Ecology of Frillneck Lizards, Chlamydosaurus-Kingii (Agamidae), in Tropical Australia

1989 ◽  
Vol 16 (5) ◽  
pp. 491 ◽  
Author(s):  
R Shine ◽  
R Lambeck
Keyword(s):  
Activity Patterns ◽  
Common Species ◽  
Body Temperatures ◽  
Wet Season ◽  
Ambient Temperatures ◽  
Air Temperatures ◽  
Highly Correlated ◽  
Vantage Points ◽  
Reproductive Cycles ◽  
Free Ranging

Radiotelemetric monitoring of 18 free-ranging frillneck lizards in Kakadu National Park, combined with dissection of museum specimens, provided extensive data on the natural history and general ecology of this large and spectacular lizard. Activity patterns and reproductive cycles are highly seasonal, with lizards inactive during the drier (and cooler) months of the year. Frillnecks are primarily arboreal and are relatively unselective with regard to the species of tree used except that one common species, Eucalyptus confertyora, is avoided. Telemetered lizards usually clung to branches high in the canopy. During the mating season (November-December), males had larger activity ranges than did females (means of 2.5 vs 0.7 ha) and made longer daily movements (means of 69 vs 23 m). Frillneck lizards bask briefly in the morning, but body temperatures follow ambient temperatures for most of the day. Thermal heterogeneity in the lizards' habitat is low, so opportunities for behavioural regulation (especially reduction) of body temperature are limited. Body temperatures are highly correlated with air temperatures and are often close to 40�C. Female frillnecks are considerably smaller than males, and they produce 4-13 eggs during the wet season. Chlamydosaurus are apparently unique among reptiles in using bipedal locomotion during routine foraging. These lizards are 'sit and wait' predators, descending from arboreal vantage points to seize lepidopteran larvae or massed swarms of hymenopteran or isopteran alates. Many different types of insects are eaten, but vertebrate prey items are rarely taken.

scholarly journals Contrasting capabilities of two ungulate species to cope with extremes of aridity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Melinda Boyers ◽  
Francesca Parrini ◽  
Norman Owen-Smith ◽  
Barend F. N. Erasmus ◽  
Robyn S. Hetem
Keyword(s):  
Climate Change ◽  
High Water ◽  
Future Climate Change ◽  
Body Temperatures ◽  
Wet Season ◽  
Trade Off ◽  
Ambient Temperatures ◽  
Mammalian Herbivores ◽  
Dry Seasons ◽  
Connochaetes Taurinus

AbstractSouthern Africa is expected to experience increased frequency and intensity of droughts through climate change, which will adversely affect mammalian herbivores. Using bio-loggers, we tested the expectation that wildebeest (Connochaetes taurinus), a grazer with high water-dependence, would be more sensitive to drought conditions than the arid-adapted gemsbok (Oryx gazella gazella). The study, conducted in the Kalahari, encompassed two hot-dry seasons with similar ambient temperatures but differing rainfall patterns during the preceding wet season. In the drier year both ungulates selected similar cooler microclimates, but wildebeest travelled larger distances than gemsbok, presumably in search of water. Body temperatures in both species reached lower daily minimums and higher daily maximums in the drier season but daily fluctuations were wider in wildebeest than in gemsbok. Lower daily minimum body temperatures displayed by wildebeest suggest that wildebeest were under greater nutritional stress than gemsbok. Moving large distances when water is scarce may have compromised the energy balance of the water dependent wildebeest, a trade-off likely to be exacerbated with future climate change.

Behavioural ecology ofTropidurus hispiduson isolated rock outcrops in Amazonia

1996 ◽  
Vol 12 (1) ◽  
pp. 81-101 ◽  
Author(s):  
Laurie J. Vitt ◽  
Peter A. Zani ◽  
Janalee P. Caldwell
Keyword(s):  
Observational Studies ◽  
Activity Period ◽  
Microhabitat Use ◽  
Body Temperatures ◽  
Insect Larvae ◽  
Wet Season ◽  
Rock Outcrops ◽  
Air Temperatures ◽  
Mean Size ◽  
Northern Brazil

