Spotlight Surveys Research Articles

Sheoak woodlands: a newly identified habitat for western ringtail possums

ABSTRACTAlthough critically endangered western ringtail possums (Pseudocheirus occidentalis) have been recorded from a variety of vegetation types in southwestern Australia, the extent to which many of these vegetation types are occupied by the species remains unknown. We conducted spotlight surveys for western ringtail possums between March and April 2018 in Albany, southwestern Australia, to determine the species’ occupancy in 2 vegetation types. Using occupancy models, we demonstrated that sheoak (Allocasuarina fraseriana) woodlands, previously unrecognized as providing western ringtail possum habitat, support the species, although the median probability of their occupancy was lower than in marri (Corymbia calophylla) and eucalypt (Eucalyptus marginata and E. staeri) woodlands. Use of trees and other habitat components by western ringtail possums varied within and between vegetation types. Sheoak woodlands are likely critical for western ringtail possums and given the apparent flexibility in vegetation types used by the species, investigation of the potential value of other vegetation types for this species has conservation merit. © 2019 The Wildlife Society.

A Spatially and Temporally Concurrent Comparison of Popular Abundance Estimators for White-tailed Deer

The enumeration of Odocoileus virginianus (White-tailed Deer, hereafter, Deer) populations is an important objective for many managers, but no consensus regarding the most appropriate scientific methodology exists. Extensive research has been conducted involving comparisons of multiple methods to evaluate the effectiveness of estimating demographics of free-ranging populations; however, most fail to account for spatial or temporal differences in their comparisons. We estimated the density of an open population of Deer on a strict concurrent spatial and temporal scale during 3 separate 14-day periods (August 2012, February 2013, August 2013) using 4 methods: road-based distance sampling using spotlight surveys, FLIR surveys, and camera surveys using both the Jacobson analysis method or an N-mixture model abundance analysis. Spotlight surveys were affordable but required substantial effort to achieve the precision necessary for management decisions. FLIR surveys had greater detection probabilities relative to spotlight surveys and required less effort to achieve sufficient precision. Jacobson camera surveys appeared to overestimate Deer density and provided no measures of precision. The N-mixture model camera surveys provided sufficient precision and generated point estimate and detection probabilities similar to FLIR surveys. Camera surveys were costlier and more labor intensive relative to road-based surveys. We recommend road-based distance sampling using FLIR technology to estimate Deer density, but managers should understand the limitations and biases associated with any density estimate before incorporating the results into a management program.

Influence of salinity on relative density of American crocodiles (Crocodylus acutus) in Everglades National Park: Implications for restoration of Everglades ecosystems

The status of the American crocodile (Crocodylus acutus) has long been a matter of concern in Everglades National Park (ENP) due to its classification as a federal and state listed species, its recognition as a flagship species, and its function as an ecosystem indicator. Survival and recovery of American crocodiles has been linked with regional hydrological conditions, especially freshwater flow to estuaries, which affect water levels and salinities. We hypothesize that efforts to restore natural function to Everglades ecosystems by improving water delivery into estuaries within ENP will change salinities and water levels which in turn will affect relative density of crocodiles. Monitoring ecological responses of indicator species, such as crocodiles, with respect to hydrologic change is necessary to evaluate ecosystem responses to restoration projects. Our objectives were to monitor trends in crocodile relative density within ENP and to determine influences of salinity on relative density of crocodiles. We examined count data from 12 years of crocodile spotlight surveys in ENP (2004–2015) and used a hierarchical model of relative density that estimated relative density with probability of detection. The mean predicted value for relative density (λ) across all surveys was 2.9 individuals/km (95% CI: 2.0–4.2); relative density was estimated to decrease with increases in salinity. Routes in ENP’s Flamingo/Cape Sable area had greater crocodile relative density than routes in the West Lake/Cuthbert Lake area and Northeast Florida Bay areas. These results are consistent with the hypothesis that restored flow and lower salinities will result in an increase in crocodile population size and provide support for the ecosystem management recommendations for crocodiles, which currently are to restore more natural patterns of freshwater flow to Florida Bay. Thus, monitoring relative density of American crocodiles will continue to be an effective indicator of ecological response to ecosystem restoration.

