Peer Reviewed Science March ’17


Hello nerds. Welcome to March and its science.


Woolway EE, Goodenough AE. Effects of visitor numbers on captive European red squirrels (Sciurus vulgaris) and impacts on visitor experience. Zoo Biology. 2017; 9999:18.


Visitors to zoological collections can have substantial effects on captive animals that vary according to species, enclosure design, visitor proximity, and husbandry methods. One particularly intense form of visitor interaction occurs in immersive exhibits such as walk-through enclosures. Such enclosures are increasingly common but effects on animal behavior are currently understudied. Here, the behavior of captive European red squirrels (Sciurus vulgaris) is studied in relation to visitor numbers in a walk-through enclosure. We also quantify the correlation between squirrel encounters and visitor experience. Interaction with humans increased significantly as the number of visitors inside the enclosure increased. The number of children present significantly increased locomotion and decreased eating, possibly due to disturbance and squirrels moving away from busy areas. By contrast, the number of adults significantly increased eating and decreased inactivity due to squirrels approaching visitors. The positive reinforcement training used by the keepers (offering food rewards to the squirrels for coming to them to allow routine medical checks) meant that squirrels associated adults with food opportunities. Squirrel encounter rate (number of squirrels seen by each group of visitors) was significantly affected by the number of adults and visitor duration (positive relationships) and noise as perceived by visitors (negative relationship). Encounter rate was positively correlated with overall visitor experience. Our results indicate that visitors affect behavior but this effect is influenced by husbandry methods. It is vital that visitors, especially children, minimize noise, and move slowly in the enclosure, both for the sake of the animals and their own experience.

Serres A, Delfour F. Environmental changes and anthropogenic factors modulate social play in captive bottlenose dolphins (Tursiops truncatus). Zoo Biology. 2017; 9999:113.

Social play varies among species and individuals and changes in frequency and duration during ontogeny. This type of play is modulated by environmental changes (e.g., resource availability). In captivity, cetaceans and their environment are managed by humans, and training sessions and/or public presentations punctuate the day as well as other frequent or occasional events. There is a lack of research on the effects of environmental events that occur in captivity and might affect dolphins’ behavior. We studied the context in which nine bottlenose dolphins (Tursiops truncatus) played socially and the events that could potentially impact this social interaction. The dolphins’ social play behavior was significantly more frequent and lasted longer in the morning than in the afternoon and was present before and after interactions with their trainers with a non-significant tendency to be more frequent before and after a training session than a public presentation. In an experimental paradigm using familiar environmental enrichment, our results demonstrated that environmental enrichment tended to increase social play duration whereas temporary noisy construction work around the pool and display of agonistic behaviors by members of the group significantly decreased it. These results contribute to better understand the social play distribution in captive bottlenose dolphins and the impact of different events within their daily lives. Since play decreases or disappears when animals are facing unfavorable conditions, the evaluation of social play may relate to the animals’ current well-being. We suggest that social play has potential to become an indicator of bottlenose dolphins’ current welfare state.

Hulbert AJ, Hunt KA, Rose PE. A multi-zoo investigation of nutrient provision for captive red-crested turacos. Zoo Biology. 2017; 9999:19.


Turacos (Musophagidae) are common zoo birds; the 14 species of Tauraco being most often exhibited. Turacos possess unique non-structural, copper-based feather pigments, and a specialized dietary strategy. Tauraco inhabit tropical woodlands, foraging for predominantly folivorous and/or frugivorous food items. Using a study population of 16 red-crested turacos (T. erythrolophus) at seven zoos in the United Kingdom, the nutrient composition of diets from diet sheets was calculated, using Zootrition v.2.6, Saint Louis Zoo, USA for analyses of important nutrients within each diet, and compared against an example of currently available literature. For all nutrients analyzed, significant differences were noted between amounts presented in each zoo’s diet (as fed). Turacos are presented with a wide range of ingredients in diets fed, and all zoos use domestic fruits to a large extent in captive diets. Similarities exist between zoos when comparing amounts of as-fed fiber. Analysis of the calcium to phosphorous ratio for these diets showed there to be no significant difference from the published ratio available. While this is a small-scale study on only a limited number of zoos, it provides useful information on current feeding practice for a commonly-housed species of bird and highlights potential areas of deviation away from standard practice, as well as identifying ways of reducing wastage of food. Data on wild foraging behavior and food selection, or collaboration with tauraco keepers from institutions in the tropics, is recommended as a way of improving feeding regimes and updating feeding practice for this and other Tauraco species.


