Browsing by Author "Sandercock, Brett K."
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- Composition and Drivers of Gut Microbial Communities in Arctic-Breeding ShorebirdsGrond, Kirsten; Santo Domingo, Jorge W.; Lanctot, Richard B.; Jumpponen, Ari; Bentzen, Rebecca L.; Boldenow, Megan L.; Brown, Stephen C.; Casler, Bruce; Cunningham, Jenny A.; Doll, Andrew C.; Freeman, Scott; Hill, Brooke L.; Kendall, Steven J.; Kwon, Eunbi; Liebezeit, Joseph R.; Pirie-Dominix, Lisa; Rausch, Jennie; Sandercock, Brett K. (2019-10-09)Gut microbiota can have important effects on host health, but explanatory factors and pathways that determine gut microbial composition can differ among host lineages. In mammals, host phylogeny is one of the main drivers of gut microbiota, a result of vertical transfer of microbiota during birth. In birds, it is less clear what the drivers might be, but both phylogeny and environmental factors may play a role. We investigated host and environmental factors that underlie variation in gut microbiota composition in eight species of migratory shorebirds. We characterized bacterial communities from 375 fecal samples collected from adults of eight shorebird species captured at a network of nine breeding sites in the Arctic and sub-Arctic ecoregions of North America, by sequencing the V4 region of the bacterial 16S ribosomal RNA gene. Firmicutes (55.4%), Proteobacteria (13.8%), Fusobacteria (10.2%), and Bacteroidetes (8.1%) dominated the gut microbiota of adult shorebirds. Breeding location was the main driver of variation in gut microbiota of breeding shorebirds (R-2 = 11.6%), followed by shorebird host species (R-2 = 1.8%), and sampling year (R-2 = 0.9%), but most variation remained unexplained. Site variation resulted from differences in the core bacterial taxa, whereas rare, lowabundance bacteria drove host species variation. Our study is the first to highlight a greater importance of local environment than phylogeny as a driver of gut microbiota composition in wild, migratory birds under natural conditions.
- Delayed egg-laying and shortened incubation duration of Arctic-breeding shorebirds coincide with climate coolingKwon, Eunbi; English, Willow B.; Weiser, Emily L.; Franks, Samantha E.; Hodkinson, David J.; Lank, David B.; Sandercock, Brett K. (Wiley, 2017)Biological impacts of climate change are exemplified by shifts in phenology. As the timing of breeding advances, the within-season relationships between timing of breeding and reproductive traits may change and cause long-term changes in the population mean value of reproductive traits. We investigated long-term changes in the timing of breeding and within-season patterns of clutch size, egg volume, incubation duration, and daily nest survival of three shorebird species between two decades. Based on previously known within-season patterns and assuming a warming trend, we hypothesized that the timing of clutch initiation would advance between decades and would be coupled with increases in mean clutch size, egg volume, and daily nest survival rate. We monitored 1,378 nests of western sandpipers, semipalmated sandpipers, and red-necked phalaropes at a subarctic site during 1993–1996 and 2010–2014. Sandpipers have biparental incubation, whereas phalaropes have uniparental incubation. We found an unexpected long-term cooling trend during the early part of the breeding season. Three species delayed clutch initiation by 5 days in the 2010s relative to the 1990s. Clutch size and daily nest survival showed strong within-season declines in sandpipers, but not in phalaropes. Egg volume showed strong within-season declines in one species of sandpiper, but increased in phalaropes. Despite the within-season patterns in traits and shifts in phenology, clutch size, egg volume, and daily nest survival were similar between decades. In contrast, incubation duration did not show within-season variation, but decreased by 2 days in sandpipers and increased by 2 days in phalaropes. Shorebirds demonstrated variable breeding phenology and incubation duration in relation to climate cooling, but little change in nonphenological components of traits. Our results indicate that the breeding phenology of shorebirds is closely associated with the temperature conditions on breeding ground, the effects of which can vary among reproductive traits and among sympatric species.
