Survival and Capture Efficiency of River Otters in Southern Illinois

River otter (Lontra canadensis) populations in Illinois have rebounded considerably after \u3e80 years of harvest protection and a successful reintroduction program. However, few studies of river otter ecology exist in the Midwestern U.S. where river otter numbers have increased in recent decades. Capturing study animals safely and efficiently is a critical part of wildlife research, and difficulties associated with live capture of river otters have contributed to the dearth of research on the species. Furthermore, estimating survival rates and identifying causes of mortality are important in effectively managing river otters. To address these knowledge gaps, my objectives were determine survival rates and mortality causes for river otters in southern Illinois, and to measure injury rates of river otters captured using Comstock traps. During 2014-16, I captured 42 river otters 49 times at Crab Orchard National Wildlife Refuge (CONWR) in southern Illinois. Eight river otters (3 M, 5 F) were captured in foot-hold traps during 788 trap nights (1 capture/88 trap nights), and the remaining 34 (19 M, 15 F) were captured in Comstock traps during 2,540 trap nights (1 capture/64 trap nights). I detected no significant differences in efficiency or escape rate between the 2 trap types, but Comstock traps did have higher rates for both unavailability and non-target captures. Eleven of the 20 river otters inspected for injuries received some type of injury as a result of capture in a Comstock trap (55%). The most common injury was claw loss (45%), followed by tooth fracture (25%), and lacerations (10%). The ease of setting the Comstock traps and of releasing non-target captures made them a more appealing option than foot-hold traps; however, river otters have a propensity for doing permanent damage to their teeth when live captured in Comstock traps. My study provides information on the functionality and safety of a novel live capture method for river otters. Thirty-four (16 F, 18 M) river otters were successfully radio-marked and monitored for survival for a total of 8,235 radio-days (¯x days/river otter = 242.2 ± 20.6 [SE throughout]). Two river otters (2 M) died during the period of radio-telemetry monitoring: 1 was trapped during nuisance wildlife control activities at an adjacent fish hatchery, and the other died of unknown causes. Annual survival rates were 1.0 ± 0.00 (lower confidence bound = 0.83) and 0.85 ± 0.09 for females and males, respectively, and similar between sexes (χ_1^2 = 1.7, P = 0.19). Pooled-sex breeding season survival was 0.96 ± 0.04. Trapping was the primary source of mortality over the course of my study. After radio-telemetry ended, 2 river otters were harvested by recreational trappers, at 114 (1 M) and 120 (1 F) weeks post-capture, and 1 male was killed by a vehicle collision at 52 weeks post-capture. Primary mortality sources for river otters in southern Illinois are similar to those reported elsewhere (i.e., trapping and vehicle collisions). Although I found no significant difference in survival rates between sexes, the majority of otters that died during my study were male (4 M, 1 F). As river otters occupying CONWR are protected from harvest, males may be more likely to leave the confines of CONWR, thereby putting themselves at greater risk to recreational trapping mortality. My study provides useful demographic information for Illinois’ recently-recovered river otter population

Spatio-temporal influence of tundra snow properties on Ku-band (17.2 GHz) backscatter

During the 2010/11 boreal winter, a distributed set of backscatter measurements was collected using a ground-based Ku-band (17.2 GHz) scatterometer system at 26 open tundra sites. A standard snow-sampling procedure was completed after each scan to evaluate local variability in snow layering, depth, density and water equivalent (SWE) within the scatterometer field of view. The shallow depths and large basal depth hoar encountered presented an opportunity to evaluate backscatter under a set of previously untested conditions. Strong Ku-band response was found with increasing snow depth and snow water equivalent (SWE). In particular, co-polarized vertical backscatter increased by 0.82 dB for every 1 cm increase in SWE (R2 = 0.62). While the result indicated strong potential for Ku-band retrieval of shallow snow properties, it did not characterize the influence of sub-scan variability. An enhanced snow-sampling procedure was introduced to generate detailed characterizations of stratigraphy within the scatterometer field of view using near-infrared photography along the length of a 5m trench. Changes in snow properties along the trench were used to discuss variations in the collocated backscatter response. A pair of contrasting observation sites was used to highlight uncertainties in backscatter response related to short length scale spatial variability in the observed tundra environment

Spoken word recognition in adolescents with autism spectrum disorders and specific language impairment