ABSTRACTA population of the tropical lizardTropidurus hispidus, isolated on a granitic rock outcrop in tropical forest of northern Brazil, was studied during the 1993 wet season. Four types of observational studies revealed that lizards are active throughout most of the day. During 10-minute intervals, individual lizards moved five times for an average of 240 cm and tongue-flicked once. Habitat temperatures vary considerably during the day, with rock and air temperatures in sun exceeding body temperatures of lizards during much of the activity period. During most of the day, lizards thermoregulate by moving among shady, filtered sun, and sunny microhabitats maintaining body temperatures near 35°C. Temperatures of lizards active during cloudy periods were significantly lower than temperatures of lizards during sunny periods, indicating that clouds decrease the ability of lizards to effectively thermoregulate. Most feeding occurs in the afternoon at edges of rock outcrops with ants, insect larvae, termites and beetles dominating the diet. Comparisons with a near-by savanna population revealed differences in body size (males only), activity period (longer on rocks), body temperatures (higher on rocks), number of prey categories consumed (lower on rocks), mean size of prey (larger on rocks), number of prey eaten (fewer on rocks) and microhabitat use (more restricted on rocks).

scholarly journals Spatial ecology of hatchling water pythons (Liasis fuscus) in tropical Australia

2009 ◽  
Vol 25 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Lígia Pizzatto ◽  
Thomas Madsen ◽  
Gregory P. Brown ◽  
Richard Shine
Keyword(s):  
Habitat Use ◽  
Spatial Ecology ◽  
Radio Telemetry ◽  
Soil Surface ◽  
Primary Method ◽  
Body Temperatures ◽  
Wet Season ◽  
Air Temperatures ◽  
Tropical Australia ◽  
Soil Cracks

Abstract:Young snakes are rarely seen in the field and little is known about their habits, mostly because they are too small for radio-telemetry (the primary method for studying snake spatial ecology). However, the offspring of some larger species can be fitted with transmitters and we investigated the spatial ecology and habitat use of ten hatchling water pythons (Liasis fuscus: Pythonidae) in the floodplain of the Adelaide River, tropical Australia. Patterns of habitat use in the late wet season and during the dry season were similar to those of adults tracked in the same vicinity in an earlier study. Soon after release the young snakes moved to the floodplain, avoiding pasture areas. Diurnal refuge sites were typically in the base of grass clumps or below the soil surface, especially in sites with thick vegetation and deep, wide soil cracks. Adult snakes are more sedentary but move longer absolute distances (mean ± SE = 252 ± 50 m wk−1) than hatchlings (66.3 ± 41 m wk−1). However, hatchling snakes moved longer distances relative to body size (84.4 ± 1.1 body lengths wk−1) than did the previously studied adults (66.0 ± 1.1 body lengths wk−1). Mean and minimum body temperatures of the hatchlings were correlated with mean and minimum air temperatures, respectively.

scholarly journals Patterns of activity and inactivity in echidnas (Tachyglossus aculeatus) free-ranging in a hot dry climate: correlates with ambient temperature, time of day and season

2002 ◽  
Vol 50 (5) ◽  
pp. 461 ◽  
Author(s):  
P. H. Brice ◽  
G. C. Grigg ◽  
L. A. Beard ◽  
J. A. Donovan
Keyword(s):  
Ambient Temperature ◽  
Activity Patterns ◽  
Time Of Day ◽  
Temperature Sensitive ◽  
Ambient Temperatures ◽  
Radio Transmitters ◽  
Stevenson Screen ◽  
Hot Weather ◽  
Free Ranging ◽  
Temperature Time

Echidnas occur throughout Australia. They exhibit daily fluctuations in body temperature (Tb) and use torpor to various degrees throughout much of their range. Echidnas elsewhere are commonly diurnal except during hot weather. This study used temperature-sensitive radio-transmitters to investigate the activity patterns and temperature relations of echidnas in the relatively hot, dry climate of south-west Queensland with respect to temperature and photoperiod. During activity, echidnas were characterised by rising, but not necessarily high, Tbs. Activity was seen only within an ambient temperature range (as measured in a nearby Stevenson Screen: Tss) of 9–33�C so that activity was seen during the day and at night during the cool weather but only at night in summer. Echidnas used caves, burrows and logs when inactive. Tbs of inactive echidnas declined except when affected by rising ambient temperatures, as determined within these shelters (Ta). In summer, Tbs of echidnas in these shelters changed little or rose with increasing Ta to levels even higher than in active echidnas.Torpor was used by echidnas for periods up to nine days during winter and occasionally for up to one day during summer. Due to the difficulty of identifying the occurrence of torpor from Tb alone in warm conditions, the possibility that echidnas utilise torpor for less than one day remains inconclusive. Nevertheless, at least five bouts of torpor were identified in four (of eight) echidnas during winter/spring and two bouts of torpor from two echidnas in summer.

scholarly journals Foraging Ecology and Diurnal Activity Patterns of Klipspringer (Oreotragus oreotragus) in Yetefet Woyenat Forest, East Gojjam, Ethiopia