Habitat suitability, live abundance and their link to road mortality of Tasmanian wildlife

ContextTasmania has been called the roadkill capital of Australia. However, little is known about the population-level impact of vehicle mortality on native mammals in the island state. AimsThe aims were to investigate the predictability of roadkill on a given route, based on models of species distribution and live animal abundance for three marsupial species in Tasmania – the Tasmanian pademelon (Thylogale billardierii), Bennett’s wallaby (Macropus rufogriseus) and the bare-nosed wombat (Vombatus ursinus) – and to assess the possibility of predicting the magnitude of state-wide road mortality based on live animal abundance. MethodsRoad mortality of the three species was measured on eight 15-km road segments in south-eastern Tasmania, during 16 weeks over the period 2016–17. Climate suitability was predicted using state-wide geographical location records, using species distribution models, and counts of these species from 190 spotlight survey roads. Key resultsThe Tasmanian pademelons were the most frequently killed animal encountered over the study period. Live abundance, predicted by fitting models to spotlight counts, did not correlate with this fatality rate for any species. However, the climate suitability index generated by the species distribution models was strongly predictive for wombat roadkill, and moderately so for pademelons. ConclusionsAlthough distributional and wildlife abundance records are commonly available and well described by models based on climate, vegetation and land-use predictors, this approach to climate suitability modelling has limited predictability for roadkill counts on specific routes. ImplicationsRoad-specific factors, such as characteristics of the road infrastructure, nearby habitats and behavioural traits, seem to be required to explain roadkill frequency. Determining their relative importance will require spatial analysis of roadkill locations.

Long-Term Monitoring of Scripps's Murrelet and Guadalupe Murrelet at San Clemente Island, California: Evaluation of Baseline Data in 2012–2016

San Clemente Island (SCI) supports one of the smallest Scripps's Murrelet (Synthliboramphus scrippsi; SCMU) colonies in the world, and perhaps the only colony of Guadalupe Murrelets (S. hypoleucus; GUMU) in California. In 2012–2016, the U.S. Navy sponsored development of a long-term murrelet monitoring program at SCI that utilized nocturnal spotlight surveys, night-lighting at-sea captures, and nest monitoring. Standardized spotlight survey transects were established in nearshore waters off breeding areas at Seal Cove and southeast SCI (SESCI). Baseline mean spotlight counts were 29 ± 15 murrelets (n = 31) at Seal Cove in 2013–2016 and 21 ± 10 murrelets (n = 15) at SESCI in 2014–2016. We banded 201 SCMU captured in congregations at Seal Cove (n = 158) and SESCI (n = 43); 12% of the SCMU from Seal Cove and 7% from SESCI were recaptured ≥1 year after banding. We also banded 21 GUMU at Seal Cove, but none were recaptured. Murrelet nests or eggs were found in 6 shoreline breeding “refuges” at Seal Cove and SESCI that were seldom if ever visited by island foxes (Urocyon littoralis clementae) and feral cats (Felis catus). Incubating SCMU were observed in 4 nest sites, but in 8 other sites only eggs or eggshells were found. Overall hatching success was very low (12%; n = 17 clutches) in 2012–2016, apparently due to intraspecific competition for limited nest crevices at Seal Cove and predation (or possibly abandonment and subsequent egg scavenging) by foxes or black rats (Rattus rattus) at SESCI. Using spotlight survey data, we estimated 115 murrelet pairs (range 79–208) at SCI, including 110 pairs (range 76–199) of SCMU and 5 pairs (range 3–9) of GUMU, although a GUMU nest has not yet been found. Power analyses of Seal Cove spotlight data indicated that surveys conducted over 9 nights per year for 20 years could reliably (power ≥ 0.90) detect minimum population changes of ±1.7% per annum. Additional efforts are needed to (1) confirm the breeding status of GUMU; (2) investigate alternative methods of rat control to increase hatching success in murrelet breeding refuges; and (3) enhance breeding habitats to reduce intraspecific competition for nest sites and increase the number of monitored nests.

