@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.} } @article {KNZ001282, title = {Exposure of nonbreeding migratory shorebirds to cholinesterase inhibiting contaminants in the Western Hemisphere}, journal = {The Condor}, volume = {112}, year = {2010}, pages = {15 -28}, abstract = {

Migratory shorebirds frequently forage and roost in agricultural habitats, where they may be exposed to cholinesterase-inhibiting pesticides. Exposure to organophosphorus and carbamate compounds, common anti-cholinesterases, can cause sublethal effects, even death. To evaluate exposure of migratory shorebirds to organophosphorus and carbamates, we sampled birds stopping over during migration in North America and wintering in South America. We compared plasma Cholinesterase activities and body masses of individuals captured at sites with no known sources of organophosphorus or carbamates to those captured in agricultural areas where agrochemicals were recommended for control of crop pests. In South America, plasma acetylcholinesterase and butyrylcholinesterase activity in Buff-breasted Sandpipers was lower at agricultural sites than at reference sites, indicating exposure to organophosphorus and carbamates. Results of plasma Cholinesterase reactivation assays and foot-wash analyses were inconclusive. A meta-analysis of six species revealed no widespread effect of agricultural chemicals on Cholinesterase activity. However, four of six species were negative for acetylcholinesterase and one of six for butyrylcholinesterase, indicating negative effects of pesticides on Cholinesterase activity in a subset of shorebirds. Exposure to Cholinesterase inhibitors can decrease body mass, but comparisons between treatments and hemispheres suggest that agrochemicals did not affect migratory shorebirds\&$\#$39; body mass. Our study, one of the first to estimate of shorebirds\&$\#$39; exposure to cholinesterase-inhibiting pesticides, suggests that shorebirds are being exposed to cholinesterase-inhibiting pesticides at specific sites in the winter range but not at migratory stopover sites. Future research should examine potential behavioral effects of exposure and identify other potential sites and levels of exposure.

}, keywords = {LTER-KNZ, Buff-breasted Sandpiper, carbamate, nonbreeding, organophosphate, population declines, sandpiper, Tryngites subruficollis, waders}, doi = {10.1525/cond.2010.090026}, url = {https://doi.org/10.1525/cond.2010.090026}, author = {Strum, K.M. and Hooper, M.J. and Johnson, K.A. and Lanctot, R.B. and Zaccagnini, M.E. and Sandercock, B.K.} } @mastersthesis {KNZ001218, title = {Exposure of migratory shorebirds to organophosphorus and carbamate pesticides at migratory stopover and non-breeding sites in the western hemisphere}, volume = {MS Thesis}, year = {2008}, pages = {1 -76}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, abstract = {