- Demographic Consequences of Conservation Reserve Program Grasslands for Lesser Prairie-ChickensSullins, Daniel S.; Kraft, John D.; Haukos, David A.; Robinson, Samantha G.; Reitz, Jonathan H.; Plumb, Reid T.; Lautenbach, Joseph M.; Lautenbach, Jonathan D.; Sandercock, Brett K.; Hagen, Christian A. (2018-11)Knowledge of landscape and regional circumstances where conservation programs are successful on working lands inagricultural production are needed. Convertingmarginal croplands to grasslands using conservation programs such as the United States Department of Agriculture Conservation Reserve Program (CRP) should be beneficial for many grassland-obligate wildlife species; however, addition of CRP grasslands may result indifferent population effects based on regional climate, characteristics of the surrounding landscape, or species planted or established. Within landscapes occupied by lesser prairie-chickens (Tympanuchus pallidicinctus), CRP may provide habitat only for specific life stages and habitat selection for CRP may vary between wet and dry years. Among all study sites, we captured and fitted 280 female lesser prairie-chickens with very high frequency (VHF)- and global positioning system (GPS) transmitters during the spring lekking seasons of 2013-2015 to monitor habitat selection for CRP in regions of varying climate. We also estimated vital rates and habitat selection for 148 individuals, using sites in northwest Kansas, USA. The greatest ecological services of CRP became apparent when examining habitat selection and densities. Nest densities were approximately 3 times greater in CRP grasslands than native working grasslands (i.e., grazed), demonstrating a population-level benefit (CRP = 6.0 nests/10 km(2) +/- 1.29 [ SE], native working grassland = 1.7 nests/10 km(2) +/- 0.62). However, CRP supporting high nest density did not provide brood habitat; 85% of females with broods surviving to 7 days moved their young to other cover types. Regression analyses indicated lesser prairie-chickens were approximately 8 times more likely to use CRP when 5,000-ha landscapes were 70% rather than 20% grassland, indicating variation in the level of ecological services provided by CRP was dependent upon composition of the larger landscape. Further, CRP grasslands were 1.7 times more likely to be used by lesser prairie-chickens in regions receiving 40 cm compared to 70 cm of average annual precipitation and during years of greater drought intensity. Demographic and resource selection analyses revealed that establishing CRP grasslands in northwest Kansas can increase the amount nesting habitat in a region where it may have previously been limited, thereby providing refugia to sustain populations through periods of extreme drought. Nest survival, adult survival during breeding, and nonbreeding season survival did not vary between lesser prairie-chickens that used and did not use CRP grasslands. The finite rate of population growth was also similar for birds using CRP and using only native working grasslands, suggesting that CRP provides habitat similar to that of native working grassland in this region. Overall, lesser prairie-chickens may thrive in landscapes that are a mosaic of native working grassland, CRP grassland, with a minimal amount of cropland, particularly when nesting and brood habitat are in close proximity. (C) 2018 The Wildlife Society
- Effects of environmental conditions on reproductive effort and nest success of Arctic-breeding shorebirdsWeiser, Emily L.; Brown, Stephen C.; Lanctot, Richard B.; Gates, H. River; Abraham, Kenneth F.; Bentzen, Rebecca L.; Bety, Joel; Boldenow, Megan L.; Brook, Rodney W.; Donnelly, Tyrone F.; English, Willow B.; Flemming, Scott A.; Franks, Samantha E.; Gilchrist, H. Grant; Giroux, Marie-Andree; Johnson, Andrew; Kendall, Steven J.; Kennedy, Lisa V.; Koloski, Laura; Kwon, Eunbi; Lamarre, Jean-Francois; Lank, David B.; Latty, Christopher J.; Lecomte, Nicolas; Liebezeit, Joseph R.; McKinnon, Laura; Nol, Erica; Perz, Johanna; Rausch, Jennie; Robards, Martin; Saalfeld, Sarah T.; Senner, Nathan R.; Smith, Paul A.; Soloviev, Mikhail; Solovyeva, Diana; Ward, David H.; Woodard, Paul F.; Sandercock, Brett K. (2018-07)The Arctic is experiencing rapidly warming conditions, increasing predator abundance, and diminishing population cycles of keystone species such as lemmings. However, it is still not known how many Arctic animals will respond to a changing climate with altered trophic interactions. We studied clutch size, incubation duration and nest survival of 17 taxa of Arctic-breeding shorebirds at 16 field sites over 7years. We predicted that physiological benefits of higher temperatures and earlier snowmelt would increase reproductive effort and nest survival, and we expected increasing predator abundance and decreasing abundance of alternative prey (arvicoline rodents) to have a negative effect on reproduction. Although we observed wide ranges of conditions during our study, we found no effects of covariates on reproductive traits in 12 of 17 taxa. In the remaining taxa, most relationships agreed with our predictions. Earlier snowmelt increased the probability of laying a full clutch from 0.61 to 0.91 for Western Sandpipers, and shortened incubation by 1.42days for arcticola Dunlin and 0.77days for Red Phalaropes. Higher temperatures increased the probability of a full clutch from 0.60 to 0.93 for Western Sandpipers and from 0.76 to 0.97 for Red-necked Phalaropes, and increased daily nest survival rates from 0.9634 to 0.9890 for Semipalmated Sandpipers and 0.9546 to 0.9880 for Western Sandpipers. Higher abundance of predators (foxes) reduced daily nest survival rates only in Western Sandpipers (0.9821-0.9031). In contrast to our predictions, the probability of a full clutch was lowest (0.83) for Semipalmated Sandpipers at moderate abundance of alternative prey, rather than low abundance (0.90). Our findings suggest that in the short-term, climate warming may have neutral or positive effects on the nesting cycle of most Arctic-breeding shorebirds.
