The Canadian Field-Naturalist

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2021-06-23T09:01:07-07:00

News and Comment

2021-06-22T20:50:06-07:00

A tribute to Arthur T. Bergerud, 1930–2019

2021-06-16T09:55:20-07:00

Additions to the lichens, allied fungi, and lichenicolous fungi of the Ottawa region in Ontario and Quebec, with reflections on a changing biota

2020-05-29T09:18:29-07:00

The inventory of lichens, allied fungi, and their parasites in the Ottawa region has grown from 391 in 1988 to 543 today, almost entirely because of the discovery of species overlooked in previous years and the inclusion of fungal parasites. In addition, almost 140 names have changed with reclassifications and re-identifications. These changes are presented here together with a list of synonyms updating the 1988 list. Vouchers are cited for all new records, and notes are presented for many species neither described nor keyed out in easily accessible literature. Reference is made to the new, complete list of lichens and lichenicolous fungi available online. The new checklist includes one species new for North America (Tremella christiansenii); five species and one variety new for Canada (Caloplaca parvula, Caloplaca reptans, Cladonia petrophila, Enchylium tenax var. ceranoides, Leprocaulon adhaerens, and Merismatium peregrinum); four new for Ontario (Caloplaca reptans, Kiliasia tristis, Lempholemma chalazanum, and Rinodina fimbriata); and nine new for Quebec (Arthonia helvola, Arthonia hypobela, Caloplaca parvula, Cladonia petrophila, Lempholemma chalazanum, Leprocaulon adhaerens, Merismatium peregrinum, Rimularia badioatra, and Tremella christiansenii). Although the climate of the region is warming, especially with higher minimum temperatures in winter, the lichen biota has not increased as a result but, in fact, may be threatened by the effects of climate change on the health of the forests and the trees that support lichens. Air quality has improved in recent decades, allowing numerous lichens to again become established in urban areas. Local areas of especially rich lichen diversity can be found on both the Ontario and Quebec sides of the region, and some of these “hot-spots” are mentioned. Other factors influencing the decrease or increase of lichen cover are also discussed.

Loon abundance and behaviour over four decades at a remote ecological reserve on Haida Gwaii, British Columbia, Canada

2020-12-17T11:34:45-08:00

Early studies (1976–1982) of the Drizzle Lake Ecological Reserve on Haida Gwaii, British Columbia focussed on the endemic Giant Threespine Stickleback (Gasterosteus aculeatus) and their predators. These surveys showed daily visits to the small lake (110 ha) by up to 59 adult non-breeding Common Loon (Gavia immer), an important stickleback predator and up to 19 breeding and non-breeding adult Red-throated Loon (Gavia stellata), which leave daily to forage in nearby marine waters. We continued loon surveys for 17 additional years (1983–1989, 2011–2020) and found that aggregations of non-breeding Common Loons occurred annually on the lake during July with maximum daily numbers of 78–83 individuals in 1987, 2018, and 2020 and a large increase from 2011 to 2020. We did not detect any relationship of these differences with the Pacific Decadal Oscillation but a significant inverse correlation with average wind speed. Average yearly numbers of Red-throated Loons declined by 50% from 1976 to 1989 and have remained low, with lowest numbers (<2) occurring in 2017. Two Red-throated Loon nesting territories on the lake were occupied from 1976 to 1995, with chicks occurring in 24 of 36 nests, but no successful nesting was observed on the lake over the last decade. The relative decline of Red-throated Loon in this reserve is similar to that reported in Arctic and Subarctic surveys of the species in the north Pacific and northern Europe. We discuss the implications for the evolutionary ecology of the sticklebacks and the conservation of the ecological reserve.

Timing of pair formation and male acquisition of alternate plumage by three wintering dabbling ducks

2020-10-03T13:42:18-07:00

Pair formation in ducks is thought to be influenced by the acquisition of breeding plumage, the occurrence of courtship display, or both. We examined the frequency of pair formation in Mallard (Anas platyrhynchos), Green-winged Teal (Anas crecca carolinensis), and Northern Shoveler (Spatula clypeata) in the central valley of California in relation to the frequencies of male attainment of breeding plumage and courtship display. Predictions related to two hypotheses are: (1) the timing of pair formation is directly related to the attainment of breeding (definitive alternate) plumage by males, and (2) frequencies of courtship display are highest during pair formation. Most female Mallard were paired by the end of October, with >80% in pairs by early December. Of Northern Shoveler, 90% were paired by early January and 90% of female Green-winged Teal were paired by early February. The highest rates of courtship display by Mallard were observed during October through November, by Northern Shoveler in November, and by Green-winged Teal in November through January. Courtship display was, therefore, relatively frequent at the same time as pair formation for all three species. Northern Shoveler spent less time in courtship display than the other two species. Most (90%) male Mallard had acquired alternate plumage by mid-November, Northern Shoveler by early February, and Green-winged Teal by mid-December. Thus, timing of pair formation coincided with timing of attainment of breeding plumage in Mallard and Green-winged Teal but not Northern Shoveler.

Terrestrial dispersal of juvenile Mink Frog (Lithobates septentrionalis) in Algonquin Provincial Park, Ontario

2020-12-10T14:41:38-08:00

Dispersal following metamorphosis is critical for sustaining anuran metapopulations. Mink Frog (Lithobates septentrionalis) is a primarily aquatic species that is common in eastern Canada. The species is not well studied, and little is known about the terrestrial dispersal of recently metamorphosed individuals. Here we present our observations on the phenology of terrestrial activity in recently metamorphosed Mink Frogs in Algonquin Provincial Park, Ontario, Canada. Despite a sampling effort of over 26 000 trap nights over two years (2010 and 2011) in an area with a known population of Mink Frogs, we observed only 35 individuals, all of which were recent metamorphs, in late summer 2011, suggesting annual variability of recruitment. Because all Mink Frogs were observed in a riparian area, it is likely that this species uses riparian corridors to disperse toward other wetlands, thus avoiding forested areas.

