Following Regulation, Imidacloprid Persists and Flupyradifurone Increases in Nontarget Wildlife.

After regulation of pesticides, determination of their persistence in the environment is an important indicator of effectiveness of these measures. We quantified concentrations of two types of systemic insecticides, neonicotinoids (imidacloprid, acetamiprid, clothianidin, thiacloprid, and thiamethoxam) and butenolides (flupyradifurone), in off-crop nontarget media of hummingbird cloacal fluid, honey bee (Apis mellifera) nectar and honey, and wildflowers before and after regulation of imidacloprid on highbush blueberries in Canada in April 2021. We found that mean total pesticide load increased in hummingbird cloacal fluid, nectar, and flower samples following imidacloprid regulation.

Quantifying phenology and migratory behaviours of hummingbirds using single-site dynamics and mark-detection analyses.

Nuanced understanding of seasonal movements of partially migratory birds is paramount to species and habitat conservation. Using nascent statistical methods, we identified migratory strategies of birds outfitted with radio-frequency identification (RFID) tags detected at RFID feeders in two sites in California, USA. We quantified proportions of migrants and residents and the seasonal phenology for each movement strategy in Allen's and Anna's hummingbirds; we also validated our methodology by fitting our model to obligate migratory black-chinned hummingbirds.

Bioaccumulation and effects of selenium from surface coal mining in an aquatic songbird.

Open-pit mining operations are hailed for safe working conditions for miners as well as economically and logistically favourable outcomes for mining companies. However, ecological impacts of these operations may persist for decades. Expansions of open-pit coal mining in British Columbia of Western Canada are planned.

Bluebirds Experience Impaired Hatching Success in Conventionally Sprayed Apple Orchard Habitats: A 31-Year Study.

We analyzed the reproductive success of eastern bluebirds (Sialia sialis) nesting in apple orchards and non-orchard nest-boxes in southern Ontario, Canada, from 1988 to 2018. Using data from 2397 nest-boxes monitored at 20 orchard sites and 52 non-orchard sites, we first modeled phenological parameters typically linked to climate change across both site types. We found that the first egg of each brood was laid significantly earlier in the season each year over our 31-year study.

Current contrasting population trends among North American hummingbirds.

As pollinators, hummingbirds play a critical role for both the function of ecological communities and in providing ecosystem services for people. To examine the conservation status of North American hummingbirds, we analyzed Breeding Bird Survey data for 8 species and 3 genera from 1970 to 2019 (long-term) and from 2009 to 2019 (short-term, approximately three generations). Among the Selasphorus genus, Allen's, rufous, and broad-tailed hummingbirds have declined since 1970, and the rate of decline increased from 2009 to 2019.

Neonicotinoid pesticides exert metabolic effects on avian pollinators.

Neonicotinoids are neurotoxic systemic insecticides applied extensively worldwide. The impacts of common neonicotinoids like imidacloprid on non-target invertebrate pollinators have been widely studied, however effects on vertebrate pollinators have received little attention. Here, we describe the first study evaluating the effects of short-term (3 d) exposure to a range of environmentally relevant concentrations ([Formula: see text] to [Formula: see text]Body Weight) of imidacloprid on wild-caught ruby-throated hummingbirds.

MicroRNAs regulate survival in oxygen-deprived environments.

Some animals must endure prolonged periods of oxygen deprivation to survive. One such extreme model is the northern crayfish (), that regularly survives year-round hypoxic and anoxic stresses in its warm stagnant summer waters and in its cold, ice-locked winter waters. To elucidate the molecular underpinnings of anoxia resistance in this natural model, we surveyed the expression profiles of 76 highly conserved microRNAs in crayfish hepatopancreas and tail muscle from normoxic, acute 2 h anoxia, and chronic 20 h anoxia exposures.

Regulation of nuclear factor of activated T cells (NFAT) and downstream myogenic proteins during dehydration in the African clawed frog.

Xenopus laevis, otherwise known as the African clawed frog, undergoes natural dehydration of up to 30% of its total body water during the dry season in sub-Saharan Africa. To survive under these conditions, a variety of physiological and biochemical changes take place in X. laevis.