Use Of Perches Research Articles

A multi-metric approach to characterize variability in Yellow Perch (Perca flavescens) use of Lake Ontario and two barrier-protected coastal wetlands

Yellow Perch (Perca flavescens) inhabit both nearshore and coastal wetland habitats of the Laurentian Great Lakes throughout their lifetime and are known to exhibit different movement life histories. However, uncertainty persists in the spatial extent of this variation and in the duration of habitat use. To explore these uncertainties, we used a multi-metric approach that included water and otolith microchemistry and tissue stable isotope ratios (δ13C, δ15N). The ratio of manganese to calcium in otoliths was used to identify transitional movements between nearshore Lake Ontario and wetland habitats while carbon and nitrogen tissue isotope ratios revealed variable duration of wetland inhabitance. Our research suggests that the multi-metric approach was useful for addressing questions that could not be answered by one method alone. Our results demonstrate individual differences in duration of coastal wetland habitat residence among Yellow Perch, which may influence their susceptibility to recreational harvest. As Yellow Perch are an important species of consideration for management agencies such as the Great Lakes Fishery Commission, exposing such diversity is important when considering the potential for differential contributions of individuals with variable movement life histories to overall population stability and resilience over time.

Perch use in 11-wk-old turkey hens: impact on performance, health, and behavior

Commercial turkeys are traditionally reared in floor barns, however, like most poultry species, turkeys display a natural desire to perch when given the opportunity. Perch use has typically been evaluated in laying hens, however due to size, weight, and postural differences, turkeys may have different preferences in perch design. The objectives were to examine perching preferences of turkey hens reared to 11 wk, as well as to examine the impact of perch use on hen health and performance. Nicholas Select (n=620) 11-d old turkey hens were randomly allocated to 20 pens (4 pen replicates/treatment) and assigned 1 of 5 perch design treatments (no perch (NP), 5 cm round dowel (5Rnd), 5 × 5 cm (5Sq), 10 × 5 cm (10Rec), or 15 × 5 cm (15Rec)). Data were analyzed via ANOVA as a complete randomized design, with significance declared when P≤0.05. Perch design did not affect hen performance or keel bone deviations and no fractures were found. Perching treatment had no effect on gait or footpad score at wk 7. At wk 11 gait scores were poorer in NP hens compared with 5Rnd (P=0.04) and footpad scores were poorer in NP hens compared with 15Rec (P=0.02). There were more turkey hens on the perch, as perch width increased at both 9 and 11 wk of age, demonstrating a preference for wider and flat perches. The results of this study demonstrate that turkeys will utilize perches when given the opportunity, with no detrimental effects seen on performance or bird health.

Practical and Theoretical implications of perch use for avian predators on rodent populations

We hypothesized that the vertical structure of the habitat is a determining feature of avian predation intensity on rodents, other habitat conditions being equal.Two trap grids for rodents were set up in a field with com stubble at two times, before and after setting up perches in the experimental plot; one of the trap grids served as a control. There was no significant difference in captures between control and experimental grids before setting up perches (control validation). However, more rodents were captured in the control than in the experimental plot after the treatment. Predation lowered rodent density by roughly 40%. Calomys laucha was the affected species. Differential predation was not observed according to size or sex. We conclude that habitat vertical structure causes significant changes in rodent abundance, and it should be considered in rodent control and raptor management.

Phenotype alteration causes long-term changes to the social strategies of victimised birds

Phenotype alterations can occur naturally during the life span of the domestic fowl. These alterations increase the risk to become a target of aggression and may cause a severe impact on the welfare of affected birds. We analysed the behavioural consequences of sequential phenotype alterations and their long-term effects within stable social groups of adult birds differing in group size. Phenotypically homogeneous groups, with 100% or 0% marked individuals, and heterogeneous groups, with 70%, 50% or 30% marked birds, were housed at constant density in groups of 10, 20 or 40. We applied sequential phenotype alterations to homogeneous groups (by marking or unmarking birds) and compared their behavioural response to heterogeneous groups considered controls. Results show that aggression was greatly affected by phenotype alteration but, unexpectedly, group size did not play any relevant role modulating social responses. Aggression was directed towards the first altered birds and was significantly higher than in control groups. Long term effects were detected, as victimized individuals failed to engage in aggression at any time and adapted their behaviour to minimize aggressive encounters (e.g. high perch use). Therefore, we provide evidence of long-lasting submissive strategies in stable groups of adult domestic fowl, highlighting the relevance of phenotype alteration on the social dynamics of affected birds. Phenotype alterations could help explain much of the targeted aggression observed in producing flocks which severely affects animal welfare.

