Behavior Of Ducks Research Articles

Variations in gut microbiota composition and reproductive hormone levels between laying and broody Muscovy ducks

High broodiness in Muscovy ducks impedes animal husbandry growth. The interaction between endocrine hormones and gut microbiota has been proven to play a crucial role in reproductive performance, and whether it can regulate the broody behavior of Muscovy ducks requires further research. Nine laying ducks (Laying group) and nine broody ducks (Broodiness group) were selected. Corresponding serum, ileum, and cecum chyme were collected for further research. The results showed that, compared to the laying group, the serum concentration of prolactin decreased, while the levels of Mullerian inhibiting substance, follicle-stimulating hormone, and follistatin increased in the broodiness group (P < 0.05). 16S rDNA sequencing showed that, the broodiness group exhibited lower abundance levels of Rothia, Streptococcus, and Lactobacillus, whereas the abundance of Turicibacter, Aliicoccus, and Facklamia was higher in the ileum compared to the laying group (P < 0.05). In the cecum, the broodiness group exhibits a significant reduction in the abundance of Butyricicoccus and unclassified_f_Rikenellaceae, while the abundance of Christensenellaceae_R-7_group, Ruminococcus_torques_group, Parabacteroides, norank_f_Oscillospiraceae, Cloacibacillus, Sellimonas, Shuttleworthia, norank_f_UCG-010, unclassified_f_Lachnospiraceae, Oscillospira, Synergistes, Family_XIII_AD3011_group and Eubacterium_nodatum_group is higher compared to the laying group. A Spearman correlation analysis reveals that both in the ileum and cecum, serum hormones exhibit significant correlations with the top 20 abundant intestinal microbial genera. Among these, serum follistatin has most entries of significant correlations with the detected microbial genera (P < 0.05). In conclusion, the broody behavior of Muscovy ducks can be modulated by the interaction between hormones and gut microbiota. Notably, the relationship between Follistatin and the composition of gut microbiota, specifically Firmicutes, is the most prominent.

Chance of Shadows

An observational memoir unraveled from pandemic poetry about duck behavior interacting with the weather. The writing thread induces memory as non-sequential, and employs parataxis in vignettes, with no claims to live up to a Nature as individually experienced by a reader. Excerpted from a work in progress, a non-manual on Drawing entitled The World of Minuses.

Case report: first data on the foraging behaviour of velvet scoters (Melanitta fusca) in soft-bottom coastal waters of the southeast Baltic Sea

BackgroundThe foraging behaviour of sea ducks has always been difficult to study due to their exclusive occupancy of coastal waters during the wintering season. In this study we investigated the foraging behaviour of seven wintering velvet scoters (Melanitta fusca) in Lithuanian soft-bottom coastal waters by attaching a solar-powered external GPS‐GSM transmitter to each individual bird. This transmitter data allowed us to analyse the dive phase parameters and feeding depths during December 2021 and March 2022.ResultsThe results showed that velvet scoters dived deeper than a 30-m depth, with the dive duration lasting up to 90 s on average. The bottom duration increased rapidly in the first 5 m and then levelled off at around 40 s for deeper waters. The underwater duration varied between 2 and 7.5 h a day. The dive effort (as total underwater time) and the bottom duration of velvet scoters were related to the depth and prey biomass, although both factors were demonstrated to be interdependent. Moreover, the results showed that velvet scoters were less active in December than in March in terms of both average diving duration and diving frequency. The results also confirmed the high diurnal activity of the velvet scoter, although the birds demonstrated night activity in December and not in March.ConclusionThis information on the velvet scoter’s foraging behaviour may have important implications for the conservation of the species, and provides new insights into the improvement of conservation measures for the species in the Baltic Sea.

