Feeding Bouts Research Articles

Feeding characteristics and prey profitability in five herring‐feeding killer whales (Orcinus orca) in northern Norway

AbstractThis study used multisensory data tags with integrated 4K video to investigate feeding behavior and prey profitability in five adult male killer whales (Orcinus orca) at herring wintering grounds in Norway, in 2016 and 2017. Video recorded two killer whales engaged in carousel feeding, and two engaged in seiner feeding (i.e., feeding on herring discards around purse seiner vessels). The feeding behaviors identified from the video data allowed for determination of associated kinematic signatures, which were used to further identify and characterize carousel feeding and deep feeding dives over the entire logger duration. Prey consumption during on camera feeding bouts was also measured to calculate profitability of feeding bouts for the different behaviors. Average number of prey consumed per minute was 1.08 ± 0.43 for carousel feeding and 0.43 ± 0.07 for seiner feeding (n = 122 prey capture events). Using kinematic data, a total of 18 carousel feeding bouts and 206 deep feeding dives were identified. Whales spent at least 37%–65% of time over 24 hr feeding. Using field metabolic rate estimates from the literature and the energetic content of herring caught locally, killer whales required an estimated 285–578 herring/day to balance daily energy requirements.

Effects of the dopamine depleting agent tetrabenazine on detailed temporal parameters of effort-related choice responding.

The dopamine-depleting agent tetrabenazine alters effort-based choice, suppressing food-reinforced behaviors with high response requirements, while increasing selection of low-cost options. In the present experiments, rats were tested on a concurrent fixed ratio 5/chow feeding choice task, in which high-carbohydrate Bio-serv pellets reinforced lever pressing and lab chow was concurrently available. Detailed timing of lever pressing was monitored with an event recording system, and the temporal characteristics of operant behavior seen after 1.0 mg/kg tetrabenazine or vehicle injections were analyzed. Tetrabenazine shifted choice, decreasing lever pressing but increasing chow intake. There was a small effect on the interresponse-time distribution within ratios, but marked increases in the total duration of pauses in responding. The postreinforcement-pause (PRP) distribution was bimodal, but tetrabenazine did not increase the duration of PRPs. Tetrabenazine increased time feeding and duration and number of feeding bouts, but did not affect feeding rate or total time spent lever pressing for pellets and consuming chow. Thus, TBZ appears to predominantly affect the relative allocation of lever pressing versus chow, with little alteration in consummatory motor acts involved in chow intake. Tetrabenazine is used to model motivational symptoms in psychopathology, and these effects in rats could have implications for psychiatric research.

Rush or relax: migration tactics of a nocturnal insectivore in response to ecological barriers

During their annual migration, avian migrants alternate stopover periods, for refuelling, with migratory flight bouts. We hypothesise that European Nightjars (Caprimulgus europaeus) adapt their daily migration tactics in association with biomes. We tracked the autumn migration of 24 European Nightjars, from breeding populations in Mongolia, Belgium and UK, using GPS-loggers and multi-sensor data loggers. We quantified crepuscular and nocturnal migration and foraging probabilities, as well as daily travel speed and flight altitude during active migration in response to biomes. Nightjars adopt a rush tactic, reflected in high daily travel speed, flight altitude and high migration probabilities at dusk and at night, when travelling through ecological barriers. Migration is slower in semi-open, hospitable biomes. This is reflected in high foraging probabilities at dusk, lower daily travel speed and lower migration probabilities at dusk. Our study shows how nightjars switch migration tactics during autumn migration, and suggest nightjars alternate between feeding and short migratory flight bouts within the same night when travelling through suitable habitats. How this may affect individuals’ fuel stores and whether different biomes provide refuelling opportunities en route remains to be investigated, to understand how future land-use change may affect migration patterns and survival probabilities.

The VIP/VPAC1R Pathway Regulates Energy and Glucose Homeostasis by Modulating GLP-1, Glucagon, Leptin and PYY Levels in Mice.

