Peer reviewed science September ’16

Here are the papers for volume 4, much busier than last month, published in and around August 2016 directly relevant to zoo keepers and aquarists.

Aquaculture Nutrition– August 2016 Volume 22 issue 4 requires subscription .

Effect of oregano (Origanum onites L.) essential oil on growth, lysozyme and antioxidant activity and resistance against Lactococcus garvieae in rainbow trout, Oncorhynchus mykiss (Walbaum).

Nutr. Diler, O., Gormez, O., Diler, I. and Metin, S. (2016),

Addition of Oragano oil (about £4 from Amazon) significantly improved growth and disease resistance in Rainbow Trout.  Levels of 3.0 ml per kg of feed showed higher levels of antioxidant activity, higher final weights and highest resistance to a bacterial infection.

Reviews in Aquaculture – August 2016 Volume 8, Issue 2. Requires subscription

Coral aquaculture: applying scientific knowledge to ex situ production. Rev Aquacult, 8: 136–153.

Leal, M. C., Ferrier-Pagès, C., Petersen, D. and Osinga, R. (2016),

“This review presents a holistic overview of coral aquaculture in relation to coral biology, with particular focus on ex situ aquaculture.  Success factors for commercial coral aquaculture are outlined, which include qualitative aspects, such as shape, coloration and natural product content, and quantitative parameters such as growth and volumetric productivity. Manipulation of environmental factors to maximize coral quality and volumetric productivity is thoroughly discussed, and a comprehensive overview of current propagation techniques is provided.”

Direct application of ozone in aquaculture systems. Rev Aquacult.

Powell, A. and Scolding, J. W.S. (2016),

Defined as exposure to residual ozone (ie, not directly ozoning a tank, but not providing degassing from an ozone filtration unit).  This “direct application” has shown benefits in finfish/shellfish/live food production systems. From the abstract “This review paper concentrates on the observed benefits and drawbacks of direct ozonation, influencing


Applied Animal Behaviour Science September 2016 Volume 182, p1-100 and in press – requires subscription

Does Enrichment Improve Reptile Welfare? Leopard geckos (Eublepharis macularius) respond to five types of environmental enrichment

Meredith J. Bashaw, Mallory D. Gibson, Devan M. Schowe, Abigail S. Kucher

In Press Accepted Manuscript

  • Enrichment improves animal welfare, but reptile enrichment has been rarely studied.
  • We measured leopard geckos’ responses to five enrichment types.
  • Geckos responded like carnivorous mammals, except for abnormal repetitive behaviors.
  • All enrichment types except provision of a mirror improved gecko welfare.
  • Captive geckos and other reptiles benefit from increased behavioral opportunities


Can changes in nasal temperature be used as an indicator of emotional state in cows?

Helen Proctor and Gemma Carder

In press Accepted Manuscript

  • We explored if nasal temperature can be used as an indicator of high arousal positive and negative emotional states in cows.
  • There is still little known about the use of peripheral temperatures as an indication of emotional state in non-human animals.
  • Both positive and negative high arousal experiences caused a significant reduction in nasal temperature in cattle.

[useful in other similar taxa??]

Is behavioural enrichment always a success? Comparing food presentation strategies in an insectivorous lizard (Plica plica)

Inez Sukuna Januszczak, Zoe Bryant, Benjamin Tapley, Iri Gill, Luke Harding, Christopher John Michaels

Publication stage: In Press Corrected Proof

  • Behavioural enrichment device using crickets was provided to Plica plica.
  • Device resulted in decreased amount of activity compared to scatter feed.
  • Difference in feeding duration between the enrichment and scatter feed was not significant.
  • The complex enclosure design and live food use are suggested as the reason behind this.
  • Hence enclosure design can negatively affect the success of enrichment devices.

Horses can learn to use symbols to communicate their preferences

Cecilie M. Mejdell, Turid Buvik, Grete H.M. Jørgensen, Knut E. Bøe

In Press Corrected Proof

  • Horses can learn to use symbols boards for communication with humans.
  • Horses could tell if they wanted a blanket put on or taken off, or stay unchanged.
  • Speed of learning varied.
  • All horses performed well within 2 weeks of training.
  • Training was successful for 23/23 horses of various age and breeds.

[Useful in similar zoo based taxa??]

Social behaviour of endangered European mink (Mustela lutreola) litters in captivity

Kairi Kiik, Tiit Maran, Nadja Kneidinger, Toomas Tammaru


  • A detailed ethogram of social behaviour among the European mink cubs was compiled.
  • Social behaviour of the juveniles in captivity was diverse and included all expected elements.
  • Inter-cub aggression did not increase with the age of the juveniles.
  • There were no litters with outlying behaviour, and the behaviour did not depend on the parameters of the litter.
  • No evidence was found to ascribe the abnormal behaviour of the captive-born adults to conditions experienced during the litter period.

