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Human activities may impact animal habitat and resource use, potentially influencing contemporary evolution in animals. In the United Kingdom, COVID-19 lockdown restrictions resulted in sudden, drastic alterations to human activity. We hypothesized that short-term daily and long-term seasonal changes in human mobility might result in changes in bird habitat use, depending on the mobility type (home, parks and grocery) and extent of change. Using Google human mobility data and 872 850 bird observations, we determined that during lockdown, human mobility changes resulted in altered habitat use in 80% (20/25) of our focal bird species. When humans spent more time at home, over half of affected species had lower counts, perhaps resulting from the disturbance of birds in garden habitats. Bird counts of some species (e.g. rooks and gulls) increased over the short term as humans spent more time at parks, possibly due to human-sourced food resources (e.g. picnic refuse), while counts of other species (e.g. tits and sparrows) decreased. All affected species increased counts when humans spent less time at grocery services. Avian species rapidly adjusted to the novel environmental conditions and demonstrated behavioural plasticity, but with diverse responses, reflecting the different interactions and pressures caused by human activity. [ABSTRACT FROM AUTHOR]

Conservation of seabirds in remote polar regions requires accurate information on the location of breeding sites, which is often limited by logistical constraints of surveying large areas. On the Antarctic Peninsula, many seabird colonies are visited briefly but regularly by commercial cruise vessels, a platform from which we were able to collect presence/absence data on the entire community of seabirds. We used a multistate occupancy model, accounting for limited detection during surveys, to estimate the probability of presence and breeding of all 16 species native to the area. Our results provide a much clearer view than that was previously available of how avian diversity is distributed across the region's network of multi-species colonies and reveals species-specific differences in the effect of sea-ice concentration and site fidelity on breeding probability. Several breeding sites host an unusually large number of breeding species, but these known richness hotspots are scattered throughout the region and we were unable to identify any clear gradients in species richness that might explain why some sites are so species rich. While accounting for detection failure accelerates the pace of reliable inference on species occupancy, we find that as many as ten years of repeated visits are often required to fully catalog the seabird richness at bare rock sites along the Antarctic Peninsula. This work highlights the challenges of identifying high priority sites for special protection or management and the importance for continued surveys, even at nominally well-studied locations. [ABSTRACT FROM AUTHOR]

Biological invasions of aquatic systems disrupt ecological communities, and cause major changes in diversity and ecosystem function. The Laurentian Great Lakes of North America have been dramatically altered by such invasions, especially zebra (Dreissena polymorpha) and quagga (D. rostriformis bugensis) mussels. Responses to mussel invasions have included increased water clarity, and decreased chlorophyll and phytoplankton abundance. Although not all systems have responded similarly, in general, mussels have changed nutrient dynamics and physical habitat conditions. Therefore examination of different impacts can help us further understand mechanisms that underlie ecosystem responses to biological invasions. To aid our understanding of ecosystem impacts, we sampled established locations along a well-studied trophic gradient in Green Bay, Lake Michigan, after the 1993 zebra mussel invasion. A strong trophic gradient remained during the period sampled after the mussel invasion (2000-2012). However, mean summer chlorophyll increased and other measures of phytoplankton biomass (microscope and electronic cell counting) did not change significantly. Multivariate analyses of phytoplankton community structure demonstrate a significant community shift after the invasion. Cyanobacteria increased in dominance, with Microcystis becoming the major summer taxon in lower Green Bay. Diatom diversity and abundance also increased and Chlorophyta became rare. Phytoplankton responses along the trophic gradient of Green Bay to zebra mussel invasion highlight the importance of mussel effects on nutrient dynamics and phytoplankton diversity and function. [ABSTRACT FROM AUTHOR]