Effect of Oxytocin on the Body Weight of Male Rabbits

This study was carried out to investigate the effect of two different doses of oxytocin on weight. Adult male rabbits (15) were weighed and provided with food twice daily for 3 weeks to determine the amount of food consumed daily and the time spent feeding by each rabbit. After 3 weeks the rabbits were weighed and divided randomly into 3groups: the control group, the low dose group, and the high dose group. The animals were injected daily for 3 weeks. During that time the amount of food consumed and the time spent feeding in both periods were determined. After the end of the treatment period the rabbits were weighed, and sacrificed. The results of this study showed that before treatment the rabbits consumed more food in the evening period than they did in the afternoon period. The mean time spent feeding in the evening period was slightly higher than that spent in the afternoon period; however, this difference was not statistically significant. After treatment, there was still significant difference between the means of the consumed food in the afternoon and the evening period for the control group. The mean amounts of food consumed in both periods by the treated groups were slightly reduced, but this reduction was not statistically significant. Furthermore, the mean time spent feeding in the evening period was slightly higher than that of the afternoon period for the 3 groups; however, these differences were not significant. The mean weight of the control group was slightly increased after treatment with the hormone; and the mean weights of the treated groups were slightly reduced after treatment. However, changes in body weighs were not statistically significant.

Plant Tannins and Essential Oils Have an Additive Deterrent Effect on Diet Choice by Kangaroos

Tannins and essential oils are well recognised as antiherbivore compounds. We investigated the relative effectiveness of the polyphenol, tannin, and the essential oils, 1,8-cineole and pine oil, as feeding deterrents against western grey kangaroos. Both groups of secondary metabolites are naturally abundant in many Australian plants. These three metabolite groups were incorporated separately or together into standard pellets for presentation to kangaroos, and their behaviour (sequence of food choice and feeding time) and amounts consumed were observed. The control (with no secondary metabolites) was much preferred. There was a sharp reduction in the ingestion of pellets containing tannins, 1,8-cineole or pine oil. Combinations of the metabolites resulted in almost no consumption. In association with tannin, pellets containing either 1,8-cineole or pine oil were as effective deterrents as both combined. There was a strong correlation between time spent feeding on the different diets and the amount of food consumed, although the rate of intake was markedly slower when secondary metabolites were present. Behavioural observations showed that the amount of food ingested is initially guided by the presence/absence of essential oils, apparently detected by smell, and later by the presence/absence of tannins, by taste. Both groups of secondary metabolites work in concert by stimulating different senses that minimise herbivory by marsupials, such as the western grey kangaroo, and help to explain their abundance in the Australian flora.

Behavioural Indicators of Intra- and Inter-Specific Competition: Sheep Co-Grazing with Guanaco in the Patagonian Steppe

In extensive livestock production, high densities may inhibit regulation processes, maintaining high levels of intraspecific competition over time. During competition, individuals typically modify their behaviours, particularly feeding and bite rates, which can therefore be used as indicators of competition. Over eight consecutive seasons, we investigated if variation in herd density, food availability, and the presence of a potential competitor, the guanaco (Lama guanicoe), was related with behavioural changes in domestic sheep in Chilean Patagonia. Focal sampling, instantaneous scan sampling, measures of bite and movement rates were used to quantify behavioural changes in domestic sheep. We found that food availability increased time spent feeding, while herd density was associated with an increase in vigilant behaviour and a decrease in bite rate, but only when food availability was low. Guanaco presence appeared to have no impact on sheep behaviour. Our results suggest that the observed behavioural changes in domestic sheep are more likely due to intraspecific competition rather than interspecific competition. Consideration of intraspecific competition where guanaco and sheep co-graze on pastures could allow management strategies to focus on herd density, according to rangeland carrying capacity.

Effects of Visitor Presence and Crowd Size on Zoo-Housed Red Kangaroos (Macropus Rufus) During and After a COVID-19 Closure

Macropods, particularly kangaroos and wallabies, are common species included in walk-through habitats that put them in close proximity to zoo visitors. However, there has been little research into how visitor presence and density impact the welfare of these individuals. We monitored the behavior and space use of fifteen red kangaroos (Macropus rufus) for a total of ten weeks during and after a nearly three-month zoo closure due to the COVID-19 pandemic. Our findings revealed potential visitor effects, evidenced by more time spent in social proximity, greater inactivity, and more restricted space use after the zoo reopened. Although temperature and weather likely played a role in at least some of these behavioral changes, social proximity and space use changed with crowd size in a manner consistent with our zoo status (i.e., open or closed) results. Additionally, time spent feeding was significantly related to crowd size but not zoo status, such that the kangaroos spent more time feeding when there were no visitors in the habitat. These findings suggest that visitor effects explain these behavioral changes better than seasonal confounds. We also noted several individual differences in response to visitor presence and crowd size, highlighting the importance of evaluating behavioral responses to visitors on an individual basis.