Simple SummaryThe current study is the first complete characterization of the phenotypic, metabolic, calorimetric, and homeostatic effects of VPAC1R in a null murine model. To evaluate the role of VPAC1R on body phenotype, feeding behavior, glucose/energy homeostasis, metabolic rate and plasma hormones, a long-term study was conducted in VPAC1R−/− and WT mice. The outcome data document that VPAC1R−/− mice have altered metabolism and insulin intolerance, with significant increase of feeding bouts, reduction of total energy expenditure and respiratory gases during both the dark and light cycle, together with elevated fasting levels of GLP-1 and PYY, and higher postprandial levels of GLP-1, glucagon leptin and PYY. These findings suggests that VPAC1R controls glucose homeostasis and energy balance by regulating plasma metabolic hormones.Vasoactive Intestinal Peptide binds with high affinity to VPAC1R and VPAC2R, thus regulating key physiologic functions. Previously, we documented in VIP−/− mice a leaner body phenotype and altered metabolic hormones. Past reports described in VPAC2−/− mice impaired circadian rhythm, reduced food intake, and altered metabolism. To better define the effects of VPAC1R on body phenotype, energy/glucose homeostasis, and metabolism, we conducted a 12-week study in a VPAC1R null model. Our results reveal that VPAC1−/− mice experienced significant metabolic alterations during the dark cycle with greater numbers of feeding bouts (p = 0.009), lower Total Energy Expenditure (p = 0.025), VO2 (p = 0.029), and VCO2 (p = 0.016); as well as during the light cycle with lower Total Energy Expenditure (p = 0.04), VO2 (p = 0.044), and VCO2 (p = 0.029). Furthermore, VPAC1−/− mice had significantly higher levels of GLP-1 and PYY during fasting, and higher levels of GLP-1, glucagon leptin and PYY during postprandial conditions. In addition, VPAC1−/− mice had lower levels of glucose at 60′ and 120′, as assessed by insulin tolerance test. In conclusion, this study supports a key role for VPAC1R in the regulation of body glucose/energy homeostasis and metabolism.

Social associations in common carp (Cyprinus carpio): Insights from induced feeding aggregations for targeted management strategies.

Heterogeneity in social interactions can have important consequences for the spread of information and diseases and consequently conservation and invasive species management. Common carp (Cyprinus carpio) are a highly social, ubiquitous, and invasive freshwater fish. Management strategies targeting foraging carp may be ideal because laboratory studies have suggested that carp can learn, have individual personalities, a unique diet, and often form large social groups. To examine social feeding behaviors of wild carp, we injected 344 carp with passive integrated transponder (PIT) tags and continuously monitored their feeding behaviors at multiple sites in a natural lake in Minnesota, USA. The high‐resolution, spatio‐temporal data were analyzed using a Gaussian mixture model (GMM). Based on these associations, we analyzed group size, feeding bout duration, and the heterogeneity and connectivity of carp social networks at foraging sites. Wild carp responded quickly to bait, forming aggregations most active from dusk to dawn. During the 2020 baiting period (20 days), 133 unique carp were detected 616,593 times. There was some evidence that feeding at multiple sites was constrained by basin geography, but not distance alone. GMM results suggested that feeding bouts were short, with frequent turnover of small groups. Individual foraging behavior was highly heterogeneous with Gini coefficients of 0.79 in 2020 and 0.66 in 2019. “Superfeeders”—those contributing to 80% of total cumulative detections (top 18% and top 29% of foragers in 2020 and 2019 respectively)—were more likely to be detected earlier at feeding stations, had larger body sizes, and had higher network measures of degree, weighted degree, and betweenness than non‐superfeeders. Overall, our results indicate that wild carp foraging is social, easily induced by bait, dominated by large‐bodied individuals, and potentially predictable, which suggests social behaviors could be leveraged in management of carp, one of the world's most recognizable and invasive fish.

