The Canadian Field-Naturalist (E-Journal)
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Status, distribution, and nesting ecology of Snapping Turtle (Chelydra serpentina) on Cape Breton Island, Nova Scotia, Canada
Get PDFBased on current knowledge of the ecology and distribution of Snapping Turtle (Chelydra serpentina), both in eastern Canada and elsewhere, we conclude this species is native to Cape Breton Island. Seventy-two reports of Snapping Turtle from Cape Breton (1999–2017) indicate a range centred in the area south of Bras d’Or Lake. Date of oviposition ranged from 19 June to 10 July (median = 26 June) among 26 nests observed during 2012–2014. Clutch size for these nests was 23–65 eggs (mean = 46) and among 25 protected nests average rate of hatchling emergence was 21.5%. Time from oviposition to emergence of hatchlings (n = 256) was 75–120 days (mean = 87.2; SD = 9.0) among 20 nests. First emergence ranged from 9 September to 20 October (75–114 nest days; mean = 90) and last emergence ranged from 13 September to 28 October (86–120 nest days; mean = 100). Duration of emergence ranged from one day (i.e., synchronous emergence; five nests) to 37 days (mean = 11 days). The number of days on which hatchlings emerged at a nest ranged from one to nine days (mean = 4 days). Maximum carapace length was 25.0–31.8 mm (mean = 29.0 mm) and maximum carapace width was 23.5–30.0 mm (mean = 27.0 mm) for 256 hatchlings that emerged from 20 protected nests. Mass of hatchlings was 4.9–9.9 g (mean = 7.8 g)
"Rise of the Necrofauna: The Science, Ethics and Risks of De-Extinction" by Britt Wray, 2017. [book review]
No full text"The Skeleton Revealed: An Illustrated Tour of the Vertebrates" by Steve Huskey, 2017. [book review]
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Ready for bed: pre-hibernation movements and habitat use by Fowler’s Toads (Anaxyrus fowleri)
Get PDFWe used radio-tracking to investigate movement patterns and habitat use of Fowler’s Toads (Anaxyrus fowleri) during late summer and early fall in a relatively undisturbed lakeshore dune and beach habitat at Long Point, Ontario. Small radio transmitters were fitted to 11 adult toads with an external harness made from fine surgical plastic tubing wrapped around the body behind the front limbs. We located radio-tagged toads morning and evening, for a maximum of 9 days, recording their locations using Global Positioning System units. Initially, the toads were located on the upper beach or in the fore-dunes during the day, either dug in under the sand or hiding beneath debris; in the evening, they were generally active on the lower beach close to the water line. After a storm and the onset of cooler autumn weather, the toads tended to move further from the water line. They also curtailed their nightly activity and retreated deeper into the sand. As this sort of behaviour was not observed during the summer, we interpret it as pre-hibernation movement to more stable sites away from the beach where the animals can burrow deeply into the sand to lie dormant during the winter
The observed decline of Western Toads (Anaxyrus boreas) over several decades at a novel winter breeding site
Get PDFThe Western Toad (Anaxyrus boreas) population of the Atlin Warm Springs in northwestern British Columbia has persisted since at least 1924. An extraordinary feature of the population has been winter breeding in late February to early March, while nearby cold-water populations breed in late-May. Metamorphosis of tadpoles, enhanced by the warm water, occurs as early as late-March. In 2008, Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) was documented in toadlets at the warm springs. Until 2005, as many as eight egg clutches and 25 breeding adults had been observed at the warm springs, after which the population declined. In 2017, novel spring breeding occurred in a cooler pond in the spring complex. Future observations will help determine whether the population is recovering and whether breeding phenology and habitat use have changed
Observations of Beachcast Bowhead Whales (Balaena mysticetus) in the Southeastern Beaufort Sea and Amundsen Gulf, 1987–2016
Get PDFEach spring, most Bowhead Whales (Balaena mysticetus) of the Bering-Chukchi-Beaufort (BCB) population migrate to the Canadian Beaufort Sea and Amundsen Gulf for summer feeding. Occasionally, Inuvialuit hunters and others observe beachcast (stranded) or adrift Bowhead Whale carcasses. From 1987 to 2016, 26 such occurrences were recorded. Most (65%) were found by Inuvialuit hunters travelling on the land, with the majority (54%) reported during 2000–2006. Bowhead Whale carcasses were found widely distributed throughout the region, with twice as many in Amundsen Gulf (65%) compared with the southeastern Beaufort Sea (35%). It was possible to measure or estimate standard length for 17 of 26 specimens, and all were either provisional ‘subadults’ (7–9.5 m; n = 10; 59%) or provisional ‘mature adults’ (13–16 m; n = 7; 41%). The cause(s) of mortality was not determined for any of the specimens. Whales in the ‘subadult’ group were likely 1–4 years old, while the ‘mature adult’ group were likely mostly mature animals (~25 y), including some potentially very old (>100 y). There was evidence or direct observation of Polar Bears (Ursus maritimus) and/or Grizzly Bears (U. arctos) scavenging at 60% of the carcasses for which presence or absence of bears or bear sign (scats and/or tracks) was reported. It is important to continue to record incidental observations of beachcast Bowhead Whales, as this may enable stranding rates to be evaluated
