Temperature and site selection by Blanding’s Turtles (Emydoidea blandingii) during hibernation near the species’ northern range limit

2009 ◽  
Vol 87 (9) ◽  
pp. 825-834 ◽  
Author(s):  
C. B. Edge ◽  
B. D. Steinberg ◽  
R. J. Brooks ◽  
J. D. Litzgus
Keyword(s):  
Dissolved Oxygen ◽  
Water Depth ◽  
Respiratory Acidosis ◽  
Ice Cover ◽  
Range Limit ◽  
Emydoidea Blandingii ◽  
Northern Range Limit ◽  
Overwintering Survival ◽  
Prolonged Dormancy ◽  
Selection Of

Many animals that live in northern climates enter a state of prolonged dormancy during winter. These animals possess a suite of physiological and behavioural adaptations that minimize threats to survival while overwintering. There are three major threats to overwintering survival: metabolic and respiratory acidosis, freezing, and predation. Selection of hibernation sites should minimize these threats. We monitored dissolved oxygen, water depth, and temperature at overwintering locations of Blanding’s Turtles ( Emydoidea blandingii (Holbrook, 1838)) and at stations located haphazardly in six different habitat types over two winters in Algonquin Park, Ontario, Canada. Water depth and dissolved oxygen in overwintering sites used by turtles were similar to those measured at haphazard stations. In contrast, estimated turtle body temperatures (~0 °C) were significantly lower and less variable than water temperatures measured at haphazard stations. These data and those reported elsewhere suggest that there are two alternatives for selection of suitable hibernacula by anoxia tolerant turtles. In areas where there is periodic access to aerial oxygen, turtles select sites where ice cover may not be present for the entire winter, but in areas where ice cover restricts access to air, turtles select sites where water temperatures are close to 0 °C.

scholarly journals Blanding's Turtle, Emydoidea blandingii, Habitat Use During Hibernation in Eastern Ontario

2010 ◽  
Vol 124 (3) ◽  
pp. 263 ◽  
Author(s):  
David C. Seburn
Keyword(s):  
Habitat Use ◽  
Range Limit ◽  
Emydoidea Blandingii ◽  
Blanding's Turtle ◽  
Northern Range Limit ◽  
Eastern Ontario ◽  
Blanding’S Turtle

Seven Blanding's Turtles (Emydoidea blandingii) were followed using radiotelemetry to determine their habitat use during hibernation near Ottawa, Ontario. During May to August, five of the seven turtles occupied wetlands in which they would eventually hibernate. The turtles hibernated in five different wetlands: three in Organic Shallow Marsh Ecosites and two in Organic Thicket Swamp Ecosites. One Blanding's Turtle over-wintered in a temporary marsh that did not form until October. Blanding's Turtles do not appear to be limited in their choice of suitable hibernation sites even near the northern range limit of the species.

Green Turtles Nesting at Their Northern Range Limit in the United States Represent a Distinct Subpopulation

2018 ◽  
Vol 17 (2) ◽  
pp. 314 ◽  
Author(s):  
Brian M. Shamblin ◽  
Matthew H. Godfrey ◽  
S. Michelle Pate ◽  
William P. Thompson ◽  
Hope Sutton ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Range Limit ◽  
Green Turtles ◽  
Distinct Subpopulation ◽  
Northern Range Limit

Breeding behaviour of ectotherms at high latitudes: the case of the natterjack toad Epidalea calamita at its northern range limit

Behaviour ◽  
2021 ◽  
pp. 1-20
Author(s):  
Linda Saare ◽  
Riinu Rannap
Keyword(s):  
Climatic Conditions ◽  
Energetic Cost ◽  
Breeding Period ◽  
High Latitudes ◽  
Range Limit ◽  
Photo Identification ◽  
Breeding Behaviour ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Northern Range Limit