Spoken word recognition, during gating, appears intact in specific language impairment (SLI). This study used gating to investigate the process in adolescents with autism spectrum disorders plus language impairment (ALI). Adolescents with ALI, SLI, and typical language development (TLD), matched on nonverbal IQ listened to gated words that varied in frequency (low/high) and number of phonological onset neighbors (low/high density). Adolescents with ALI required more speech input to initially identify low-frequency words with low competitor density than those with SLI and those with TLD, who did not differ. These differences may be due to less well specified word form representations in ALI

Sex differences in eye gaze and symbolic cueing of attention

Observing a face with averted eyes results in a reflexive shift of attention to the gazed-at location. Here we present results that show that this effect is weaker in males than in females (Experiment 1). This result is predicted by the ‘extreme male brain’ theory of autism (Baron-Cohen, 2003), which suggests that males in the normal population should display more autism-like traits than females (e.g., poor joint attention). Indeed, participants′ scores on the Autism-Spectrum Quotient (Baron-Cohen, Wheelwright, Stott, Bolton, & Goodyear, 2001) negatively correlated with cueing magnitude. Furthermore, exogenous orienting did not differ between the sexes in two peripheral cueing experiments (Experiments 2a and 2b). However, a final experiment showed that using non-predictive arrows instead of eyes as a central cue also revealed a large gender difference. This demonstrates that reduced orienting from central cues in males generalizes beyond gaze cues. These results show that while peripheral cueing is equivalent in the male and female brains, the attention systems of the two sexes treat noninformative symbolic cues very differently

Genome-wide gene by environment study of time spent in daylight and chronotype identifies emerging genetic architecture underlying light sensitivity

Study Objectives: Light is the primary stimulus for synchronizing the circadian clock in humans. There are very large interindividual differences in the sensitivity of the circadian clock to light. Little is currently known about the genetic basis for these interindividual differences.Methods: We performed a genome-wide gene-by-environment interaction study (GWIS) in 280 897 individuals from the UK Biobank cohort to identify genetic variants that moderate the effect of daytime light exposure on chronotype (individual time of day preference), acting as “light sensitivity” variants for the impact of daylight on the circadian system.Results: We identified a genome-wide significant SNP mapped to the ARL14EP gene (rs3847634; p < 5 × 10−8), where additional minor alleles were found to enhance the morningness effect of daytime light exposure (βGxE = −.03, SE = 0.005) and were associated with increased gene ARL14EP expression in brain and retinal tissues. Gene-property analysis showed light sensitivity loci were enriched for genes in the G protein-coupled glutamate receptor signaling pathway and genes expressed in Per2+ hypothalamic neurons. Linkage disequilibrium score regression identified Bonferroni significant genetic correlations of greater light sensitivity GWIS with later chronotype and shorter sleep duration. Greater light sensitivity was nominally genetically correlated with insomnia symptoms and risk for post-traumatic stress disorder (PTSD).Conclusions: This study is the first to assess light as an important exposure in the genomics of chronotype and is a critical first step in uncovering the genetic architecture of human circadian light sensitivity and its links to sleep and mental healt

Time‐lapse photogrammetry reveals hydrological controls of fine‐scale High‐Arctic glacier surface roughness evolution

In a warming Arctic, as glacier snowlines rise, short- to medium-term increases in seasonal bare-ice extent are forecast for the next few decades. These changes will enhance the importance of turbulent energy fluxes for surface ablation and glacier mass balance. Turbulent energy exchanges at the ice surface are conditioned by its topography, or roughness, which has been hypothesized to be controlled by supraglacial hydrology at the glacier scale. However, current understanding of the dynamics in surface topography, and the role of drainage development, remains incomplete, particularly for the transition between seasonal snow cover and well-developed, weathered bare-ice. Using time-lapse photogrammetry, we report a daily timeseries of fine (millimetre)-scale supraglacial topography at a 2 m2 plot on the Lower Foxfonna glacier, Svalbard, over two 9-day periods in 2011. We show traditional kernel-based morphometric descriptions of roughness were ineffective in describing temporal change, but indicated fine-scale albedo feedbacks at depths of ~60 mm contributed to conditioning surface topography. We found profile-based and two-dimensional estimates of roughness revealed temporal change, and the aerodynamic roughness parameter, z0, showed a 22–32% decrease from ~1 mm following the exposure of bare-ice, and a subsequent 72–77% increase. Using geostatistical techniques, we identified ‘hole effect’ properties in the surface elevation semivariograms, and demonstrated that hydrological drivers control the plot-scale topography: degradation of superimposed ice reduces roughness while the inception of braided rills initiates a subsequent development and amplification of topography. Our study presents an analytical framework for future studies that interrogate the coupling between ice surface roughness and hydro-meteorological variables and seek to improve parameterizations of topographically evolving bare-ice areas