Flacke GL, Tomkins JL, Black R, Steck B. Demographics of polycystic kidney disease and captive population viability in pygmy hippopotamus (Choeropsis liberiensis). Zoo Biology. 2017; 9999:116.

Polycystic kidney disease (PKD) was previously diagnosed at necropsy in several pygmy hippopotami (Choeropsis liberiensis) from the Smithsonian National Zoo and Zoo Basel, suggesting a threat to the long-term viability of the captive population. We determined the incidence and demographics of PKD in the captive population historically; we tested if the condition is linked to pedigree; we investigated mode of inheritance; we examined effects of PKD on longevity; we conducted survival analysis; and we examined long-term population viability. Thirty-seven percent of 149 necropsied adult pygmy hippos were affected by PKD, and it was more common in females, controlling for the overall female-biased sex-ratio. Prevalence increased significantly with age, but most hippos were beyond their reproductive prime before developing clinical signs; thus fecundity was likely unaffected. PKD was linked to pedigree and may exhibit X-linked dominance, but further research is needed to definitively establish the mode of inheritance. PKD did not affect longevity, overall or within any age class. There was no significant correlation between inbreeding coefficient (F) and PKD, and the prevalence in wild-caught and captive-born animals was similar. Longevity for both captive-born and inbred hippos (F > 0) was significantly shorter than longevity for their wild-caught and non-inbred counterparts. Demographic projections indicated the extant population will likely experience a slow increase over time, provided there are no space constraints. We conclude that although PKD is an important cause of morbidity and mortality in pygmy hippos, the condition is not a primary concern for overall viability of the captive population.


*** A lot of companion horse papers in this issue, some findings might relate to similar exotic taxa – please go to

Chimpanzees with positive welfare are happier, extraverted, and emotionally stable 2017. Lauren M. Robinson, Drew M. Altschul, Emma K. Wallace, Yulán Úbeda, Miquel Llorente, Zarin Machanda, Katie E. Slocombe, Matthew C. Leach, Natalie K. Waran, Alexander Weiss



Facilities housing captive animals are full of staff who, every day, interact with the animals under their care. The expertise and familiarity of staff can be used to monitor animal welfare by means of questionnaires. It was the goal of our study to examine the association between chimpanzee (Pan troglodytes) welfare, happiness, and personality. To these ends we collected two waves of welfare and subjective well-being ratings of 18 chimpanzees housed at the Edinburgh Zoo and one set of ratings of 13 chimpanzees housed at Fundació Mona. Ratings were made on a welfare questionnaire that included 12 items related to stress, psychological stimulation, and behavioural indicators of negative and positive welfare states, and a 4-item subjective well-being questionnaire. In addition, ratings were made on the 54-item Hominoid Personality Questionnaire and an abbreviated version of this scale consisting of 37 antonym pairs. We used generalizability theory to test whether welfare ratings generalized across items, raters, chimpanzees, and time. We then assessed the validity of the welfare and subjective well-being questionnaires by examining their associations with behaviour. Finally, we tested whether the welfare and subjective well-being ratings were associated with personality. Welfare ratings generalized across items, raters, chimpanzees, and time. Principal components analysis and regularized exploratory factor analysis indicated that ten welfare items and all four subjective well-being items formed a single dimension (welfareSWB). LASSO regression found that lower welfare SWB was associated with regurgitation, coprophagy, urophagy, and decreased proximity to nearest neighbour. A linear model that adjusted for age, sex, and facility, indicated that higher Extraversion and lower Neuroticism were related to higher welfareSWB. Welfare ratings were reliable and associated with subjective well-being and personality, demonstrating that staff ratings are a valid and potentially valuable tool for chimpanzee welfare assessment.


