Importance of characterising sleep breaks within the 24-h movement behaviour framework

Accelerometers measure the acceleration of the body part they are attached and allow to estimate time spent in activity levels (sedentary behaviour, light, and moderate-to-vigorous physical activity) and sleep over a 24-h period for several consecutive days. These advantages come with the challenges to analyse the large amount of data while integrating dimensions of both physical activity/sedentary behaviour and sleep domains. This commentary raises the questions of 1) how to classify sleep breaks (i.e. wake after sleep onset) during the night within the 24-h movement behaviour framework and 2) how to assess their impact on health while also accounting for night time sleep duration and time in sedentary behaviour and physical activity during the day. The authors advocate for future collaborations between researchers from the physical activity/sedentary behaviour and sleep research fields to ensure appropriate analysis and interpretation of the tremendous amount of data recorded by the newer generation accelerometers. This is the only way forward to provide meaningfully accurate evidence to inform future 24-h movement behaviour guidelines.

Application of Extended Lattice Gas Automata Model in Ship Evacuation Simulation

Lattice gas automaton is a mathematical model that is used to simulate the horizontal uniform evacuation behaviour of a group. However, extended lattice gas automata model is proposed to examine marine evacuation behaviour, which is subject to deck heeling. The application of distance accumulation algorithm and the conversion probability mostly make the extended model, while the approach deals with the most complicated ship evacuation. Moreover, the suggested model is expected to enhance the safety and efficiency of evacuation. The distance accumulation lattice gas automata model considers multiple movement behaviours, flow density, deck heeling, counterflow, and congestion. Movement behaviour will be severely affected in deck heeling process where people may walk normally, walk while bent over, or crawl. To verify the proposed model, 11 test scenarios and several emergency evacuation scenarios are demonstrated. The simulation results explain the validity of another experimental model. The number of people in counterflow, deck heeling, and difference in movement have a direct effect on evacuation, which is as discussed in results. This research article provides a brief study on ship design and crew response behaviour in case of mishap/accident.

Survival, predation, and behaviour of the Mahoenui giant wētā ('Deinacrida mahoenui': Anostostomatidae: Orthoptera)

<p>Introduced mammalian pests, such as rats (Rattus spp.), house mice (Mus musculus), brushtail possums (Trichosurus vulpecula), and European hedgehogs (Erinaceus europaeus), have been implicated in the suppression or extinction of many endemic invertebrate species in New Zealand, including the large-bodied giant wētā (Anostostomatidae: Deinacrida). The Mahoenui giant wētā (MGW; D. mahoenui) is the only lowland giant wētā species still naturally present on the mainland of New Zealand, where the last remaining individuals of the original population are currently restricted to an 187ha mainland reserve (Mahoenui Giant Wētā Scientific Reserve; MGWSR) in Mahoenui, western King Country. Having sought refuge in the introduced woody shrub, gorse (Ulex europaeus), these wētā have survived in the presence of introduced mammalian predators for almost six decades. However, due to natural succession, the reserve is gradually reverting to native bush and wētā monitoring data shows potential signs of population decline. Concerns for the species survival have been raised as it is unknown how wētā will cope in an altered habitat alongside mammalian predators. In chapter 2, we used 14-years’ of site-occupancy monitoring data to explore changes to the reserves’ gorse mosaic and MGW population. We additionally assessed the effect of abiotic covariates on MGW occupancy and detection probabilities in 2005 and 2018. Furthermore, we assessed mammalian pest population dynamics within the reserve over the past seven years. Significant changes to the reserve’s gorse mosaic were identified, whereby unbrowsed, tall bushes, which may provide less protection to wētā, are now dominant in 2018. Population trajectory analysis revealed the MGW population has decline since 2012. This result was consistent with naïve occupancy estimates and the increase in search time (0.3hrs/year) required to find wētā, suggesting the population is in a state of decline. Plot location was identified as an important covariate for predicting MGW occupancy in 2018, whereby plots in edge habitat, potentially being preferred or safer, had a higher occupancy probability. Mammalian pests (rats, house mice, brushtail possums, and European hedgehogs) appear to be present within the reserve year-round, populations peaking in summer and autumn. In chapter 3, we used radiotelemetry to explore MGW survival rates, movement patterns, and diurnal refuge use in gorse and native vegetation during summer (n=14), autumn (n=31), and spring (n=10). Survival rates, in relation to predation, revealed MGW inhabiting native vegetation were nine times more likely to be predated than those inhabiting gorse. This result suggests native species such as mahoe (Melicytus ramiflorus), and tree ferns (Dicksonia fibrosa and Cyathea spp.) do not provide good protection to MGW from mammalian predators. Assessment of movement behaviour revealed MGW move less in autumn (~3m/48hrs) compared to summer (~10m/48hrs) and spring (~8m/48hrs), and most commonly follow a movement pattern consistent with random-walk. Movement behaviour was also found to be temperature dependant, with both male and female MGW moving significantly further in warmer weather (>13.5°C). Radiotracked MGW were found to take refuge above 2.5m in the canopy of native vegetation, whereas in gorse habitat, wētā were most commonly found taking refuge between 0.62 – 2.38m in the denser foliage of unbrowsed gorse bushes. Furthermore, no radiotracked wētā were observed with another individual in autumn, compared to eight and 26 observations in summer and spring. In chapter 4, we attempted to identify potential mammalian predators of the MGW by analysing the stomach contents of ship rats (R. rattus; n=10), house mice (n=10), brushtail possums (n=5), and feral cats (Felis catus; n=2). Ship rats were identified as likely predators of MGW within the MGWSR. However, due to the limited number of stomachs and species analysed, further analysis is recommended. Collectively, these results provide an overview of the MGW reserve and population status, in addition to important ecological information that can be used to inform future management, monitoring, and translocation.</p>