Abstract We explored the breeding behaviour of a threatened amphibian, the natterjack toad, at its northern range limit in Estonia, to determine the extent to which reproduction is affected by harsh and unstable climatic conditions. Using photo identification of specimens, we found that in optimal weather conditions males formed three breeding cohorts, while in adverse conditions only a single cohort occurred and under extreme conditions reproduction was skipped entirely. During the extended breeding season, larger males participated in reproduction throughout the breeding period, while smaller males appeared in later cohorts. Breeding success was related to the calling effort of a male, where larger males had greater mating success than smaller ones. We found that the natterjack toad males exhibit significant plasticity in reproductive behaviour at the northern range limit, which, given the energetic cost of reproduction and the increased risk of predation, allows them to increase their fitness at high latitudes.

scholarly journals Frontier mutualism: coevolutionary patterns at the northern range limit of the leaf-cutter ant–fungus symbiosis

2011 ◽  
Vol 278 (1721) ◽  
pp. 3050-3059 ◽  
Author(s):  
Ulrich G. Mueller ◽  
Alexander S. Mikheyev ◽  
Scott E. Solomon ◽  
Michael Cooper
Keyword(s):  
Range Limits ◽  
Peripheral Populations ◽  
Range Limit ◽  
Long Distance ◽  
Dispersal Barrier ◽  
The Andes ◽  
Genetic Patterns ◽  
Northern Range Limit ◽  
Traditional Assumption ◽  
Ant Fungus

Tropical leaf-cutter ants cultivate the fungus Attamyces bromatificus in a many-to-one, diffuse coevolutionary relationship where ant and fungal partners re-associate frequently over time. To evaluate whether ant– Attamyces coevolution is more specific (tighter) in peripheral populations, we characterized the host-specificities of Attamyces genotypes at their northern, subtropical range limits (southern USA, Mexico and Cuba). Population-genetic patterns of northern Attamyces reveal features that have so far not been observed in the diffusely coevolving, tropical ant– Attamyces associations. These unique features include (i) cases of one-to-one ant– Attamyces specialization that tighten coevolution at the northern frontier; (ii) distributions of genetically identical Attamyces clones over large areas (up to 81 000 km 2 , approx. the area of Ireland, Austria or Panama); (iii) admixture rates between Attamyces lineages that appear lower in northern than in tropical populations; and (iv) long-distance gene flow of Attamyces across a dispersal barrier for leaf-cutter ants (ocean between mainland North America and Cuba). The latter suggests that Attamyces fungi may occasionally disperse independently of the ants, contrary to the traditional assumption that Attamyces fungi depend entirely on leaf-cutter queens for dispersal. Peripheral populations in Argentina or at mid-elevation sites in the Andes may reveal additional regional variants in ant– Attamyces coevolution. Studies of such populations are most likely to inform models of coextinctions of obligate mutualistic partners that are doubly stressed by habitat marginality and by environmental change.

Rule based control of a periodic activated sludge process

1998 ◽  
Vol 38 (3) ◽  
pp. 281-289 ◽  
Author(s):  
S. Isaacs ◽  
D. Thornberg
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Control Strategy ◽  
Periodic Operation ◽  
Rule Based ◽  
Criterion Functions ◽  
Strategy Performance ◽  
Working Region ◽  
And Control ◽  
Selection Of

A rule based control strategy for automatically adjusting phase lengths and aeration intensity for an activated sludge nutrient removal process based on a periodic operation is examined using simulations based on the Activated Sludge Model No. 1. The strategy is based on four criterion functions, two which determine the switching of the roles of two nitrifying/denitrifying reactors and two which adjust the dissolved oxygen setpoint levels in the two reactors as functions of ammonia and nitrate concentrations. Trajectory plots of reactor concentrations in the ammonia-nitrate plane are shown to be a useful means of visualizing process and control performance. Together, the trajectories from a working region in the ammonia-nitrate plane, the size and location of which can to some extent be predetermined by selection of the criterion functions. The presented results include the influence of one of the criterion functions on control strategy performance, how an incompatibility between two criterion functions can lead to unsymmetric reactor loading, and the effect of allowing simultaneous nitrification and denitrification during nitrifying periods by reducing the dissolved oxygen level as ammonia is consumed.

