The Canadian Field-Naturalist

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2025-01-17T21:41:18-08:00

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2025-01-17T21:44:07-08:00

The “perrrck” vocalization of Ruffed Grouse (Bonasa umbellus)

2023-11-03T06:49:34-07:00

The vocal repertoire of Ruffed Grouse (Bonasa umbellus) has been known for decades, but because of the rarity of vocal recordings in the field, few data exist on spectral characteristics of their vocalizations. Here, we provide a spectrogram and analysis of a vocalization rarely heard in the field: the “perrrck” call, which is ~0.5 s in duration and has a fundamental frequency of 613 Hz with several harmonics. We compare this call with the more commonly heard “peet” call, which is much shorter and of higher frequency. Although the function of the perrrck call remains unknown, our analyses show that Ruffed Grouse vocalizations vary in frequency, despite their purportedly weak syrinx.

News and Comment

2025-01-17T21:38:47-08:00

A new species of testate amoeba, Arcella prismatica sp. nov. (Amoebozoa: Arcellinida), from peatlands in Ontario and Quebec, Canada

2023-06-07T12:34:15-07:00

Arcella is a genus of testate amoebae with a radially symmetrical shell composed of secreted material arranged in hexagonal units. Within the genus, species are distinguished by the morphology and dimensions of the shell. We describe a new species, Arcella prismatica sp. nov., discovered in a brown-water lake in the Mer Bleue Bog Conservation Area, a protected wetland in the city of Ottawa, Ontario, Canada. Specimens of the same morphotype have also been found in a subarctic peatland on the James Bay coast, near the village of Chisasibi, Quebec, Canada. The species has a polyhedral shell with a relatively flat dorsal surface and an irregularly crenulated aperture, a combination of characters not found in other members of the genus. The discovery of a novel and evidently widely distributed Arcella within the limits of a populous North American city is a reminder that the diversity of microbial eukaryotes is still poorly understood. Further exploration of undersampled peatland habitats can be expected to reveal new organisms and new relationships among known species.

Breeding pair and reproductive estimates of a recently expanded Red-necked Grebe (Podiceps grisegena) population in parkland Manitoba

2021-06-27T05:08:27-07:00

Conservation of wildlife populations requires reliable information on population size, trends, and demographic processes.
Such information is sparse for Red-necked Grebe (Podiceps grisegena), a species that is vulnerable to changing wetland conditions in the prairie pothole region. During 2008–2019, I collected breeding pair and reproductive estimates of a recentlyexpanded Red-necked Grebe population on 109 semi-permanent and permanent wetlands (mean ± SE: 2.92 ± 0.41 ha, range 0.01–24.2) in agriculturally-dominated habitat in southwestern Manitoba, Canada, to determine population status and reproductive success. I also looked for effects of changing wetland water levels and the presence of conspecifics and/or wetland size on productivity. Red-necked Grebe breeding densities were the highest reported for solitary-nesting pairs in North America and the breeding population currently appears to be stable. I found that chicks/breeding pair are mostly lower but chicks/successful pair are similar or greater than values reported from other studies. Pairs breeding with conspecifics appeared to be as productive as those on single-pair wetlands. Productivity was positively associated with wetland water levels suggesting that prolonged drought or climate change leading to warmer, drier summers on the prairies could reduce Rednecked Grebe breeding populations.

Barred Owl (Strix varia) activity and diet recorded with a camera trap at a natural cavity nest in Manitoba, Canada (2016–2017)

2023-01-12T10:07:58-08:00

Camera trap images (n = 27 092) collected at a natural Barred Owl (Strix varia) nest site in Manitoba, Canada, 2016–2019, were used to quantify nesting behaviour and identify prey delivered to the nest. Adult Barred Owl activity increased prior to egg laying and again after incubation. Adults were mostly active at night, but daytime activity increased during the nestling period in 2016 and more so with a larger brood in 2017. Nestlings were active at the nest entrance both day and night for 8–9 days prior to fledging at ≤27–32 d old. Two of three nestling activity peaks (0400 and 2000 Central Daylight Time [CDT]) corresponded to prey delivery activity peaks whereas a third (1200 CDT) did not. Only 31/65 prey were identified to species, but 12 new prey taxa were documented for Barred Owl in Manitoba. Activity at the cavity during the non-breeding season before and after a nest predation event were documented; the nest site was abandoned after an American Black Bear (Ursus americanus) visited the nest cavity in May 2018. Factors affecting the quality and quantity of images, and hence data obtained from them, included camera position relative to the nest cavity entrance, light levels, camera trigger speed, non-target species, and the configuration and settings of motion detection sensors. Improved camera traps may overcome these limitations. This is the first published study on this owl species using this increasingly popular technology.