Survival, predation, and behaviour of the Mahoenui giant wētā ('Deinacrida mahoenui': Anostostomatidae: Orthoptera)

<p>Introduced mammalian pests, such as rats (Rattus spp.), house mice (Mus musculus), brushtail possums (Trichosurus vulpecula), and European hedgehogs (Erinaceus europaeus), have been implicated in the suppression or extinction of many endemic invertebrate species in New Zealand, including the large-bodied giant wētā (Anostostomatidae: Deinacrida). The Mahoenui giant wētā (MGW; D. mahoenui) is the only lowland giant wētā species still naturally present on the mainland of New Zealand, where the last remaining individuals of the original population are currently restricted to an 187ha mainland reserve (Mahoenui Giant Wētā Scientific Reserve; MGWSR) in Mahoenui, western King Country. Having sought refuge in the introduced woody shrub, gorse (Ulex europaeus), these wētā have survived in the presence of introduced mammalian predators for almost six decades. However, due to natural succession, the reserve is gradually reverting to native bush and wētā monitoring data shows potential signs of population decline. Concerns for the species survival have been raised as it is unknown how wētā will cope in an altered habitat alongside mammalian predators. In chapter 2, we used 14-years’ of site-occupancy monitoring data to explore changes to the reserves’ gorse mosaic and MGW population. We additionally assessed the effect of abiotic covariates on MGW occupancy and detection probabilities in 2005 and 2018. Furthermore, we assessed mammalian pest population dynamics within the reserve over the past seven years. Significant changes to the reserve’s gorse mosaic were identified, whereby unbrowsed, tall bushes, which may provide less protection to wētā, are now dominant in 2018. Population trajectory analysis revealed the MGW population has decline since 2012. This result was consistent with naïve occupancy estimates and the increase in search time (0.3hrs/year) required to find wētā, suggesting the population is in a state of decline. Plot location was identified as an important covariate for predicting MGW occupancy in 2018, whereby plots in edge habitat, potentially being preferred or safer, had a higher occupancy probability. Mammalian pests (rats, house mice, brushtail possums, and European hedgehogs) appear to be present within the reserve year-round, populations peaking in summer and autumn. In chapter 3, we used radiotelemetry to explore MGW survival rates, movement patterns, and diurnal refuge use in gorse and native vegetation during summer (n=14), autumn (n=31), and spring (n=10). Survival rates, in relation to predation, revealed MGW inhabiting native vegetation were nine times more likely to be predated than those inhabiting gorse. This result suggests native species such as mahoe (Melicytus ramiflorus), and tree ferns (Dicksonia fibrosa and Cyathea spp.) do not provide good protection to MGW from mammalian predators. Assessment of movement behaviour revealed MGW move less in autumn (~3m/48hrs) compared to summer (~10m/48hrs) and spring (~8m/48hrs), and most commonly follow a movement pattern consistent with random-walk. Movement behaviour was also found to be temperature dependant, with both male and female MGW moving significantly further in warmer weather (>13.5°C). Radiotracked MGW were found to take refuge above 2.5m in the canopy of native vegetation, whereas in gorse habitat, wētā were most commonly found taking refuge between 0.62 – 2.38m in the denser foliage of unbrowsed gorse bushes. Furthermore, no radiotracked wētā were observed with another individual in autumn, compared to eight and 26 observations in summer and spring. In chapter 4, we attempted to identify potential mammalian predators of the MGW by analysing the stomach contents of ship rats (R. rattus; n=10), house mice (n=10), brushtail possums (n=5), and feral cats (Felis catus; n=2). Ship rats were identified as likely predators of MGW within the MGWSR. However, due to the limited number of stomachs and species analysed, further analysis is recommended. Collectively, these results provide an overview of the MGW reserve and population status, in addition to important ecological information that can be used to inform future management, monitoring, and translocation.</p>