Scripps's Murrelet at San Miguel Island, California: Status of a Small Population at the Northwest Limit of the Breeding Range

San Miguel Island (SMI) and its adjacent islets, Prince Island and Castle Rock, support a small population of Scripps's Murrelets (Synthliboramphus scrippsi) at the northwest limit of their breeding range. In 1994–1996, 2004, 2007, and 2015, we conducted at-sea surveys and nest searches to determine the breeding distribution and population size of the Scripps's Murrelet at the SMI group. During at-sea vocal surveys in 1994–1996, murrelet calls were heard at 4 stations around Prince Island (43–167 calls), 2 stations off Castle Rock (6 calls and 80 calls), and 4 stations off northeast SMI (5–123 calls), but none were detected at 8 stations off southern and northwestern SMI. At-sea spotlight surveys in 2004, 2007, and 2015 confirmed murrelet congregations off Prince Island and northeast SMI. Annual mean (±SD) spotlight counts on a standard transect off of northeast SMI and Prince Island were 9 ± 0 murrelets (n = 2) in 2004, 19 ± 4 (n = 3) in 2007, and 91 ± 15 (n = 2) in 2015; much higher spotlight counts at Prince Island accounted for the higher mean in 2015. We found murrelet nests in 4 of the 12 areas searched at SMI and Prince Island. In 2007 the first murrelet nests ever found on SMI proper were discovered at Harris Point, Bay Point, and Hoffman Point in isolated shoreline habitats that were inaccessible to endemic Island Foxes (Urocyon littoralis littoralis) but accessible to nonnative Black Rats (Rattus rattus). Using spotlight counts we estimated 100–263 breeding pairs at the SMI group in 2015, mainly at Prince Island (90%) where foxes and rats were absent. Spotlight surveys have not been conducted at Castle Rock, but <5 pairs were suspected. Introducing rats from SMI proper to the offshore islets is the most serious threat to murrelets at this remote island, although a large oil spill could also extirpate this population. Spotlight surveys and nest searches should be conducted at least every 5 years to confirm persistence of this vulnerable species at SMI and to detect major changes in population size.

How to estimate population size in crocodylians? Population ecology of American crocodiles in Coiba Island as study case

AbstractReliable estimates of crocodylian population size are desirable for both understanding the ecology and natural history of species and developing sound conservation and management plans. However, choosing appropriate methods to estimate population numbers can be difficult due to the paucity of comprehensive analyses regarding their effectiveness, robustness, and applicability. We estimated the American crocodile population size in the southern tip of Coiba Island, Panama, using both spotlight surveys (Messel's and King's visible fraction estimations) and mark–recapture (POPAN formulation–superpopulation) methods. We assessed and compared the outcomes of these methods with the overall capture record for the study area from 2009 to 2013, evaluating their applicability, accuracy, strengths, and limitations. Using historical and current capture data, we defined a minimum population size of ~112 non‐hatchling animals in our study area, which was larger than both Messel's (19.00 ± 7.50 individuals) and King's (25.71 ± 7.25 individuals) population size estimates, revealing that these latter approaches clearly underestimate population numbers. We estimated a total population size that range between 147 and 257 individuals based on POPAN formulation grouping the data by sex and age groups as the most plausible population size of the American crocodile population in this area at the time. We analyzed and discussed sources of bias in population size estimations for all methods used in the present study, providing recommendations to minimize errors and improve estimations. Finally, we analyzed and compared population ecology attributes obtained in our study with what have been reported in other insular and coastal areas across the American crocodile range, increasing knowledge about the ecology of the species.

