Red Squirrel (Tamiasciurus hudsonicus) feeding on Balsam Poplar (Populus balsamifera) galls induced by aphids

Red Squirrel (Tamiasciurus hudsonicus) specializes in feeding on conifer cone seeds but will feed opportunistically on a wide variety of other food items, including fungi, eggs, small vertebrates, and invertebrates. In much of their range, Red Squirrels experience fluctuations in the availability of their primary diet (conifer seeds) seasonally and annually because of variation in seed production. We document a seemingly uncommon or unreported feeding behaviour by a Red Squirrel in a year of an exceedingly low conifer cone production in Yukon, Canada: a squirrel foraging for and feeding on aphids hidden within galls formed on Balsam Poplar (Populus balsamifera). We searched for community-reported observations of Red Squirrels through iNaturalist and found additional evidence of apparently similar gall feeding behaviour elsewhere in Canada. We estimate that aphids can be a substantial source of caloric energy for Red Squirrels. Our observation represents another example of the diet breadth of Red Squirrels during periods of low conifer seed availability

First records of the ant genus Dolichoderus (Hymenoptera: Formicidae) from Saskatchewan, Canada

We report the first provincial records of the genus Dolichoderus in Saskatchewan, represented by two species: Taschenberg’s Long-necked Ant (Dolichoderus taschenbergi) and Mary’s Long-necked Ant (Dolichoderus mariae). These species are previously known from eastern Canada and the eastern United States. The new discoveries fill in the range for D. taschenbergi, which has previously been found in Alberta and Manitoba, but has not been reported from Saskatchewan, and they represent a significant westerly range expansion of D. mariae, which has previously been reported in southeastern Manitoba and Ontario.

Declining population of Harlequin Duck (Histrionicus histrionicus) on the Bow River, Alberta, Canada: 25 years of monitoring: 25 years of monitoring

Harlequin Duck (Histrionicus histrionicus) is a small sea duck that winters in coastal waters and breeds on fast-movingmountain streams in western North America. Because of its dependency on streams and coastal near-shore habitat with healthy macroinvertebrate populations, population trends of this species can be used as an indication of healthy freshwater and marine ecosystems. From 1995 to 2020 we conducted roadside surveys for Harlequin Ducks on the Bow River in Banff National Park, Alberta. We calculated the population’s trend by modelling maximum annual count, which showed a population decline over the 25 years of 3.3% per year. The trajectory varied over time: a relatively stable population from 1995 to 2005, a steep decline until 2011, then stabilising at a much lower level with a slight rebound in recent years. The predicted number of ducks from our state-space model closely tracked the maximum number of ducks observed in annual counts. During stable or slightly increasing population estimates the male:female (M:F) ratio fluctuated considerably but stayed high (1.4:1 and 1.3:1, respectively), and during the period of steep population decline the M:F ratio was at its lowest (1.1:1). This declining population trend is concerning because it is occurring in a protected area, but it is similar to data from other studies in the Rocky Mountains and at the coastal wintering area, suggesting that causes may not be solely due to issues on the breeding streams