The behavioral effects of exhibit size versus complexity in African elephants: A potential solution for smaller spaces

Population‐level analyses suggest that habitat complexity, but not necessarily space availability, has important welfare outcomes for elephants in human care. At the Dallas Zoo, the opening of a new exhibit complex allowed us to measure the behavior of two female African elephants across three treatments to evaluate the independent effects of complexity and space. Preoccupancy observations were conducted in the elephants’ older exhibit, which consisted of a smaller, more simple yard (630 m²). Subsequent postoccupancy observations measured behavior in two different spaces in the new exhibit: a larger, complex yard (15,000 m²), and a smaller, but complex yard (1,520 m²). The elephants’ overall activity levels were greater in complex habitats, regardless of their size. Similar effects of habitat complexity oversize were observed with greater rates of foraging and lower rates of being stationary. Furthermore, elephants were out of view of visitors significantly more in the small, simple yard compared to either of the more complex habitats. However, exhibit size affected the incidence of stereotypic behavior (with lower rates of stereotypy in the larger exhibit compared to the smaller yards) and investigatory behavior (elephants investigated their environments more with increasing size and complexity). Behavioral diversity also increased with exhibit size and complexity. These results indicate that space availability alone is not sufficient to enhance the behavioral welfare of zoo elephants. Therefore, facilities with limited space can still encourage species‐appropriate behaviors and improved welfare for the elephants in their care by converting a small, simple area into a more complex habitat.     

GPS determination of walking rates in captive African elephants (Loxodonta africana)

The movements of elephants in captivity have been an issue of concern for animal welfare activists and zoological professionals alike in recent years. In order to fully understand how movement rates reflect animal welfare, we must first determine the exact distances these animals move in the captive environment. We outfitted seven adult female African elephants (Loxodonta africana) at Disney's Animal Kingdom with collar-mounted global positioning recording systems to document their movement rates while housed in outdoor guest viewing habitats. Further, we conducted preliminary analyses to address potential factors impacting movement rates including body size, temperature, enclosure size, and social grouping complexity. We found that our elephants moved at an average rate of 0.409±0.007 km/hr during the 9-hr data collection periods. This rate translates to an average of 3.68 km traveled during the observation periods, at a rate comparable to that observed in the wild. Although movement rate did not have a significant relationship with an individual's body size in this herd, the movements of four females demonstrated a significant positive correlation with temperature. Further, females in our largest social group demonstrated a significant increase in movement rates when residing in larger enclosures. We also present preliminary evidence suggesting that increased social group complexity, including the presence of infants in the herd, may be associated with increased walking rates, whereas factors such as reproductive and social status may constrain movements. Zoo Biol 28:16–28, 2009. © 2008 Wiley-Liss, Inc.     

Nocturnal behavior in a group of female African elephants

The nocturnal behavior of a stable group of female, African elephants (Loxodonta africana africana) was studied to: (1) examine their behavior as a function of hour of night; (2) qualitatively compare the elephants' activity budgets to those reported in a previous study; and (3) document the presence of aggressive and stereotypic behaviors that might necessitate a change in their management. The elephants were systematically observed at least five times per week for 10 weeks between 17:00 and 08:00. Instantaneous focal samples of behavior, location, and proximity were taken every minute on a rotating basis, and all observed occurrences of social behavior were recorded. The hour of night affected elephant activity: significant relationships were found between hour of night and percent of time they spent feeding, lying, and standing. The overall activity budgets of the elephants were similar to the activity budgets reported in a previous study, although differences were evident in lying, stereotypic, and social behaviors. These differences might be a function of age. Affiliative behaviors accounted for 57% of the elephants' social behaviors, and agonistic behaviors among the elephants occurred infrequently and caused no injuries. Additionally, the elephants used all areas to which they had access. These findings provide compelling evidence that unrestricted social access during the night is the appropriate management strategy for these elephants. The results from the present study also highlight the importance of replicating existing studies and using multiple behavioral measures to make decisions regarding the welfare and management of stable groups of captive elephants. Zoo Biol 25:173–186, 2006. © 2006 Wiley‐Liss, Inc.     

Sequential sampling: a novel method in farm animal welfare assessment

Lameness in dairy cows is an important welfare issue. As part of a welfare assessment, herd level lameness prevalence can be estimated from scoring a sample of animals, where higher levels of accuracy are associated with larger sample sizes. As the financial cost is related to the number of cows sampled, smaller samples are preferred. Sequential sampling schemes have been used for informing decision making in clinical trials. Sequential sampling involves taking samples in stages, where sampling can stop early depending on the estimated lameness prevalence. When welfare assessment is used for a pass/fail decision, a similar approach could be applied to reduce the overall sample size. The sampling schemes proposed here apply the principles of sequential sampling within a diagnostic testing framework. This study develops three sequential sampling schemes of increasing complexity to classify 80 fully assessed UK dairy farms, each with known lameness prevalence. Using the Welfare Quality herd-size-based sampling scheme, the first ‘basic’ scheme involves two sampling events. At the first sampling event half the Welfare Quality sample size is drawn, and then depending on the outcome, sampling either stops or is continued and the same number of animals is sampled again. In the second ‘cautious’ scheme, an adaptation is made to ensure that correctly classifying a farm as ‘bad’ is done with greater certainty. The third scheme is the only scheme to go beyond lameness as a binary measure and investigates the potential for increasing accuracy by incorporating the number of severely lame cows into the decision. The three schemes are evaluated with respect to accuracy and average sample size by running 100 000 simulations for each scheme, and a comparison is made with the fixed size Welfare Quality herd-size-based sampling scheme. All three schemes performed almost as well as the fixed size scheme but with much smaller average sample sizes. For the third scheme, an overall association between lameness prevalence and the proportion of lame cows that were severely lame on a farm was found. However, as this association was found to not be consistent across all farms, the sampling scheme did not prove to be as useful as expected. The preferred scheme was therefore the ‘cautious’ scheme for which a sampling protocol has also been developed.     

