Cardiovascular system in larval zebrafish responds to developmental hypoxia in a family specific manner

BACKGROUND: Genetic and environmental variation are both known to influence development. Evolution of a developmental response that is optimized to the environment (adaptive plasticity) requires the existence of genetic variation for that developmental response. In complex traits composed of integrated sets of subsidiary traits, the adaptive process may be slowed by the existence of multiple possible integrated responses. This study tests for family (sibship) specific differences in plastic response to hypoxia in an integrated set of cardiovascular traits in zebrafish. RESULTS: Cardiac output, which is the integrated product of several subsidiary traits, varied highly significantly between families, and families differed significantly in the degree and direction of response to developmental oxygen level. The cardiac output response to oxygen environment was entirely family specific with no significant overall trend due to oxygen level. Constituent physiological variables that contribute to cardiac output all showed significant family specific response to hypoxia. Traits that were not directly related to cardiac output, such as arterial and venous diameter, and red blood cell velocities did not respond to hypoxia in a family specific manner. CONCLUSION: Zebrafish families vary in their plastic response to hypoxia. Genetic variation in plastic response to hypoxia may therefore provide the basic ingredient for adaptation to a variable environment. Considerable variation in the degree of familial response to hypoxia exists between different cardiovascular traits that may contribute to cardiac output. It is possible that the integration of several subsidiary traits into cardiac output allows the maintenance of genetic variance in cardiac response

Zoo‐housed mammals do not avoid giving birth on weekends

There is evidence that zoo visitor presence can influence the behaviour and, in some cases, adrenal response of zoo animals, and can sometimes compromise animal welfare. In some laboratory studies, significantly more primate births have been reported on weekends, when fewer people are working there, compared with weekdays when staffing levels are at their highest. Here, we investigate whether there is evidence of a "weekend effect" on births in zoo animals as a result of visitor numbers. Unlike laboratories, zoos are typically busier with visitors on weekends than on weekdays, although staffing levels remain fairly consistent across days of the week. If zoo animal parturition is sensitive to human presence, then fewer births would be expected on weekends compared with weekdays. We tested this using birth data and visitor numbers on the entrance gate from zoo records across 16 species representing artiodactyls, perissodactyls, carnivores and primates at four British zoos, to see whether there is an association between mean daily birth rates and average visitor numbers. We predict that, if there is a visitor effect, daily births should be lower on weekends than weekdays and should correlate with mean daily visitor numbers. Results showed that births for all 16 species were randomly distributed through the week, and there was no significant decline in births on weekends. We conclude that the “weekend effect”, if such a thing exists, does not appear to be a feature of zoo births, suggesting that elevated weekend visitor numbers are not sufficiently stressful to trigger delayed parturition

Keeper-animal interactions: differences between the behaviour of zoo animals affect stockmanship

Stockmanship is a term used to describe the management of animals with a good stockperson someone who does this in a in a safe, effective, and low-stress manner for both the stock-keeper and animals involved. Although impacts of unfamiliar zoo visitors on animal behaviour have been extensively studied, the impact of stockmanship i.e familiar zoo keepers is a new area of research; which could reveal significant ramifications for zoo animal behaviour and welfare. It is likely that different relationships are formed dependant on the unique keeper-animal dyad (human-animal interaction, HAI). The aims of this study were to (1) investigate if unique keeper-animal dyads were formed in zoos, (2) determine whether keepers differed in their interactions towards animals regarding their attitude, animal knowl- edge and experience and (3) explore what factors affect keeper-animal dyads and ultimately influence animal behaviour and welfare. Eight black rhinoceros (Diceros bicornis), eleven Chapman’s zebra (Equus burchellii), and twelve Sulawesi crested black macaques (Macaca nigra) were studied in 6 zoos across the UK and USA. Subtle cues and commands directed by keepers towards animals were identified. The animals latency to respond and the respective behavioural response (cue-response) was recorded per keeper-animal dyad (n=93). A questionnaire was constructed following a five-point Likert Scale design to record keeper demographic information and assess the job satisfaction of keepers, their attitude towards the animals and their perceived relationship with them. There was a significant difference in the animals’ latency to appropriately respond after cues and commands from different keepers, indicating unique keeper-animal dyads were formed. Stockmanship style was also different between keepers; two main components contributed equally towards this: “attitude towards the animals” and “knowledge and experience of the animals”. In this novel study, data demonstrated unique dyads were formed between keepers and zoo animals, which influenced animal behaviour