Effects of Body-Mounted Inertial Measurement Unit (IMU) Backpacks on Space Use and Behaviors of Laying Hens in a Perchery System

Body-mounted sensors have significantly enhanced our understanding of individual animals through location tracking, behavior monitoring, and activity determination. However, attaching sensors may alter the behavior of the tested animals, which would, potentially, invalidate the collected data. The objective of this study was to evaluate the effects of wearable backpacks on space use (feeder, nest box, and perch) and behaviors (aggressive, comfort, and locomotion behaviors) of laying hens in a perchery system. Nineteen laying hens were reared for 21 days, and each was fitted with a lightweight inertial measurement unit (IMU) backpack on day 0. Instantaneous scan samples were adopted to record the number of laying hens, using each space at a 5-min interval over the 16 h lights-on period at −6 d to −1 d, 1 d to 4 d, and 10 d to 15 d. Six hens were randomly selected for observation of behaviors during six 20-min periods at −5 d to −3 d, and 13 d to 15 d. Feeder use reduced at 1 d to 4 d, 11 d, and 13 d to 15 d, and nest box use reduced at 1 d, 3 d, and 10 d to 12 d, while it increased on 15 d. Hens perched more often at 1 d to 4 d and 10 d to 14 d. Space use was affected by wearing a backpack in the first few days after installation. As hens gradually accustomed to the devices, the effects on feeder, nest box, and perch use disappeared at 10 d, 13 d and 15 d, respectively. The diurnal pattern of hens using the nest box largely returned to the state before being backpacked, and there were slight recoveries in the use of feeder and perch use during the 15-day trial period. There was no observed difference in the amount of pecking, preening bouts, aerial ascent/descent, or the time spent on preening and walking at −5 d to −3 d and 13 d to 15 d. No differences were found in body weight and plumage condition score between 0 d and 16 d. The results demonstrated that the IMU backpack only had marginal and non-lasting effects on space use and behaviors of laying hens, and it seems suitable for further behavioral research after short-term acclimation. However, when the diurnal pattern serves as the variable of interest, researchers need to re-evaluate the effect of the device on birds, rather than implying there is no effect.

Is it like night and day? Nocturnal versus diurnal perch use by dwarf chameleons (Bradypodion pumilum)

ABSTRACT Arboreal chameleons must navigate a complex, three-dimensional landscape consisting of trees, bushes and/or grasses of various sizes. This complexity equates to the microhabitat of chameleons, that is, the branches upon which they perch and through which they move. Therefore, chameleons rely on their ability to grip perches available to them, and this is evident by their specialised adaptations such as their prehensile tail and their grasping hands and feet. To date, ecological studies of chameleons have relied on gathering data on perch use only at night because locating chameleons during the daytime is extremely difficult. However, the night-time perch represents the sleeping perch of individuals, and this is not necessarily reflective of overall diel perch use. Many other arboreal reptiles are constrained to using thin perches at night, but by day their microhabitat is more variable, using thicker branches, limbs or tree trunks. To assess whether this well-entrenched paradigm (night-time perch use being constrained to thin perches) also extends to fully arboreal chameleons, daytime and night-time perch diameters were measured for the Cape Dwarf Chameleon, Bradypodion pumilum, and were compared using analyses of variance statistical approaches. Neither perch diameters nor variance in perch diameters differed between the two photoperiods, and the variance in diameters of perches used was remarkably high. Despite this variance, there was a significant, positive relationship between body size and the diameter of perches used. Unlike other reptiles, the results show that for B. pumilum the night-time perch use is not different than diurnal perch use, and there appears to be a fairly wide range of perches used by chameleons of a given body size over both photoperiods. Nevertheless, the positive trend for chameleons of larger body sizes to choose larger perches than smaller chameleons implies that there are some upper and lower constraints for the diameters of perches used, possibly relating to their ability to effectively grip a range of perch sizes.