Microplastic and Organic Fibres in Feeding, Growth and Mortality of Gammarus pulex

Microplastic fibres (MPFs) are a major source of microplastic pollution, most are released during domestic washing of synthetic clothing. Organic microfibres (OMF) are also released into the environment by the same means, with cotton and wool being the most common in the UK. There is little empirical evidence to demonstrate that plastic fibres are more harmful than organic fibres if ingested by freshwater animals such as Gammarus pulex. Using our method of feeding Gammarus MPFs embedded in algal wafers, we compared the ingestion, feeding behaviour and growth of Gammarus exposed to 70 µm sheep wool, 20 µm cotton, 30 µm acrylic wool, and 50 µm or 100 µm human hair, and 30 µm cat hair at a concentration of 3% fibre by mass. Gammarus would not ingest wafers containing human hair, or sheep wool fibres. Given the choice between control wafers and those contaminated with MPF, cat hair or cotton, Gammarus spent less time feeding on MPF but there was no difference in the time spent feeding on OMFs compared to the control. Given a choice between contaminated wafers, Gammarus preferred the OMF to the MPF. There were no significant differences in growth or mortality among any of the treatments. These results conclude that MPFs are less likely to be ingested by Gammarus if alternative food is available and are not more harmful than OMFs.

Feeding ecology of Walia Ibex Capra walie (Mammalia: Artiodactyla: Bovidae) in Simien Mountains National Park, Ethiopia

Walia Ibex Capra walie is an endemic and endangered species residing in Simien Mountains National Park, Ethiopia. It has shifted its range within the Park in the last decade, and in this study our main objective was to provide information on their feeding ecology to inform recovery goals. We used a scan sampling method to collect foraging information during October 2009 to November 2011. Our observations suggest a diverse diet of more than 28 species of grasses, forbs, and shrubs. The most commonly used plants were Festuca sp., Lobelia rhynchopetalum, Helichrysum citrispinum, and Helichrysum horridum. Walia Ibex were active in feeding before and after mid-day, and time spent feeding was the highest compared with other diurnal activities. The percentage of time spent feeding on major plant species did not differ between wet and dry seasons (p> 0.05). Walia Ibex, however, tended to spend more time browsing than grazing. The generalist nature of foraging behaviour in Walia Ibex most likely contributes to complaints from the local people who witness Walia Ibex raiding crops cultivated in and around the Park. Thus, the contribution of crop raiding to the shifts in the species’ range towards higher altitudes at Sebatminch within Simien Mountains National Park emphasizes the need to consider foraging ecology as community-based conservation efforts are developed to support Walia Ibex in the Park.

Automatic Supplement Weighing Units for Monitoring the Time of Accessing Mineral Block Supplements by Rangeland Cattle in Northern Queensland, Australia

Time spent feeding by grazing cattle is an important predictor of intake and feed efficiency. This study examined the use of automatic supplement weighing (ASW) units for monitoring voluntary access of breeding cows (n = 430) to mineral block supplements in an extensive rangeland of northern Australia. The ASW units (n = 10) were located within each of experimental sites (5 units per site; Bore and Eldons). Over the 62 days of data collection, 85%, 13%, and 2% of cows spent <600, 600–1200, >1200 min accessing supplements, respectively, with between-animal variation (CV) of 107%. A total of 133 cows visited both sites while 142 and 155 cows visited only Bore and Eldons, respectively. Most visits (80–90%) were recorded during the day (800–1700 h), 7–17% during the night (1800–2300 h), and 3% during the dawn (0–700 h). Time spent accessing supplements differed between ASW units across the two sites (p < 0.001) and varied according to the day of visits (p < 0.001). There was a significant relationship between time spent at the ASW units and supplement intake on a herd basis (p < 0.001; R2adj = 0.70). The results showed that the ASW units were capable of monitoring access to mineral block supplements that may reflect the supplement intake of rangeland cattle.

