The Canadian Field-Naturalist (E-Journal)
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Sighting rates and prey of Minke Whales (Balaenoptera acutorostrata) and other cetaceans off Cormorant Island, British Columbia
Get PDFFrom June to August 2012, we conducted over 500 h of visual surveys from Cormorant Island, British Columbia, to determine behaviour and habitat use patterns of nearby cetaceans. Seven species were documented, but Minke Whales (Balaenoptera acutorostrata) were by far the most common and were observed lunge feeding at the surface on 15 occasions. In addition, this species was documented surface lunge feeding on Pacific Herring (Clupea pallasi) and Pacific Sand Lance (Ammodytes personatus) on 32 occasions during vessel-based cetacean surveys around Cormorant Island between 2010 and 2014. Although Minke Whales are relatively uncommon in British Columbia, these results indicate that they can regularly be found in specific feeding areas during the summer
A reconnaissance survey for Collared Pika (Ochotona collaris) in northern Yukon
Get PDFCollared Pika (Ochotona collaris) is a cold-adapted Beringian species that occurs on talus slopes and is sensitive to climate warming. Collared Pikas are patchily distributed throughout the sub-Arctic mountains of northwestern Canada and Alaska; however, information on their occurrence in the northern part of their distributional range is limited. In particular, no survey information is known from the southern Richardson Mountains and the Nahoni Mountains. We conducted aerial- and ground-based surveys to document Collared Pika occurrence and general habitat suitability in northern Yukon. We flew 505 km of aerial survey (not including ferrying to targetted survey areas) and performed ground surveys at 22 sites within the Richardson Mountains (including a portion of Dàadzàii Vàn Territorial Park) and the Nahoni Mountains in and adjacent to Ni’iinlii Njik (Fishing Branch) Territorial Park. Overall, suitable habitat for Collared Pikas was patchy in the mountains of northern Yukon—talus was sparse and many patches of talus appeared to be unsuitable. Collared Pikas were detected at eight of 22 (36%) sites visited, representing important new records for the species in the northern portion of their range. Our reconnaissance provides a first approximation of habitat suitability for Collared Pikas of the mountains of northern Yukon, as well as new records for the species in the region. These data are useful in better determining the contemporary distribution of Collared Pika through species distribution modelling, and may serve to identify areas for more detailed survey and monitoring initiatives for this climate-sensitive mammal
Duckling mortality at a river weir
Get PDFRiver weirs are low-head dams that dissipate energy by creating hydraulic recirculation zones at their base. These recirculation zones are a major cause of human drownings and have been referred to as “drowning machines”. We observed an event that allowed us to add ducklings to the list of weir victims. As a Mallard (Anas platyrhynchos) hen and her brood floated over the Calgary weir, the mother flew safely over the hydraulic recirculation. The ducklings drifted into the recirculation and three quickly passed through; four were stalled, repeatedly recirculated, and died. We observed other regional weirs where adult birds commonly flew over the hazard. We did not observe any other waterfowl drifting into recirculation zones, and we found no prior report of this lethal hazard. Although mortality might be rare at each weir, with hundreds of thousands of low-head dams worldwide, the collective hazard could be substantial. Weirs can be designed to eliminate the lethal recirculation zone, and the apparent hazard to ducklings could provide another motivation to redesign or modify these common structures
"The Ascent of Birds: How Modern Science is Revealing Their Story" by John Reilly, 2018. [book review]
No full text"Immersion: The Science and Mystery of Freshwater Mussels" by Abbie Gascho Landis, 2017. [book review]
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Book Reviews of "The New Beachcomber’s Guide to the Pacific Northwest", "A Field Guide to Marine Life of the Protected Waters of the Salish Sea", and "A Field Guide to Marine Life of the Outer Coasts of the Salish Sea and Beyond"
No full textBook Reviews of:1) "The New Beachcomber’s Guide to the Pacific Northwest" by J. Duane Sept, 2019.2) "A Field Guide to Marine Life of the Protected Waters of the Salish Sea" by Rick M. Harbo, 2019.3) "A Field Guide to Marine Life of the Outer Coasts of the Salish Sea and Beyond" by Rick M. Harbo, 2019.