Effect of perch access on perching, health and production outcomes in commercial broiler breeder flocks

There is a need for more knowledge about perch use in broiler breeders and the potential effects of perches on health and production outcomes. The aim of this study was to investigate the use of perches by commercial broiler breeders, effect of perch access on keel bone fractures (KBF), footpad dermatitis (FPD) and number of floor eggs. Two commercial breeder flocks (Ross 308) reared at the same facility were observed during the production period. Half of each flock was provided with 15 cm perch/bird and the other half had no perches. The perch group had two types of perches; a steel plate mounted on the hen feeder lines “feeder perch” (15 cm high) and elevated plastic perches (5 cm high). Perching by hens and roosters was recorded during the dark period by counting birds on each of the two perch types in 10 sections and in the corresponding patches on the control side at 25, 35, and 45 wk of age (WOA). FPD was scored in 100 random hens in each group at 30 WOA and end of lay, KBF was scored by postmortem in 100 random hens in each group at end of lay, and number of floor eggs (n) in each treatment was scored daily. More hens perched on the feeder perch with the steel plate mounted, compared to the feeder line without the steel plate, but this difference decreased with age (P < 0.0001). Within the perch treatment, more hens perched on the feeder lines compared to the plastic perches at all ages (P < 0.0001). When combining number of hens on the plastic and feeder perches, on average 6.7 birds perched per meter perch, which is full capacity given an average shoulder width of 15 cm/bird. Perch use among the roosters was low overall, but more roosters perched in the perch group compared to the control group at 35 WOA (P = 0.007). Between 47 and 53% of the hens had KBF at the end of the lay. At 30 WOA, birds housed with perches were more likely to have lower FPD. Perch treatment did not affect number of floor eggs. In conclusion, broiler breeder hens perch when the perches are sufficiently high and allow all birds to perch simultaneously, and access to perches may have positive effects on FPD.

Perch use in commercial broiler breeders – Preference for perch material and effect of age

Unlike for laying hens in most European countries, few broiler breeders have access to perches, and there is a need for more knowledge on perching behavior in broiler breeders. The aim of this study was to investigate the overall use of perches by broiler breeders throughout the production period and to investigate preferences for different perch materials in a commercial setting. Four breeder flocks (Ross 308, n = 2, Ranger Gold, n = 1, Hubbard JA 757, n = 1) were each given five different perches. Four of the perches (each 6 m long) were placed on the elevated slats; steel round, steel square, plastic and wooden perch, while the three Siesta perches (plastic, 15 cm high) were placed in the litter area. From week 30, one of the Siesta perches (3 m long) was placed on the elevated slats. Perch use was recorded by counting number of birds on the perches during the last hour before the light went off, once in week 20, 25, 30, 40, 45 and 50. Footpad dermatitis were scored at end of lay in 100 random hens across the house. Overall, perching behavior was constant with age, and there were no significant differences between the flocks with regards to perch use (birds/m perch). At 20 weeks of age, the square steel perches were most used (0.90 birds/m perch) and the wooden perches were the least used (0.41 birds/m perch) (P = 0.09). From week 30, more birds were perching on the Siesta perches on the slats (1.6 birds/m perch) compared to all other types of perches (P < 0.003). There was no relationship between body weight and footpad score (P > 0.05). The average perch use in the present study was only 0.44 birds/m perch which is a capacity utilization of less than 10 %. The Siesta perch on the elevated slats was the most popular perch, possibly due to its height. In conclusion, broiler breeders use perches, but perch type and placement of the perches must be considered carefully.

Commercial broiler breeder pullet hens use perches but show no preference for perch type or height

An important behavioral need for laying hens is perching, but few studies have investigated perching behavior in commercial broiler breeder pullets. The aim of this study was to investigate perching behavior throughout the pullet period and preferences for different perch types and heights. We also investigated the effect of hybrid on perching and the potential effect of perches on keel bone damage (KBD) and footpad dermatitis (FPD). We followed four commercial broiler breeder pullet hen flocks (Ross 308, n = 2 and Hubbard JA 757, n = 2), each with three groups of birds (n = 2 500 hens); A-group; four A frames consisting of four perch types (plastic, steel square, steel round and wood) placed on different heights (35 cm and 95 cm); S-group; Siesta perches (a plastic perch 15 cm high) and C-group; control group without perches. Perch use was recorded by counting number of birds on the perches during the last hour before the light went off, at week 2, 5, 6, 7, 10, 12 and 15. At week 16, footpad dermatitis, keel bone deformations and keel bone fractures were scored in 30 random birds in each group (n = 90 birds/flock). Hubbard birds perched significantly more than Ross birds (P < 0.0001), and more birds perched on the Siesta perches than on the A frames (P = 0.046). Perching increased with age for Hubbard birds (P < 0.05), but not for the Ross birds. There were no effects of perch height or perch types on number of birds observed on the perches. There were no observed cases of bumblefoot, breast blisters, keel bone deformations or keel bone fractures. The incidence of FPD was low, with 73.6% of assessed birds receiving a score of 0, with no significant differences between hybrids or perch groups. In conclusion, Hubbard birds perched more than Ross 308 birds, and all birds perched more with age. None of the hybrids showed any preferences for perch type or height and increased perching had no negative effects on important health parameters. Broiler breeder pullets should therefore be given access to perches from day 1 to promote training and perch use.

