The Canadian Field-Naturalist

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2022-08-05T07:17:49-07:00

A tribute to George W. Scotter, 1933–2021

2022-06-09T20:51:52-07:00

A tribute to James Edwin Cruise, Ph.D., L.L.D., 1925–2021

2022-02-20T14:23:14-08:00

Cover

2022-07-29T17:16:21-07:00

"A Trillion Trees: Restoring Our Forests by Trusting in Nature" by Fred Pearce, 2022. [book review]

2022-07-29T17:04:14-07:00

New Titles

2022-07-29T17:07:05-07:00

A highly anomalous Red-winged Blackbird (Agelaius phoeniceus) song

2021-12-04T03:00:07-08:00

Red-winged Blackbird (Agelaius phoeniceus) is a highly vocal species with a repertoire of similar, yet acoustically distinct songs. These songs may be altered drastically if, as a nestling, the male goes deaf or becomes acoustically isolated. In deaf Red-winged Blackbirds, these dramatic song alterations may present as songs bearing slight resemblance to the introductory phrase of their normal song. Here, we present a Red-winged Blackbird song observed in Ottawa, Ontario, Canada, that is far outside any normal variation in Red-winged Blackbird songs. Given the individual’s age and the consistency of the anomalous song, it is possible that this is a deaf bird.

First report of Eastern Red-backed Salamander (Plethodon cinereus) on Newfoundland

2021-08-10T06:44:49-07:00

The island of Newfoundland has no native amphibian taxa, although six species of Anura (i.e., frogs and toads) have been introduced since European colonisation, four of which have established self-sustaining populations. Here, we document Eastern Red-backed Salamander (Plethodon cinereus) on Newfoundland for the first time, in what appears to be a self-sustaining population near Conception Bay South. This is the first species of Caudata (i.e., newts and salamanders) to have been introduced to the island, as well as the first occurrence of Eastern Red-backed Salamander establishing a population outside its native range. The impact that this non-native species might have on forest ecosystems on Newfoundland is unclear and further study is required to determine whether eradication of the species from Newfoundland is necessary or feasible.

Key observations of flexed-leg urination in the free-ranging Gray Wolf (Canis lupus)

2021-08-09T08:35:49-07:00

Flexed-leg urination (FLU) in female Gray Wolves (Canis lupus) has been little studied in the wild. Captive females in packs do not exhibit FLU unless they are both mature and dominant to an associate female, but these characteristics have not been confirmed in free-ranging wolves. We present observations of wolves in Yellowstone National Park that accord with those of wolves in captivity, extend our knowledge of FLU in Gray Wolf, pose additional questions about it, and suggest new areas of study to better understand it.

A male Little Brown Myotis (Myotis lucifugus) recaptured after 28 years at the same site in southwest Saskatchewan, Canada

2021-11-19T05:16:18-08:00

Little Brown Myotis (Myotis lucifugus) is one of the most common and widely distributed mammals in Canada and has been recorded to live over 30 years in the wild. As part of a long-term bat research project in Cypress Hills Interprovincial Park, Saskatchewan, we recaptured a male Little Brown Bat in a mist net over Battle Creek on 12 June 2021. The bat was recaptured within 100 m of where it was first captured and banded as an adult in 1993, indicating that this bat was at least 29 years old and exhibited repeated use of the same summer flying, foraging, and drinking site. The bat was not caught in the intervening years; therefore, its frequency of use of this site is unknown. In eastern North America, this species has declined because of high mortality rates associated with White-nose Syndrome (WNS). WNS has been moving westward and has now been detected in eastern and western Saskatchewan. Understanding aspects of the natural history of Little Brown Bat, including longevity, is important before WNS is detected in a region and leads us to advocate continued marking of individuals (e.g., banding, PIT tagging) to continue learning about bat longevity and survival before and after WNS infection.

Raven (Corvus corax) as a novel food item for lynx (Lynx canadensis)

2021-08-04T06:31:38-07:00

Canada Lynx (Lynx canadensis) is a specialist predator of Snowshoe Hare (Lepus americanus), which dominates its diet. However, hare populations cycle over 9–11 years, and many lynx disperse or starve during cyclic lows of their prey. Here, I report observations of Canada Lynx scavenging and attempting to prey on Common Raven (Corvus corax). In addition, I provide a brief review of birds as a food item of lynx. These are the first observations of ravens as a food source for lynx and may be a response to lynx being malnourished. The value of these observations is that they highlight the adaptability of some lynx to opportunistically use novel prey species during the decline phase of cyclic Snowshoe Hare.