 Survey of Baylisascaris spp. in captive striped skunks (Mephitis mephitis) in some European areasd’Ovidio, D.; Pantchev, N.; Noviello, E.; et al. PARASITOLOGY RESEARCH   Volume: 116   Issue: 2   Pages: 483-486   Published: FEB 2017

Skunks are popular carnivore species kept both in zoological institutions and in households where they are hand raised as exotic pets. These small carnivores are considered the main definitive hosts of the roundworm Baylisascaris columnaris. The purpose of this survey was to investigate the occurrence of Baylisascaris spp. in striped skunks kept as pets or in private zoo collections in some European areas. Copromicroscopic data from two laboratories, one in Italy and one in Germany, were used. A total of 60 animals were selected. Samples came from Germany (n = 30), Italy (n = 23), United Kingdom (n = 5), Austria (n = 1), and the Netherlands (n = 1). Twenty-eight animals were certainly kept as pets in private households in Italy and the UK. Fifteen out of 60 animals (25%) were positive for Baylisascaris spp. Molecular identification of adult parasites was performed in ten of those animals, revealing B. columnaris in all cases. To the authors’ knowledge, this is the first survey of Baylisascaris spp. in captive skunks in Europe.

Interactive technology and human-animal encounters at the zoo. 2017 Webber, S Carter, M; Smith, W Vetere, F INTERNATIONAL JOURNAL OF HUMAN-COMPUTER STUDIES Volume: 98 Pages: 150-168

In this paper we investigate social dimensions of technology use in human-animal interactions, through a study of interactive systems at the zoo.
Zoos are a familiar place for encounters between humans and non-domesticated animals. Accordingly, we examine zoos as a significant site to extend research into animal-computer interaction (ACI). We present a case study that examines the deployment and use of new digital technologies that intervene in, and influence, human-animal relationships.  The paper reports on interactive systems in use at Melbourne Zoo. The study investigates the use and impact of technology in the course of human-animal encounters, including how human use of technology in this setting shapes encounters in subtle ways. We examine five interactive systems used by visitors (Digital Signs and the Zoopermarket), by zoo personnel with visitors (Educator Screens and Volunteer iPads), and by zoo personnel with animals (Apps for Apes). Our work draws broad insights for the design and understanding of animal-human-computer interaction at the zoo, as a catalyst for further research into this site of considerable significance to animal computer interaction. We identified four key themes in the ways that interactive systems are intervening in human-animal encounters at the zoo. Firstly, interactive technology at the zoo risks distracting from visitors’ encounters with animals. Secondly, the appearance and use of technology moreover runs counter to expectations of naturalistic zoo landscapes. Thirdly, interactive systems however offer opportunities to enhance important aspects of visitors’ experience of animal encounters, and to widen the temporal and spatial dimensions of the encounter. Finally, we interpret these insights by examining how technology is used in the context Of interactions between numerous human and animal actors, and in a setting impacted by complex social and organisational forces. From this, we identify the need for ACI to consider technology use by diverse people and animals; that multiple interactions may occur at once; the diverse social activities that may surround human-animal interactions; the distributed form of interactions between multiple participants; and the performative nature of some human-animal encounters.

Effects of Ambient Environmental Factors on the Stereotypic Behaviors of Giant Pandas (Ailuropoda melanoleuca) Liu, H, Duan, HJ; Wang, C LOS ON Volume: 12 Issue: 1

Stereotypies are commonly observed in zoo animals, and it is necessary to better understand whether ambient environmental factors contribute to stereotypy and how to affect animal welfare in zoo settings. This study investigated the relationships between stereotypic behaviors and environmental factors including ambient temperatures, humidity, light intensity, sound intensity and number of visitors. Seven giant pandas were observed in three indoor enclosures and three outdoor enclosures. Environmental factors were measured for both indoor and outdoor enclosures and the effect they had on stereotypical behaviors was investigated. Our research found that light intensity significantly correlated with all stereotypies behaviors. Higher environmental temperature reduced the duration of pacing but increased the frequency of pacing, the duration and frequency of door-directed, meanwhile the duration of head-toss. However, we found no noticeable effect of humidity on stereotypic behaviors except for the frequency of head-toss. We also found that sound intensity was not correlated with stereotypies. Finally, the growth of visitors was negatively associated with the duration of door-directed. These results demonstrated that various environmental factors can have significant effects on stereotypic behaviors causing the expression of various stereotypies. Thus, stereotypies in zoo animals may not simply represent suboptimal welfare, but rather might be adopted as a means of coping with an aversive environment.