Out on a limb: female chameleons (Bradypodion pumilum) position themselves to minimise detection, whereas males maximise mating opportunity

ABSTRACT Although reproductive strategies are poorly documented in chameleons, sperm storage has been confirmed among some species for which male reproductive success may be maximised by increasing the number of females inseminated and/or preventing subsequent female copulation with rival males. Behaviour, such as mate searching, may enable males to maximise the number of mating opportunities with different partners and mate guarding may increase the likelihood that a male will sire offspring with a particular female. In this study, we investigated behavioural differences in movement (distance travelled) and perch choice between sexes of the Cape Dwarf Chameleon, Bradypodion pumilum, to offer data for a better understanding of mate searching and mate guarding behaviours. Wild chameleons were radio-tracked in 2010 (n = 8) and 2014 (n = 5) for approximately two weeks. The geographic location and perch height above ground were recorded multiple times per day to capture both the scale of movement and their perch use. Linear mixed effect models were used to assess differences between sexes. Our results indicated that females perched lower than males and moved shorter distances, offering support of a mate searching strategy in males. Ad hoc field observations revealed behaviours consistent with mate guarding by some males, and mate avoidance by some unreceptive females. Our results could indicate that males increase their reproductive fitness by using higher perches in both a mate guarding and mate searching context and moving further distances in search of receptive females.

홰 종류 및 높이 설정에 따른 육계 생산성, 행동특성, 계육품질에 미치는 영향

This study investigates the effect of perch type and height on the growth performance, footpad dermatitis (FPD), blood parameters, behavioral characteristics, and meat quality of broilers. A total of 912 one-day-old male Ross 308 broilers (48.23± 0.264 g) were subjected to a three x two factorial design of three types of perch (wood, steel, plastic) and two levels of perch height (10→30 cm change, 10 cm fixed) over a five-week experiment. Growth performance, perch availability, litter quality, FPD incidence, serum biochemical parameters, and meat quality of the broilers were evaluated. There were no significant differences in the body weight, feed conversion ratio, and biochemical parameters (except for aspartate aminotransferase), pH, color, and water holding capacity. The incidence of FPD was significantly higher in the plastic perch group than in the wood and steel perch groups (<i>P</i>&lt;0.05) at five weeks of age. Perch use was high in the order of wood, steel, and plastic groups in the daytime and nighttime at one, three, and five weeks of age (<i>P</i>&lt;0.05). Perch use was higher in the 10 cm fixed group than the 10→30 cm group (<i>P</i>&lt;0.05). The shear force of the breast significantly increased in the order of wood, steel, and plastic groups (<i>P</i>&lt;0.05). In conclusion, the group with a fixed perch height of 10 cm had high perch usage. Additionally, the use of wooden perches was higher than that of other materials, and it lowered the incidence of FPD in broilers.

Do I stay or do I go? Shifts in perch use by lizards during morning twilight suggest anticipatory behaviour.

Anticipatory behaviour is the expectation of a near-future event based on information processed in the past and influences an animal's tactical decisions, particularly when there are significant fitness consequences. The grass lizard (Takydromus viridipunctatus) perches on blades of grass at night which likely reduces the probability of predation by terrestrial predators such as snakes, rodents and shrews. During twilight (starting 30 min before sunrise), they move from above the grass to within grass clumps and this is thought to afford the lizard protection while reducing detection by avian predators. Here, we examined how lizards shift their behaviour as a function of visual detectability to their primary predator, the cattle egret (Bubulcus ibis). We show that the lizards shift from their perch site during twilight at the earliest time at which egrets depart communal roosts. At the same time, visual modelling shows a dramatic increase in the detectability of the lizards to the visual system of egrets. Therefore, anticipatory behaviour in response to environmental cues acts to reduce predation risk as lizards become more conspicuous and predators become more active. Grass lizard anticipatory behaviour appears to be finely tuned by natural selection to adjust to temporal changes in predation risk.