Effect of dietary concentrations of Metabolisable energy and crude protein on the performance and behavior of ducks

ABSTRACT 1. The study evaluated the effect of dietary metabolisable energy (ME) content and crude protein (CP) level on the growth performance and behaviour of ducks. 2. A total of 720, Cherry Valley ducks were allocated to 36 pens in groups of 20 birds. For the initial period, from 1 to 21 d age, six diets, containing a standard (SME), low (LME) and high (HME) ME of 12.14, 11.93 and 12.35 MJ/kg, and standard (SCP) or high (HCP) CP contents of 210 or 220 g/kg diet, respectively, were mixed. For the period from 22 to 42 d age, the diets contained ME of 12.98 (SME), 12.77 (LME), 13.19 (HME) MJ/kg and the levels of CP were 170 (SCP) or 180 (HCP) g/kg, respectively. 3. An ME by CP interaction was seen from 1 to 21 d age in ducks fed HME + HCP diet, which had greater weight gain than those fed LME + SCP (P < 0.05). Compared to LME + SCP, dietary HME decrease feeding but increased walking behaviour compared to LME + SCP and SME + SCP (P < 0.05). High CP in LME and SME diets increased drinking behaviour (P < 0.05), but there was no change in HME diet. Compared to LME, feeding HME reduced ground pecking (P < 0.05). Feeding HME reduced feeding behaviour (P < 0.05) from 22 to 42 d age. During the same period, standing behaviour was reduced in HCP + LME (P < 0.05). Drinking was reduced in LME + SCP compared to SME + HCP and HME + HCP (P < 0.05). 4. A diet formulated with HME and HCP is effective for enhancing growth performance of ducks aged 1-21 d and saving time for feeding or ground pecking, which may induce spending more time on other activities.

An Aerial–Aquatic Robot with Tunable Tilting Motors Capable of Multimode Motion

Aerial–aquatic robots have promising applications due to their ability to operate in air and water with different motion modes. However, challenges such as water/air transition and multimedia movement still limit their development. Inspired by the aerial–aquatic behavior of wild ducks, an aerial–aquatic robot with tunable tilting motors and a delta wing is introduced. The robot can perform multimode motion, including flying in air, swimming on the water surface, transitioning between air and water, and diving underwater. Besides, the buoyancy design enables the robot to float at the air–water interface without consuming energy. Herein, the performance of the robot, including vertical and horizontal cross‐media performance, power consumption, and endurance in various motion modes, is evaluated. The field experiments show that the proposed robot possesses multimode motion and high maneuverability. This study provides a new idea for the structural design of next‐generation practical aerial–aquatic robots.

Integration of Grape-Duck Production Pattern Boosts Duck Behavior, Meat Quality, Fecal Microbiota and Soil Microorganisms

The combination of planting and breeding, an agricultural production system, makes full use of land, ecological space and time, increasing the utilization rate and yield of both plant and animal production. This experiment aimed to explore the effects of the grape-duck farming system by analyzing behavior, meat quality, and fecal microbiota of ducks and the soil microbiota. The results differed significantly on the expressions of positive behaviors between the breeding group and the combination of planting and breeding group, including actions of foraging, feeding and walking (p &lt; 0.05), while the free-range group showed more stereotyped behavior of no apparent purpose or significance. In terms of meat quality, the yellow value b* of the combination group was significantly higher than that of the free-range group (p &lt; 0.05). The drip loss rate of the planting and breeding group was 1.80%, and the drip loss rate of the combination group was 3.80%, with a significant difference (p &lt; 0.05). The combination of planting and rearing increased the alpha diversity of soil microbiota (p &lt; 0.05), but it had no obvious effect on the fecal microbiota of ducks. PCoA showed that soil microorganisms and fecal microbiota are obviously separated and clustered. In conclusion, the combination production mode of “grape-duck” had a positive effect on duck behavior, meat quality, and soil microorganisms, however, it changed virtually nothing in duck production performance and fecal microbiota.

Physico-Chemical Parameters, Oxidative Stress, and Fatty Acid Profile of American Pekin Ducks (Anas Platyrhynchos Domesticus) Raised under Different Production Systems

Rearing of American Pekin ducks in different production systems plays a vital role in the determination of the internal climatic conditions of the house for optimum health and meat quality parameters. The experiment was designed to evaluate the influence of different rearing systems fed on kitchen waste on meat quality parameters of American Pekin ducks. A total of 180 ducklings (10 days old) were distributed randomly into three experimental groups; intensive production system (IPS), free-range production system (FRPS), and pool with yard production system (PYPS). We investigate the physicochemical parameters, meat coloration, oxidative stress, and fatty acid (FA) profile of Pekin ducks. Ducks reared in PYPS showed better physico-chemical parameters and meat coloration than those of ducks reared in IPS and FRPS. Drip loss % and cooking loss % are significantly low in FPRS while (L*) l-lightness, (a*) redness, and (b*) yellowness are significantly higher in IPS (p≤0.05). The oxidative stress was reduced in PYPS due to the natural behavior of ducks. Moreover, the fatty acid profile was improved in PYPS fed with 100% kitchen waste. In conclusion, this experiment confirmed that ducks reared in PYPS improve their meat quality parameters, fatty acid, and oxidative stress.