Research and research training in BIAZA zoos and aquariums: an analysis of the BIAZA research database

The BIAZA research database is a spreadsheet containing details that member collections submit about research (postgraduate and professional) and research training (up to undergraduate) projects being undertaken within their collection. The database contains information on 4816 projects since 1969, and these have been analysed to discern trends in numbers, taxa and subjects studied, academic institutions and collections involved. Thirty-eight collections contributed information to the database (31.4% of BIAZA membership). Both research and research training projects have increased substantially since 2000, which parallels a growth in animal care, welfare and behaviour courses in academic institutions. Projects in both categories are skewed heavily towards behavioural studies on mammals, with smaller numbers of projects on members of other taxa, or other topics. A small number of zoos and academic institutions are responsible for the majority of projects in both categories, although the number of academic institutions that have carried out projects in BIAZA zoos is very large (n=246 in 18 different countries). It is concluded that both research and research training are significant and widespread activities in BIAZA collections, but that more needs to be done to promote a wider diversity of topics and taxa studied

Effect of Pitching Restrictions and Mound Distance on Youth Baseball Pitch Counts.

BACKGROUND: Studies have shown that higher pitch counts are directly related to a greater incidence of elbow and shoulder pain among youth baseball pitchers. PURPOSE/HYPOTHESIS: The purpose of this study was to examine the effect of different pitching restriction rules on the number of pitches thrown in youth baseball leagues. We hypothesized that more pitches would be thrown in leagues with inning restrictions versus leagues with pitch count restrictions as well as in leagues with a longer mound distance (from pitching mound to home plate). STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Pitch count data were collected for 2 consecutive years over a 10-week season from 3 different leagues of 9- to 12-year-old baseball players in a single city. The Eastern league had a pitch count restriction and 46-ft (14.02-m) mound distance. The Southeastern and South leagues\u27 pitching restrictions were based on innings per week. The Southeastern league had a 50-ft (15.24-m) mound distance, while the South league had a 46-ft mound distance. Comparisons of total seasonal pitches thrown were made of the 3 highest-volume pitchers on each team. League averages for each value were then compared utilizing analysis of variance with Bonferroni post hoc analysis. The number of pitchers in each league who threw \u3e600 pitches per season was compared using the chi-square test. RESULTS: No significant difference in seasonal pitch counts or innings pitched was noted between the Eastern and South leagues, which differed only in their pitching restrictions. The Southeastern league, with a longer mound distance, was found to have higher seasonal pitch counts per thrower (598 ± 195 pitches) than the South league (463 ± 198 pitches) for the 3 highest-volume throwers for each team ( CONCLUSION: There was no significant difference in seasonal pitch counts when the leagues in this study differed based on pitching restrictions. However, the league with a greater mound distance (Southeastern) had higher seasonal pitch counts for the highest-volume throwers. Pitching restrictions based on pitch counts, as opposed to innings, may be advisable

Enrichment and animal age, not biological variables, predict positive welfare indicators in zoo-housed carnivores

The development of evidence-based zoo animal welfare science and the use of the 'five domains' have inspired zoos to increase animal welfare, particularly recognising positive welfare states. We tested whether natural biology (number of habitats, latitudinal range, sociality, body weight) or husbandry variables (mean age of group, group size and presence of extra enrichment) predict rates of positive welfare indicators (activity, play and engagement with the environment) in the Order Carnivora from collecting data from previously published articles. For each behaviour, species (n = 23) medians were analysed using phylogenetically informed mixed-model regression. Activity data were from 136 animals (n = 23 species), environmental interaction from 55 animals (n = 15 species) and play from 27 animals (n = 7 species). Biological variables did not predict rates of behaviour at a species or an individual animal level, but husbandry variables did. At an individual level, activity and play decreased in older animals. Activity and interaction with environment also increased with additional enrichment. This study is the first to quantify positive behaviours performed by zoo housed Carnivora and shows that they display indicators of positive welfare, if appropriate husbandry including environmental enrichment is provided