Seasonal Variation in Thermal Ecology and Microhabitat Use of Anolis carlliebi (Squamata: Dactyloidae) from a Xeric Scrubland in Central Mexico

Thermal ecology and microhabitat use by lizards are affected directly and indirectly by intrinsic (e.g., sex and body size) and extrinsic (e.g., environmental seasonality, vegetation cover, and wind speed) factors. Herein we evaluate the effect of seasonality and sex on field thermal ecology and microhabitat utilization of a population of Anolis carlliebi inhabiting a xeric scrubland in Central Mexico. Lizards were found primarily in full and filtered sun conditions, strongly associated, respectively, with inflorescences and leaves of Agave stricta. Males were slightly larger than females. Mean field body temperature did not differ between sexes within seasons, but males used higher perches than females in the warm season. We observed a seasonal shift in body temperature and perch use in males, which exhibited higher body temperatures and occupied wider and higher perches in the warm season. Female body temperature and perch use did not differ between seasons. This study reports the first case of a population of Anolis specializing in a species of Agave as microhabitat. These results add to our understanding of thermoregulation and microhabitat use of mainland species of Anolis since they face different environmental pressures than Caribbean species.

Associations between behaviour and health outcomes in conventional and slow-growing breeds of broiler chicken

Broiler chickens are prone to a range of complex health and welfare issues. To support informed selection of welfare traits whilst minimising impact on production efficiency and to address a major gap in understanding, we systematically explored associations between health and behavioural indicators of broiler welfare. One conventional (CNV, n = 350) and two slow-growing broiler breeds (SGH and SGN, respectively n = 400) were reared from hatch in pens of 50 birds. Birds were assessed for health (gait, plumage cover and dirtiness, pododermatitis, hockburn, and leg deviations) at 2.2 kg liveweight according to the Royal Society for the Prevention of Cruelty to Animals Broiler Breed Welfare Assessment Protocol. Behaviour and resource-use of 10% of birds per pen, on days 29 (all breeds) and 43 (SGH and SGN), was (i) scan sampled every 60 min between three to six and between twelve to fifteen hours after photoperiod onset; and (ii) continuously sampled sequentially from focal birds for 3 min each in a random order, during 15 min observation periods at three and twelve hours after photoperiod onset. Binary logistic generalized linear models were used, to assess respective associations between pen prevalence of each health outcome and (i) pen mean percentage scans of behaviour, and (ii) pen mean frequency and duration per 3 min focal observation of behaviour. Better growth rate and feed conversion but poorer health outcomes (mortality, gait, pododermatitis, feather cover) were more prevalent in CNV. Strong associations between behaviour and several heath indicators revealed, (i) increases in side-lying inactive, sitting inactive, and use of the litter relative to other resources, as primary and general indicators of poorer health, and (ii) increases in standing inactive, perch use, walking, Comfort, High Energy and Exploratory behaviour as primary and general indicators of better health. Of these, changes in side-lying, standing inactive, walking, Comfort and High Energy behaviour were particularly sensitive to small differences in health outcomes important for breed acceptance in high-welfare schemes. Crucially these behavioural measures additionally represent motivational and affective aspects of welfare not captured by health measures and allow opportunity for earlier intervention. Thus, to provide a comprehensive assessment of broiler experience, behaviour should be incorporated into broiler welfare assessments.