Aquaculture – March 2017 Volume 471

Wattanakul W., Thongprajukaew K., Songnui A., Satjarak J., Kanghae H., (2017) Pre-soaking feed pellet significantly improved feed utilization in Asian seabass (Lates calcarifer), Aquaculture, 471:106-112
Abstract: Effects of water pre-soaking a commercial dry feed pellet on growth, feed utilization, specific activity of digestive enzymes, fecal thermal properties, hematological parameters, muscle quality and carcass composition were investigated in Asian seabass, Lates calcarifer. The 2 months old fish (6.02 ± 0.04 g body weight) were subjected to four dietary treatments with three replications under a completely randomized design. The dietary treatment pellets were pre-soaked with 0, 0.25, 0.5 or 0.75 (v/w) fold amounts of water per pellets, here termed soaking ratios. After rearing for three months, there were no differences in survival (95% on average) or in growth performance (specific growth rate 1.64% body weight day− 1 on average) of the fish across the four dietary treatments (P > 0.05). Superior feed utilization (feeding rate, feed conversion ratio, and protein efficiency ratio) was observed in the fish receiving the last treatment. This treatment significantly increased the specific activities of chymotrypsin and lipase, but not those of pepsin, trypsin, or amylase, relative to the baseline control. An improved feed utilization was well supported by the thermal properties of feces, assessed in relation to the available nutrients. Data on hematological parameters, muscle quality and carcass composition indicated no negative effects on the fish reared with this dietary treatment. Findings from the current study indicate an optimal pre-soaking ratio of 1:0.75 w/v of pellet to water, for enhancing the feed utilization in Asian seabass.

Aquaculture – April 2017 Volume 473

Knaus U., Palm H.W., 2017,  Effects of the fish species choice on vegetables in aquaponics under spring-summer conditions in northern Germany (Mecklenburg Western Pomerania), Aquaculture, 473:62-73

Abstract:The effect of juvenile Nile tilapia (Oreochromis niloticus, in unit I) and Common carp (Cyprinus carpio, in unit II) on plant growth (cucumber – Cucumis sativus, tomato – Solanum lycopersicum and lettuce – Lactuca sativa in co-cultivation) was investigated in two identical gravel substrate ebb-and-flood coupled aquaponic units (I, II) with 3.81 m3total water volume and without addition of fertiliser for 70 days. The daily extruded floating feed input of 1.2% (200 g) of initial fish biomass (16.7 kg) per unit equalled 12.0 g feed per kg fish or 52.5 g m− 3. Growth of O. niloticus (unit I) was better (p < 0.05) in final weight (57.4 g ± 27.9), final biomass (27,683.3 g ± 160.7), specific growth rate (0.70% d− 1 ± 0.01) and feed conversion ratio (1.31 ± 0.02) in comparison to C. carpio (unit II, 42.7 g ± 22.2, 21,866.7 g ± 568.6, 0.39% d− 1 ± 0.02, 2.69 ± 0.20). Tomato gross biomass was two times higher in combination with O. niloticus and tomato fruit weight was slightly higher. Plant growth in cucumber showed higher total fresh biomass in the C. carpio unit. Lettuce yield was near zero as a result of inter-specific competition. The Aquaponic Growth Factor (AGF), describing the growth performance of fish and plant combinations, was highest in tomato (1.12) combined with O. niloticus compared with C. carpio (0.53). However, the AGF of cucumber was slightly higher in combination with C. carpio (0.14) compared with O. niloticus (0.12). This study demonstrates best plant growth for the combination of O. niloticus with tomato and C. carpio with cucumber. The unit stocked with C. carpio had higher levels of oxygen (6.3 mg L− 1 ± 0.8) and oxygen saturation (78.6% ± 8.4) in contrast to O. niloticus (5.8 mg L− 1 ± 0.8, 73.2% ± 8.9). The long steady state of dissolved oxygen inside both units allowed a higher daily feed input of 0.3% of fish initial biomass during spring and summer seasons, 25% above the optimal feed input estimated for the same units during winter time (0.9% = 150 g). C. carpio extended the equilibrium phase during plant production before a significant oxygen drop occurred, beneficial for coupled aquaponics. Different growth performance of fish and plant combinations suggest multiple fish species use or polyponics (polyculture + aquaponics) in coupled aquaponics to increase plant yield

