Conservation success or increased crop damage risk? The Natura 2000 network for a thriving migratory and protected bird

Protected areas are important to support biodiversity and endangered species. However, they are often too small to fulfill the resource requirements of many large and mobile wildlife species, especially when congregating in large numbers. In such cases, wildlife may overflow onto surrounding human-dominated land and cause impacts. The aim of the EU Natura 2000 network is to increase supranational connectivity between protected areas for migratory and protected species such as the common crane (Grus grus). The crane population along the Western European flyway has been increasing rapidly in recent decades, with peaks of 200,000 cranes at specific Natura 2000 sites. We studied 32 GPS-tagged cranes over four migration periods, to test the use of the network by cranes and the potential for impacts on adjacent farmland. During the nighttime, the probability that roosting cranes were located on Natura 2000 sites was 97%. During daytime, the probability of foraging cranes being located on arable land was 68%. The probability of foraging cranes occurring on agricultural fields close to Natura 2000 sites decreased with distance. Such foraging patterns may fuel conflicts between conservation and agricultural objectives. To resolve these conflicts we suggest improved cross-boundary collaboration and policy development among involved states, combined with stakeholder participation to implement effective compensation and damage prevention strategies which are focused upon networks of protected area

Diurnal timing of nonmigratory movement by birds: the importance of foraging spatial scales

Timing of activity can reveal an organism's efforts to optimize foraging either by minimizing energy loss through passive movement or by maximizing energetic gain through foraging. Here, we assess whether signals of either of these strategies are detectable in the timing of activity of daily, local movements by birds. We compare the similarities of timing of movement activity among species using six temporal variables: start of activity relative to sunrise, end of activity relative to sunset, relative speed at midday, number of movement bouts, bout duration and proportion of active daytime hours. We test for the influence of flight mode and foraging habitat on the timing of movement activity across avian guilds. We used 64 570 days of GPS movement data collected between 2002 and 2019 for local (non‐migratory) movements of 991 birds from 49 species, representing 14 orders. Dissimilarity among daily activity patterns was best explained by flight mode. Terrestrial soaring birds began activity later and stopped activity earlier than pelagic soaring or flapping birds. Broad‐scale foraging habitat explained less of the clustering patterns because of divergent timing of active periods of pelagic surface and diving foragers. Among pelagic birds, surface foragers were active throughout all 24 hrs of the day while diving foragers matched their active hours more closely to daylight hours. Pelagic surface foragers also had the greatest daily foraging distances, which was consistent with their daytime activity patterns. This study demonstrates that flight mode and foraging habitat influence temporal patterns of daily movement activity of birds.We thank the Nature Conservancy, the Bailey Wildlife Foundation, the Bluestone Foundation, the Ocean View Foundation, Biodiversity Research Institute, the Maine Outdoor Heritage Fund, the Davis Conservation Foundation and The U.S. Department of Energy (DE‐EE0005362), and the Darwin Initiative (19-026), EDP S.A. ‘Fundação para a Biodiversidade’ and the Portuguese Foundation for Science and Technology (FCT) (DL57/2019/CP 1440/CT 0021), Enterprise St Helena (ESH), Friends of National Zoo Conservation Research Grant Program and Conservation Nation, ConocoPhillips Global Signature Program, Maryland Department of Natural Resources, Cellular Tracking Technologies and Hawk Mountain Sanctuary for providing funding and in-kind support for the GPS data used in our analyses

Migration distance affects how closely Eurasian wigeons follow spring phenology during migration

Background: The timing of migration for herbivorous migratory birds is thought to coincide with spring phenologyas emerging vegetation supplies them with the resources to fuel migration, and, in species with a capital breedingstrategy also provides individuals with energy for use on the breeding grounds. Individuals with very long migrationdistances might however have to trade of between utilising optimal conditions en route and reaching the breeding grounds early, potentially leading to them overtaking spring on the way. Here, we investigate whether migrationdistance afects how closely individually tracked Eurasian wigeons follow spring phenology during spring migration. Methods: We captured wigeons in the Netherlands and Lithuania and tracked them throughout spring migration toidentify staging sites and timing of arrival. Using temperature-derived indicators of spring phenology, we investigatedhow maximum longitude reached and migration distance afected how closely wigeons followed spring. We furtherestimated the impact of tagging on wigeon migration by comparing spring migratory timing between tracked individuals and ring recovery data sets. Results: Wigeons migrated to locations between 300 and 4000 km from the capture site, and migrated up to1000 km in a single day. We found that wigeons migrating to more north-easterly locations followed spring phenology more closely, and increasingly so the greater distance they had covered during migration. Yet we also found thatdespite tags equalling only around 2% of individual’s body mass, individuals were on average 11–12 days slower thanring-marked individuals from the same general population. Discussion: Overall, our results suggest that migratory strategy can vary dependent on migration distance withinspecies, and even within the same migratory corridor. Individual decisions thus depend not only on environmentalcues, but potentially also trade-ofs made during later life-history stages