Behavioural patterns of two native Leiopelma frogs and implications for their conservation

<p>Amphibian populations are in general decline internationally. The current situation of amphibian populations highlights the urgent need for comprehensive information on species’ ecology to better assess conservation and management strategies. Movement behaviour and microhabitat selection give insights into how amphibians use the environment and interact with their surroundings, and are essential to establishing their sensitivity to the global decline phenomenon and identifying the critical habitat features essential for their success. New Zealand native frogs (Anura: Leiopelmatidae, Leiopelma, nine species) were formerly distributed throughout New Zealand, but habitat modification and predation by introduced mammalian predators have influenced recent (Holocene) extinctions and declines, reducing the fauna to four species with major range reductions. All extant Leiopelma are classified as threatened both nationally and internationally, creating an urgent need for species-specific behavioural research to support conservation management. I investigated activity, movement behaviour and microhabitat use of L. archeyi and L. pakeka for better evaluation of long term population viability and improved husbandry in captivity. L. archeyi is the smallest of the Leiopelma species and has been able to co-occur with introduced predators (e.g. rats), whereas L. pakeka is the largest, and the only natural population is confined to a predator-free island. I used a fine-scale tracking technique (i.e. non-toxic fluorescent powders) to track L. archeyi and L. pakeka movements throughout their activity periods when on the surface in their natural habitats, Whareorino Forest and Maud Island, respectively, to obtain detailed information on their activity patterns, movement behaviour, and microhabitat and retreat site use. I investigated in more detail L. pakeka retreat sites by measuring the dimensions of the retreat site entrances (width, height and diameter) as well as the activity inside those retreat sites. Lastly, I used long-term frog survey data to examine the indirect impacts (i.e. behavioural changes) ship rats (Rattus rattus) may have on L. archeyi by studying the microhabitat use and home range of this species in an area with and without rat control within Whareorino Forest. L. archeyi had a longer activity period than L. pakeka with the former being active up to two hours after sunrise, but L. pakeka moved more and further than L. archeyi during their activity periods. Additionally, L. archeyi had a smaller home range compared to L. pakeka which suggests more prominent site fidelity and more sedentary behaviour in this species. Both species actively sought out specific microhabitats among the ones that were available, either to use during movement or to use as retreat sites, but those microhabitat types also differed between species. L. archeyi were more often found above ground level than L. pakeka and tended to use microhabitats that provided cover. L. archeyi preferred to use trees as retreat sites (roots, branches or trunk) whereas L. pakeka used trees (roots) and rocks. L. pakeka retreat sites had lower and more stable temperatures than outside retreats. Frogs were active inside retreats with no evidence of sleep behaviour for at least the first few hours of retreat use. In the rat control area, L. archeyi used more soil, leaf litter and ferns, and were also more likely to be found at ground level than frogs in the presence of higher numbers of rats. Abiotic factors also influenced movement patterns and microhabitat selection of both species, affirming water balance and thermoregulation are important drivers in frog behaviour. Behavioural attributes and small body size could be aiding in the persistence of L. archeyi in the presence of rats, and large body size and differences in behavioural attributes are likely to put L. pakeka at risk if rats were to reach their habitat. My findings inform on the ecology and behaviour of two Leiopelma species providing valuable information on their habitat requirements, which will enable more effective captive husbandry and better assessment of the appropriateness of translocation sites, aiding in their conservation management.</p>