The behavioural effects of supplementing diets with synthetic and naturally sourced astaxanthin in an ornamental fish (Puntius titteya)

Lewis Eaton, Kristian Clezy, Donna Snellgrove, Katherine Sloman

  • Astaxanthin consumption caused subtle changes in fish colouration.
  • Mate-choice associations were effected by dietary astaxanthin consumption.
  • Red colouration and UV-reflectance influenced mate-choice association.
  • Astaxanthin reduced mirror-image aggression in male fish, regardless of source.


Journal of Zoo and Aquarium Research Vol 4, No 3 (2016) – Open access

Seasonal body mass changes and feed intake in spectacled bears (Tremarctos ornatus) at Zurich Zoo

Kerstin Gerstner, Annette Liesegang, Jean-Michel Hatt, Marcus Clauss, Cordula Galeffi

During an obesity-control program in Andean bears (Tremarctos ornatus) at Zoo Zurich, a seasonal fluctuation of body mass war observed once ideal body mass had been reached. The focus of this study was the question if metabolism of a male and three female animals was affected by seasonality according to their seasonal breeding behaviour, using data on pelleted food intake (from computer controlled feeders) and body mass (from regular weighing). Body mass showed a seasonal fluctuation with maxima in spring and minima in autumn, in contrast to the pattern typically observed in animals from the temperate zone; in the male, the body mass maximum occurred later than in the females. The data indicate that body mass fluctuation in a range considered ideal for the species was mostly based on the additional food whose amount was adjusted – within limits – by the keepers on a daily basis.

Assessing Risk Factors for Reproductive Failure and Associated Welfare Impacts in Elephants in European Zoos

Matt Hartley

Reproductive failure in elephants is thought to be caused or influenced by a range of factors such as obesity, infectious disease, husbandry, facilities, stress, behaviour, maternal experience, herd size and social grouping. This study takes an epidemiological approach using risk analysis methodologies to collate information from expert opinion, data set analysis and a targeted questionnaire to identify and assess a range of physical, behavioural and husbandry based risk factors, which may affect reproductive success in elephants housed in European Zoos. This work is to be used in the development of evidence-based elephant management and welfare recommendations and highlights priority areas for further research.

Survey of Reproduction and Calf Rearing in Asian and African Elephants in Europe.

Matt Hartley, Christina Stanley

Acyclicity, conception failure, abortion, stillbirth, dystocia, infanticide and neonatal mortality have all been reported as causes of reproductive failure in zoo elephants. This study is the largest and most comprehensive study of reproduction in the European zoo elephant population to date. Two questionnaires collected data from throughout the reproductive process from assessing cyclicity to independence of the calf at 5 years old. Information was collected regarding 189 birth events. This work provides evidence to support changes to elephant management in European zoos in order to encourage development of social and affiliative herd behaviours and improve reproductive success.

Introducing tool-based feeders to zoo-housed chimpanzees as a cognitive challenge: spontaneous acquisition of new types of tool use and effects on behaviours and use of space

Yumi Yamanashi, Masayuki Matsunaga, Kanae Shimada, Ryuichiro Kado, Masayuki Tanaka

Practical enrichment devices that can facilitate animals’ natural behaviours and accommodate individual variation are still limited. We created two types of feeders to facilitate tool-using behaviour in captive chimpanzees: pounding and dipping feeders. These results suggest that these tool-based feeders provided an appropriate challenge for the chimpanzees.

Music as enrichment for Sumatran orangutans (Pongo abelii)

Sarah E Ritvo, Suzanne E MacDonald

Music is commonly employed as auditory enrichment in NHP facilities under the assumption that music is as enriching for NHPs as it is for humans.  Taken together, results strongly suggest that these orangutans did not experience the musical stimuli as reinforcing and that use of music as enrichment in captive NHP facilities may be more aversive than enriching for some species.

Captive Breeding of the Shark Bay Mouse Pseudomys fieldi to Facilitate Species Recovery in the Wild

Cathy Lambert, Vicki Power, Glen Gaikhorst

Shark Bay Mice (P. fieldi) were bred at Perth Zoo to provide animals for release to the wild as part of recovery actions for the species.  Three-hundred and thirty-five young were produced from 93 litters, with an average litter size of 3.6 (range 1 – 6).  Sexual maturity for both sexes was reached at 65 days of age, and breeding was observed all year round.  The oldest female to give birth was 625 days of age and the oldest male to sire young was 531 days of age.  Following a planned interruption to the program and the separation of breeding pairs, there was some difficulty in later re-establishing reproduction.  A strategy to stimulate a return to breeding, along with detailed husbandry methods, is described.

