Natural history of the common tree snake, Dendrelaphis punctulatus (Serpentes:Colubridae), in the wet - dry tropics of north Queensland

2010 ◽  
Vol 58 (6) ◽  
pp. 384 ◽  
Author(s):  
S. Fearn ◽  
D. F. Trembath

Common tree snakes, Dendrelaphis punctulatus, are medium to large colubrid snakes that are relatively common in the eastern and northern parts of tropical Australia. The only previous study on this species involved museum specimens from across the taxon’s range. During a seven-year period we collected data on 131 field-caught specimens from a melanotic population in the Townsville district of north Queensland. Dendrelaphis punctulatus was found to be primarily diurnal, with a peak in activity centred around the reproductive period during the transition from dry to wet seasons. Females were larger than males with respect to all measured parameters, including mass and head size. Reproduction in females was strongly seasonal and clutch size was related to maternal body size. Prey items consisted of frogs, lizards and locusts.

2016 ◽  
Vol 130 (2) ◽  
pp. 146 ◽  
Author(s):  
William D. Halliday

Diet is an important aspect of the natural history of all animals, but diet can vary through space and time because of variations in prey availability. The diet of the Common Gartersnake (Thamnophis sirtalis) consists mainly of earthworms and frogs, but other prey items might be important when they are locally abundant. I report an observation of a female Eastern Gartersnake (Thamnophis sirtalis sirtalis) regurgitating 2 nestling birds in Ottawa, Ontario, Canada. Birds are seldom present in the diet of the Common Gartersnake. This rare food choice highlights the opportunistic nature of foraging by adult Common Gartersnakes and, further, demonstrates that diet depends not only on prey preference, but also on prey availability.


1972 ◽  
Vol 79 (3) ◽  
pp. 165-178 ◽  
Author(s):  
Allen M. Young

This paper summarizes the life cycle and some aspects of natural history of the tropical pierid, Dismorphia virgo (Dismorphiinae) in Costa Rica. The precise taxonomic status of the butterfly in Central America has not been established, and it may represent a variable northern isolate of the common South American D. critomedia. Therefore, independent of whether the Central American form discussed in this paper has achieved full species status as the more northern virgo or is a subspecies or variety of critomedia evolving towards species status, this paper provides new information on the biology of the butterfly in Costa Rica. The establishment of precise taxonomic position awaits further study, and for the present purpose, I refer to the butterfly as D. virgo.


2019 ◽  
Vol 116 (7) ◽  
pp. 2618-2623 ◽  
Author(s):  
Tai Kubo ◽  
Manabu Sakamoto ◽  
Andrew Meade ◽  
Chris Venditti

Terrestrial mammals have evolved various foot postures: flat-footed (plantigrady), tiptoed (digitigrady), and hooved (unguligrady) postures. Although the importance of foot posture on ecology and body size of mammalian species has been widely recognized, its evolutionary trajectory and influence on body size evolution across mammalian phylogeny remain untested. Taking a Bayesian phylogenetic approach combined with a comprehensive dataset of foot postures in 880 extant mammalian species, we investigated the evolutionary history of foot postures and rates of body size evolution, within the same posture and at transitions between postures. Our results show that the common ancestor of mammals was plantigrade, and transitions predominantly occurred only between plantigrady and digitigrady and between digitigrady and unguligrady. At the transitions between plantigrady and digitigrady and between digitigrady and unguligrady, rates of body size evolution are significantly elevated leading to the larger body masses of digitigrade species (∼1 kg) and unguligrade species (∼78 kg) compared with their respective ancestral postures [plantigrady (∼0.75 kg) and digitigrady]. Our results demonstrate the importance of foot postures on mammalian body size evolution and have implications for mammalian body size increase through time. In addition, we highlight a way forward for future studies that seek to integrate morphofunctional and macroevolutionary approaches.


2009 ◽  
Vol 49 (4) ◽  
pp. 881-885 ◽  
Author(s):  
Toby Richards ◽  
Asela Dharmadasa ◽  
Rachael Davies ◽  
Michael Murphy ◽  
Rafael Perera ◽  
...  

PEDIATRICS ◽  
1965 ◽  
Vol 36 (2) ◽  
pp. 191-191
Author(s):  
JOHN L. GREEN

This is a neatly organized, practical medical text written in easily understandable language covering the major physical and emotional problems of school-age children. The eighteen chapters review for non-medical personnel each organ system of the body including the special senses; there are sections, too, on the physical, emotional, intellectual, and social maturation of children. The appendices outlining the latest recommended immunization schedules and the essential information concerning the natural history of the common communicable diseases are complete and up to date.