Exploring the cross-sectional association between outdoor recreational facilities and leisure-time physical activity: the role of usage and residential self-selection

BackgroundThe availability of outdoor recreational facilities is associated with increased leisure-time physical activity (PA). We investigated how much of this association is attributable to selection effects, and explored whether usage of recreational facilities was an explanatory mechanism.MethodsWe analysed data from 5199 participants in the SPOTLIGHT survey residing in five European urban regions. Adults completed a survey and a Google Street View-based virtual audit was conducted to objectively measure the availability of outdoor recreational facilities in the residential neighbourhood. We used negative binomial GEE models to examine the association between objective and subjective availability of outdoor recreational facilities and leisure-time PA, and explored whether this association was attenuated after adjustment for socioeconomic status and preference for neighbourhoods with recreational facilities (as indicators of self-selection). We examined whether reported use of recreational facilities was associated with leisure-time PA (as explanatory mechanism), and summarized the most important motivations for (not) using recreational facilities.ResultsSubjective – but not objective – availability of outdoor recreational facilities was associated with higher levels of total leisure-time PA. After adjustment for self-selection (which attenuated the association by 25%), we found a 25% difference in weekly minutes of total leisure-time PA between individuals with and without self-reported availability of outdoor recreational facilities. For our study population, this translates to about 28 min per week. Participants who reported outdoor recreational facilities to be present but indicated not to use them (RR = 1.19, 95% CI = 1.03;1.22), and those reporting outdoor recreational facilities to be present and to use them (RR = 1.33, 95% CI = 1.22, 1.45) had higher levels of total leisure-time PA than those who reported outdoor recreational facilities not to be present. Proximity to outdoor recreational facilities was the most important motivation for use.ConclusionThe modest attenuation in the association between availability of outdoor recreational facilities and self-reported leisure-time PA suggests that individuals’ higher activity levels may be due more to the perceived availability of outdoor recreational facilities than to self-selection. The use of these facilities seemed to be an important underlying mechanism, and proximity was the main motivator for using recreational facilities.

Terrestrial invertebrates: An underestimated predator guild for small vertebrate groups

A fundamental goal of ecology is to describe how organisms co-exist in environments, including predator–prey interactions. However, one challenge for this field of study is that predation events can be rare and relatively difficult to observe, thus they are seldom quantified in nature. Vertebrates are the top predators in many systems, but large invertebrates such as spiders, mantids, and centipedes may also be important predators of small vertebrate groups. We used several approaches to determine the relative frequency of predation by invertebrate and vertebrate predators in terrestrial systems. We conducted 500h of visual surveys and compiled observations of in situ predation events from 2014 to 2016 in north Queensland, Australia. Predation events were rarely observed: in 500h of visual searches, we observed 9 instances of predation (vertebrates consuming another vertebrate, n=4; invertebrates consuming a vertebrate, n=5). In addition to spotlight surveys, we deployed 800 lizard-shape models to quantify attack frequencies on small lizards. While vertebrate predators were responsible for the most attacks on lizard models (76.7% and 93.3%, wet and dry season respectively), invertebrate predators were responsible for 23.3% and 6.8% of attacks. While predation events (of any kind) were rarely observed, we suggest that predation by invertebrate predators on vertebrate prey should not be overlooked in terrestrial systems. Invertebrate predators may play an important predatory role in shaping populations of small vertebrates, similar to more “typical” predators such as snakes, birds, and mammals.

