Observations of 18 radio-tracked snakes in the field, combined with dissection of museum
specimens, provided data on reproductive biology of eastern Australian diamond pythons
(Morelia spilota). Both sexes mature at about 150 cm snout-vent length (SVL). Pelvic spurs ...
DJ Slip and R Shine
Australian Wildlife Research 15(5) 515 - 531
Published: 1988
Abstract
Miniature radio transmitters were surgically implanted in 15 adult diamond pythons from two areas near Sydney, N.S.W., in south-eastern Australia, and the snakes monitored for intervals of 4-32 months. We document patterns of habitat use and movements, and interpret these in terms of the feeding habits and reproductive biology of the pythons. These snakes were usually sedentary in summer and autumn, with occasional long movements to new sites. During spring (the mating season), males moved long distances, often daily. Telemetered pythons were generally diurnal and terrestrial rather than arboreal. Snakes were most commonly recorded coiled under vegetation which provided filtering cover (34% of locations). The relative use of different habitats by diamond pythons changed with season. In summer and autumn, snakes were most frequently in disturbed habitats (such as areas around houses), where prey are relatively common. In winter the snakes used rocky habitats, especially sandstone crevices. No winter aggregations were observed. The radio-tracked snakes had large (up to 124 ha), well-defined but overlapping home ranges, and these varied significantly between sexes and among seasons. Detailed analysis of python movements shows that at least two assumptions of many home-range analyses (normally distributed data and adequacy of small sample sizes) are invalid for our study.
Will Bird.
Consistent success in breeding snakes requires an understanding of the biological needs the animals have, but keepers must also be able to interpret signals that behaviors convey and possess other inherent skills that either come naturally or are gleaned through experience. In this article I hope to share some general information about some of the different carpet pythons I have kept and also impart some of my experiences and observations that have led to breeding success over many years.
Sexual dimorphism is usually interpreted in terms of reproductive adaptations, but the degree of sex divergence also may be affected by sex-based niche partitioning. In gape-limited animals like snakes, the degree of sexual dimorphism in body size (SSD) or relative head size can determine the size spectrum of ingestible prey for each sex. Our studies of one mainland and four insular Western Australian populations of carpet pythons (Morelia spilota) reveal remarkable geographical variation in SSD, associated with differences in prey resources available to the snakes. In all five populations, females grew larger than males and had larger heads relative to body length. However, the populations differed in mean body sizes and relative head sizes, as well as in the degree of sexual dimorphism in these traits. Adult males and females also diverged strongly in dietary composition: males consumed small prey (lizards, mice and small birds), while females took larger mammals such as possums and wallabies. Geographic differences in the availability of large mammalian prey were linked to differences in mean adult body sizes of females (the larger sex) and thus contributed to sex-based resource partitioning. For example, in one population adult male snakes ate mice and adult females ate wallabies; in another, birds and lizards were important prey types for both sexes. Thus, the high degree of geographical variation among python populations in sexually dimorphic aspects of body size and shape plausibly results from geographical variation in prey availability. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 77, 113–125.
Nidovirus-Associated Proliferative
Pneumonia in the Green Tree Python
(Morelia viridis)
Eva Dervas,a Jussi Hepojoki,a,b Andrea Laimbacher,c Fernando Romero-Palomo,a
Christine Jelinek,a Saskia Keller,a Teemu Smura,b Satu Hepojoki,a Anja Kipar,a
Udo Hetzela
Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerlanda
; University of Helsinki, Medicum, Department of Virology, Helsinki, Finlandb; Institute of Virology, Vetsuisse Faculty,
University of Zurich, Zurich, Switzerlandc
ABSTRACT
In 2014 we observed a noticeable increase in the number of sudden
deaths among green tree pythons (Morelia viridis). Pathological examination revealed
the accumulation of mucoid material within the airways and lungs in association
with enlargement of the entire lung. We performed a full necropsy and
histological examination on 12 affected green tree pythons from 7 different
breeders to characterize the pathogenesis of this mucinous pneumonia. By histology
we could show a marked hyperplasia of the airway epithelium and of
faveolar type II pneumocytes. Since routine microbiological tests failed to identify
a causative agent, we studied lung tissue samples from a few diseased
snakes by next-generation sequencing (NGS). From the NGS data we could assemble
a piece of RNA genome whose sequence was 85% identical to that of
nidoviruses previously identified in ball pythons and Indian pythons. We then
employed reverse transcription-PCR to demonstrate the presence of the novel nidovirus
in all diseased snakes. To attempt virus isolation, we established primary
cultures of Morelia viridis liver and brain cells, which we inoculated with homogenates
of lung tissue from infected individuals. Ultrastructural examination of
concentrated cell culture supernatants showed the presence of nidovirus particles,
and subsequent NGS analysis yielded the full genome of the novel virus
Morelia viridis nidovirus (MVNV). We then generated an antibody against MVNV
nucleoprotein, which we used alongside RNA in situ hybridization to demonstrate
viral antigen and RNA in the affected lungs. This suggests that in natural
infection MVNV damages the respiratory tract epithelium, which then results in
epithelial hyperplasia, most likely as an exaggerated regenerative attempt in association
with increased epithelial turnover.