Monitoring programs indicate that numerous shorebird populations are subject to ongoing declines. The U.S. Shorebird Conservation Plan lists twenty-seven shorebird species as species of high concern and seven as highly imperiled, including the Buff-breasted Sandpiper (Tryngites subruficollis). One hypothesis for ongoing population declines is exposure to toxic chemicals and pollutants. The purpose of this project was to characterize plasma cholinesterases (ChEs) of migratory shorebirds and address potential exposure to organophosphorus (OP) and carbamate (CB) pesticides. Consumption or contact with these pesticides can cause mortality and a variety of sub-lethal effects. Buff-breasted Sandpipers and other upland shorebirds are particularly likely to encounter agrochemicals due to their habitat use at the non-breeding grounds. I sampled migratory shorebirds over three seasons, during north- and southbound migration in 2006 and 2007 in Texas, Kansas, and Nebraska and during the non-breeding season in 2007 in Argentina, Uruguay, and Paraguay. I collected blood samples and footwashings from reference sites, where OP and CB pesticides were not used, and agricultural sites, where these two insecticides were recommended for control of crop pests. I assessed several variables known to affect plasma ChE activity including body size, date of capture, time of capture, condition, sex, and region. Small-bodied species had higher levels of ChE activity in plasma than large-bodied species. Plasma ChE activities varied with date of capture in 3 of 5 species sampled in North America. Sex differences were significant in 1 of 4 species tested. Plasma acetylcholinesterase (AChE) activity was higher among White-rumped Sandpipers sampled in North America but there was no difference between regions among Buff-breasted Sandpipers. Time of capture and individual condition did not affect plasma ChE activity. Estimates of exposure to ChE inhibitors were addressed in five species. Plasma AChE and butyrylcholinesterase (BChE) activities of Buff-breasted Sandpipers were lower at agricultural sites in South America but BChE activity was higher at agricultural sites in North America. There were no differences between sites in four other species tested. A meta-analysis across all species indicated that in 4 of 6 comparisons habitat type had a negative effect on AChE activity consistent with exposure to ChE inhibitors but there was a regional positive effect of agricultural habitat on BChE activity in North America. Comparison of body mass between sites suggested that use of habitats with potential pesticide application did not affect mass gain. Project results suggest that 1 of 5 shorebird species tested was exposed to ChE-inhibiting pesticides at the nonbreeding grounds and future monitoring is necessary to assess potential effects at the population level. This study highlights the importance of complete sampling and addressing variability in plasma ChEs before making estimates of exposure to OP and CB pesticides. It provides the first estimates of migratory shorebird exposure to OP and CB pesticides, a potential conservation issue. Future research should include continued monitoring of Buff-breasted Sandpiper ChE levels and habitat use. Other sources of anthropogenic declines such as habitat loss and illegal hunting should be investigated for species that did not show evidence of exposure.

}, keywords = {LTER-KNZ}, url = {http://krex.k-state.edu/dspace/handle/2097/807}, author = {Strum, K.M.} } @article {KNZ001159, title = {Plasma cholinesterases for monitoring pesticide exposure in Nearctic-Neotropical migratory shorebirds}, journal = {Ornitholog{\'\i}a Neotropical}, volume = {19 (Suppl)}, year = {2008}, pages = {641 -651}, abstract = {Organophosphorus (OP) and carbamate (CB) pesticides are commonly used agrochemicals throughout the Western Hemisphere. These pesticides have caused mortalities in migratory birds and adverse physiological effects in trials with captive birds. Migratory shorebirds use a variety, of habitats during the austral summer in temperate South America and during migration through the Great Plains of the United States. Habitats where risk of exposure is high include rice fields and turf grass farms where agrochemicals are used. Cholinesterase (ChE) is a specific biomarker for monitoring OP and CB exposure and can be measured using standard laboratory procedures. Plasma ChE activity is useful as a non-lethal means of monitoring avian exposure to OP and CB pesticides. Many variables can affect enzyme activity and reactivation assays are not always possible, thus reference ChE values are a necessary component of monitoring exposure. During northbound migration in 2006, we sampled four upland and five wetland shore-bird species at four pesticide-free sites in North America, characterizing and measuring plasma ChEs in all shorebird species. Small-bodied species had higher levels of ChE activity in plasma than large-bodied species. Acetylcholinesterase (AChE), the enzyme whose inhibition leads to poisoning symptoms, showed less inter-specific variation than butyrylcholinesterase (BChE). Plasma ChE activities varied with date of capture in three of five species. Sex differences were significant in one of two species tested. Our baseline ChE values for migratory shorebirds provide a framework for future ecotoxicological studies of Nearctic-Neotropical migrant shorebirds.}, keywords = {LTER-KNZ}, url = {https://www.researchgate.net/publication/254414753_Plasma_cholinesterases_for_monitoring_pesticide_exposure_in_Nearctic-Neotropical_migratory_shorebirds}, author = {Strum, K.M. and Alfaro, M. and Haase, B. and Hooper, M.J. and Johnson, K.A. and Lanctot, R.B. and Lesterhuis, A.J. and L{\'o}pez, L. and Matz, A.C. and Morales, C. and Paulson, B. and Sandercock, B.K. and Torres-Dowdall, J. and Zaccagnini, M.E.} }