Feeding tactics of resident Bryde's whales in New Zealand

AbstractLarge predators typically feed on proportionally sized prey but the world's largest animals, baleen whales, bulk feed on plankton and small fishes. While most baleen whales migrate to feed on polar aggregations of nutritious zooplankton prey, Bryde's whales (Balaenoptera edeni brydei and B. e. edeni) inhabit less productive warm‐temperate waters with variable prey abundance and quality. Off New Zealand, Bryde's whales target both fish and zooplankton, some with lower calorific value. We use multisensor tags (n = 4) and visual observations from drones and boats (n = 52) to reveal that Bryde's whales employ specialized feeding tactics matched to prey type. Zooplankton‐feeding at the surface involved multiple head‐slaps that presumably aggregate zooplankton followed by a side‐lunge. Whales exploiting plankton patches swam in tight circles, performing up to 33 lunges (M = 5.5 ± 6.1) per feeding bout. In contrast, whales targeting fish performed faster vertical lunges. With both prey types, whales concluded lunges with a ~90° roll probably to minimize prey escape at the surface. The diet plasticity and dynamic behaviors of Bryde's whales are key to increasing their foraging efficiency. This may be essential for the whales to meet energetic demands year‐round with a variety of prey in New Zealand waters.

Behavioral responses to spatial variation in perceived predation risk and resource availability in an arboreal primate

AbstractPrey species must often face a trade‐off between acquiring resources and minimizing predation risk. The spatial variation in predation risk across a landscape, as perceived by prey across their foraging or home range, creates a “landscape of fear” by which individuals modify their behavior in response to the level of perceived risk. Here, we explored the influence of perceived predation risk, habitat features associated with risk, and fruit availability, on the spatial variation in behavior of the endangered forest‐dwelling samango monkey (Cercopithecus albogularis schwarzi). We collected behavioral and location data on two habituated samango monkey groups in the Soutpansberg Mountains, South Africa, between 2012 and 2016. We further collected location data of the samango monkey's acoustically distinct alarm call, which has an unambiguous association with aerial predators, to spatially map perceived risk across the landscape. Using generalized linear mixed models, we found that perceived risk from eagles significantly influenced the spatial distribution of critical life‐functioning behaviors, with samango monkeys increasing feeding and foraging in high‐risk areas. To mitigate this risk, samangos increased cohesion between group members, which subsequently reduced vigilance levels. Group cohesion further increased in high‐risk areas with abundant fruit, relative to high‐risk, fruit‐poor areas, demonstrating the monkey's foraging/risk trade‐off. Feeding was also reduced in areas of low canopy height, while vigilance decreased with increasing understory visibility and distance from sleep site, showing the influence of landscape features on risk perception from other predator guilds. Thus, for arboreal species foraging in a 3‐D landscape, risk perception may occur at multiple scales and in response to multiple predator guilds. Only moving was influenced by fruit availability, either due to moving between localized food patches or from escaping high‐risk areas following feeding bouts. These findings highlight that risk‐taking in samango monkeys is only associated with behaviors fundamental to survival at a given location and that increased cohesion between neighbors is the main antipredator response in this species.

Eating driven by the gustatory insula: contrasting regulation by infralimbic vs. prelimbic cortices.

Subregions within insular cortex and medial prefrontal cortex (mPFC) have been implicated in eating disorders; however, the way these brain regions interact to produce dysfunctional eating is poorly understood. The present study explored how two mPFC subregions, the infralimbic (IL) and prelimbic (PRL) cortices, regulate sucrose hyperphagia elicited specifically by a neurochemical manipulation of the agranular/dysgranular region of gustatory insula (AI/DI). Using intra-AI/DI infusion of the mu-opioid receptor (µ-OR) agonist, DAMGO (1 µg), sucrose hyperphagia was generated in ad-libitum-maintained rats, while in the same rat, either the IL or prelimbic (PRL) subregion of mPFC was inactivated bilaterally with muscimol (30 ng). Intra-IL muscimol markedly potentiated AI/DI DAMGO-induced sucrose hyperphagia by increasing eating bout duration and food consumption per bout. In contrast, PRL attenuated intra-AI/DI DAMGO-driven sucrose intake and feeding duration and eliminated the small DAMGO-induced increase in feeding bout initiation. Intra-IL or -PRL muscimol alone (i.e., without intra-AI/DI DAMGO) did not alter feeding behavior, but slightly reduced exploratory-like rearing in both mPFC subregions. These results reveal anatomical heterogeneity in mPFC regulation of the intense feeding-motivational state engendered by µ-OR signaling in the gustatory insula: IL significantly curtails consummatory activity, while PRL modestly contributes to feeding initiation. Results are discussed with regard to potential circuit-based mechanisms that may underlie the observed results.

