Increasing browse and social complexity can improve zoo elephant welfare.

While recent work has assessed how environmental and managerial changes influence elephant welfare across multiple zoos, few studies have addressed the effects of management changes within a single institution. In this paper, we examine how management changes related to social structure and diet affect the behavior of a group of zoo elephants over a 23-month period while also considering underlying factors, such as time of day, hormonal cycle, and individual differences. We recorded individual behaviors using 2-min scan samples during 60-min sessions. We analyzed behavioral changes across several study variables using generalized linear mixed models. We found that increasing browse can improve opportunities for foraging throughout the day but may not be sufficient to reduce repetitive behaviors. We observed that increasing group size and integration of bulls with cows can lead to increased social interaction in African elephants. Our results highlight the importance of using multiple management alterations to address elephant welfare, and considering environmental factors, when making management decisions.

Circulating nutrients and hematological parameters in managed African elephants (Loxodonta Africana) over a 1-year period.

African elephants (Loxodonta Africana) are currently considered a vulnerable species. One key to improving methods of species management is to better monitor and understand elephant nutrition. Analyzing circulating nutrients is one of the best and least invasive methods of monitoring managed elephant nutrition, but limited reference values are available. This study examined the circulating basic hematology concentrations, minerals, vitamins A, D, and E, and fatty acids of six African elephants (two males and four females) at the North Carolina Zoo collected monthly from March 2016 to April 2017 and compared levels among seasons. Creatinine (CRE) and albumin had seasonal differences (p ≤ .05). Calcium, magnesium, phosphorus, potassium, selenium, zinc, cobalt, manganese, and molybdenum displayed seasonal differences (p ≤ .05). Retinol and 25-hydroxyvitamin D2 had seasonal differences (p ≤ .05). Linoleic acid, α-linolenic acid, arachidonic acid, total omega-3 fatty acids, total omega-6 fatty acids, and the omega-6 to omega-3 ratio showed seasonal differences (p ≤ .05). Findings suggest that exogenous vitamin E supplements may not be necessary with a mixed feedstuff diet (hay, fortified concentrate pellet, browse, and produce) based on circulating values. This data offer updated information on circulating reference values and novel circulating concentrations of nutrients for Southeastern US managed African elephants that can be used to inform nutritional and health management in all similar habitats.

Air temperature and diet influence body composition and water turnover in zoo-living African elephants (Loxodonta africana).

African elephants, the largest land animal, face particular physiological challenges in captivity and the wild. Captive elephants can become over- or under-conditioned with inadequate exercise and diet management. Few studies have quantified body composition or water turnover in elephants, and none to date have examined longitudinal responses to changes in diet or air temperature. Using the stable isotope deuterium oxide (2H2O), we investigated changes in body mass, estimated fat-free mass (FFM, including fat-free gut content) and body fat in response to a multi-year intervention that reduced dietary energy density for adult African elephants housed at the North Carolina Zoo. We also examined the relationship between air temperature and water turnover. Deuterium dilution and depletion rates were assayed via blood samples and used to calculate body composition and water turnover in two male and three female African elephants at six intervals over a 3-year period. Within the first year after the dietary intervention, there was an increase in overall body mass, a reduction in body fat percentage and an increase in FFM. However, final values of both body fat percentage and FFM were similar to initial values. Water turnover (males: 359 ± 9 l d-1; females: 241 ± 28 l d-1) was consistent with the allometric scaling of water use in other terrestrial mammals. Water turnover increased with outdoor air temperature. Our study highlights the physiological water dependence of elephants and shows that individuals have to drink every 2-3 days to avoid critical water loss of approximately 10% body mass in hot conditions.