Prediction as a Basis for Skilled Reading: Insights from Natural Language Engineering Models

Reading is not an inborn human capability, and yet, English-speaking adults read with impressive speed. This study considered how predictions of upcoming words impact on this skilled behaviour. We used a powerful computer model from natural language engineering (GPT-2) to derive predictions of upcoming words in text passages. These predictions were highly accurate, and showed a tight relationship to fine-grained aspects of eye-movement behaviour when adults read those same passages, including whether to skip the next word and how long to spend on it. Strong predictions that did not materialise resulted in a prediction error cost on fixation durations. Our findings suggest that predictions for upcoming words can be made based on relatively superficial statistical information in reading, and that these predictions guide how our eyes interrogate text. This study is the first to demonstrate a relationship between the internal state of a modern natural language engineering model and eye-movement behaviour in reading, opening substantial new opportunities for language research and application.

Behavioural patterns of two native Leiopelma frogs and implications for their conservation

<p>Amphibian populations are in general decline internationally. The current situation of amphibian populations highlights the urgent need for comprehensive information on species’ ecology to better assess conservation and management strategies. Movement behaviour and microhabitat selection give insights into how amphibians use the environment and interact with their surroundings, and are essential to establishing their sensitivity to the global decline phenomenon and identifying the critical habitat features essential for their success. New Zealand native frogs (Anura: Leiopelmatidae, Leiopelma, nine species) were formerly distributed throughout New Zealand, but habitat modification and predation by introduced mammalian predators have influenced recent (Holocene) extinctions and declines, reducing the fauna to four species with major range reductions. All extant Leiopelma are classified as threatened both nationally and internationally, creating an urgent need for species-specific behavioural research to support conservation management. I investigated activity, movement behaviour and microhabitat use of L. archeyi and L. pakeka for better evaluation of long term population viability and improved husbandry in captivity. L. archeyi is the smallest of the Leiopelma species and has been able to co-occur with introduced predators (e.g. rats), whereas L. pakeka is the largest, and the only natural population is confined to a predator-free island. I used a fine-scale tracking technique (i.e. non-toxic fluorescent powders) to track L. archeyi and L. pakeka movements throughout their activity periods when on the surface in their natural habitats, Whareorino Forest and Maud Island, respectively, to obtain detailed information on their activity patterns, movement behaviour, and microhabitat and retreat site use. I investigated in more detail L. pakeka retreat sites by measuring the dimensions of the retreat site entrances (width, height and diameter) as well as the activity inside those retreat sites. Lastly, I used long-term frog survey data to examine the indirect impacts (i.e. behavioural changes) ship rats (Rattus rattus) may have on L. archeyi by studying the microhabitat use and home range of this species in an area with and without rat control within Whareorino Forest. L. archeyi had a longer activity period than L. pakeka with the former being active up to two hours after sunrise, but L. pakeka moved more and further than L. archeyi during their activity periods. Additionally, L. archeyi had a smaller home range compared to L. pakeka which suggests more prominent site fidelity and more sedentary behaviour in this species. Both species actively sought out specific microhabitats among the ones that were available, either to use during movement or to use as retreat sites, but those microhabitat types also differed between species. L. archeyi were more often found above ground level than L. pakeka and tended to use microhabitats that provided cover. L. archeyi preferred to use trees as retreat sites (roots, branches or trunk) whereas L. pakeka used trees (roots) and rocks. L. pakeka retreat sites had lower and more stable temperatures than outside retreats. Frogs were active inside retreats with no evidence of sleep behaviour for at least the first few hours of retreat use. In the rat control area, L. archeyi used more soil, leaf litter and ferns, and were also more likely to be found at ground level than frogs in the presence of higher numbers of rats. Abiotic factors also influenced movement patterns and microhabitat selection of both species, affirming water balance and thermoregulation are important drivers in frog behaviour. Behavioural attributes and small body size could be aiding in the persistence of L. archeyi in the presence of rats, and large body size and differences in behavioural attributes are likely to put L. pakeka at risk if rats were to reach their habitat. My findings inform on the ecology and behaviour of two Leiopelma species providing valuable information on their habitat requirements, which will enable more effective captive husbandry and better assessment of the appropriateness of translocation sites, aiding in their conservation management.</p>