Field evidence of UK wild bird exposure to fludioxonil and extrapolation to other pesticides used as seed treatments

We determine the exposure of wild birds to pesticides via consumption of fludioxonil-treated winter wheat seeds following autumn drilling. We recorded the density of seeds left on the soil surface, bird density, and consumption of pesticide-treated seed by birds using camera traps. We calculated the dose ingested by each bird species in a single feeding bout and if they ate treated seeds exclusively for 1 day. We extrapolated this for an additional 19 pesticides commonly used as seed treatments, assuming equal consumption rates. All three fields contained grains on the soil surface (mean 7.14 seeds/m2 on sowing day). In total, 1,374 granivorous birds spanning 18 different species were observed in the fields, with 11 species filmed eating the seeds. Fludioxonil appears to pose a low risk to birds, with <1.14% of the LD50 potentially ingested by a bird for a daily maximum amount of seeds. Analysis of the further 19 pesticides commonly used as seed dressings suggests that the neonicotinoid insecticides imidacloprid, clothianidin, and thiamethoxam represent the highest risk for granivorous birds. For example, chaffinch (Fringilla coelebs) could consume 63% of LD50 of imidacloprid in a single feeding bout, and 370% in a day. Further investigation is clearly required to determine whether seeds treated with these other pesticides are consumed as readily as those treated with fludioxonil, as if so this is likely to cause significant harm.

Validation of an alternate method for monitoring the presence of cows at the feed bunk in a Calan Broadbent Feeding System using a 3-axis, data-logging accelerometer

Daily dry matter intake is a key observation in dairy nutrition, and observation of feeding behavior provides insight into the physiological control of hunger and satiety that regulate intake. The objective of the study was to develop and validate an alternative method to observe feeding behavior, including meal length and frequency, in a Calan Broadbent Feeding System (American Calan) using a 3-axis accelerometer (Hobo Pendant G, Onset Computer Corp.). Sensors were mounted between the door and the feed divider using commonly available materials without making permanent modifications to the feeding system. Forty-eight sensors were deployed with a recording frequency of 30 s for the last 7 d of each period in a crossover experiment with 24 multiparous and 24 primiparous animals housed in a freestall barn. The tilt angle on the Z-axis was used to determine when the door was open to indicate feeding activity. The sensor system was in very high agreement with 6 h of visual observation (Cohen's κ = 0.92 ± 0.014; estimate ± 95% confidence interval). The minimum intermeal interval is the time between 2 feeding bouts that is still considered one meal. This essential criterion to characterize meals was calculated by determining the intersection of a mixture of Gaussian distributions fitted to the log-transformed between-feeding intervals. The best fitting mixture of Gaussian distributions was determined with the distribution module of JMP Pro 14.3.0 (SAS Institute Inc.). The minimum intermeal interval was 31.3 min using the best fitting model, a mixture of 3 Gaussian distributions. Using the determined minimum intermeal interval, meal length averaged 37.3 min/meal and meal frequency averaged 7.3 meals/d. In conclusion, data-logging 3-axis accelerometers are adequate to monitor presence of cows in the feed gate in the Calan Broadbent Feeding System, and this approach allows for reasonable estimation of meal length and frequency.