Behavior and welfare impacts of water provision via misting in commercial Pekin ducks.

Ducks will access water to maintain feather condition and exhibit natural water-related behaviors such as wet preening. Providing water to ducks commercially is challenging as it may reduce litter and air quality leading to higher duck mortality or illness. This research aimed to measure the behavioral and welfare impacts of water provision via a misting system for commercial Pekin grower ducks in Victoria, Australia. Seven grower flocks were observed (four misted and three nonmisted in open-sided sheds) during May and November 2021. From 26 until 33 d of age, treatment ducks were provided 1 h of misting with shed curtains closed in both treatment and control sheds. At the start and end of the misting application period, external health and welfare measures were taken directly on the ducks via transect walks throughout each shed and catch-and-inspect observations on a sample of 150 ducks from each shed. Video recordings were also made of the misted and nonmisted ducks for 3 h representing time periods prior to, during, and after the 1-h misting across all sheds for all 8 d of the treatment period. Observations were made of all behavior that ducks exhibited at 10-min scan sample intervals across four cameras per shed, totaling 4,198 scans across the seven sheds. General linear mixed models showed the misting application predominantly had impacts on the patterns of behavioral change across the treatment time periods between the misted and nonmisted ducks rather than increasing or decreasing the overall expression of specific behaviors (interaction terms all P ≤ 0.003). The misted ducks increased drinking, tail wagging, and walking, and reduced preening, rooting litter, sitting, and stretching during misting relative to what they showed prior. The nonmisted ducks showed less sitting and more panting during misting relative to prior. Pearson's Chi-square tests showed some differences between the treatment groups in feather cleanliness on the back and wings (both P < 0.0001), likely resulting from pre-existing differences between sheds in blood from pin feathers. Most welfare indicators showed no positive or negative effect of the misting treatment. These results indicate overhead misting does affect duck behavior to some degree without compromising their welfare, but further research with larger water droplet sizes resulting in greater accumulation of surface water or extended durations of misting may lead to greater effects.

Effects of meal frequency on performances, appearance and behaviour of mule ducks housed in confinement

Effects of meal frequency on performances, appearance and behaviour of mule ducks housed in confinement

The number, behaviour, and population indices of Mallard ducks (Anas platyrhynchos L.) in non-urban and urban environments of the Lublin region

The paper presents indicators of the number, reproduction and behavior of mallard ducks living in unurbanized and urbanized environments in the Lublin region. The research carried out in urban areas and beyond showed significant changes in the behavior of birds in terms of their timidity due to the presence of humans, as well as the distance of departure of birds and re-landing on the water surface. These distances between the described types of environment were four times higher for unurbanized areas. Significantly higher numbers, and thus also the bird density indicators, were found, as well as the average size of the assemblages in urbanized areas, which, depending on the date of the study, was higher by 2.0-3.2 birds in the community in favor of anthropogenic environments. There were no significant differences in the sex structure and reproductive rates between the study sites, with male predominance in all types of environments. The conducted analyzes indicate a progressive adaptation to urbanized environments by mallard ducks. This is done through behavioral changes, which does not significantly affect the course of natural selection and breeding processes of birds in these environments, as compared to unurbanized or low-urbanized environments typical for this species until recently.

Evaluation of the time-activity budgets of captive ducks (Anatidae) compared to wild counterparts