Lack of interest in physical activity - individual and environmental attributes in adults across Europe: The SPOTLIGHT project

A considerable proportion of European adults report little or no interest in physical activity. Identifying individual-level and environmental-level characteristics of these individuals can help designing effective interventions and policies to promote physical activity. This cross-sectional study additionally explored associations between level of interest and physical activity, after controlling for other individual and environmental variables. Measures of objective and perceived features of the physical environment of residence, self-reported physical activity and other lifestyle behaviors, barriers towards physical activity, general health, and demographics were obtained from 5205 European adults participating in the 2014 online SPOTLIGHT survey. t-Tests, chi-square tests, and generalized estimating equations with negative binomial log-link function were conducted. Adults not interested in physical activity reported a higher BMI and a lower self-rated health, were less educated, and to a smaller extent female and less frequently employed. They were more prone to have less healthy eating habits, and to perceive more barriers towards physical activity. Only minor differences were observed in environmental attributes: the non-interested were slightly more likely to live in neighborhoods objectively characterized as less aesthetic and containing more destinations, and perceived as less functional, safe, and aesthetic. Even after controlling for other individual and environmental factors, interest in physical activity remained a significant correlate of physical activity, supporting the importance of this association. This study is among the first to describe characteristics of individuals with reduced interest in physical activity, suggesting that (lack of) interest is a robust correlate of physical activity in several personal and environmental conditions.

Contextual correlates of happiness in European adults.

ObjectivesWe aimed to examine the associations of both objectively assessed and perceived physical and social neighborhood characteristics with happiness in European adults. In addition, we aimed to study how these associations differed among subgroups.MethodsParticipants (N = 6037) of the cross-sectional SPOTLIGHT survey reported on their level of happiness using a 5-point Likert scale, and on perceived physical and social environmental neighborhood characteristics. Objective physical environmental characteristics were assessed using a Google Street View-based neighborhood audit. Associations of 14 physical and social environmental characteristics with happiness were analyzed using multivariable multinomial regression analyses with clustered standard errors.ResultsLiving in neighborhoods with higher levels of aesthetics and more water and green space was associated with being very happy. Individuals who perceived their neighborhood to be safer, more functional and more aesthetic were more likely to be very happy. The associations of functionality and aesthetics with happiness were strongest in the Ghent region (Belgium), the Randstad (the Netherlands) and Greater London (United Kingdom). Perceived absence of air pollution was only associated with higher levels of happiness in more highly educated participants. Individuals with a larger social network, more social cohesion and who trusted their neighbors were more likely to be very happy. The association between social networks and happiness was somewhat stronger in men than in women. In general, the associations between environmental characteristics and happiness had similar directions and sizes across socio-economic and socio-demographic subgroups.ConclusionsThis European study provided evidence that both objectively assessed and perceived physical and social characteristics of the neighborhood environment are associated with the happiness of its residents.

The effect of landscape heterogeneity on population density and habitat preferences of the European hare (Lepus europaeus) in contrasting farmlands

We assessed the effect of habitat heterogeneity and predator density on the European hare (Lepus europaeus), a declining farmland specialist, in intensive farmlands in Central Europe. Using spotlight surveys we explored population density and habitat preference of the European hare in spring and autumn during 2014–2015 in seven farmland regions, of which six were located in the Czech Republic and one in Austria. The average population density of European hares significantly differed between study regions in the Czech Republic and Austria, however, we found no differences in population density between autumn and spring. In particular, the average European hare population density in study regions in the Czech Republic varied between 6.8–17.0 individuals/100ha, whereas in Austria the population density reached 65.3 individuals/100ha. Differences between spring and autumn population densities were not significant. European hare population density was significantly negatively affected by mean patch size and positively by area of arable land. We did not find a significant effect of red fox (Vulpes vulpes) presence on the numbers of European hares in individual regions. Habitat preferences differed among regions with contrasting population densities and field sizes, hares in regions of high density and small fields were more equally distributed among available habitats compared to regions of low or intermediate density and large fields. To conclude, conservation measures focusing on enhancing habitat heterogeneity by reducing field size may be an effective tool to support populations of European hares in arable farmland landscapes.