Diurnal and nocturnal scavenger communities differ at two shallow-water depths in an Irish marine lough

We report on still/video photographic studies in 2018/9 of diurnal and nocturnal benthic scavenging on carrion in shallow water (2 m and 12 m depths) within Lough Hyne (a biodiverse Irish sea lough) using natural light during replicated 6 h daytime deployments and dim red light (630 nm) during 6 h deployments at night. In 2018 at 2 m depth in the North Basin, bait was present throughout day-time deployments, showing little evidence of scavenging; scavenger species' richness and abundance were low. At night, baits disappeared or were skeletonised; they were scavenged by a significantly more abundant and species-rich scavenger guild. At 12 m depth in the same basin, baits were removed or skeletonised during day and night. This confirmed our hypothesis that scavengers avoid well-lit very shallow water during the day, probably to avoid predation. Multivariate analysis of 2018/19 still photo data (12 m depth) revealed pronounced and statistically significant separate clustering of day, night and basin abundance/species data, although overall species' richness values did not differ significantly. These analyses together reflected differences in species’ compositions associated with contrasting sediments, flow regimes and night/day. Nephrops norvegicus, Pagurus bernhardus and Crangon crangon were only found in the low flow rate North Basin; Homarus gammarus, Trigla sp., Callionymus lyra, Agonus, Tritia reticulata and Marthasterias glacialis were only found in the high flow rate South Basin. Most scavenger species foraged in both day and night (though in different proportions). However, prawns (Palaemon serratus) only appeared at night. Small mobile scavenging fish, small crabs and prawns arrived at baits within seconds to minutes, as did locally-abundant slow movers (e.g. anemones (Anthopleura ballii), whelks (T. reticulata)). These times are shorter than recorded in earlier studies in deeper water. Larger crustaceans (e.g. Cancer pagurus, H. gammarus) took tens of minutes to hours before arrival; similar times have previously been recorded in deeper water. Large crustacean scavengers (C. pagurus, Maja squinado, H. gammarus) took substantial quantities of bait during long feeding bouts, but catsharks (Scyliorhinus canicula) often took similar quantities in a few seconds. All of the dominant scavenger species are broad-spectrum omnivores; only one obligate scavenger species (Tritia reticulata) was present (only in South Basin) and consumed negligible quantities of bait.

Olfactory learning and memory in the greater short-nosed fruit bat Cynopterus sphinx: the influence of conspecifics distress calls.

This study was designed to test whether Cynopterus sphinx distress calls influence olfactory learning and memory in conspecifics. Bats were exposed to distress calls/playbacks (PBs) of distress calls/modified calls and were then trained to novel odors. Bats exposed to distress calls/PBs made significantly fewer feeding attempts and bouts of PBs exposed to modified calls, which significantly induced the expression of c-Fos in the caudomedial neostriatum (NCM) and the amygdala compared to bats exposed to modified calls and trained controls. However, the expression of c-Fos in the hippocampus was not significantly different between the experimental groups. Further, protein phosphatase-1 (PP-1) expression was significantly lower, and the expression levels of E1A homologue of CREB-binding protein (CBP) (P300), brain-derived neurotrophic factor (BDNF) and its tyrosine kinase B1 (TrkB1) receptor were significantly higher in the hippocampus of control/bats exposed to modified calls compared to distress calls/PBs of distress call-exposed bats. Exposure to the call possibly alters the reciprocal interaction between the amygdala and the hippocampus, accordingly regulating the expression levels of PP1, P300 and BDNF and its receptor TrkB1 following training to the novel odor. Thus, the learning and memory consolidation processes were disrupted and showed fewer feeding attempts and bouts. This model may be helpful for understanding the contributions of stressful social communications to human disorders.