- Effects of Landscape Characteristics on Annual Survival of Lesser Prairie-ChickensRobinson, Samantha G.; Haukos, David A.; Plumb, Reid T.; Kraft, John D.; Sullins, Daniel S.; Lautenbach, Joseph M.; Lautenbach, Jonathan D.; Sandercock, Brett K.; Hagen, Christian A.; Bartuszevige, Anne; Rice, Mindy A. (2018-07)Agriculture and development have caused landscape change throughout the southwestern Great Plains in the range of the lesser prairie-chicken (Tympanuchus pallidicinctus). Landscape alteration within the lesser prairie-chicken range may contribute to range contraction and population losses through decreases in survival rates. Our objectives were to determine if: (1) landscape configuration (i.e., the spatial arrangement of habitat) or composition (i.e., the amount of habitat), at the study.site scale, affected annual survival of females, (2) relationships exist between landscape context (i.e., landscape configuration and composition) and weekly survival to assess effects of landscape composition and configuration on lesser prairie-chicken populations, and (3) anthropogenic features influenced daily mortality risk. We captured 170 female lesser prairie-chickens and used very-high-frequency and GPS (Global Positioning System) transmitters to track their movement and survival for 2 y. We used known-fate survival models to test if landscape configuration or composition within three sites in Kansas were related to differences in female survival among sites. In addition we tested for relationships between weekly survival and landscape configuration or composition within home ranges. Finally, we used Andersen-Gill models to test the influence of distance to anthropogenic features on daily mortality risk. Differences in survival were evident between sites with differing landscape compositions as annual survival in Northwestern Kansas (S=0.27) was half that of Clark County, Kansas (S=0.56), which corresponded with 41.9% more grassland on the landscape in Clark County; landscape configuration did not measurably differ among sites. Survival was greater for prairie-chickens with home-ranges that had greater patch richness and in areas with 30% crop and 57% grassland. Female lesser prairie-chickens also experienced greater mortality risk closer to fences at patch edges. Further conversion of grassland landscapes occupied by lesser prairie-chickens should be avoided to reduce habitat loss and fragmentation thresholds that could affect survival. We suggest continued encouragement of Conservation Reserve Program enrollment in western areas of the lesser prairie-chicken range to maintain or increase the amount of grassland to increase annual survival.
- Effects of leg flags on nest survival of four species of Arctic-breeding shorebirdsWeiser, Emily L.; Lanctot, Richard B.; Brown, Stephen C.; Gates, H. River; Bentzen, Rebecca L.; Boldenow, Megan L.; Cunningham, Jenny A.; Doll, Andrew C.; Donnelly, Tyrone F.; English, Willow B.; Franks, Samantha E.; Grond, Kirsten; Herzog, Patrick; Hill, Brooke L.; Kendall, Steven J.; Kwon, Eunbi; Lank, David B.; Liebezeit, Joseph R.; Rausch, Jennie; Saalfeld, Sarah T.; Taylor, Audrey R.; Ward, David H.; Woodard, Paul F.; Sandercock, Brett K. (2018-09)Marking wild birds is an integral part of many field studies. However, if marks affect the vital rates or behavior of marked individuals, any conclusions reached by a study might be biased relative to the general population. Leg bands have rarely been found to have negative effects on birds and are frequently used to mark individuals. Leg flags, which are larger, heavier, and might produce more drag than bands, are commonly used on shorebirds and can help improve resighting rates. However, no one to date has assessed the possible effects of leg flags on the demographic performance of shorebirds. At seven sites in Arctic Alaska and western Canada, we marked individuals and monitored nest survival of four species of Arctic-breeding shorebirds, including Semipalmated Sandpipers (Calidris pusilla), Western Sandpipers (C. mauri), Red-necked Phalaropes (Phalarope lobatus), and Red Phalaropes (P. fielicarius). We used a daily nest survival model in a Bayesian framework to test for effects of leg flags, relative to birds with only bands, on daily survival rates of 1952 nests. We found no evidence of a difference in nest survival between birds with flags and those with only bands. Our results suggest, therefore, that leg flags have little effect on the nest success of Arctic-breeding sandpipers and phalaropes. Additional studies are needed, however, to evaluate the possible effects of flags on shorebirds that use other habitats and on survival rates of adults and chicks.