First record of Azalea Sawfly (Euura lipovskyi, Hymenoptera: Tenthredinidae) in Canada

2021-09-09T13:16:01-07:00

Azalea Sawfly (Euura lipovskyi) larvae found feeding on foliage and flowers of cultivated Flame Azalea (Rhododendron calendulaceum) in Ottawa, Ontario, in late May 2021 are the first records of this sawfly in Canada. The native range of Azalea Sawfly includes the eastern United States, but the species has extended its distribution recently to the Pacific northwest of North America and Europe. Recorded foodplants include Rhododendron calendulaceum, Rhododendron luteum, Rhododendron obtrusum, Rhododendron occidentale, Rhododendron molle, Rhododendron viscosum, and possibly Early Azalea (Rhododendron prinophyllum), all in Rhododendron section Pentanthera. The new combinations Euura lipovskyi and Euura azaleae are proposed.

Apparent wing-assisted incline running in a Common Grackle (Quiscalus quiscula)

2021-10-23T05:41:16-07:00

Wing-assisted incline running (WAIR) has been observed in bird taxa from multiple clades. Its wide phylogenetic distribution in modern birds suggests that it is an ancestral trait for class Aves. WAIR as a behaviour is speculated to predate the evolution of full-powered flight, and to have formed a behavioural and physiological stepping stone between terrestrial and aerial life. Here I report an observation of apparent WAIR in a Common Grackle (Quiscalus quiscula) photographed incidentally on a trail camera deployed in an urban backyard in Guelph, Ontario, Canada. To my knowledge this is the first documented observation of apparent WAIR for the family Icteridae. Furthermore, it highlights the value of non-systematic use of trail cameras for making unique natural history observations.

News and Comment

2022-07-29T17:18:40-07:00

Serum biochemistry suggests a physiological response to environmental stress in a native urban Eastern Gray Squirrel (Sciurus carolinensis) population

2021-07-08T08:13:43-07:00

Urban wildlife populations experience human-driven environmental changes that can be both beneficial and detrimental to individual health. We measured body condition and serum chemistry (electrolyte levels, markers of kidney and liver function, protein, glucose, and cholesterol) in a native urban and rural population of Eastern Gray Squirrel (Sciurus carolinensis) to assess whether we could detect physiological responses to environmental stressors or dietary differences. We found no differences in body condition between habitats and no evidence of malnutrition at either site. However, urban squirrels had higher blood glucose, lower potassium, phosphorus, chloride, and albumin:globulin ratios. These results align with previous findings of increased dietary sugar in cities and suggest that urban populations of gray squirrels are under greater environmental stress than rural populations, providing future directions for studying physiological responses to urbanization.

Foraging patterns vary with the degree of sociality among Common Loon (Gavia immer) overwintering on a freshwater lake

2021-07-30T07:28:34-07:00

Little is known about the behaviour of Common Loon (Gavia immer) during the critical overwintering period, let alone the behaviour of the small, but increasing number of loons that overwinter on freshwater lakes in North America. We examined the diurnal time-activity budgets of Common Loon overwintering on a large reservoir in northwest South Carolina between 2018 and 2020. Similar to previous studies of breeding individuals and individuals that overwinter in marine waters, loons (n = 132) overwintering on this reservoir spent most of their time (52%) foraging. However, we found distinct differences in the activity budgets of individuals associated with their degree of sociality. Solitary birds (individuals spending 0–20% of time within 20 m of conspecifics) spent significantly more time foraging than did those that were either loosely-social (>20–<70% of time within 20 m of conspecifics) or strongly-social (70–100% of time). Although solitary loons made as many foraging dives as social birds, their dives were much longer, likely reflecting dives for larger predatory fish. In contrast, social individuals made much shorter, shallower dives, often foraging on shallower baitfish that they appear to pursue to the water surface and consume collectively. Such findings add to our understanding of loon winter behaviour and raise interesting questions regarding social behaviour and the short- and long-term trade-offs associated with social foraging in this species.

The Ottawa Field-Naturalists’ Club Awards for 2021, presented February 2022

2022-07-29T17:00:31-07:00

Draft Minutes of the 143rd Annual Business Meeting (ABM) of the Ottawa Field-Naturalists’ Club, 11 January 2022

2022-07-29T16:47:57-07:00

Annual Reports of OFNC Committees for October 2020–September 2021

2022-07-29T16:55:57-07:00