Mechanical properties of food and masticatory behavior in llamas, Llama glama

Abstract Mammals typically process food items more extensively in their oral cavities than do other vertebrates. Dental morphology, jaw-muscle activity patterns, mandibular movements, and tongue manipulation work to facilitate oral fragmentation of dietary items. While processing mechanically challenging foods, mammals modulate mandibular movements and bite forces via recruitment of greater jaw-adductor muscle forces and protracted biting or chewing. Because jaw-loading patterns are influenced by magnitude; frequency; and duration of muscular, bite, and reaction forces during routine feeding behaviors, relatively larger jaws are thought to be more characteristic of mammals that experience higher masticatory loads due to the processing of mechanically challenging foods. The ease of food fracture during post-canine biting and chewing is mainly determined by food stiffness and toughness. Such foods have been associated with increased loading magnitude and/or greater amounts of cyclical loading (i.e., chewing duration). Dietary properties are thought to modulate cyclical loading through changes in chewing frequency and chewing investment. On the other hand, chewing frequency has been found to be independent of dietary properties in rabbits and primates; however, little evidence exists regarding the influence of dietary properties on these parameters in a broader range of mammals. Here, we assessed chewing behavior in seven adult llamas (Llama glama) processing foods with a wide range of mechanical properties (grain, hay, carrots, and dried corn). Each subject was filmed at 60 frames/s, with video slowed for frame-by-frame computer analysis to obtain length of feeding bout and number of chewing cycles for each food type. These parameters were used to calculate chewing frequency (chews/s), chewing investment (chews/g), and chewing duration (s/g). Chewing frequency was not significantly related to mechanical properties of food, but chewing investment and chewing duration were significantly related to dietary stiffness and toughness. Therefore, cyclical loading is positively influenced by stiff and tough foods. This suggests that variation in jaw morphology in extinct and extant mammals is positively related to dietary stiffness and toughness, which requires greater chewing investment and increased chewing duration.

What, how, and how much do herbivores eat? The Continuous Bite Monitoring method for assessing forage intake of grazing animals.

Determining herbage intake is pivotal for studies on grazing ecology. Direct observation of animals allows describing the interactions of animals with the pastoral environment along the complex grazing process. The objectives of the study were to evaluate the reliability of the continuous bite monitoring (CBM) method in determining herbage intake in grazing sheep compared to the standard double‐weighing technique method during 45‐min feeding bouts; evaluate the degree of agreement between the two techniques; and to test the effect of different potential sources of variation on the reliability of the CBM. The CBM method has been used to describe the intake behavior of grazing herbivores. In this study, we evaluated a new approach to this method, that is, whether it is a good proxy for determining the intake of grazing animals. Three experiments with grazing sheep were carried out in which we tested for different sources of variations, such as the number of observers, level of detail of bite coding grid, forage species, forage allowance, sward surface height heterogeneity, experiment site, and animal weight, to determine the short‐term intake rate (45 min). Observer (Pexp1 = 0.018, Pexp2 = 0.078, and Pexp3 = 0.006), sward surface height (Pexp2 < 0.001), total number of bites observed per grazing session (Pexp2 < 0.001 and Pexp3 < 0.001), and sward depletion (Pexp3 < 0.001) were found to affect the absolute error of intake estimation. The results showed a high correlation and agreement between the two methods in the three experiments, although intake was overestimation by CBM on experiments 2 and 3 (181.38 and 214.24 units, respectively). This outcome indicates the potential of CBM to determining forage intake with the benefit of a greater level of detail on foraging patterns and components of the diet. Furthermore, direct observation is not invasive nor disrupts natural animal behavior.

Feeding below the thermocline: implications for prey capture kinematics

AbstractThermal stratification can significantly impact the distribution of species in aquatic systems. Organisms often travel between these thermoclines in order to locate prey and find optimal thermal condition. Since most aquatic animals are ectotherms, changes in ambient temperature can have immediate impacts on performance. We aimed to understand how prey capture kinematics change when bluegill sunfish (Lepomis macrochirus) are exposed to brief acute temperature changes that represent foraging bouts below the thermocline. To do this, we exposed bluegills to either 21°C (above thermocline) or 17°C (below thermocline) and fed them a cloud of defrosted brine shrimp. After digitizing high‐speed videography, we found that performance increased at the below thermocline temperature contrary to our prediction. During these feeding bouts, we noticed high variability in prey capture behaviors as the fish encountered the first prey item and subsequent prey items. In these successive feeding events, they demonstrated a remarkable amount of modulation in close succession. We conclude that acute exposure to the thermocline temperature tested here does not negatively impact prey capture. Furthermore, feeding in rapid succession could be a way to maximize prey captured while reducing energy for searching and capture.