Ducks are commonly housed in captive environments where their abilities for flight are constrained, either temporarily or permanently. The use of flight restraint in modern animal management is contentious and ethically questioned yet any associated impacts on behaviour remain poorly documented and evaluated. Comparison of information on wild ecology and activity of free-living individuals with information from the same species when captive-housed can reliably inform on “naturalness” of behaviour patterns if standardised methods are used. This research aimed to compare the activity of several species of ducks (Order Anseriformes) with information contained in the literature, and that collected from direct observation, to identify differences between the behaviours of captive and wild ducks. Observational data on the state behaviours for 17 duck species were collected at three Wildfowl & Wetland Trust (WWT) centres in the UK from 2015 to 2018, with behavioural data on two species of wild duck also collected via direct observation. A meta-analysis of time spent on key state behaviours (papers published up until 2018) was performed to provide comparison with the information provided on time-activity budgets of the captive birds. Results showed a multitude of factors influenced captive duck behaviour, but resting, maintenance and locomotion behaviours were most commonly observed. Wild birds differed significantly in their time-activity budgets compared to captive individuals and data from the meta-analysis revealed that foraging rates were higher in the wild than in captivity. Records of abnormal behaviour in captive birds were non-existent to very low in performance, suggesting that flight restrained ducks do not fill part of their time budget with stereotypic behaviour. Human presence may potentially influence of the behaviour of both wild and captive ducks living in wetland areas that attract human visitors. Seasonal, temporal and sex differences significantly also affected wild and captive duck behaviour. Further study should continue to investigate behavioural responses of these species to a range of captive housing to determine the most optimal way of providing for good welfare under human care. Research that investigates the behaviour of fully winged captive ducks to extend our evaluation of behaviour patterns in flight restrained birds (and to provide further review against wild data) is recommended.

Identification and Analysis of Emergency Behavior of Cage-Reared Laying Ducks Based on YoloV5

The behavior of cage-reared ducks is an important index to judge the health status of laying ducks. For the automatic recognition task of cage-reared duck behavior based on machine vision, by comparing the detection performance of YoloV4 (you only look once), YoloV5, and Faster-RCNN, this work selected the YoloV5 target detection network with the best performance to identify the three behaviors related to avoidance after a cage-reared duck emergency. The recognition average precision was 98.2% (neck extension), 98.5% (trample), and 98.6% (spreading wings), respectively, and the detection speed was 20.7 FPS. Based on this model, in this work, 10 duck cages were randomly selected, and each duck cage recorded video for 3 min when there were breeders walking in the duck house and no one was walking for more than 20 min. By identifying the generation time and frequency of neck extension out of the cage, trample, and wing spread, it was concluded that the neck extension, trampling, and wing spread behaviors of laying ducks increase significantly when they feel panic and fear. The research provides an efficient, intelligent monitoring method for the behavior analysis of cage-rearing of ducks and provides a basis for the health status judgment and behavior analysis of unmonitored laying ducks in the future.

Agro-ecological mechanisms for weed and pest suppression and nutrient recycling in high yielding complex rice systems

Recent research has revealed that complex rice systems (CRSs), in which several plant and animal species, including azolla, fish, ducks and border plants have been integrated, can produce high and stable rice yields over time. However, the mechanisms that support these benefits have not been examined in detail. On-farm experiments were conducted in Indonesia during five rice cropping cycles. We compared three monoculture rice systems receiving chemical or organic inputs, and four organic polyculture rice systems that varied in level of complexity. To investigate the agro-ecological mechanisms of weed and pest suppression and nutrient cycling that determine rice productivity and stability, the dynamics of weeds, pests, nutrients and rice yields were monitored and related to rice system complexity. The observations revealed that increasing the level of complexity resulted in lower levels of weed and pest infestation. Analysis of duck behaviour and their gizzard composition showed that ducks foraged intensively on weeds, insects, and snails. Furthermore, nutrient cycling was accelerated by ducks via feeding and excretion as well as by their movement in the field. This could explain why rice yields increased along the gradient of complexity, and overall were higher and less variable in the most complex systems in comparison to the rice monocultures. In complex rice systems, increasing the number of species that are compatible to the rice ecosystems and could play a role in generating ecosystem services of weed and pest suppression as well as nutrient recycling, can lead to higher and less variable rice yields.

A comparison of white/red and white/blue LED light fixtures on Pekin duck production, stress and behaviour

