Neither hope nor fear: empirical evidence should drive biodiversity conservation strategies

In biodiversity conservation, the prevailing consensus is that optimistic messages should be used to inspire people to change their behaviour, but there is scarce empirical evidence that optimistic messages lead to favourable conservation behaviour change

Breeding data from a nestbox population of great tits with individuals identified earlier than standard protocol

These data were collected in the field (Wytham Woods, UK, Oxfordshire) as part of a long term study of great tits. RFID technology was used to identify individuals earlier in their breeding attempt than the traditional protocol

Data from: Who escapes detection? Quantifying the causes and consequences of sampling biases in a long-term field study

Inferences drawn from long-term field studies are vulnerable to biases in observability of different classes of individuals, which may lead to biases in the estimates of selection, or fitness. Population surveys that monitor breeding individuals can introduce such biases by not identifying individuals that fail early in their reproductive attempts. Here, we quantify how the standard protocol for detecting breeding females introduces bias in a long-term population study of the great tit, Parus major. We do so by identifying females whose breeding attempts fail before they would normally be censused, and explore whether this early failure can be predicted by a number of intrinsic and extrinsic factors. We investigate the effect of these biases on estimates of reproductive performance and selection. We show that females that go undetected by standard censusing because they fail early in their breeding attempt were less likely to have been previously trapped within our study site and were more likely to breed in poor quality habitats. Furthermore we demonstrate that this bias sampling had lead previous studies on this population to overestimate the reproductive performance of unringed females, which are likely to be immigrants to the population. Finally, we show that these biases in detectability influence estimates of selection on a key life history trait. While these conclusions are specific to this study, we suggest that such effects are likely to be widespread, and that more attention should be given to whether or not methods for surveying natural populations introduce systematic bias that will influence conclusions about ecological and evolutionary processes

Appendix B. Simulation study results.

Simulation study results

Supplement 1. R and C code used for the analysis of the great tits data set and for the simulation study presented in Appendix B.

<h2>File List</h2><div> <p><a href="Supplement/AllFunctions.R">AllFunctions.R</a> (MD5: d3120c7372ab36b802dd9f0c01138f1a)</p> <blockquote> <p>Functions needed to fit the models presented in the paper.</p> </blockquote> <p><a href="Supplement/AllFits.R">AllFits.R</a> (MD5: f7caa2c394d6c710195c1bca762d1851)</p> <blockquote> <p>R code for fitting the models to the data set of great tits.</p> </blockquote> <p><a href="Supplement/Simulations.R">Simulations.R</a> (MD5: d3a8a230b93a10bc74420f6694b6e8b1)</p> <blockquote> <p>R code for performing the simulation study presented in Appendix B.</p> </blockquote> <p><a href="Supplement/PMdata.csv">PMdata.csv</a> (MD5: 6fa6abb6c8240ba8eb0100c8031182ae)</p> <blockquote> <p>The data set of already marked female great tits. </p> </blockquote> <p><a href="Supplement/PUdata.csv">PUdata.csv</a> (MD5: 19f72c2afdc3736b87c8956dd9c94a3e)</p> <blockquote> <p>The data set of previously unmarked female great tits. </p> </blockquote> <p><a href="Supplement/Effort.csv">Effort.csv</a> (MD5: 95b7da2637fd9b08b9818832e23cb7f5)</p> <blockquote> <p>Data on sampling effort. </p> </blockquote> <p><a href="Supplement/WithBreeding.dll">WithBreeding.dll</a> MD5: ffe47405123db8b78289af44f4e050d3)</p> <blockquote> <p>The log-likelihood in compiled C code. </p> </blockquote> <p><a href="Supplement/C.zip">C.zip</a> (MD5: 9452e29327a86ce7bc2ab968bdd720dc)</p> <blockquote> <p>The original C code containing the log-likelihood.</p> </blockquote> </div><h2>Description</h2><div> <p>All of the functions needed to fit the models presented in the paper are in AllFunctions.R. The log-likelihood function is evaluated in C via R and is contained in the WithBreeding.dll file. The original C file is in the folder C.zip.</p> <p>The analysis of the great tits data set (PMdata.csv is the data set of already marked birds and PUdata.csv is the data set of previously unmarked birds) presented in the paper was performed using the functions in AllFits.R while the simulation study presented in Appendix B was performed using Simulations.R. Information on capture and resight effort (number of sites visited etc) is in effort.csv.</p> </div

Appendix C. Model selection steps.

