The use of biologging devices continues to increase with technological advances yielding remarkable ecological insights and generating new research questions. However, as devices develop and are deployed more widely, there is a need to update our knowledge of the potential ethical impacts to allow scientists to balance these against the knowledge gained. We employed a suite of phylogenetically controlled meta‐analyses on a dataset comprising more than 450 published effect sizes across 214 different studies to examine the effects of biologger tagging on five key traits in birds. Overall, we found small but significant negative effects of tagging on survival, reproduction, parental care. In addition, tagging was positively associated with foraging trip duration, but had no effect on body mass. Meta‐regressions revealed that flying style, migration distance and proportional tag mass were significant influences producing these deleterious effects, with attachment type and position additionally important covariates influencing survival‐ and reproduction‐based effect sizes. There was a positive correlation between the effects of tagging on survival and reproduction, highlighting that effects may be cumulative, with the full effects of tagging not necessarily apparent in studies focused on single traits. We discuss the tradeoff between these negative effects and the advances gained through the use of biologgers. Finally, given the number of studies from our initial literature search that lacked sufficient data for inclusion in analyses, we provide recommendations on the essential information that all biologging studies should report in order to facilitate future assessments of impacts on animals.

Insight to the spatial and temporal scales of coevolution is key to predicting the outcome of host–parasite interactions and spread of disease. For bacteria infecting long-lived hosts, selection to overcome host defences is just one factor shaping the course of evolution; populations will also be competing with other microbial species and will themselves be facing infection by bacteriophage viruses. Here, we examine the temporal and spatial patterns of bacterial adaptation against natural phage populations from within leaves of horse chestnut trees. Using a time-shift experiment with both sympatric and allopatric phages from either contemporary or earlier points in the season, we demonstrate that bacterial resistance is higher against phages from the past, regardless of spatial sympatry or how much earlier in the season phages were collected. Similarly, we show that future bacterial hosts are more resistant to both sympatric and allopatric phages than contemporary bacterial hosts. Together, our results suggest the evolution of relatively general bacterial resistance against phages in nature and are contrasting to previously observed patterns of phage adaptation to bacteria from the same tree hosts over the same time frame, indicating a potential asymmetry in coevolutionary dynamics.

Coevolution shapes diversity within and among populations but is difficult to study directly.Time shift experiments, where individuals from one point in time are experimentally challenged against individuals from past, contemporary, and/or future time points, are a powerful tool to measure coevolution. This approach has proven useful in both directly measuring coevolutionary change and in distinguishing among coevolutionary models. However, these data are only as informative as the time window over which they were collected, and inference from shorter coevolutionary windows might conflict those from longer time periods. Previous time-shift experiments from natural microbial communities of horse chestnut tree leaves uncovered an apparent asymmetry, whereby bacterial hosts were more resistant to bacteriophages from all earlier points in the growing season while phages were most infective to hosts from only the recent past. Here we extend the time window over which these infectivity and resistance ranges are observed to across years and confirm that the previously observed asymmetry holds over longer timescales. These data suggest existing coevolutionary theory should be revised to include the possibility of differing models for hosts and their parasites, and examined for how such asymmetries might reshape the predicted outcomes of coevolution.

Birds that migrate across high altitude mountain ranges are faced with the challenge of maintaining vigorous exercise in environments with limited oxygen. Ruddy shelducks are known to use wintering grounds south of the Tibetan Plateau at sea level and breeding grounds north of Himalayan mountain range. Therefore, it is likely these shelducks are preforming high altitude migrations. In this study we analyse satellite telemetry data collected from 15 ruddy shelduck from two populations wintering south of the Tibetan Plateau from 2007 to 2011. During north and south migrations ruddy shelduck travelled 1481 km (range 548–2671 km) and 1238 km (range 548–2689 km) respectively. We find mean maximum altitudes of birds in flight reached 5590 m (range of means 4755–6800 m) and mean maximum climb rates of 0.45 m s–1 (range 0.23–0.74 m s–1). The ruddy shelduck is therefore an extreme high altitude migrant that has likely evolved a range of physiological adaptations in order to complete their migrations.

Parr, Nicole, Matt Wilkes, and Lucy Alice Hawkes. Natural climbers: insights from avian physiology at high altitude. High Alt Med Biol. 20:427-437, 2019.-High altitudes are physiologically challenging: the hypobaric hypoxia, cold, and increased ultraviolet radiation mean humans ascending to high altitude faster than they acclimatize risk life-threatening illnesses. Despite such challenges, birds can thrive at high altitudes and some even complete metabolically costly migrations across the world's highest mountain ranges. We outline the aspects of avian anatomy and physiology that confer advantages at each level of the oxygen transport cascade and compare them with those of human and nonhuman mammals. We also discuss additional adaptations that have been described for high-altitude specialist species of birds and how these are mirrored in high-altitude adapted mammals.