Population trends for Scripps's murrelet following eradication of black rats

ABSTRACTNest monitoring at Anacapa Island, California, USA, in 2001–2010 documented considerable benefits for Scripps's murrelets (Synthliboramphus scrippsi) following the eradication of black rats (Rattus rattus) in 2002. In 2014, post‐eradication monitoring resumed at Anacapa to update the number of occupied nests in monitored plots, count murrelets in nocturnal at‐sea congregations near Anacapa using round‐island spotlight surveys, and compare post‐eradication rates of population change (λ) estimated from nest counts and spotlight surveys. Nest counts and spotlight counts demonstrated increases; the overall number of nests increased 4.45 times from 2001 (11 nests) to 2014 (60 nests) and mean round‐island counts in 2014 (869 ± 592 [SD]) were higher than in 2001–2003 (227 ± 151). Time series regression yielded annual increases that were marginally higher for nests (λ = 1.151) compared to round‐island counts (λ = 1.122). The slight difference may have resulted from inherent differences in the indices used to measure λ, spatial biases in nest plots, data gaps in the regressions, and small sample biases for round‐island counts. The post‐eradication λ for murrelets at Anacapa was slightly higher than the mean response reported for other Alcidae (λ = 1.113). This was the first use of spotlight surveys to estimate λ based on counts of seabirds congregating at‐sea near breeding areas. This study provided vital information needed to better assess the risks and benefits of future island restoration actions, justification for further murrelet conservation efforts, and confirmation of spotlight surveys as a population monitoring tool for Scripps's murrelets. © 2017 The Wildlife Society.

Individual and environmental correlates of objectively measured sedentary time in Dutch and Belgian adults.

As the detrimental health effects of sedentary behaviour are well established, insight into the individual and environmental factors that influence adults’ sedentary behaviour is needed. Most studies to date rely on self-reported measures of sedentary time. Therefore, the aim of the current study was to examine individual and environmental correlates of objectively measured sedentary time in Dutch and Belgian adults. Between March and August 2014, Belgian (n = 133) and Dutch (n = 223) adults, recruited as sub-sample of the SPOTLIGHT survey, wore an ActiGraph accelerometer to provide objectively measured sedentary and moderate to vigorous physical activity time. Participants completed a questionnaire assessing sociodemographic (country of residence, age, gender and educational level), lifestyle (sleep, smoking, sugar-containing beverage consumption, alcohol intake), health (body mass index, self-rated health), work (employment status and type of work), happiness, physical environmental (owning a car, number of screens, socioeconomic status and residential density) and social environmental factors (social network, social cohesion). Univariate and multivariable regression analyses showed that Belgian participants had a lower odds of being sedentary for at least 9 hours per day compared to Dutch participants. Women, older participants and those meeting the WHO recommendation for physical activity were also less likely to sit for 9 hours or more per day. Participants doing (heavy) manual work or being in education, homemaker, unemployed had lower odds of being sedentary for at least 9 hours per day compared to participants with a sitting job. Those with a higher self-reported social network also had lower odds for sedentary time. No associations between physical and other social environmental characteristics and sedentary time were found. Our findings add to the growing evidence of factors associated with prolonged sedentary time in adults. These findings may be used to inform the development of strategies and interventions aimed at reducing sedentary time, and to identify high risk groups.

Estimating Cape hare occupancy and abundance in southern Tunisia using spotlighting data

This study outlines the importance of integrating spotlighting data and occupancy modelling to estimate the spatial occupancy, abundance and habitat preferences of Cape hares Lepus capensis in southern Tunisia. Exploring the spatial distribution pattern of this species is problematic because of its nocturnal and secretive behaviour. In order to overcome these constraints, we used spotlight surveys on equidistant points along tracks to collect presence/absence data. Using a likelihood-based approach, we estimated occupancy and relative abundance of Cape hare populations in three national parks: Sidi Toui, Bouhedma and Jbil. We also combined the three parks in a single area to represent ‘southern Tunisia’ for investigating the factors affecting its distribution pattern. Sidi Toui showed the highest occupancy and relative abundance values (88.84 ± 10.95% and 7.97 hares km−2, respectively). Bouhedma was also recognised as high-quality hare habitat with occupancy and relative abundance values of 61.70 ± 11.70% and 2.85 hares km−2, respectively. The lowest occupancy (49.65 ± 26.25%) and relative abundance (2.10 hares km−2) estimates were encountered in Jbil. The combined parks model suggested that part of the distribution pattern of Cape hares can be explained by habitat quality. Spatial occupancy over southern Tunisia showed a positive relationship between its occurrence and the availability of Poaceae and Plantaginaceae.