Author(s):  
Kenji Yoshino ◽  
Manato Nagayoshi ◽  
Masanori Sato ◽  
Toshiya Katano ◽  
Yuji Ito ◽  
...  

The life history of the Japanese sternaspid polychaeteSternaspis costatavon Marenzeller, 1879 was investigated in the inner part of Ariake Bay from May 2010 to May 2011, with additional sampling in July and September 2011. All the worms were measured by the width of the ventral shield (WS) as an indicator of body size, and their coelomic contents were also examined. Ovigerous females occurred throughout the year, except during October and March, with the highest ovigerous rate (number of ovigerous females/number of adults with a WS larger than that of the smallest ovigerous female, i.e. 1.8 mm) noted in September (43.8% in 2010, 34.7% in 2011). The ovigerous rate was less than 10% in the other months, except in April 2011 (30%). Although the coelomic oocytes ranged from 90 to 160 μm in diameter, the diameters of most of the oocytes were 140–160 μm in September. The number of adults drastically decreased from September to October, suggesting that most of the adults died after spawning in the major reproductive period, although a small fraction of adults seemed to reproduce earlier or later. A cohort of recruits with an approximately 1.2 mm WS was identified in March and April. Most of the recruits grew to adult size in July–September, when many ovigerous females occurred. These results indicated that this species is fundamentally semelparous, with longevity around 1 year, and they mostly reproduce in September, with a few adults reproducing almost throughout the year.


2019 ◽  
Vol 99 (06) ◽  
pp. 1363-1377 ◽  
Author(s):  
Uliana A. Nekliudova ◽  
Ksenia V. Shunkina ◽  
Alexey V. Grishankov ◽  
Marina A. Varfolomeeva ◽  
Andrey I. Granovitch ◽  
...  

AbstractQuantifying interconnected performances of the modules in a colonial organism (feeding, sexual reproduction, rejuvenation, dormancy) into an integral picture enables studying functional dynamics and resource allocation at different levels – from module to population. Testing this approach on the common boreal-Arctic bryozoan Cribrilina annulata in the White Sea, we describe its life history, comparing colonies on two algal substrates with contrasting size and lifespan. Colonies living on kelps were much larger and had a higher proportion of dormant zooids, whereas the percentage of reproducing, feeding and rejuvenating zooids was higher in colonies on red algae (with the colonies also exhibiting longer reproductive period). Colony lifespan was dependent both on substrate type and on time of colony establishment, lasting from 4–5 to up to 17 months on kelps and 14–18 months on red algae. During the reproductive season (May–September) the C. annulata population consisted of colonies of three cohorts on both substrata: overwintered and two summer generations that behaved differently. Whereas overwintered and summer colonies established in June–early August produced larvae, most of the colonies established after mid-summer were preparing for hibernation and postponed reproduction until next spring. Moreover, young reproducing colonies formed brooding hermaphrodite zooids of ordinary size, whereas overwintered colonies budded smaller-sized basal and frontal (dwarf) hermaphrodites. Finally, overall zooidal performance in co-existing colonies of the overwintered and young generations was different on kelps, but similar on red algae. Altogether our findings indicate that the life histories of colonial epibionts are much more complex and evolutionarily flexible than generally acknowledged.


The Lancet ◽  
1949 ◽  
Vol 253 (6541) ◽  
pp. 71-75 ◽  
Author(s):  
C.H. Andrewes

2021 ◽  
pp. 6-11
Author(s):  
LUIS ORTIZ-CATEDRAL

Cannibalism is a common behaviour among snakes, but it has not yet been verified for any of the nine species of Galápagos racer (Pseudalsophis spp.), a group endemic to the Galápagos archipelago, Ecuador. Galápagos racers are opportunistic generalists feeding on a variety of vertebrate prey. There are a few anecdotal and suspected attempts of cannibalism among Galápagos racers, but it is unclear whether this behaviour occurs and if so, how frequent it is. We analysed 61 faecal samples from western Galápagos racers (Pseudalsophis occidentalis). In addition to the remains of well known prey items such as lizards, we found snake teeth and skin fragments in 11 samples. Combined with previous observations of attempted cannibalism between western Galápagos racers, our results represent evidence that this species consumes other racers as prey. Our study contributes to a growing knowledge of the natural history of Galápagos racers and highlights the role of these reptiles in complex trophic interactions in the Galápagos islands.


Sign in / Sign up

Export Citation Format

Share Document