@article {KNZ001968, title = {Habitat selection and space use of Upland Sandpipers at nonbreeding grounds}, journal = {Avian Conservation and Ecology}, volume = {14}, year = {2019}, pages = {14:art18}, abstract = {

Habitat requirements of migratory birds can be dynamic during the annual cycle, and understanding habitat use during the nonbreeding season is important for conservation planning. In grassland birds, habitat selection is often determined by features of vegetative structure that are associated with predation risk, food resources, or thermal environments. And, these habitats are affected by anthropogenic influences such as agriculture conversion and production of livestock. In our four-year field study, we examined the space use and habitat selection of Upland Sandpipers (Bartramia longicauda) during the nonbreeding season in an area of private grasslands managed for livestock production within the Northern Campos ecoregion of Uruguay. We radio-tracked sandpipers during the nonbreeding season to test the hypothesis that space use, habitat selection, and flock size were determined by vegetative structure in managed grasslands with different grazing and agricultural management regimes. We captured and tagged 62 sandpipers during the nonbreeding season in the austral summer, and recorded a total of 506 locations for our sample of radio-marked birds. Foraging Upland Sandpipers primarily selected two types of native grasslands associated with shallow, rocky soils. The vegetation configuration of disturbed pastures were open landscapes that were good for detection of arthropod prey but offered little cover for avoidance of predators. Sandpipers were usually found in small groups of 2\–20 birds, and the largest flocks of 40\–50 birds were found in pastures with relatively short grass cover (20 to 40\% tall grass cover). Low to moderate stocking densities of domestic livestock created variation in vegetation height and cover in large areas and allowed for coexistence of grassland birds with different habitat requirements. Upland Sandpipers preferred disturbed areas, which may not support the needs of other species of grasslands birds. Our results emphasize the need for habitat heterogeneity and disturbance forces such as grazing in grassland systems. Our research contributes new information on the ecology of migratory grassland birds and provides insights for biodiversity conservation on private lands used for livestock production.

}, keywords = {LTER-KNZ}, doi = {10.5751/ACE-01461-140218}, url = {https://brage.nina.no/nina-xmlui/handle/11250/2632763}, author = {M. Alfaro-Barrios and Liguori, L. and Sandercock, B.K. and Berazategui, M. and Arim, M.} } @article {KNZ001860, title = {Body condition and feather molt of a migratory shorebird during the non-breeding season}, journal = {Journal of Avian Biology}, volume = {49}, year = {2018}, pages = {jav-01480}, abstract = {

Migratory shorebirds have some of the highest fat loads among birds, especially species which migrate long distances. The Upland Sandpiper (Bartramia longicauda) makes long-distance migrations twice a year, but variation in body condition or timing of feather molt during the non-breeding season has not been studied. Molt is an important part of the annual cycle of migratory birds because feather condition determines flight performance during migration, and long-distance movements are energy costly. Howerver, variation in body condition during molt has been poorly studied. The objective of our field study was to examine the timing and patterns of feaher molt of a longo distance migratory shorebird during the non-breeding season and test for relationships with body size, fat depots, mass, and sex. Field work was conducted at four ranches in the Northern Campos of Uruguay (Paysand{\'u} and Salto Departments). We captured and marked 62 sandpipers in a 2-month period (Nov-Jan) during four non-breeding season (2008-2012). Sex was determinded by genetic analyses of blood samples taken at capture. Molt was measured in captured birds using rank scores based on published standards. Body mass and tarsus length measurements showed female-biased sexual size dimorphism with males smaller than females. Size-corrected body mass (body condition) showed a U-shaped relationship with the day of the season, indicating that birds arrived to non-breeding grounds in relatively good condition. Arriving in good body condition at non-breeding grounds is probably important because of the energetic demands due to physiological adjustments after migration and the costs of feather molt.