ABSTRACT 1. The objective of this study was to determine the effects of two mixed LED light spectra on duck production, stress and fear responses. Pekin ducks were reared under either white/red (WR) or white/blue (WB) LED light. 2. No differences were observed in feed conversion ratio (P = 0.690) or d 35 body weight (P = 0.919). Furthermore, no differences were observed in plasma interleukin-12 concentrations (P = 0.449), anti-keyhole limpet haemocyanin IgG titre (P = 0.503) or composite physical asymmetry score (P = 0.839). WR caused lower heterophil to lymphocyte ratios (0.40 ± 0.03, P = 0.029) and plasma corticosterone concentrations (4498 ± 534 pg/ml, P = 0.038) than WB (0.58 ± 0.08; 6518 ± 795 pg/ml, respectively). No differences were found in the number of attempts to induce tonic immobility (TI) or in inversion intensity. A shorter latency to first head movement during TI (9.44 ± 1.22 s, P = 0.06) and an overall shorter latency to right from TI (25.66 ± 2.99 s, P < 0.001) was observed for birds under WR compared to WB (20.91 ± 6.01 s; 58.76 ± 8.86 s). The duration of time spent in the second stage of TI, where birds observed their environment using head movements while still remaining immobile on their backs, was shorter in WR (16.23 ± 1.73 s, P = 0.001) compared to WB (37.85 ± 6.38 s). 3. The results indicated that rearing ducks under WR caused less stress susceptibility and fear responses compared to ducks under WB. Pekin duck welfare may be compromised by blue LED light exposure, even at supplemental levels utilised in commercial poultry lighting.

Self- and conspecific-directed pecking behavior of commercial Pekin ducks

Injurious pecking behavior affects commercial Pekin duck welfare, but little information is available regarding the characteristics thereof. This study investigated self- and conspecific-directed pecking behavior of ducks, including 1) the prevalence, frequency and duration, 2) age-related changes in pecking and preening behavior, and body locations affected; 3) influence of time of day and location within the barn; and 4) occurrence of feather removal and feather eating. Behavior of two commercial flocks was video-recorded at 20–22 d (Period 1), 27–29 d (Period 2), and 34–36 d (Period 3) and analyzed using scan (n = 340 ± 91 ducks/flock per observation time point) and focal (n = 144 observation periods/flock) animal sampling. The percentage of ducks performing pecking behavior (gentle feather pecking (%GFP), severe feather pecking (SFP), aggressive pecking (AGGP) and self-picking (SELFP)) was determined every 30 min (09:00 h-15:00 h). Randomly selected focal ducks were observed for 30 min (09:45 h-10:15 h and 13:45 h-14:15 h) to determine durations and frequencies of pecking and preening behavior and the occurrence of feather removal and feather eating. Scan sampling data and focal behavioral durations were analyzed using PROC MIXED; behavioral frequencies were analyzed using PROC GLIMMIX (SAS 9.4). SFP, AGGP and SELFP were combined into one category, other pecking (OP), for analysis. GFP was observed most frequently, SFP and AGGP occurred less frequently, and SELFP was rarely observed. Feather removal (13 times) and feather eating (7 times) occurred infrequently. GFP frequency, duration and GFP% increased from Period 1 to 2 (P < 0.01), then declined from Period 2 to 3 (P < 0.01). Preening frequency and duration similarly changed with age (P < 0.01). OP frequency (P = 0.03) and duration (P = 0.03) were higher in Period 2 than Period 1. Body locations affected by GFP included the tail, wings and back. Little injurious pecking was observed; GFP between conspecifics was the most frequently observed behavior. Age was a major factor affecting the performance of pecking behavior, which peaked at Period 2 and was most frequently directed at the tail, wings and back. Further research is needed to examine seasonal effects and other factors influencing injurious pecking of ducks.

Ambient temperature and female body condition are related to night incubation behavior in wood ducks Aix sponsa

For many animals, parental care behavior is an important aspect of their life history that affects both parents and offspring. In birds, one of the most important parental care behaviors is incubation, which is costly to the parent but directly influences embryonic development and fitness of offspring. Some birds exhibit the intriguing behavior of partially incubating their eggs prior to clutch completion for only a portion of each day. This partial incubation is characterized by lower incubation temperatures and constancy than during full‐time incubation, which typically begins at clutch completion. Partial incubation may preserve the viability of eggs laid early in the laying sequence, shorten the length of the full incubation period, and/or provide a favorable microclimate to the incubating parent. It might also reduce the probability of nest predation, nest site takeover by another bird, brood parasitism, and/or predation of the adult. Although there is evidence that partial incubation is an adaptive behavior and that time invested in this behavior varies among individuals of the same species, nothing is known about what may drive this inter‐individual variation. To investigate how environmental and parental characteristics may be related to partial incubation behavior, we studied the partial incubation behavior of wood ducks Aix sponsa using artificial egg temperature loggers within nest boxes. Our results suggest that females with greater mass relative to their structural size invest more time in partial incubation. Additionally, the incubation temperature and length of on‐bouts of partial incubation increased over the course of the partial incubation period, and ambient temperature during on‐bouts was positively related to incubation temperature. Ultimately, our study suggests that characteristics of both the environment and parent may influence the partial incubation behavior of wood ducks, and improves our understanding of an important, but understudied, aspect of avian parental care.