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Melaku Bireda ◽  
Mesele Yihune
Keyword(s):  
Foraging Ecology ◽  
Activity Patterns ◽  
Early Morning ◽  
Visual Observation ◽  
Diurnal Activity ◽  
Wet Season ◽  
Ambient Temperatures ◽  
Dry Seasons ◽  
Trees And Shrubs ◽  
Wet And Dry Seasons

The foraging ecology and diurnal activity patterns of the klipspringer (Oreotragus oreotragus) were studied in Yetefet Woyenat Forest from September 2017 to August 2018 during the dry and wet seasons. Data were collected by visual observation using focal and scan sampling methods. The result indicated that klipspringers were observed feeding on grasses, herbs, trees, and shrubs, but were primarily browsers during both wet and dry seasons. Carissa edulis was the most consumed plant species in the study area, followed by Rosa abyssinica and Maytenus arbutifolia. Despite moderate ambient temperatures, klipspringers were mostly active during early morning and late afternoon, feeding 45.56% of the daylight hours during the dry season and 43.75% during the wet season. Klipspringers were facing threats due to human activities in the study area. Thus, appropriate conservation measures should be taken to reduce disturbance of their ecology.

Radiotelemetry of body temperatures of free-ranging snapping turtles (Chelydra serpentina) during summer

1990 ◽  
Vol 68 (8) ◽  
pp. 1659-1663 ◽  
Author(s):  
Gregory P. Brown ◽  
Ronald J. Brooks ◽  
James A. Layfield
Keyword(s):  
Body Temperature ◽  
Chelydra Serpentina ◽  
Body Temperatures ◽  
Mean Body Temperature ◽  
Mean Temperature ◽  
Snapping Turtles ◽  
Air Temperatures ◽  
Foraging Tactics ◽  
The Mean ◽  
Free Ranging

We wished to determine whether free-ranging snapping turtles (Chelydra serpentina) would use aquatic and atmospheric basking to maintain body temperature at the mean temperature (28–30 °C) selected by snapping turtles placed in a controlled aquatic thermal gradient. Body temperatures from eight adult snapping turtles in three different lakes in Algonquin Provincial Park were monitored by radiotelemetry during July and August 1987. Mean body temperature of all eight turtles over the study period was 22.7 °C, and mean temperature of every individual was well below the reported mean selected temperature for this species. The turtles did not maintain body temperatures near the available maximum environmental temperature. The mean body temperatures of the turtles were not significantly different among the three study lakes although these lakes had different physical characteristics. Similarly, there were no significant differences, among individual turtles, between air temperatures or operative environmental temperatures recorded concurrently with their body temperatures Nevertheless, mean body temperatures differed significantly among individuals; foraging tactics, metabolic rates, and home range structure may account for these differences.

The reproductive cycles and geographical distribution of some common eastern Australian prosobranchs (Mollusca: Gastropoda)

1974 ◽  
Vol 25 (1) ◽  
pp. 63 ◽  
Author(s):  
AJ Underwood
Keyword(s):  
Reproductive Cycle ◽  
Common Species ◽  
Food Sources ◽  
Southern Limit ◽  
Air Temperatures ◽  
Eastern Australia ◽  
Planktotrophic Larvae ◽  
The Times ◽  
Reproductive Cycles ◽  
Spawning Periods