THE ANOLES OF LA SELVA: NICHE PARTITIONING AND ECOLOGICAL MORPHOLOGY IN A MAINLAND COMMUNITY OF ANOLIS LIZARDS

Describing the relationships among morphology, behavior, and ecology is central to understanding the processes of evolutionary diversification. Anolis lizards are an excellent group for studying such ecomorphological relationships. Extensive research on anole ecological morphology has been conducted in the Caribbean, where sympatric species have repeatedly and convergently evolved to partition habitat through differential perch use. Six ecomorphs have been described, each with particular behavioral, morphological, and ecological characteristics well-suited for the microhabitat it occupies. However, little research has been conducted in mainland Central or South America, and a few case studies suggest that mainland anoles may not conform to the ecomorph classes recognized for Greater Antillean anoles. In this study, we examine the ecological morphology of sympatric mainland species of Anolis in a tropical lowland rainforest in Costa Rica and compare these species to the Caribbean ecomorphs. Our results show overlapping niches and substantial variability in habitat use across many species. Moreover, the relationship between relative hindlimb morphology and habitat use in Anolis humilis and Anolis limifrons does not conform to that of Caribbean species. Predation and fluctuating environmental conditions likely structure morphological variation differently in the mainland, leading the independent radiation of mainland anoles to produce divergent ecomorphological relationships compared with the Caribbean islands.

Perch time allocation and feeding efficiency of flycatching Rhinolophus formosae: an optimal foraging behavior?

BackgroundFlycatching bats are species-rare and comprise predominantly horseshoe bats (Rhinolophidae). Their hang-and-wait foraging mode and long constant-frequency echolocation calls offer advantages in energetics and prey detection, and may enable them apt to foraging optimally, yet not much is known about the foraging behavior of flycatching bats. Thus we assessed the perch use and foraging performance in the field by one of the largest horseshoe bats, Rhinolophus formosae, and offered insights on their perch time allocation.ResultsThe perching-foraging behaviors of the bats did not differ significantly between forest settings, but the residence and giving-up time, mean attack, and attack rate were higher in the late spring-early summer, whereas the mean capture, capture rate, and attack efficiency were lower in the late summer when volant juveniles joined the nocturnal activity. The bats maintained flycatching and exhibited largely similar attack rates through the night with peak residence time around the midnight, but the capture rate and attack efficiency both reduced toward midnight and then increased toward the hours right before dawn. The attack rate was negatively correlated to the number of perches used and perch switch; by contrast, the capture rate was positively correlated with both factors. The total residence time at a site increased but mean residence time per perch decreased as the number of perches used and perch-switch increased. The giving-up time was inversely correlated to the attack rate and attack efficiency, and decreased with an increasing capture rate.ConclusionsThe bats increased perch switch at lower attack rates in early spring, but switched less frequently in late spring and prime summer months when insect abundance is higher. By scanning through a broad angular range for prey detection, and switching more frequently among perches, R. formosae foraged with an increased capture rate, and were able to remain at the site longer by slightly reducing their mean residence time per perch. Our results concur with the predictions of optimal foraging theory for patch selection and offer implications for further exploration of the foraging behavior of flycatching horseshoe bats.

Forest restoration by different nucleation techniques in Urochloa grassland

Abstract: The objective of this work was to evaluate the effect of brushwood, black plastic mulch, herbicide, and artificial perch on the natural regeneration of native species in Urochloa grassland. The experiment was conducted between February 2014 and February 2016 in the Dense Ombrophilous Forest, in the municipality of Morretes, in the state of Paraná, Brazil. The treatments were: herbicide, herbicide + perch, black plastic mulch, black plastic mulch + perch, brushwood + herbicide, brushwood + herbicide + perch, and a control treatment. The evaluations were carried out at 4, 8, 12, 18, and 24 months after the installation of the experiment, by counting and identifying regenerating woody species and estimating visually the percentage of herbaceous coverage. Initially, brushwood and black plastic mulch reduced the Urochloa grasses; however, this effect was lost over time due to the rapid growth of the grasses from the edges to the center of the plots. The use of perches in the treatments does not allow a significant increase of other species because of the continued inhibiting conditions for the establishment of seedlings. The herbicide is effective in removing the grasses; however, the recruitment of woody species is only satisfactory when perches are used to attract the dispersing fauna. For a successful ecological restoration of pastures, there is a need for the local elimination of Urochloa grasses.