Large‐scale responses of herbivore prey to canid predators and primary productivity

AbstractAimThe primacy of top‐down (consumption) and bottom‐up effects (primary productivity) as forces structuring ecological communities is a controversial topic. The exploitation ecosystems hypothesis (EEH) was invoked to explain biogeographical trends in plant and consumer biomass, and differs from the top‐down/bottom‐up dichotomy by predicting that the relative strength of these processes will vary along gradients of primary productivity. Here we test the prediction of the EEH that herbivore biomass should increase with increasing primary productivity where predators are rare, but show a negligible response to primary productivity where predators are common due to population regulation by predators.LocationBoreal and temperate regions of North America and Eurasia, and deserts of Australia.Time period1970–2016.Major taxa studiedCervids and kangaroos.MethodsWe obtained abundance indices of cervids at 42 locations from the literature and conducted spotlight surveys at 27 locations to derive estimates of kangaroo abundance. For analyses, herbivore abundances were converted to biomass per km2. We tested our prediction using linear mixed effects models.ResultsHerbivore biomass showed divergent responses to increasing primary productivity and the abundance of canid predators (grey wolves, Canis lupus/dingoes, Canis dingo). The slope of the relationship between herbivore biomass and net primary productivity did not differ between Australia and the northern boreal and temperate regions. Herbivore biomass increased in response to primary productivity where canid predators were rare, but showed muted responses to increasing productivity where canid predators were common.Main conclusionsCanid predators have strong suppressive effects on herbivore biomass that scale with primary productivity. Our study shows that the EEH has wide application to canid‐predator–herbivore dynamics and may be relevant to the management of herbivores because it can provide an indication of how herbivore biomass and densities may vary in relation to ecosystem productivity and the presence and absence of canid predators.

Exploring the mediating role of energy balance-related behaviours in the association between sleep duration and obesity in European adults. The SPOTLIGHT project.

Sleep restriction is a risk factor for weight gain and obesity. Few studies have formally investigated the mediating role of energy balance-related behaviours in the sleep - obesity association. The aim of this study was to explore the mediating role of physical activity, sedentary behaviours and dietary habits in the association of sleep duration with obesity in adults in five European urban regions. Data on self-reported sleep duration, energy balance-related behaviours, height and weight and other covariates were collected between February and September 2014 from participants to the SPOTLIGHT survey (N=5900, mean age 52years). Participants were recruited from 60 urban neighbourhoods in Belgium, France, Hungary, the Netherlands and the United Kingdom. Multilevel logistic regression analyses were used to assess the associations of sleep duration, energy balance-related behaviours and obesity and mediating effects were calculated using MacKinnon's product-of-coefficients method. Results indicated that a 1h increase in sleeping time was associated with a 14% lower likelihood of being obese (OR=0.86, 95%CI=0.80; 0.93). Only work-related sedentary behaviour was identified as a statistically significant mediator in the association between sleep duration and obesity for the total sample, and youngest and oldest age group. We did not find evidence for a mediating role of dietary habits and physical activities.