The taxonomic positions and Australian distributions of 10 common species of intertidal prosobranchs from eastern Australia were established from museum collections and published records. Patellanax peroni (Blainville), Subninella undulata (Solander) and Littorina unifasciata Gray have a southern distribution (from latitude 43� 30'S.) reaching as far north as 26� S., but not to the tropic of Capricorn. Austrocochlea constricta (Lamarck), Nerita atramentosa Reeve and Bembicium nanum (Lamarck) have the same southern limit as the former species but extend northwards to the tropic of Capricorn. Montfortula rugosa (Quoy & Gaimard) and Cellana tramoserica (Sowerby) extend further north to northern Queensland (17�S.). Nodilittorina pyramidalis (Quoy & Gaimard) and Morula marginalba Blainville have a northern distribution, occurring throughout the Pacific, and extend southwards to southern New South Wales (37� 30'S.). These four types of distribution are briefly discussed in relation to the Australian faunistic provinces. Monthly samples from March 1972 to May 1973 of the ovaries of the 10 species were fixed for examination by light microscopy. The numbers of immature and mature oocytes were recorded to establish the times and seasonal duration of gametogenesis, vitellogenesis and spawning. The time of spawning for most species was confirmed from the presence on the shore of egg capsules or newly settled juveniles. The external appearance of male and female gonads proved unreliable for estimation of the phases of reproductive cycle. The 10 species showed a wide variety of pattern and timing of reproductive cycle at one locality, which did not correlate with their overall geographical distributions, zonation pattern on the shore or phylogenetic relationships. The possible importance of seawater and air temperatures as stimuli for initiation and cessation of phases of the reproductive cycles is discussed. Some species are influenced by temperature changes. The spawning periods of N. pyramidalis, L. unifasciata, M. marginalba and B. nanum fell within the period of maximum availability of phytoplankton (August to March). All these species have long-term planktotrophic larvae. With the possible exception of Nerita atramentosa, which breeds during the same period as the previous species, all the other species are archaeogastropods with short-term lecithotrophic larvae, which are independent of the availability of phytoplankton food sources. Austrocochlea constricta breeds throughout the year, Patellanax peroni either from June to September or from February to May. Cellana tramoserica breeds from March to October and Subninella undulata and Montfortula rugosa from October/November to May. All of the archaeogastropods, especially Patellanax peroni, retain unshed mature oocytes from one year to the next. Nodilittorina pyramidalis, Littorina unifasciata, Bembicium nanum, Nerita atramentosa and Morula marginalba all show cytolysis and resorption of unshed oocytes.

scholarly journals Multi-species and multi-tissue methylation clocks for age estimation in toothed whales and dolphins

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Todd R. Robeck ◽  
Zhe Fei ◽  
Ake T. Lu ◽  
Amin Haghani ◽  
Eve Jourdain ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Age Estimation ◽  
Species Conservation ◽  
Genome Wide ◽  
Epigenetic Aging ◽  
Highly Correlated ◽  
Methylation Patterns ◽  
Cg Dinucleotides ◽  
Free Ranging ◽  
Unique Species

AbstractThe development of a precise blood or skin tissue DNA Epigenetic Aging Clock for Odontocete (OEAC) would solve current age estimation inaccuracies for wild odontocetes. Therefore, we determined genome-wide DNA methylation profiles using a custom array (HorvathMammalMethyl40) across skin and blood samples (n = 446) from known age animals representing nine odontocete species within 4 phylogenetic families to identify age associated CG dinucleotides (CpGs). The top CpGs were used to create a cross-validated OEAC clock which was highly correlated for individuals (r = 0.94) and for unique species (median r = 0.93). Finally, we applied the OEAC for estimating the age and sex of 22 wild Norwegian killer whales. DNA methylation patterns of age associated CpGs are highly conserved across odontocetes. These similarities allowed us to develop an odontocete epigenetic aging clock (OEAC) which can be used for species conservation efforts by provide a mechanism for estimating the age of free ranging odontocetes from either blood or skin samples.

Phenological development and seasonal distribution of the rutherglen bug, Nnysius vinitor Bergroth (Hemiptera: Lygaeidae), on various hosts in Victoria, south-eastern Australia

1988 ◽  
Vol 78 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Garrick McDonald ◽  
A. Mark Smith
Keyword(s):  
Rapid Development ◽  
Early Spring ◽  
Common Source ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Polygonum Aviculare ◽  
Developmental Thresholds ◽  
Eastern Australia ◽  
Weed Hosts ◽  
Maximum Temperatures

AbstractPopulations of Nysius vinitor Bergroth were studied from 1979 to 1982 in two weed hosts, Arctotheca calendula and Polygonum aviculare, and eight irrigated sunflower crops in a summer cropping area of northern Victoria, Australia. The spring generation began with the adults colonizing flowering A.calendula plants in September and concluded with the rapid development of late stage nymphs and an exodus of adults from these plants from mid-November to December. Gradual invasion of sunflowers occurred mostly in late December and reached a peak at flowering, after which nymphs appeared. P. aviculare attracted adults from February and hosted a number of overlapping generations until winter. The weed sustained diminishing numbers of adults through the winter, except in 1982, when a further generation produced an early spring peak. Immigrant populations were regarded as a common source of adults for initiating the spring and summer generations. The rate of development of N. vinitor in spring was more rapid than that predicted by phenological simulation based on ambient temperatures and laboratory-derived day-degree estimates. This was attributed to increased body temperatures through absorption of solar radiation, and the simulation model was adjusted by increasing daily minimum and maximum temperatures by 1·3 and 5·5°C for young and older instars, respectively. This suggested that older nymphs have lower developmental thresholds or are better able to optimize body temperatures.

scholarly journals Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Growing Season ◽  
Near Surface ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Filling Method ◽  
Highly Correlated

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.

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