Aquaculture International- Febuary 2017 Volume 25 Issue 1


Jepsen P.M., Bjørbæk N.S., Rayner T.A.. (2016). Recommended feeding regime and light climate in live feed cultures of the calanoid copepod Acartia tonsa Dana, Aquaculture International, 25:1 1-20, doi:10.1007/s10499-016-0063-4

Abstract: Understanding and optimising the parameters that controls the success for copepod cultures are the foundation for large scaled copepod cultures. Many underlying copepod culture parameters are already quantified and comprehended, but there is a lack in knowledge of optimising feeding regimes for copepod cultures. In the present study, quantification and observations on how three different feeding regimes affected Acartia tonsa cultures, in terms of development time, specific growth rate, egg production, and egg hatching success were done. The three feeding regimes where dispensed as; once a day (spiked feeding), in four equal pulses (pulsed feeding), and evenly over 24 h (continuous feeding). The feeding regimes were investigated at low food levels (*200 lg C L-1) and at full-saturated food levels (*1800 lg C L-1). As photoperiod may have an effect on feeding uptake and productivity, the present experiments were segregated into two light regimes, one in darkness (0L:24D) and one in light (24L:0D). Acartia tonsa exposed to fully saturate feed levels developed twice as fast as at low saturated feed levels. A significantly higher total egg production from copepods was observed, equal to 53.5 % more eggs produced in dark cultures. Also, a 2.3 % significantly higher egg hatching success was obtained when culturing in dark. Since feeding regimes do not affect cultures, it is recommended that feeding of A. tonsa should be conducted as practical as possible for the individual copepod farmer, since optimal performance will be met as long as feed is supplied in excess. Furthermore, it is recommended that cultures are kept in dark for optimal egg production and sub sequent hatching success.


Karadal O., Guroy D., Turkmen G., (2016), Effects of feeding frequency and Spirulina on growth performance, skin coloration and seed production on kenyi cichlids (Maylandia lombardoi), Aquaculture International, 25:1  121-134, DOI 10.1007/s10499-016-0017-x


Abstract: Kenyi cichlids belong to mbuna group which is specific to Lake Malawi. Gender discrimination is easy because males have yellow, females have blue colors and their spawning efficiency is good. Cichlid producers prefer kenyi cichlids in recent years due to reproduction performance and coloring of kenyi. In this study, effects of Spirulina-based diet and feeding frequency on coloration, seed production, growth and survival on kenyi cichlids (Maylandia lombardoi) were investigated for 112 days. The study was carried out in a recirculating system which has 100 L each tank and 12 fiberglass tanks with three replicates. Ten fish (3 months old, mean body weight 2.00 ± 0.05 g and mean total length 4.51 ± 0.42 cm) were randomly placed in each tank. Experimental groups were designed with commercial granule (C) and commercial granule Spirulina (S) feeds. In the present study, two feeding frequencies were applied: one feeding daily at 09:00 (namely C1, S1) and three times daily at 09:00, 12:00 and 17:00 (namely C3, S3). The growth and seed production of cichlid fed three times daily were significantly higher compared to fish fed one feeding daily, irrespective of feed source (P\0.05). Moreover, the specific growth rate of cichlid fed Spirulina-based diet was significantly elevated compared to fish fed non- Spirulina-based diet. The Spirulina-based diets affected skin coloration giving a bluish hue and a typical chroma values for the females of kenyi cichlid. In conclusion, growth performance, seed production and skin coloration of kenyi cichlid fed Spirulina diets three times daily enhanced under the study condition.


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