- Identifying the diet of a declining prairie grouse using DNA metabarcodingSullins, Daniel S.; Haukos, David A.; Craine, Joseph M.; Lautenbach, Joseph M.; Robinson, Samantha G.; Lautenbach, Jonathan D.; Kraft, John D.; Plumb, Reid T.; Reitz, Jonathan H.; Sandercock, Brett K.; Fierer, Noah (2018-07)Diets during critical brooding and winter periods likely influence the growth of Lesser Prairie-Chicken (Tympanuchus pallidicinctus) populations. During the brooding period, rapidly growing Lesser Prairie-Chicken chicks have high calorie demands and are restricted to foods within immediate surroundings. For adults and juveniles during cold winters, meeting thermoregulatory demands with available food items of limited nutrient content may be challenging. Our objective was to determine the primary animal and plant components of Lesser Prairie-Chicken diets among native prairie, cropland, and Conservation Reserve Program (CRP) fields in Kansas and Colorado, USA, during brooding and winter using a DNA metabarcoding approach. Lesser Prairie-Chicken fecal samples (n = 314) were collected during summer 2014 and winter 2014-2015, DNA was extracted, amplified, and sequenced. A region of the cytochrome oxidase I (COI) gene was sequenced to determine the arthropod component of the diet, and a portion of the trnL intron region was used to determine the plant component. Relying on fecal DNA to quantify dietary composition, as opposed to traditional visual identification of gut contents, revealed a greater proportion of soft-bodied arthropods than previously recorded. Among 80 fecal samples for which threshold arthropod DNA reads were obtained, 35% of the sequences were most likely from Lepidoptera, 26% from Orthoptera, 14% from Araneae, 13% from Hemiptera, and 12% from other orders. Plant sequences from 137 fecal samples were composed of species similar to Ambrosia (27%), followed by species similar to Lactuca or Taraxacum (10%), Medicago (6%), and Triticum (5%). Forbs were the predominant (>50% of reads) plant food consumed during both brood rearing and winter. The importance both of native forbs and of a broad array of arthropods that rely on forbs suggests that disturbance regimes that promote forbs may be crucial in providing food for Lesser Prairie-Chickens in the northern portion of their distribution.
- Strategic conservation for lesser prairie-chickens among landscapes of varying anthropogenic influenceSullins, Daniel S.; Haukos, David A.; Lautenbach, Joseph M.; Lautenbach, Jonathan D.; Robinson, Samantha G.; Rice, Mindy B.; Sandercock, Brett K.; Kraft, John D.; Plumb, Reid T.; Reitz, Jonathan H.; Hutchinson, J. M. Shawn; Hagen, Christian A. (2019-10)For millennia grasslands have provided a myriad of ecosystem services and have been coupled with human resource use. The loss of 46% of grasslands worldwide necessitates the need for conservation that is spatially, temporally, and socioeconomically strategic. In the Southern Great Plains of the United States, conversion of native grasslands to cropland, woody encroachment, and establishment of vertical anthropogenic features have made large intact grasslands rare for lesser prairie-chickens (Tympanuchus pallidicinctus). However, it remains unclear how the spatial distribution of grasslands and anthropogenic features constrain populations and influence conservation. We estimated the distribution of lesser prairie-chickens using data from individuals marked with GPS transmitters in Kansas and Colorado, USA, and empirically derived relationships with anthropogenic structure densities and grassland composition. Our model suggested decreased probability of use in 2-km radius (12.6 km(2)) landscapes that had greater than two vertical features, two oil wells, 8 km of county roads, and 0.15 km of major roads or transmission lines. Predicted probability of use was greatest in 5-km radius landscapes that were 77% grassland. Based on our model predictions, similar to 10% of the current expected lesser prairie-chicken distribution was available as habitat. We used our estimated species distribution to provide spatially explicit prescriptions for CRP enrollment and tree removal in locations most likely to benefit lesser prairie-chickens. Spatially incentivized CRP sign up has the potential to provide 4189 km2 of additional habitat and strategic application of tree removal has the potential to restore 1154 km(2). Tree removal and CRP enrollment are conservation tools that can align with landowner goals and are much more likely to be effective on privately owned working lands.