Zoo Biology July/August 2016 Volume 35, Issue 4 Pages 279–366 – Requires subscription

Behavioral research as physical enrichment for captive chimpanzees

Lydia M. Hopper, Marisa A. Shender and Stephen R. Ross (pages 293–297)

In this study, we evaluated the potential for a behavioral research study, designed to evaluate chimpanzee decision-making behavior, to also encourage increased activity in a group of zoo-housed chimpanzees. This study emphasizes the role that research can have in providing enrichment, the importance for long-term enrichment plans, and the essential need to evaluate the impact of research on animal participants, just as we evaluate the efficacy of enrichment strategies.

Behavioral changes in female Asian elephants when given access to an outdoor yard overnight

David M. Powell and Cathy Vitale(pages 298–303)

A study was conducted at the Bronx Zoo to determine whether providing elephants with access to an outdoor corral at night had any significant effects on behavior, use of space, and use of a sand corral. Standing and play behavior increased when the elephants had outdoor access while lying down and feeding behavior decreased. Swaying behavior decreased significantly when the elephants had access to the outdoor yard. The elephants made very little use of a sand-floor stall regardless of whether or not they had access to outdoors. The results of this study, suggest that having access to alternate areas overnight can promote well-being by reducing repetitive behavior and allowing animals to express their preferences for different locations.

Behavioral responses of three armadillo species (Mammalia: Xenarthra) to an environmental enrichment program in Villavicencio, Colombia

Alexandra Cortés Duarte, Fernando Trujillo and Mariella Superina (pages 304–312)

Stress-related health and behavioral problems, as well as reproductive failure, are frequent in armadillos (Xenarthra, Cingulata, Dasypodidae) under human care, which hinders the development of successful ex situ conservation programs. The objective of this study was to assess the impact of an enrichment program on the behavior of armadillos under human care. The behavior of 12 individuals of three species (Dasypus novemcinctus, D. sabanicola, and Cabassous unicinctus) maintained at Finca El Turpial, Villavicencio, Colombia, was recorded using scan sampling during three daily time blocks of 2 hr each before (4 weeks) and after (4 weeks) implementing an enrichment program. Our results suggest that separate enrichment programs need to be developed for different armadillo species, and that they should be applied during the time of day at which they are most active.

Evaluation of thermal regimes for transported ambassador ectotherms: One size does not fit all

Sasha J. Tetzlaff, Kristin E. Tetzlaff and Richard J. Connors II (pages 339–345)

Providing appropriate environmental temperatures for captive ectotherms should be a husbandry priority. This can be especially challenging for ectotherms that are routinely transported, such as those used in education programs at zoos, because they are unable to thermoregulate while confined in non-temperature controlled, compact carriers. We suggest further thermal monitoring of ectotherms during transit with the aim of identifying appropriate heat sources and developing efficient and effective transportation protocols.

Zoo visitor perceptions, attitudes, and conservation intent after viewing African elephants at the San Diego Zoo Safari Park

Charlotte E. Hacker and Lance J. Miller (pages 355–361)

The purpose of this research was to analyze visitor perceptions and attitudes toward elephant conservation and outcomes post-exhibit visit. Providing guests with the opportunity to witness or experience such occurrences may aid in a more successful delivery of the zoo’s conservation message. Further research into guest emotions and affective states in relation to viewing elephants in a zoological institution would provide greater insight into improving the guest experience and helping zoos meet their conservation mission.

PLOS 1 – open access

Molluscs for Sale: Assessment of Freshwater Gastropods and Bivalves in the Ornamental Pet Trade

Ng TH, Tan SK, Wong WH, Meier R, Chan S-Y, Tan HH, et al. (2016) PLoS ONE 11(8): e0161130.

The ornamental pet trade is often considered a key culprit for conservation problems such as the introduction of invasive species (including infectious diseases) and overharvesting of rare species. Here, we present the first assessment of the biodiversity of freshwater molluscs in the ornamental pet trade in Singapore, one of the most important global hubs of the ornamental aquarium trade, and discuss associated conservation concerns. Particularly prevalent are non-ornamental species: six hitchhikers on aquarium plants and six species sold as fish feed. We found that a quarter of the trade species have a history of introduction, which includes 11 known or potentially invasive species. We conclude that potential overharvesting is difficult to assess because only half of the trade species have been treated by IUCN. Of these, 21 species are of Least Concern and three are Data Deficient. Our checklist, with accompanying DNA barcodes, images, and museum vouchers, provides an important reference library for future monitoring, and constitutes a step toward creating a more sustainable ornamental pet trade.

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