scholarly journals Spatial ecology and multi-scale habitat selection by Western Painted Turtles (Chrysemys picta bellii) in an urban area

2019 ◽  
Vol 132 (2) ◽  
pp. 108-119
Author(s):  
Kelsey A. Marchand ◽  
Christopher M. Somers ◽  
Ray G. Poulin

As urban centres expand, knowledge on the habitat and space use of native wildlife, particularly long-lived species, is required for proper management. Our objective was to understand space requirements and key habitat features necessary for long-term persistence of Western Painted Turtles (Chrysemys picta bellii) living in a Canadian urban park. Using radio telemetry, we examined seasonal habitat selection and space use over two years, 2015–2016 (n = 23), and 2016–2017 (n = 29) in Regina, Saskatchewan. Daily movements and home ranges of males and females were smaller during emergence than during nesting or post-nesting phases of the active season. Turtles inhabiting marsh sites had 2- and 4-times larger daily movements and home ranges compared to turtles inhabiting the creek. Turtles selected the shoreline habitat over urban/parkland and open water. Turtles used marsh-shoreline habitats non-randomly, selecting accessible shoreline with large trees in the active season. In contrast, turtles used creek-shoreline habitat according to availability. Overwintering sites selected by turtles were warmer and deeper than random available sites, with no difference in dissolved oxygen level. However, water was hypoxic for most overwintering sites. Our results show that turtles range widely, requiring 20–60 ha throughout the year. Urban park areas should be managed to provide accessible shorelines with a combination of cover and open basking areas. Critically, careful attention needs to be paid to managing water depth so that over-wintering sites remain viable.

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Malle F Carrasco-Harris ◽  
Dale Bowman ◽  
Steve Reichling ◽  
Judith A Cole

Abstract Urban forests and parks are important for recreation and may serve as a natural corridor for commuters. The consequences of human-mediated disturbance in natural areas are documented for avian and mammalian species. Less is known about the consequences of human disturbance on reptile species, specifically snakes, residing in natural refuges within the urban matrix. Thus, we examined the spatial activity of copperheads (Agkistrodon contortrix) in regard to pedestrian trails within an urban forest. We used radio telemetry to track snakes during the active season and estimated distances moved in between relocations, distances to the nearest trail and home range size for individuals. We found sex and season, but not distance to the nearest trail, affected the distance snakes moved. In addition, we observed a weak, positive relationship between home range size and average distance to the trail. Sex, season and body condition did not explain snake distance to the trail, but individual patterns were variable for snakes compared to random locations generated from snake relocations. Our study indicates copperheads may be tolerant of low-level human disturbances found in an urban forest. Further work should be done to quantify levels of disturbance, such as trail use, and compare the behavior of reptiles across urban park types and locations.


2021 ◽  
Author(s):  
Sarah L. Alderman ◽  
Claire L. Riggs ◽  
Oliver Bullingham ◽  
Todd E. Gillis ◽  
Daniel E. Warren

AbstractWestern painted turtles (Chrysemys picta bellii) are the most anoxia-tolerant tetrapod. Survival time improves at low temperature and during ontogeny, such that adults acclimated to 3°C survive far longer without oxygen than either warm-acclimated adults or cold-acclimated hatchlings. Since protein synthesis is rapidly suppressed to save energy at the onset of anoxia exposure, this study tested the hypothesis that cold-acclimation would evoke preparatory changes in protein expression that would support enhanced anoxia survival in adult but not hatchling turtles. To test this, adult and hatchling turtles were acclimated to either 20°C (warm) or 3°C (cold) for 5 weeks, and then the heart ventricles were collected for quantitative proteomic analysis using labeled isobaric tags and mass spectrometry. The relative abundances of 1316 identified proteins were compared between temperatures and developmental stages. The effect of cold-acclimation on the cardiac proteome was most evident when life stage was included as a covariable, suggesting that ontogenic differences in anoxia tolerance may be predicated on successful maturation of the heart from its hatchling to adult form and, only after this maturation occurs, will cold-acclimation induce protein expression changes appropriate for supporting heart function during prolonged anoxia. The main differences between the hatchling and adult cardiac proteomes reflect an increase in metabolic scope that included more myoglobin and increased investment in both aerobic and anaerobic energy pathways. Mitochondrial structure and function were key targets of life stage- and temperature-induced changes to the cardiac proteome, including reduced complex II proteins in cold-acclimated adults that may help down-regulate the electron transport system and avoid succinate accumulation during anoxia. Therefore, targeted cold-induced changes to the cardiac proteome may be a contributing mechanism for stagespecific anoxia tolerance in turtles.


2017 ◽  
Vol 65 (2) ◽  
pp. 77 ◽  
Author(s):  
Juan Lei ◽  
David T. Booth ◽  
Ross G. Dwyer

Nest predation is the main cause of hatch failure for many turtle populations. For loggerhead turtles (Caretta caretta) nesting at the Wreck Rock rookery, adjacent to Deepwater National Park in south-east Queensland, yellow-spotted goannas (Varanus panoptes) are the main nest predator. However, no studies have documented the space use of goannas in costal habitat adjacent to a sea turtle nesting beach. Here we used Global Positioning System data loggers to evaluate the spatial ecology of adult yellow-spotted goannas in order to discover their potential interaction with sea turtle nests. Male yellow-spotted goannas had larger home ranges, spent a greater proportion of their time in the beach dune area where sea turtles nest, and their home ranges overlapped with more sea turtle nests compared with females. Both males and females had a bimodal activity pattern, with peaks in activity in the early morning and mid to late afternoon. Examination of space-use patterns indicates that it is the larger male yellow-spotted goannas that are the main predators of sea turtle nests at the Wreck Rock beach-nesting aggregation. Hence, by inference, it is probable that large male yellow-spotted goannas are responsible for opening nests at other Australian mainland sea turtle beaches, and if a goanna-specific management strategy is implemented to control predation it is these large males that should be targeted.