The Purr‐fect Catch: Using accelerometers and audio recorders to document kill rates and hunting behaviour of a small prey specialist

Abstract Characterizing variation in predator behaviour and, specifically, quantifying kill rates is fundamental for parameterizing predator–prey and food web models. Yet, current methods for recording kill rates of free‐ranging predators, particularly those that consume small‐bodied (&lt;2 kg) prey, present a number of associated challenges. In this paper, we deployed custom‐adapted acoustic recorders and tri‐axial accelerometers on free‐ranging Canada lynx Lynx canadensis to assess the capacity of biologging devices to continuously document individual hunting behaviour, including prey selection and kill rates, on a predator that specializes on prey weighing &lt;2 kg. Automated classification of acoustic recordings captured 87% of snowshoe hare kills that were identified through snow‐tracking (26 of 31 kills). Classification of detailed acceleration recordings summarized over minutes, instead of seconds, captured consumption of snowshoe hare Lepus americanus, but not smaller species, at high accuracy (F1 = 0.96). By summarizing acoustic and accelerometer data from free‐ranging lynx, we demonstrate the capacity of these devices to document within‐ and between‐individual variation in diet composition (ranging from 40% to 80% snowshoe hares) and daily feeding bouts (ranging from 0 to 3.5 bouts per day). We suggest that acoustic recorders provide a promising method for characterizing several aspects of predator hunting behaviour including prey selection and chase outcomes, while broad‐scale accelerometer‐based behavioural classifications provide hare kill rates and fine‐scale non‐hunting behavioural information. Combined, the two technologies provide a means to remotely document both kills and feeding events of small‐bodied prey, allowing for individual‐based exploration of functional responses, predator–prey interactions and food web dynamics at temporal scales relevant to environmental change.

Feedlot-finishing lambs with different levels of soybean pre-cleaning by-product as the roughage source

An experiment was conducted in the Sheep Farming Laboratory at the Federal University of Santa Maria to examine the effect of different levels of replacement of sorghum silage with soybean pre-cleaning by-product (SPCB) on nutrient intake, performance and feeding behavior; as well as to undertake an economic analysis of feeding finishing lambs in a feedlot system. The study involved 32 uncastrated Texel × Ile de France crossbred male lambs weaned at 60 days of age. Treatments consisted of diets in which the roughage source (sorghum silage) was replaced with SPCB at the levels of 0, 33.5, 66.5 or 100% (DM basis). A 45:55 roughage:concentrate ratio was used (DM basis). The diets were composed of a roughage feed based on sorghum silage and/or SPCB, and a concentrate consisting of crushed maize, soybean meal and limestone. In addition, mineral salt was freely available to the animals. The lambs were slaughtered upon reaching the pre-established live weight of 35 kg. Intake on a DM basis showed a quadratic response (P ≤ 0.05) in all forms it was evaluated and expressed, except for the NDF fraction, which increased linearly (P ≤ 0.05) with SPCB inclusion. Average daily weight gain was not significantly influenced (P &gt; 0.05) by the different SPCB levels, averaging 292 g/day. As regards the feeding behavior characteristics evaluated, the number of daily feeding bouts increased linearly (P ≤ 0.01) with the SPCB content of the diets. Total feed cost decreased linearly (P ≤ 0.01), whereas the profit per kilogram of gain and profit obtained per day in the feedlot period increased linearly (P ≤ 0.01) with SPCB inclusion. The use of soybean pre-cleaning by-product as the roughage source in the finishing of feedlot lambs proved to be a viable alternative in both the productive and economic terms.