Litter and perch type matter already from the start: exploring preferences and perch balance in laying hen chicks

Early chick environment, such as provision of litter and perches, can be a predictor of laying hen welfare. Inadequate or nonpreferred litter and perch types could have similar negative effects as those seen when not providing these resources at an early stage, such as increased feather pecking and cannibalism in adult flocks. However, suitable litter and perch types for chicks are not well explored. In the present project, 6 different types of litter (crushed straw pellets, hemp shavings, peat, sand, straw, wood shavings) and 6 different types of perches (narrow or wide forms of rope, flat or round wood) were presented in a controlled way (3 at a time) to chicks in 6 pens. Usage was compared in 93 chicks of Lohmann Selected Leghorn Classic divided across the pens, during their first 3 wk after hatch. Different litter types were seen to be preferred for different behaviors. The majority of dustbathing bouts occurred in sand and peat. Chicks foraged more in wood shavings, hemp shavings, and sand than in peat and pellets (P < 0.05). Perch width and shape were found to affect both usage and perch balance, measured as the probability of successful or problematic landings. The wide rope was generally used more during the first week (P < 0.05) and was used more for sleeping or resting (P < 0.05) than the other wide perch types. Furthermore, birds were more likely to land on the wide rope or on flat perches successfully than they were to have a problematic landing (P < 0.05). That birds were more likely to be observed preening on flat perches than on the potentially shaky rope perches could further reflect a sense of security. Our results suggest that presenting several litter types could better fulfill chicks' behavioral needs and that flat perches or a wide rope (4.5-cm diameter) could be appropriate perch types for laying hen chicks and thereby promote early perch use and training.

Anti-predatory sleep strategies are conserved in the agamid lizard Monilesaurus rouxii

Sleep is an essential part of animal biology, yet its ecological aspects such as predator avoidance remain understudied, especially in the wild. Sleep behaviour is likely to be subject to selection pressure and evolution, leading to sleep strategies to ensure survival during this vulnerable state. How sleep strategies of animals respond to alteration of macro-habitat has been largely unexplored. This study aimed to determine the effect of habitat type on the sleep ecology of the agamid lizard Monilesaurus rouxii. We carried out field work in the Western Ghats (India) biodiversity hotspot, in two differing habitat types—natural wet evergreen forests and human—modified Areca catechu plantations. We collected data on perches used by lizards for sleep, both in terms of their structural characteristics and their use (e.g. lizard head direction). To determine perch selection, we compared perch use with perch availability in both habitat types. Habitat type had limited influence on sleep perch selection of M. rouxii, with lizards selecting only unstable narrow-girthed plants, suggesting a highly conserved sleep strategy driven by predator avoidance. The majority of sleeping lizards displayed an ‘inward’ head direction, towards the potential path of a predator approaching from the ground. However, this strategy to select for narrow-girthed plants constrained lizards to use lower, unsafe sleep perches in plantations (driven by availability), which could have consequences for their survival. To our knowledge, our study is the first to examine in detail the effect of habitat alteration on sleep strategies in lizards. Sleep strategies of animals in the wild could affect their chances of survival and their performance during active behaviours. ‘Where’ and ‘how’ animals sleep are important aspects of their sleep strategy. However, it is unexplored if these choices would change in response to human modification of the natural habitat. We compared sleep site selection in the semi-arboreal agamid lizard Monilesaurus rouxii in two different habitats (natural and human-modified). Lizards always chose narrow, unstable perch plants to sleep, as they allow for early detection of an approaching predator. In the human-modified habitat (Areca catechu plantations), opting for narrow unstable perches led to lizards using significantly lower perches, probably leaving them vulnerable to predators approaching from the ground. Our results show that exploring sleep strategies in the wild is necessary to properly assess the effects of habitat modification on species.

Killing time in cover crops? Artificial perches promote field use by raptors

AbstractCover crops are an increasingly common conservation practice in intensive row‐crop agriculture of the Midwestern United States and can improve wildlife habitat. However, they also benefit agricultural pest species such as voles (Microtus), which have damaged cover‐cropped soybean fields in Indiana. We tested the feasibility of attracting raptors, which are natural predators of voles, to cover‐cropped fields by supplying artificial perches from which to hunt. We assessed raptor use of artificial perches in cover‐cropped fields during the winters of 2018 and 2019. Perches were erected at three different distances from the field edge: 50, 125 and 200 m. We modelled perch use of our three most common species, great horned owl, red‐tailed hawk and American kestrel, with a logistic generalised linear mixed model. Raptors used 82% of the perches, and perch use was greatest at 200 m. However, even at peak use, our best model predicted a low probability of overall perch use for all three species. Artificial perches can attract raptors into large row‐crop fields. Sturdier perch design, extended perch availability and greater vole populations could increase use of perches. Although raptor perch use by itself is unlikely to control vole populations in cover‐cropped fields, artificial perches could form a valuable component of an integrated pest management system.