Technological innovations have led to exciting fast-moving developments in science. Today, we are living in a technology-driven era of biological discovery. Consequently, tracking technologies have facilitated dramatic advances in the fundamental understanding of ecology and animal behaviour. Major technological improvements, such as the development of GPS dataloggers, geolocators and other bio-logging technologies, provide a volume of data that were hitherto unconceivable. Hence we can claim that ornithology has entered the era of big data. In this paper, which is particularly addressed to undergraduate students and starting researchers in the emerging field of movement ecology, I summarise the current state of the art of individual-based tracking methods for birds as well as the most important challenges that, as a personal user, I consider we should address in future. To this end, I first provide a brief overview of individual tracking systems for birds. I then discuss current challenges for tracking birds with remote telemetry, including technological challenges (i.e., tag miniaturisation, incorporation of more bio-logging sensors, better efficiency in data archiving and data processing), as well as scientific challenges (i.e., development of new computational tools, investigation of spatial and temporal autocorrelation of data, improvement in environmental data annotation processes, the need for novel behavioural segmentation algorithms, the change from two to three, and even four, dimensions in the scale of analysis, and the inclusion of animal interactions). I also highlight future prospects of this research field including a set of scientific questions that have been answered by means of telemetry technologies or are expected to be answered in the future. Finally, I discuss some ethical aspects of bird tracking, putting special emphases on getting the most out of data and enhancing a culture of multidisciplinary collaboration among research groups.

https://bioone.org/journals/ardeola/volume-63/issue-1/arla.63.1.2016.rp5/Individual-Based-Tracking-Systems-in-Ornithology--Welcome-to-the/10.13157/arla.63.1.2016.rp5.pdf

Individual-Based Tracking Systems in Ornithology: Welcome to the Era of Big Data

Introduction. General Nutrient and Energy Requirements. Protein. Water. Minerals. Vitamins. Essential Fatty Acids. Energy Requirements for Maintenance. Protein Requirements for Maintenance. Reproductive Costs. Productive Costs. Food Composition. Gastrointestinal Anatomy and Function. Digestion and Nutrient Metabolism. Food Intake Regulation. Computer Models of the Nutritional Interaction. Index.

Wildlife feeding and nutrition.

Gut microbiota plays an important role for bird biological and ecological properties, and sex and diet may be important intrinsic and extrinsic factors influencing gut microbial communities. However, sex difference of gut microbiota has been rarely investigated in free-living birds, and it remains unclear how sex and diet interactively affect avian gut microbiota composition and diversity, particularly under natural conditions. Here we used non-invasive molecular sexing technique to sex the fecal samples collected from two wintering sites of Great Bustard, which is the most sexually dimorphic among birds, as well as a typical farmland-dependent wintering bird. High-throughput sequencing of 16S was applied to identify the gut microbiota communities for both sexes under two diets (wheat_corn and rice_peanut). The results showed that 9.74% of common microbiota taxa was shared among four groups (sex vs. diet), revealing the conservatism of gut microbiota. Microbiota diversity, composition and abundance varied on different diets for male and female Great Bustards, suggesting that the gut microbiota was interactively influenced by both sex and diet. Under the wheat_corn diet, females had higher abundances of the phylum Verrucomicrobia than males, but lower Bacteroidetes and Firmicutes compared to males; meanwhile, the microbiota diversity and evenness were higher for males than females. In contrast, under the rice_peanut diet, females were more colonized by the phylum Firmicutes than males, but less by the phylum Bacteroidetes; while males had lower microbiota diversity and evenness than females. This study investigated the impacts of sex and diet on microbiota of Great Bustards, and highlights the need of new studies, perhaps with the same methodology, taking into account bird ages, flock size, breeding or health status, which will contribute to the understanding of ecology and conservation of this vulnerable species.

/pdf/effects-of-sex-and-diet-on-gut-microbiota-of-farmland-pg99q8xnsy.pdf

Effects of Sex and Diet on Gut Microbiota of Farmland-Dependent Wintering Birds.