}, keywords = {LTER-KNZ}, doi = {10.1111/jav.01480}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/jav.01480}, author = {M. Alfaro-Barrios and Sandercock, B.K. and Liguori, Luciano and Arim, Matias} } @phdthesis {KNZ001861, title = {Nonreproductive ecology of a nearctic-neotropical migratory bird in the managed rangelands of northern Uruguay}, volume = {PhD Dissertation}, year = {2017}, school = {Universidad de la Rep{\'u}blica in Montevideo}, type = {Ph.D. Thesis}, address = {Montevideo, Uruguay}, keywords = {LTER-KNZ}, author = {M. Alfaro-Barrios} } @article {KNZ001717, title = {The diet of upland sandpipers (Bartramia longicauda) in managed farmland in their neotropical non-breeding grounds}, journal = {Ornitolog{\'\i}a Neotropical}, volume = {26}, year = {2015}, pages = {337-347}, abstract = {

The Upland Sandpiper (Bartramia longicauda) is a migratory shorebird that inhabits grasslands at the breeding and non-breeding grounds. The trophic ecology of the species is poorly known, but it is thought to be insectivorous. In this study, we describe the diet of the Upland Sandpiper and its temporal variation in grasslands of northern Uruguay. From 2008 to 2012, we collected 67 feces at nine different sites in the Departments of Salto and Paysand{\'u}. The diet consisted mainly of insects (present in 98\% of the feces) belonging to three orders: Coleoptera (in 80\% of feces), Orthoptera (79\%), and Hymenoptera (48\%). Consumption of Orthoptera and Hymenoptera varied among years. Plant remains and stones were also recorded in feces. Vegetation may have been consumed secondarily while stones could be used in food processing in the gizzard. Our study demonstrates that Upland Sandpipers are diet generalists and probably forage opportunistically, depending on resource availability and focusing on the most abundant prey items.

}, keywords = {LTER-KNZ, Bartramia longicauda; diet; fecal analysis; food preference; grasslands; insects; Nearctic migrant; Scolopacidae; Upland Sandpiper; Uruguay; wintering grounds}, author = {M. Alfaro-Barrios and Sandercock, B.K. and Liguori, L. and Arim, M.} } @article {KNZ001677, title = {Effects of grazing and prescribed fire on resource selection and nest survival of upland sandpipers in an experimental landscape}, journal = {Landscape Ecology}, volume = {30}, year = {2015}, pages = {325 -337}, abstract = {

Context Conservation of grassland vertebrates requires a mechanistic understanding of the effects of landscape heterogeneity on habitat selection and demographic performance. Objectives Our goal was to investigate the effects of rangeland management on resource selection and nest survival of upland sandpipers (Bartramia longicauda). Methods We conducted our project at Konza Prairie, a Long-Term Ecological Research site. The station has 60 experimental units with replicated grazing and fire treatments that create a heterogeneous landscape of different habitat patches. We radio-tracked sandpipers for two breeding seasons (2003\–2004, n = 37 birds) and monitored sandpiper nests for eight seasons (2001\–2008, n = 246 nests). We used resource utilization functions to examine resource selection with respect to five landscape features. Results Home ranges of sandpipers were large in contiguous prairie (x\¯=8.4km2x\¯=8.4km2) and explain area-sensitive occurrence in fragmented prairie. Upland sandpipers selected grazed and burned sites with short vegetation within their home range. In contrast, nest site selection was influenced by fire frequency and birds selected infrequently burned sites with greater vegetative structure. Settlement decisions affected fitness because nest survival was low in burned and grazed sites (0.068), but higher in unburned and ungrazed sites (0.201\–0.247). Conclusions Our results raise concerns for conservation because private rangelands managed for livestock production are often homogeneous landscapes with heavy grazing and frequent fires. Rotational grazing and fire could be used to restore heterogeneity to grasslands but the duration of rotation, patch size, and optimal configuration require further investigation.

}, keywords = {LTER-KNZ, Bartramia longicauda, fire, grassland, Habitat selection, Home range, Landscape heterogeneity, Nest survival, Radio-telemetry, Resource utilization functions, tallgrass prairie}, doi = {10.1007/s10980-014-0133-9}, url = {https://link.springer.com/article/10.1007\%2Fs10980-014-0133-9}, author = {Sandercock, B.K. and M. Alfaro-Barrios and Casey, A.E. and Johnson, T.N. and Mong, T.W. and Odom, K.J. and Strum, K.M. and Winder, V.L.} }