Top-down control of conditioned overconsumption is mediated by insular cortex Nos1 neurons

Associative learning allows animals to adapt their behavior in response to environmental cues. For example, sensory cues associated with food availability can trigger overconsumption even in sated animals. However, the neural mechanisms mediating cue-driven non-homeostatic feeding are poorly understood. To study this, we recently developed a behavioral task in which contextual cues increase feeding even in sated mice. Here, we show that an insular cortex to central amygdala circuit is necessary for conditioned overconsumption, but not for homeostatic feeding. This projection is marked by a population of glutamatergic nitric oxide synthase-1 (Nos1)-expressing neurons, which are specifically active during feeding bouts. Finally, we show that activation of insular cortex Nos1 neurons suppresses satiety signals in the central amygdala. The data, thus, indicate that the insular cortex provides top-down control of homeostatic circuits to promote overconsumption in response to learned cues.

Recolonizing carnivores: Is cougar predation behaviorally mediated by bears?

Conservation and management efforts have resulted in population increases and range expansions for some apex predators, potentially changing trophic cascades and foraging behavior. Changes in sympatric carnivore and dominant scavenger populations provide opportunities to assess how carnivores affect one another. Cougars (Puma concolor) were the apex predator in the Great Basin of Nevada, USA, for over 80 years. Black bears (Ursus americanus) have recently recolonized the area and are known to heavily scavenge on cougar kills. To evaluate the impacts of sympatric, recolonizing bears on cougar foraging behavior in the Great Basin, we investigated kill sites of 31 cougars between 2009 and 2017 across a range of bear densities. We modeled the variation in feeding bout duration (number of nights spent feeding on a prey item) and the proportion of primary prey, mule deer (Odocoileus hemionus), in cougar diets using mixed‐effects models. We found that feeding bout duration was driven primarily by the size of the prey item being consumed, local bear density, and the presence of dependent kittens. The proportion of mule deer in cougar diet across all study areas declined over time, was lower for male cougars, increased with the presence of dependent kittens, and increased with higher bear densities. In sites with feral horses (Equus ferus), a novel large prey, cougar consumption of feral horses increased over time. Our results suggest that higher bear densities over time may reduce cougar feeding bout durations and influence the prey selection trade‐off for cougars when alternative, but more dangerous, large prey are available. Shifts in foraging behavior in multicarnivore systems can have cascading effects on prey selection. This study highlights the importance of measuring the impacts of sympatric apex predators and dominant scavengers on a shared resource base, providing a foundation for monitoring dynamic multipredator/scavenger systems.

Linking ASI-Mobile Android-Based App on Mothers Attitude and Behavior on Exclusive Breastfeed

Exclusive breastfeeding within the Palangka Raya municipality is far below target, on which 14,99% (2016) and 16,76% (2017), respectively. There were several primary health has the feeding bout, only cover 2,58%. Due to a lack of mothers knowledge, regarding beneficial and proper breastfeeding practices. Todays technology presumably has the advantages as promotional media. The study was aimed to quantify the android-based application, so-called ASI-Mobile, towards mothers attitude and behavior, on exclusive breastfeeding within Jekan Raya district, Palangka Raya Municipality, Central Kalimantan. The Research was conducted in March - October 2019, using a quasi-experimental design, and the sample was 60 pregnant women, in the third trimester period, over the Jekan Raya District areas. ASI-Mobile was subjected to 30 pregnant women, while others 30 mothers by counseling, the conventional promotion type. Purposive sampling was used, their socio-economic was collected, descriptive analysis was conducted. Bivariate analysis, Wilcoxon ranked test was used to analyzed the effect of the treatments. We've have found a significant link on ASI-Mobile application toward mothers attitudes (p-value 0.046) and behavior (p-value 0.018). We concluded that the ASI-Mobile, an android-base application, is more effective towards shifting mothers attitudes and behavior on exclusive breastfeeding within our study area.