Quantifying Mineral Intake and the Role of Minerals on Food Selection in Angola Black and White Colobus Monkeys (Colobus angolensis palliatus)

Minerals are vital for many metabolic processes, and mineral deficiencies can adversely impact health and fitness. Mineral concentrations of food items are commonly reported in primate nutritional ecology studies and have been identified as important factors in primate food selection; however, very few studies have quantified daily mineral intake of free-ranging primates. We examined the concentration of 9 minerals (Ca, P, Mg, K, Na, Fe, Zn, Cu, and Mn) in foods consumed by <i>Colobus angolensis palliatus</i> inhabiting the Diani Forest of Kenya, and test whether individuals preferentially selected leaves in accordance with their mineral concentrations. We also examined the effects of sex, group, and season on daily mineral intake, quantifying both percentage-based and mass-based intakes. We then compared daily mineral intake values to published recommendations. Behavioral data and plant samples were collected from July 2014 to December 2015. We found that individuals preferred leaves with greater P content and lower Ca content. Daily mineral intake differed significantly between sexes and among groups and seasons. These results are interpretable via differences in time spent feeding and total energy intake. Intakes fell below percentage-based recommendations for P, Na, Fe, Cu, and Mn but met or exceeded mass-based recommendations for all minerals except Na. This discrepancy is likely explained by the conservative nature of percentage-based mineral recommendations and the difficulty of comparing and scaling mass-based mineral recommendations among primate species. Studies that quantify daily mineral intake are needed to better understand the role of minerals on dietary selection, more accurately identify potential mineral deficiencies, and provide more informed recommendations for captive primates.

Better together? How intergroup associations affect energy balance and feeding behavior in wild bonobos

When the benefits of interacting with out-group members exceed the associated costs, social groups may be expected to be tolerant towards each other. However, in many species exhibiting intergroup tolerance, the nature of benefits gained from intergroup encounters remains unclear. We investigated the potential costs and benefits associated with intergroup associations in bonobos, a species with varying degrees of intergroup tolerance, by testing whether these associations conferred energetic benefits to participants under different socioecological contexts and whether the consequences of these associations substantially differed from within-group competition. We used measures of socioecological factors (fruit abundance and group size), feeding and ranging behaviors, and a physiological marker of energy balance (urinary c-peptide of insulin) collected over a 19-month period from two neighboring wild communities in the Kokolopori Bonobo Reserve, Democratic Republic of the Congo. We found that intergroup associations were not related to individuals’ energy balance, but they were related to variations in individuals’ ranging and feeding behavior. Specifically, bonobos traveled longer distances, visited larger fruit patches, and increased the time spent feeding on fruits on days they associated with the neighboring group. These adaptations in feeding behavior may be strategies to offset the energetic costs of increased travel distances. In the absence of obvious energetic benefits and with clear strategies employed to offset energetic costs, it is likely that intergroup associations in bonobos provide benefits unrelated to energy acquisition, such as social benefits. Our study sheds light on the potential incentives promoting social networks to extend beyond and across groups in a tolerant species. Significance statement Intergroup encounters can be energetically costly due to increased competition over resources. Yet, some species associate with out-group individuals for extended periods of time when the benefits of participating in these associations exceed the potential costs. Bonobos, a species exhibiting intergroup tolerance, modified their feeding behavior during intergroup associations by feeding on larger fruit patches and increasing their time spent feeding on fruits, likely to offset energetic costs of increased travel distances. As results, individuals’ energy balance was not related with intergroup associations. The employment of such strategies in addition to the absence of clear energetic benefits suggests that intergroup associations in bonobos provide social rather than ecological benefits.

Diurnal activity patterns of walia ibex (Capra walie) in Simien Mountains National Park, Ethiopia

Walia ibex (Capra walie) is an endangered and endemic species restricted to Simien Mountains National Park (SMNP), Ethiopia. Data on activity patterns of walia ibex were collected during October 2009 to November 2011, and the main objective of the research was to determine diurnal activity patterns of walia ibex in Simien Mountains National Park in order to design sound conservation strategies for the species. Scan sampling method was used for data collection on diurnal activity patterns of walia ibex. Diurnal activity patterns in walia ibex were bimodal, in which they were active before and after noon. They rest in shade on rocks and cliffs during the mid-day to protect themselves from hot sun and predators. Activity patterns of walia ibex during the day showed statistically significant differences (F7,18228= 82.09, df=7, p<0.01). Feeding showed significant differences compared to moving, standing, resting, socializing, and other activities (p<0.05). Diurnal activity records in the walia ibex population during the wet and the dry seasons showed that time spent feeding was the highest and vigilance was the lowest. Knowledge of the pattern of this behavior can especially be useful to design conservation planning as successful reproduction in the population may be threatened by anthropogenic disturbances. Thus, information about the diurnal activity patterns of walia ibex is essential for conservation planning of the endemic and endangered walia ibex in its natural habitats.