1983 ◽  
Vol 61 (7) ◽  
pp. 1499-1509 ◽  
Author(s):  
Ross D. MacCulloch ◽  
D. M. Secoy

Western painted turtles from populations in the northern portion of their range attained greater sizes, had more rapid growth despite a shorter growing season, and appeared to mature at a larger size than turtles from farther south. Mean clutch size was 19.8, with no evidence of production of two clutches. Examination of stomach contents showed that the turtles were mainly carnivorous, even in areas of abundant vegetation. The carnivorous diet may account for the large sizes, large clutches, and rapid growth of the turtles and may permit C. picta to maintain populations farther north than other North American turtle species.


2012 ◽  
Vol 90 (3) ◽  
pp. 337-344 ◽  
Author(s):  
Amariah A. Lebsock ◽  
Christopher L. Burdett ◽  
Safi K. Darden ◽  
Torben Dabelsteen ◽  
Michael F. Antolin ◽  
...  

Space use is a fundamental characteristic that informs our knowledge of social relationships and the degree to which individuals are territorial. Until recently, relatively little was known about the spatial ecology and social organization of swift foxes ( Vulpes velox (Say, 1823)). We investigated space use of swift foxes on shortgrass prairie in northeastern Colorado. Our first objective was to evaluate sizes of seasonal and annual home ranges and core areas of 13 radio-collared swift foxes monitored continuously for 2 years. Our second objective was to compare home-range and core-area overlap of breeding pairs to that of neighboring foxes, including male–male, female–female, and nonbreeding female–male dyads. Home-range size in our study population was among the smallest previously reported for swift foxes. Males tended to have slightly larger home ranges and core areas than females, and home-range size was significantly larger in the breeding season than in both the pup-rearing and the dispersal seasons; sizes of core areas did not differ seasonally. Spatial overlap between breeding pairs was substantial, whereas spatial overlap between neighbors, particularly males, was low, suggesting territoriality.


1982 ◽  
Vol 97 (1) ◽  
pp. 87-99 ◽  
Author(s):  
G. R. Ultsch ◽  
D. C. Jackson

Western Painted Turtles, Chrysemys picta bellii (N = 5), were maintained submerged and apneic for 90 days: days 0–21 in severely hypoxic water (PO2 = 0-5 mmHg), days 22-43 in aerated water (PO2 approximately 160 mmHg), and days 44-90 again in hypoxic water. From day 90 onward, the water was aerated and the turtles were allowed access to the air; water and air temperatures were maintained at 3 degrees C. Arterial blood samples were taken periodically and analysed for PO2, PCO2, pH, [Na+], [K+] [Cl-], [lactate-], [glucose] and haematocrit. Plasma [HCO3-] was calculated for all samples and total plasma calcium was measured on samples from two animals. Each exposure to low PO2 water caused progressive lactic acidosis and a transient respiratory acidosis with an accompanying fall in plasma [Cl-] and rise in plasma [K+] and [calcium]. During the intervening period in aerated water, blood pH recovered significantly (from 7.33 to 7.74 in 7 days), due primarily to a fall in PCO2 (from 23.5 to 10.6 mmHg), while [lactate-] remained unchanged (at about 50 mM), and [HCO-3] rose slightly. Plasma [K+] promptly returned to nearly normal values. When permitted to breathe on day 90, the three surviving turtles rapidly restored pH to normal by pronounced hyperventilation (PCO2 less than 5 mmHg). Metabolic acidosis, however, disappeared slowly with a t1/2 for [lactate-] and [HCO-3] restoration of about 2 weeks. We conclude that a wintering turtle can stabilize or even slightly improve its acid-base and ionic status by moving from an anoxic environment to well-oxygenated water. Further improvements can be gained by breathing air, but recovery proceeds at a very slow rate if the animal remains at 3 degrees C.


2007 ◽  
Vol 85 (4) ◽  
pp. 526-535 ◽  
Author(s):  
A.L. Edwards ◽  
G. Blouin-Demers

Body temperature affects nearly all processes of ectotherms. Reptiles do not generate sufficient body heat to regulate their body temperature internally and therefore use behavioural thermoregulation. We determined whether thermoregulatory effort varied among seasons in an environment where large temporal differences in environmental temperatures (Te) exist. We took 31 297 internal body temperature (Tb) measurements from 18 painted turtles ( Chrysemys picta (Schneider, 1783)) throughout their active season. We estimated Te with physical models and water temperatures. We measured the range of preferred body temperatures (Tset) in a thermal gradient. Tset was 21.3–25.0 °C. We used Tb, Te, and Tset to calculate standard thermoregulation indices (Ex and de – db). An Ex of 40.7% and a de – db of 2.4 °C indicated that painted turtles are moderate thermoregulators, despite inhabiting a high-cost environment. Effort to regulate Tb increased as the thermal quality of the habitat decreased. Thermoregulatory effort was higher when Tset could not be achieved. Painted turtles put more effort in thermoregulation in the early season than in the rest of the season. This within-species pattern follows the pattern seen among species. This study is the first to measure Tb internally and to apply standard thermoregulation indices to free-ranging turtles.


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