Influence of housing systems on duck behavior and welfare.

Objective:This experiment was conducted to assess the effects of the housing system on the welfare and growth performance of the Muscovy duck.Materials and methods:A total number of 48 Muscovy duck aged 3-week old were divided randomly into two groups (24 duck on each): deep litter system and cage system. Each group was subdivided into three replicates (8 birds on each) were identified with wing rings.Results:The study showed that feeding and drinking behaviors significantly increased (p < 0.05) in duck reared at the cage system. While there was no noticeable effect on lying and feather pecking, duck raised in the deep litter had better growth performance with a substantial difference, which achieve a higher feed conversion rate with lower feed efficiency. Physical conditions were significantly better at cage management. The level of stress indicating hormones indicating free Thyroxin was increased with the cage. Therefore, the litter system improves duck welfare and their performance.Conclusion:It is concluded that the duck managed under the litter system has more opportunities that facilitate the expression of more natural behavior, and thus improve their health and performance, as a result of improved feed conversion rate and feed efficiency.

Effect of Habitat Management on Duck Behavior and Distribution During Spring Migration in Indiana

Abstract Spring migration is an important life stage for ducks because their ability to find and acquire nutrients can affect subsequent reproductive success. Therefore, providing sufficient habitat to support the energetic needs of ducks and facilitate efficient feeding is a goal of habitat management and restoration. The rapid, unpredictable flood events that regularly occur in highly modified landscapes can make habitat management challenging and justify diverse management strategies. We examined the effect of habitat management on dabbling duck behavior and distribution during spring migration in southwest Indiana. We investigated three management options for wetlands: active management, passive management, and unmanaged agricultural food plots. We assessed duck behavior and density on 14 wetlands at Patoka River National Wildlife Refuge and Management Area. The agricultural food-plot areas had the lowest estimates of food availability followed by the actively managed areas; the passively managed wetlands had the greatest estimate. Dabbling duck density was greatest on the actively managed wetlands followed by food plots coming in second and passively managed wetlands third. Most dabbling ducks fed more intensively while on the passively managed wetlands followed by the actively managed and food-plot wetlands. Conservation prioritization of passively managed areas would provide larger areas for dabbling ducks to feed, but active management provides habitat regardless of climatic variability. Moving forward, wetland complexes encompassing diverse wetland management approaches would be the best option for spring-migrating waterfowl as these complexes can provide high-quality habitats and buffer against uncontrollable climactic conditions.

Diurnal feeding strategies of the Ferruginous Duck (Aythya nyroca) in Lake Tonga (Northeastern Algeria)

Abstract Although the Ferruginous Duck (Aythya nyroca) has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present paper we studied the diurnal feeding behaviour of ducks. We monitored the annual cycle of birds through two fieldtrips per month. The instantaneous behaviour of birds was recorded in regular 30-minute intervals from 7 a.m. to 4:30 p.m., amounting a total of 456 observation hours. Food searching activity corresponds to a quarter of the total diurnal time budget of the Ferruginous Duck. Foraging behaviour was classified into five categories dominated by the “diving”, which is almost 45.61% of the total search time. Foraging activities at the water surface considered to be secondary activities, including feeding by “bill”, “neck and head”, and “beak and head” in a rate of 19.86%, 14.53%, and 13.98%, respectively. The “toggle” remains a minor activity and represents only 5.99% of foraging time. The feeding behaviour of this species correlated to several environmental parameters (rainfall, temperature and wind velocity), and linked to the group size of ducks visiting the lake. Regarding the food intensity, our results show the highest values for “bill and head” behaviour. “Diving” has the longest feeding interval (16.16±14.1 minutes), while foraging by “bill” has the shortest (0.69 ± 0.48 minutes).

Behavior and Meat Productivity of Free-ranging Satsuma Black Aigamo Ducks in Paddy Fields

Behavior and Meat Productivity of Free-ranging Satsuma Black Aigamo Ducks in Paddy Fields