Living on the edge: Fig tree phenology at the northern range limit of monoecious Ficus in China

2014 ◽  
Vol 57 ◽  
pp. 135-141 ◽  
Author(s):  
Lu-Shui Zhang ◽  
Stephen G. Compton ◽  
Hui Xiao ◽  
Qian Lu ◽  
Yan Chen
Keyword(s):  
Range Limit ◽  
Tree Phenology ◽  
Northern Range Limit ◽  
Fig Tree

scholarly journals Variable habitat selection and movement patterns among Bullsnake (Pituophis catenifer sayi) populations in Saskatchewan

2019 ◽  
Vol 132 (2) ◽  
pp. 126-139 ◽  
Author(s):  
Tera L. Edkins ◽  
Christopher M. Somers ◽  
Mark C. Vanderwel ◽  
Miranda J. Sadar ◽  
Ray G. Poulin
Keyword(s):  
Habitat Selection ◽  
Radio Telemetry ◽  
Geographic Location ◽  
Space Use ◽  
Fine Scale ◽  
Range Limit ◽  
Northern Range Limit ◽  
Range Overlap ◽  
Conservation Concern ◽  
River Valleys

Pituophis catenifer sayi (Bullsnake) is a sparsely studied subspecies of conservation concern in Canada. Basic ecological information is lacking for P. c. sayi, which reaches its northern range limit in western Canada. To address this gap, we used radio-telemetry to examine space use and habitat selection in three populations of Bullsnakes in disjunct river valley systems (Frenchman, Big Muddy, and South Saskatchewan River Valleys) across their Saskatchewan range. Bullsnakes in two valleys used up to three times more space, travelled 2.5-times farther from overwintering sites, and had lower home range overlap than the third population. Landscape-level habitat selection was flexible, with snakes in all populations using both natural and human-modified habitats most frequently. Fine-scale habitat selection was also similar among populations, with Bullsnakes selecting sites within 1 m of refuges, regardless of whether they were natural or anthropogenic. Based on these results, Bullsnakes are flexible in their broad scale habitat use, as long as they are provided with fine scale refuge sites. The distribution of key seasonal resources appears to ultimately determine space use and habitat selection by Bullsnakes, regardless of the geographic location of the population.

scholarly journals Oxygen depletion in subarctic peatland thaw lakes

2017 ◽  
Vol 3 (2) ◽  
pp. 406-428 ◽  
Author(s):  
Bethany N. Deshpande ◽  
Frédéric Maps ◽  
Alex Matveev ◽  
Warwick F. Vincent
Keyword(s):  
Dissolved Oxygen ◽  
Ice Cover ◽  
Oxygen Depletion ◽  
Freshwater Ecosystems ◽  
In Situ Sensors ◽  
Modelling Studies ◽  
Bottom Waters ◽  
Bacterial Decomposition ◽  
Permafrost Thawing ◽  
Thaw Lakes

Permafrost thawing and erosion results in the enrichment of northern lakes by soil organic matter. These allochthonous inputs favour bacterial decomposition and may cause the draw-down of dissolved oxygen to anoxic conditions that promote methanogenesis. Our objective in the present study was to determine the seasonal variations in dissolved oxygen in a set of permafrost peatland lakes in subarctic Quebec, Canada, and to relate these changes to metabolic rates, ice cover, and mixing. The lakes had high dissolved organic carbon concentrations, and their surface waters in summer had greenhouse gas concentrations that were up to one (CO2) to three (CH4) orders of magnitude above air-equilibrium values, indicating their strongly heterotrophic character. Consistent with these observations, the peatland lakes had elevated rates of bacterial production and oxygen consumption. Continuous measurements of oxygen by in situ sensors and of ice cover by automated field cameras showed that the lakes became fully anoxic shortly after freeze-up. The waters were partially re-oxygenated by mixing events in spring and fall, but in one lake, the bottom waters remained anoxic throughout the year. These observations provide a foundation for subsequent biogeochemical and modelling studies of peatland thaw lakes as an abundant class of Arctic freshwater ecosystems.

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