Model selection steps

Consistent individual differences in the social phenotypes of wild great tits, Parus major

Despite growing interest in animal social networks, surprisingly little is known about whether individuals are consistent in their social network characteristics. Networks are rarely repeatedly sampled; yet an assumption of individual consistency in social behaviour is often made when drawing conclusions about the consequences of social processes and structure. A characterization of such social phenotypes is therefore vital to understanding the significance of social network structure for individual fitness outcomes, and for understanding the evolution and ecology of individual variation in social behaviour more broadly. Here, we measured foraging associations over three winters in a large PIT-tagged population of great tits, and used a range of social network metrics to quantify individual variation in social behaviour. We then examined repeatability in social behaviour over both short (week to week) and long (year to year) timescales, and investigated variation in repeatability across age and sex classes. Social behaviours were significantly repeatable across all timescales, with the highest repeatability observed in group size choice and unweighted degree, a measure of gregariousness. By conducting randomizations to control for the spatial and temporal distribution of individuals, we further show that differences in social phenotypes were not solely explained by within-population variation in local densities, but also reflected fine-scale variation in social decision making. Our results provide rare evidence of stable social phenotypes in a wild population of animals. Such stable social phenotypes can be targets of selection and may have important fitness consequences, both for individuals and for their social-foraging associates.publishe

Individual variation in winter supplementary food consumption and its consequences for reproduction in wild birds

The provision of wild birds with supplementary food has increased substantially over recent decades. While it is assumed that provisioning birds is beneficial, supplementary feeding can have detrimental ‘carry-over’ effects on reproductive traits. Due to difficulties in monitoring individual feeding behaviour, assessing how individuals within a population vary in their exploitation of supplementary food resources has been limited. Quantifying individual consumption of supplemen- tary food is necessary to understand the operation of carry-over effects at the individual level. We used Radio Frequency Identification (RFID) technology and automated feeders to estimate individual consumption of supplementary winter food in a large wild population of great tits Parus major and blue tits Cyanistes caeruleus. Using these data, we identified demographic factors that explained individual variation in levels of supplementary food consumption. We also tested for carry-over effects of supplementary food consumption on recruitment, reproductive success and a measure of survival. Individual variation in consumption of supplementary food was explained by differences between species, ages, sexes and years. Individuals were consistent across time in their usage of supplementary resources. We found no strong evidence that the extent of supplementary food consumption directly influenced subsequent fitness parameters. Such effects may instead result from supplementary food influencing population demographics by enhancing the survival and subsequent breeding of less competitive individuals, which reduce average breeding parameters and increase density-dependent competition. Carry-over effects of supplementary feeding are not universal and may depend upon the temporal availability of the food provided. Our study demonstrates how RFID systems can be used to examine individual-level behaviour with minimal effects on fitness.publishe

The role of social and ecological processes in structuring animal populations: a case study from automated tracking of wild birds

Both social and ecological factors influence population process and structure, with resultant consequences for phenotypic selection on individuals. Understanding the scale and relative contribution of these two factors is thus a central aim in evolutionary ecology. In this study, we develop a framework using null models to identify the social and spatial patterns that contribute to phenotypic structure in a wild population of songbirds. We used automated technologies to track 1053 individuals that formed 73 737 groups from which we inferred a social network. Our framework identified that both social and spatial drivers contributed to assortment in the network. In particular, groups had a more even sex ratio than expected and exhibited a consistent age structure that suggested local association preferences, such as preferential attachment or avoidance. By contrast, recent immigrants were spatially partitioned from locally born individuals, suggesting differential dispersal strategies by phenotype. Our results highlight how different scales of social decision-making, ranging from post-natal dispersal settlement to fission-fusion dynamics, can interact to drive phenotypic structure in animal populations.publishe

Data from: Individual variation in winter supplementary food consumption and its consequences for reproduction in wild birds.

The provision of wild birds with supplementary food has increased substantially over recent decades. While it is assumed that provisioning birds is beneficial, supplementary feeding can have detrimental ‘carry-over’ effects on reproductive traits. Due to difficulties in monitoring individual feeding behaviour, assessing how individuals within a population vary in their exploitation of supplementary food resources has been limited. Quantifying individual consumption of supplementary food is necessary to understand the operation of carry-over effects at the individual level. We used Radio Frequency Identification (RFID) technology and automated feeders to estimate individual consumption of supplementary winter food in a large wild population of great tits Parus major and blue tits Cyanistes caeruleus. Using these data, we identified demographic factors that explained individual variation in levels of supplementary food consumption. We also tested for carry-over effects of supplementary food consumption on recruitment, reproductive success and a measure of survival. Individual variation in consumption of supplementary food was explained by differences between species, ages, sexes and years. Individuals were consistent across time in their usage of supplementary resources. We found no strong evidence that the extent of supplementary food consumption directly influenced subsequent fitness parameters. Such effects may instead result from supplementary food influencing population demographics by enhancing the survival and subsequent breeding of less competitive individuals, which reduce average breeding parameters and increase density-dependent competition. Carry-over effects of supplementary feeding are not universal and may depend upon the temporal availability of the food provided. Our study demonstrates how RFID systems can be used to examine individual-level behaviour with minimal effects on fitness