Search

Cummunality and Redundancy of parameters used in PLS-PM analyses

Description of latent variables used in the analyses

Correlation matrixes between latent variables by groups

Scores and graphic representation from the PCA analysis

Performance of the subset of candidate linear mixed-effect models

Habitat fragmentation is a principal threat to biodiversity and artificial river barriers are a leading cause of the global decline in freshwater biota. Whilst the impact of barriers on diadromous fish is well established, impacts on river-resident fish communities remain unclear, especially for low-head barriers. We examined the movement of five contrasting freshwater fish (topmouth gudgeon, European minnow, stone loach, bullhead, and brown trout) in an experimental cascade mesocosm with seven pools separated by small vertical barriers. Passage rates differed significantly among species and increased with body size and sustained swimming speed (Usus), ranging from an average of 0.2 passes/hr in topmouth gudgeon to 3.4 passes/hr in brown trout. A random-walk simulation indicated that barriers can result in net downstream movement and shifts in community composition. Passage rates in brown trout were leptokurtic: i.e. most individuals were relatively sedentary while a small proportion showed frequent movements. Upstream passage rates of brown trout increased with body length and boldness, while fish with lower aerobic scope tended to move downstream. Passage rates showed significant individual repeatability in brown trout, independent of body size, indicating the potential for in-stream barriers to exert selective effects on fish populations. Our results show that barrier effects can be more complex than simply blocking fish passage, and that river-resident fish can be impacted even by very small barriers. We show that fish passage depends on a wide range of morphological, physiological, and behavioural drivers, and that barriers can exert selective effects on these traits and cause shifts in community composition. Policy implications. Barrier mitigation measures need to embrace inter- and intraspecific variation in fish passage to avoid inadvertent artificial selection on fish communities. Given the high abundance of low-head structures in river systems worldwide, a paradigm shift is needed to recognise the subtle impacts of small barriers on freshwater biodiversity. Removal of small barriers or nature-like fishways should allow better passage of the wider fish community compared to widely used salmonid-centric fish passage options.

Additional file 1. Supplementary figures and dead-reckoning formulae.

Figure S1: Comparison of the rate of change of altitude and speed of an ultralight (A and C respectively) and a pigeon (B and D), flying at the same time, and with the same loggers. Violin plots show the distribution of the data during the flight; the upper and lower quartiles are represented by the upper and lower extremes of the box and the median by the thick black line.

Additional file 1. Methods expanded. Text S1. Device set up and capture protocol. Text S2. The importance of having the correct coordinate system and axis alignment. Text S3. Magnetometer calibration, rotation correction and deriving yaw (heading)—Gundog.Compass() explained. Text S4. Step counts as a distance estimate—Gundog.Peaks() explained. Text S5. Time Data in R (POSIXct). Text S6. VPC dead-reckoning—Gundog.Tracks()—explained.

Glides were clearly identifiable as periods of straight flight and sustained altitude loss between bouts of circling behaviour (see Williams et al. 2015 for details). The circling is represented by a consistent sine-wave when the tri-axial magnetometry data is plotted against time. This indicates turning within the thermal updraft.

International audience; One of the predicted consequences of climate change is a shift in body mass distributions within animal populations. Yet body mass, an important component of the physiological state of an organism, can affect key life-history traits and consequently population dynamics. Over the past decades, the wandering albatross—a pelagic seabird providing bi-parental care with marked sexual size dimorphism—has exhibited an increase in average body mass and breeding success in parallel with experiencing increasing wind speeds. To assess the impact of these changes, we examined how body mass affects five key life-history traits at the individual level: adult survival, breeding probability, breeding success, chick mass and juvenile survival. We found that male mass impacted all traits examined except breeding probability, whereas female mass affected none. Adult male survival increased with increasing mass. Increasing adult male mass increased breeding success and mass of sons but not of daughters. Juvenile male survival increased with their chick mass. These results suggest that a higher investment in sons by fathers can increase their inclusive fitness, which is not the case for daughters. Our study highlights sex-specific differences in the effect of body mass on the life history of a monogamous species with bi-parental care.

Description of the mass standardization functions

Workshop report: An international workshop on modeling the distribution and abundance of boreal waterfowlwas held during the 5th North American Duck Symposium in Toronto, Canada, 17-18 August 2009. The workshop brought together Canadian and American researchers andmanagers with an interestin waterfowl habitat and population modeling and/or in biomonitoring over large spatial extents.

Description of the Capture-Mark-Recapture method

Description of the Capture-Mark-Recapture method