Food resources are often not sufficient to satisfy the nutritional and energetic requirements during winter conditions at high latitudes. Dietary analysis is a prerequisite to fully understanding the feeding ecology of a species and the nature of trophic interactions. Previous dietary studies of Asian Great Bustard (Otis tarda dybowskii) relied on behavioral observations, resulting in categorization of diet limited to broad taxonomic groupings. Here, we applied a high-throughput sequencing meta-barcoding approach to quantify the diet of resident and migratory Asian Great Bustard in three wintering sites during early winter and late winter. We detected 57 unique plant taxa in the bustard diet, among which 15 species were confirmed by a local plant database we generated. Both agricultural and natural foods were detected, indicating a relatively broad dietary niche. Spatiotemporal dietary changes were discovered, revealing diet differences among wintering sites and a general shift toward lower plant diversity later in winter. For the nonmigratory population, we detected a significantly more diverse array of plant species in their diet. We hypothesize that dietary variation between resident and migratory populations could be involved in the recent transition to partial migration in this species, although climate change can not be excluded. Collectively, these results support protecting unharvested grain fields and naturally unplowed lands to help conserve and promote population growth of Asian Great Bustard.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.3791

Meta-barcoding insights into the spatial and temporal dietary patterns of the threatened Asian Great Bustard (Otis tarda dybowskii) with potential implications for diverging migratory strategies.

Behaviour and diet composition are critical elements in conservation biology within the scope of reintroduction programs Here we focused on addax (Addax nasomaculatus), a Critically Endangered antelope species, in the Jbil National Park, Tunisia In this study, we advanced the hypothesis that season, day period, sex and social structure have an effect on the activity budgets and diet composition of addax Three groups were selected (large group, adult pair and solitary male) Resting, moving, grazing, vigilance and other behaviours were recorded during two seasons (dry and wet) and in the morning and the afternoon In addition, faecal samples were collected The results indicate that season and day period were the main factors affecting the activity budgets The resting behaviour increased from the wet to the dry season, and from morning to afternoon The grazing and moving behaviours increased during the wet season and decreased from morning to afternoon Addax select a mixed diet composed of perennial 

Effects of seasonal variation, group size and sex on the activity budget and diet composition of the addax antelope

Capsule Reintroduced Great Bustards achieve dietary and habitat diversity despite living in an intensive agricultural setting. Aims To investigate dietary composition and habitat use of reintroduced Great Bustards Otis tarda released in southwest England and the impact of supplemental feed on autumn dietary selection. Methods Faecal samples were collected from a mixed group of free-ranging bustards without (July 2012, May, September, and November 2013) and with (October and December 2012) access to supplemental feeds. Concurrently, diurnal land use observations were recorded for all months but September and December. Composite monthly faecal samples were micro-histologically analysed to assess dietary composition. Year-round landscape-level habitat use was determined using re-sightings and satellite telemetry data for birds surviving more than 182 days post-release. Generalized linear models were used to test for differences in habitat selection across the year, by sex and within and outside release areas for each habitat type, and habitat diversity was quantified using the Shannon–Weaver Index. Results Dietary composition varied depending on plant availability and phenological stage, and invertebrates were rarely selected. Agricultural crops – primarily oil-seed rape, mustard, barley grass, lucerne, and barley seed – comprised the bulk of the diet, but grassland and weedy forbs were always important secondary foods (>25%), except when provided extruded pellets. Monthly changes in habitat use suggest sex-based habitat segregation, with females living in higher habitat diversity settings. Grasslands were used across the year. When supplemental food was provided, it came to dominate dietary intake. Conclusion Great Bustards can adapt to an intensive agricultural setting, but require unrestricted access to adjacent grasslands. They would be best served with small-scale habitat mosaics. If supplemental foods are to be provided to juvenile birds, quantities must be limited and the birds weaned off before dispersal to maximize reintroduction success.

https://www.rspb.org.uk/Images/Scientific%20paper%202_tcm9-415511.pdf

Scott Gooch

Papers

Using dietary analysis and habitat selection to inform conservation management of reintroduced Great Bustards Otis tarda in an agricultural landscape