Distribution and breeding potential of the exotic False Map Turtle (Graptemys pseudogeographica) in Canada

2023-07-14T08:42:01-07:00

False Map Turtle (Graptemys pseudogeographica) is widespread in the central United States, and its native range extends close to the Canadian border. It is common in the pet trade and has been released into the wild outside its native range. We examined observations of False Map Turtle from iNaturalist Canada, an online platform to document native and non-native species, and confirmed 20 observations in Canada from eight cities in three provinces. The earliest observation was in April 2014 from Victoria, British Columbia. Fourteen of the 20 observations (70%) were from 2020 to February 2024. All the turtles were either large juveniles or adults. Climate data from the northern part of the False Map Turtle’s native range and from Canadian cities suggest that individuals could survive the winter in parts of southern Canada and successfully breed in parts of southern Ontario during the warmest years.

The occurrence of introduced rosy red minnows (Pimephales promelas) in Alberta, Canada

2024-01-19T14:13:26-08:00

Rosy red minnows are a golden morph of Fathead Minnow (Pimephales promelas) commonly sold in pet shops and used, in some jurisdictions, as baitfish. They have formed several naturalized populations in British Columbia, where they are considered a priority conservation concern. The Government of Alberta had noted two occurrences of rosy red minnows in 2016 and 2017, but their identification could not be independently confirmed without photographic or physical vouchers. Based on our own collections, Royal Alberta Museum specimens, community science initiatives, and enquiries to other field researchers, we report that rosy red minnows have been present in Alberta earlier than previously thought, are likely breeding in Alberta, and have a widespread distribution from Fort McMurray to Lethbridge. Given that Alberta has native populations of wild-type Fathead Minnow, the impacts of rosy red minnows on native populations requires immediate attention.

Plural breeding in Gray Wolf (Canis lupus) packs: how often?

2024-07-18T08:41:50-07:00

The occurrence of more than a single female breeder in North American Gray Wolf (Canis lupus) packs, i.e., plural breeding, is well known, but its incidence has not been estimated since 1982. Using winter pack size as an index to plural breeding in
wolves, I reviewed the literature from North American populations least exploited by humans to assess the general incidence of plural breeding. Generally winter packs >15 were associated with incidents of plural breeding. Wolf packs preying primarily on White-tailed Deer (Odocoileus virginianus) and in locations south of 52°N latitude seldom exceeded 10–15. Plural breeding occurred in packs preying primarily on larger ungulates in areas mostly above 52°N. The estimated incidence of plural breeding in the overall wolf population was <15% and perhaps <10%, which is lower than a 1982 estimate of at least 20–40%. I discuss reasons why plural breeding is associated with larger prey.

Minutes of the 145th Annual Business Meeting (ABM) of the Ottawa Field-Naturalists’ Club, 10 January 2024 (draft)

2025-01-16T20:44:35-08:00

Annual OFNC Committee Reports for 2023

2025-01-16T20:53:41-08:00

The Ottawa Field Naturalists’ Club Awards for 2023, presented April 2024

2025-01-16T20:38:02-08:00

"The Power of Trees: How Ancient Forests Can Save Us if We Let Them" by Peter Wohlleben, translated by Jane Billinghurst, 2023, and "The Future is Now: Solving the Climate Crisis with Today’s Technologies" by Bob McDonald, 2022 [book review]

2025-01-14T20:45:30-08:00

"Ring of Fire: High-Stakes Mining in a Lowlands Wilderness" by Virginia Heffernan, 2023 [book review]

2025-01-14T20:49:35-08:00

"Beetles of the World: a Natural History. A Guide to Every Family Series" by Maxwell V.L. Barclay and Patrice Bouchard, 2023 [book review]

2025-01-14T20:53:16-08:00

"Essential Entomology. Second Edition" by George McGavin and Leonidas-Romanos Davranoglou, illustrations by Richard Lewington, 2022 [book review]

2025-01-14T20:56:43-08:00

"Flight Paths: How a Passionate and Quirky Group of Pioneering Scientists Solved the Mystery of Bird Migration" by Rebecca Heisman, 2023 [book review]

2025-01-14T20:59:33-08:00

"The Ecological Buffalo: on the Trail of a Keystone Species" by Wes Olson, photography by Johane Janelle, 2022 [book review]

2025-01-14T21:02:43-08:00

"Thinking Like a Wolf: Lessons from the Yellowstone Packs" by Rick McIntyre, foreword by Frans de Waal, 2024 [book review]

2025-01-14T21:05:42-08:00

New Titles

2025-01-14T20:39:15-08:00

A tribute to Allan Harvey Reddoch (1931–2023), Canadian orchidologist and conservationist

2024-12-18T21:35:38-08:00