-living Australian wildlife. While anglostrongylosis is a common cause of paresis in flying foxes, the initial clinical course cannot be differentiated from Australian bat lyssavirus infection, and wildlife carers should be urged not to attempt to rehabilitate flying foxes with neurological disease.

Effects of the paralysis tick, Ixodes holocyclus, on the electrocardiogram of the Spectacled Flying Fox, Pteropus conspicillatus

Objective To evaluate cardiac electrical function in the Spectacled Flying Fox (bat) infested with Ixodes holocyclus. Design Prospective clinical investigation of bats treated for naturally occurring tick toxicity. Procedure ECGs were performed on bats with tick toxicity (n = 33), bats that recovered slowly (n = 5) and normally (n = 5) following treatment for tick toxicity, and on normal bats with no history of tick toxicity (n = 9). Results Bats with tick toxicity had significantly prolonged corrected QT intervals, bradycardia and rhythm disturbances which included sinus bradydysrhythmia, atrial standstill, ventricular premature complexes, and idioventricular bradydysrhythmia. Conclusions The QT prolongation observed on ECG traces of bats with tick toxicity reflected delayed ventricular repolarisation and predisposed to polymorphic ventricular tachycardia and sudden cardiac death in response to sympathetic stimulation. The inability to document ventricular tachycardia in bats shortly before death from tick toxicity may be explained by a lack of sympathetic responsiveness attributable to the unique parasympathetic innervation of the bat heart, or hypothermiainduced catecholamine receptor down-regulation. Bradycardia and rhythm disturbances may be attributable to hypothermia.

The bacula of some fruit bats (Pteropus).

v.31:no.16(1947)

Biological characteristics of Telenomus alecto and Trichogramma galloi reared on eggs of the sugarcane borer Diatraea flavipennella

Diatraea flavipennella (Box) (Lepidoptera, Crambidae) is one of the most destructive pests in sugarcane plantations in the Northeast Region of Brazil. Developmental characteristics and parasitism potential of the egg parasitoids Telenomus alecto Crawford (Hymenoptera, Scelionidae) and Trichogramma galloi Zucchi (Hymenoptera, Trichogrammatidae) were compared with the aim of selecting a suitable species for biological control of D. flavipennella. Both T. alecto and T. galloi developed well and were readily adapted to D. flavipennella eggs as host. Although, T. galloi presented higher viability, with more adults emerging per host egg and higher sex ratio, the developmental period (egg-adult) was shorter in T. alecto and female longevity was extended. In addition, T. alecto exhibited significant higher levels of parasitism during the first three days after emergence than T. galloi. Thus, both parasitoids studied here offer considerable potential for the control of D. flavipennella in sugarcane.