Use of Whitebark Pine (Pinus albicaulis) seeds by GPS-collared Grizzly Bears (Ursus arctos) in Banff National Park, Alberta

2020-07-21T13:39:16-07:00

Seeds of Whitebark Pine (Pinus albicaulis) are a major food for Grizzly Bears (Ursus arctos) in the Yellowstone ecosystem. In Canada, Grizzly Bears are known to eat Whitebark Pine seeds, but little additional information, such as the extent of such use and habitat characteristics of feeding sites, is available. Because Grizzly Bears almost always obtain Whitebark Pine seeds by excavating cones from persistent caching sites (middens) made by Red Squirrels (Tamiasciurus hudsonicus), it is possible to infer Whitebark Pine feeding when bears are located near excavated middens in Whitebark Pine stands. During 2013–2018, I conducted a retrospective study in Banff National Park using data from 23 Grizzly Bears equipped by Parks Canada staff with global positioning system (GPS) collars. My objectives were to use GPS fixes to determine the percentage of these bears that had been located in close proximity to excavated middens containing Whitebark Pine seeds and to describe the habitat at these excavated middens. I linked 15 bears (65%) to excavated middens and, by inference, consumption of Whitebark Pine seeds. Excavated middens occurred on high-elevation (mean 2103 ± 101 [SD] m), steep (mean 26° ± 8°) slopes facing mostly (96%) north through west (0–270°). Use of Whitebark Pine seeds by at least 65% of the 23 studied Grizzly Bears suggests that conservation of Whitebark Pine in Banff National Park would concomitantly benefit the at-risk population of Grizzly Bears.

Further occurrences of melanism in a northern, peripheral, population of Bobcat (Lynx rufus)

2020-07-27T11:43:06-07:00

Although melanism is understood to occur commonly among some felids, it is reported to be most frequent among cat species that occur in humid, tropical, and densely vegetated habitats. Previously, a single record of a melanistic Bobcat (Lynx rufus) from eastern Canada (New Brunswick) appeared to be a northern outlier, with all other reports of melanism in this species restricted to the warm, humid, climate of southern peninsular Florida. Here, I document a further five occurrences of melanism in Bobcat from New Brunswick and review evidence that a mutation in an agouti-signalling protein gene may be responsible for melanism in New Brunswick Bobcats.

Predation of a brown bat (Vespertilionidae) by a Green Frog (Lithobates clamitans) in Ontario, Canada

2020-09-30T12:21:36-07:00

On 31 July 2019, a Green Frog (Lithobates clamitans) was observed consuming a Big Brown Bat (Eptesicus fuscus) at Meux Creek, Neustadt, Ontario. The bat was likely roosting at a nearby undercut bank when it was predated by the frog, which required nearly 90 min to consume its prey. This is the first record of a Green Frog consuming a bat species in Canada.

Changes to the Book Reviews and New Titles Sections

2021-06-22T20:55:59-07:00

"Flora of Oregon. Volume 1: Pteridophytes, Gymnosperms, and Monocots" edited by Stephen C. Myers, Thea Jaster, Katie E. Mitchell, and Linda K. Hardiston, 2015; and "Flora of Oregon. Volume 2: Dicots Aizoaceae - Fagaceae" edited by Stephen C. Myers, Thea Jaster, Katie E. Mitchell, Tanya Harvey, and Linda K. Hardiston, 2020. [book review]

2021-06-22T21:01:20-07:00

"Herbarium: The Quest to Preserve & Classify the World’s Plants" by Barbara M. Thiers, 2020. [book review]

2021-06-22T21:07:18-07:00

"Grassroots Stewardship: Sustainability Within Our Reach" by F. Stuart Chapin, III, 2020. [book review]

2021-06-22T21:10:17-07:00

"Primer of Ecological Restoration" by Karen D. Holl, 2020. [book review]

2021-06-22T21:13:06-07:00

"Pollinators & Pollination: Nature and Society" by Jeff Ollerton, 2021. [book review]

2021-06-22T21:16:45-07:00

"Essential Ornithology. Second Edition" by Graham Scott, 2020. [book review]

2021-06-22T21:19:34-07:00

"Flights of Passage: An Illustrated Natural History of Bird Migration" by Mike Unwin and David Tipling, 2020. [book review]

2021-06-22T21:23:46-07:00

"The Biology of Moult in Birds" by Lukas Jenni and Raffael Winkler, 2020. [book review]

2021-06-22T21:36:14-07:00

"The World in a Grain: The Story of Sand and How It Transformed Civilization" by Vince Beiser, 2018. [book review]

2021-06-22T21:39:23-07:00

New Titles

2021-06-22T21:41:57-07:00

Draft Minutes of the 142nd Annual Business Meeting (ABM) of the Ottawa Field-Naturalists’ Club, 12 January 2021

2021-06-22T20:30:37-07:00

Annual Reports of OFNC Committees for October 2019–September 2020

2021-06-22T20:45:03-07:00

The Ottawa Field-Naturalists’ Club Awards for 2020

2021-06-22T20:35:37-07:00

Cover

2021-06-22T21:44:31-07:00