Movement ecology of vulnerable lowland tapirs across a gradient of human disturbance

Animal movement is a key ecological process that is tightly coupled to local environmental conditions. While agriculture, urbanisation, and transportation infrastructure are critical to human socio-economic improvement, these have spurred substantial changes in animal movement across the globe with potential impacts on fitness and survival. Notably, however, human disturbance can have differential effects across species, and responses to human activities are thus largely taxa and context specific. As human disturbance is only expected to worsen over the next decade it is critical to better understand how species respond to human disturbance in order to develop effective, case-specific conservation strategies. Here, we use an extensive telemetry dataset collected over 22 years to fill a critical knowledge gap in the movement ecology of lowland tapirs (Tapirus terrestris) across a gradient of human disturbance within three biomes in southern Brazil: the Pantanal, Cerrado, and Atlantic Forest. From these data we found that the mean home range size across all monitored tapirs was 8.31 km2 (95% CI: 6.53 - 10.42), with no evidence that home range sizes differed between sexes nor age groups. Interestingly, although the Atlantic Forest, Cerrado, and Pantanal vary substantially in habitat composition, levels of human disturbance, and tapir population densities, we found that lowland tapir movement behaviour and space use were consistent across all three biomes. Human disturbance also had no detectable effect on lowland tapir movement. Lowland tapirs living in the most altered habitats we monitored exhibited movement behaviour that was comparable to that of tapirs living in a near pristine environment. Contrary to our expectations, we observed very little individual variability in lowland tapir space use and movement, and human impacts on the landscape also had no measurable effect on their movement. Lowland tapir movement behaviour thus appears to exhibit very little phenotypic plasticity. Crucially, the lack of any detectable response to anthropogenic disturbance suggests that human modified habitats risk being ecological traps for tapirs and this information should be factored into conservation actions and species management aimed towards protecting lowland tapir populations.

24-hour movement behaviour profiles and their transition in children aged 5.5 and 8 years – findings from a prospective cohort study

Background Time spent in movement behaviours, including physical activity (PA), sedentary behaviour (SB) and sleep, across the 24-h day may have distinct health consequences. We aimed to describe 24-h movement behaviour (24 h-MB) profiles in children and how profile membership changed from age 5.5 to 8 years. Methods Children in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort were asked to wear an accelerometer (ActiGraph-GT3X+) on their wrist for seven consecutive days at ages 5.5 and 8 years to measure 24 h-MB patterns. Time spent in night sleep, inactivity (proxy for SB), light PA, moderate PA (MPA), and vigorous PA (VPA) per day were calculated using the R-package GGIR 2.0. Using latent profile analyses (n = 442) we identified 24 h-MB profiles, which were given animal names to convey key characteristics. Latent transition analyses were used to describe the profile membership transition from ages 5.5 to 8 years. Associations with sex and ethnicity were examined. Results We identified four profiles, “Rabbits” (very high-MPA/VPA, low-inactivity and average-night-sleep), “Chimpanzees” (high-MPA, low-inactivity and average-night-sleep), “Pandas” (low-PA, high-inactivity and high-night-sleep) and “Owls” (low-PA, high-inactivity and low-night-sleep), among children at both time points. At ages 5.5 and 8 years, the majority of children were classified into profiles of “Chimpanzees” (51 and 39%, respectively) and “Pandas” (24 and 37%). Half of the sample (49%), particularly “Rabbits”, remained in the same profile at ages 5.5 and 8 years: among children who changed profile the predominant transitions occurred from “Chimpanzees” (27%) and “Owls” (56%) profiles to “Pandas”. Sex, but not ethnicity, was associated with profile membership: compared to girls, boys were more likely to be in the “Rabbits” profile (adjusted OR [95% CI]: 3.6 [1.4, 9.7] and 4.5 [1.8, 10.9] at ages 5.5 and 8 years, respectively) and less likely to be in the “Pandas” profile (0.5 [0.3, 0.9] and 0.4 [0.2, 0.6]) at both ages. Conclusions With increasing age about half the children stayed in the same of four 24 h-MB profiles, while the predominant transition for the remaining children was towards lower PA, higher inactivity and longer sleep duration. These findings can aid development and implementation of public health strategies to promote better health. Study registration This study was registered on 4th August 2010 and is available online at ClinicalTrials.gov: NCT01174875.