Factors Influencing the Abundance of American Alligators (Alligator mississippiensis) on Jekyll Island, Georgia, USA

Abstract Long-term management of American Alligator (Alligator mississippiensis) populations necessitates a more detailed understanding of the species' ecology in human-dominated areas. We conducted a 3-yr monitoring program of American Alligators on Jekyll Island, Georgia, USA, to investigate seasonal fluctuations in abundance and the abiotic and biotic (habitat) factors influencing American Alligator abundance in human-made stormwater lagoons. We conducted monthly daytime and evening spotlight surveys from April 2011 to September 2014. Spotlight counts yielded more accurate estimates of abundance. We observed American Alligators using human-made stormwater lagoons throughout the year; however, we observed significantly fewer individuals in the winter season (November–February) than in the mating (March–June) and nesting (July–October) seasons. We collected data on lagoon salinity, lagoon area, percentage of shoreline vegetation, and distance to nearest lagoon. We used the second-order Akaike Information...

Spring spotlight counts provide reliable indices to track changes in population size of mountain‐dwelling red deer Cervus elaphus

Monitoring changes in animal abundance is a central issue in conservation biology. Population indices may be a valuable support to wildlife managers in coarse‐scale survey programs, as they normally represent more intuitive and less expensive monitoring tools if compared with absolute estimates. Reliable indices of relative abundance, however, require validation against some known standards. We used mark‐resight estimates to investigate the performance of indices derived from spring spotlight surveys to track changes in a mountain‐dwelling population of red deer Cervus elaphus within the Stelvio National Park, central Italian Alps. Every spring between 2008 and 2015 we conducted four sessions of roadside‐counts using spotlights, recording all sightings of marked and unmarked individuals; the zero‐truncated Poisson log‐normal estimator was applied in a robust‐design fashion to return absolute estimates of spring abundance. We then compared the mark‐resight estimates with two indices of abundance, the maximum number (MNC) and the average number (ANC) of deer counted every spring in the four sampling occasions, using linear models on log‐transformed data. Both the MNC and the ANC proved reliable indices of relative abundance, as their relationships with mark‐resight estimates were positive and highly significant, and the beta coefficients of linear models were not significantly different from 1. The same analysis conducted on subsets of secondary sampling occasions suggested that at least 3 repeated counts every spring are necessary to consistently track changes in deer population size. The reliability of spotlight‐based indices to monitoring deer population changes has been widely debated, possibly owing to inconsistent performances of the method in different landscapes. For mountain‐dwelling deer populations living in similar habitats, our results suggest that spring spotlight surveys represent valuable tools in support of wildlife managers for long‐term, large‐scale monitoring programs; furthermore, they can provide appropriate indices to estimating population growth rates and thus modelling deer population dynamics.

The associations between domain-specific sedentary behaviours and dietary habits in European adults: a cross-sectional analysis of the SPOTLIGHT survey.

BackgroundSedentary behaviour has been associated with obesity and related chronic diseases. Disentangling the nature of this association is complicated due to interactions with other lifestyle factors, such as dietary habits, yet limited research has investigated the relation between domain-specific sedentary behaviours and dietary habits in adults. The aim of this paper was to examine the association between domain-specific sedentary behaviours and dietary habits in adults and to test the moderating effect of age and gender on this association.MethodsA total of 6,037 participants from five urban regions in Europe completed an online survey, of which 6,001 were included in the analyses. Multilevel mixed-effects logistic regression analyses were used to examine main associations and interaction effects.ResultsAll domain-specific sedentary behaviours, except transport-related sitting time, were significantly related to dietary habits. In general, having a higher sitting time was related to having less healthy dietary habits, especially for television viewing. Gender did not moderate any of the relations, and age was only a significant moderator in the relation between other leisure sitting time and alcohol consumption.ConclusionDomain-specific sitting behaviours were related to unhealthy dietary behaviours. However, the small effect sizes suggest that individual level behavioural interventions focusing on sedentary behaviour will not be sufficient to improve dietary habits. The fact that almost none of the associations were moderated by age or gender suggests that these associations, and possibly also the effects of interventions targeting both behaviours, may hold across age and gender groups.