Nocturnal behavior in a group of unchained female African elephants

The chaining of elephants at night is a common management strategy in zoos, yet the costs and benefits of such a strategy are relatively unknown. A study of three unchained female African elephants was undertaken to document their nocturnal behavior. The subjects were observed between the hours of 1800 and 0800 for 10 weeks in the summer of 1992 (total of 172 hr) and 14 weeks in the summer of 1994 (total of 153 hr). Scan data were collected every 5 min to gather information on activity budgets, social proximity, and space utilization. All‐occurrence data were collected on social and non‐social behaviors. In each year of the study, the subjects spent equivalent amounts of time eating, lying, standing, and walking. Additionally, subjects spent half of their time within one body length of another animal and utilized all three available enclosures. Social and non‐social behaviors were frequent, and these data plus the activity profiles reveal the animals generally were most active between the hours of 1800 and 2400 and 0600 and 0700. The findings suggest that the use of no restraints is currently an effective strategy for this elephant group. The high activity levels observed during many of the early evening hours suggest that zoos could permit increased activity and social interactions by extending the hours when the elephants are unchained. Zoo Biol 18:101–109, 1999. © 1999 Wiley‐Liss, Inc.     

Behaviour as a tool in the assessment of animal welfare

A central issue in animal welfare research is how to assess the welfare state of animals objectively and scientifically. I argue that this issue can be approached by asking two key questions: 1) is the animal physically healthy and 2) does the animal have what it wants? Behaviour is used to answer both of these questions. In the assessment of physical health, it can be used for clinical and pre-clinical diagnosis. In the assessment of what animals want, it has a major role through choice and preference testing. It is particularly important that applied ethologists develop methods for assessing welfare in situ--in the places where concern for animal welfare is greatest such as on farms and in zoos.     

Social behavior of a group of orangutans (Pongo pygmaeus) on an artificial island in Singapore Zoological Gardens

The behavior of 12 orangutans (three adult males, two adult females, two subadult males, three adolescent males, and two infant males) was observed on a 450-m² island at the Singapore Zoological Gardens (SZG). Male orangutans (6–18 years old) showed less social and solitary play as they aged; adults (over 16 years old) were not seen to play. As they grew older males increasingly spent less time making physical contact, but the amount of time they spent in proximity (within arm's length) to others increased. Adult females regularly played with other group members. Contact, allogrooming, and social play showed nonrandom relationships between individuals. Adult females showed the most allogrooming and contact, adolescent and subadult males the most play. There was no obvious dominance hierarchy. One adult male spent about 10% of his time walking around the perimeter of the island. One-year-old infants rarely interacted with other individuals apart from their own and the other infant's mother. While orangutans lead relatively solitary lives in nature, it was concluded that the opportunities for social contact and play provided by the SZG orangutan island were beneficial to this species in captivity. Opportunities for social interaction provided the animals with a means of increasing the stimulus component of their environment, thus compensating for the inevitable restriction of complexity and unpredictability as compared with the wild state.     

Use and non-use values as motivational construct dimensions for farm animal welfare: impacts on the economic outcome for the farm

This study explored how farmers’ motivation in terms of use values and/or non-use values to work with farm animal welfare are associated with the economic outcome for the farm. Use values in farm animal welfare refer to economic value derived from productivity and profitability considerations. Non-use values in farm animal welfare refer to economic value derived from good animal welfare, irrespective of the use the farmer derives from the animal, currently or in the future. The analysis was based on detailed information about the income statements of a sample of Swedish dairy farmers, obtained from the Swedish Farm Economic Survey, complemented with survey information about their perceived use and non-use values in farm animal welfare. The findings suggest that farm economic outcome is significantly associated with motivation in terms of use values, but not so much with motivation in terms of non-use values. This is interesting from a policy point of view, because it indicates that farmers with different approaches to farm animal welfare may experience different economic outcomes for their farms. Findings can, for instance, be used to strengthen farmers’ engagement in various private quality assurance standards, which generally focus on values of non-use type, by pointing to that realisation of such values will not impair the economic outcome of the farms. Moreover, findings also suggest that farmers’ economic incentives for engagement in such standards may need to be further strengthened in order to become more attractive, as findings point to that a focus on non-use values generally is not associated with more favourable economic outcomes.     

Space use as an indicator of enclosure appropriateness: A novel measure of captive animal welfare

Empirical measures of animal behavior and space use within the captive environment can provide critical information about animals’ requirements, preferences and internal states. The trend toward naturalistic environments has shown promise in terms of behavioral benefits for animals such as great apes, and there have been several studies of the effects of complex environments on captive apes. However, few recent investigations have objectively compared environmental preferences between two distinct enclosures. In this study, we assessed how ape space use varied within and across two very different environments: an indoor, hardscape enclosure and an indoor/outdoor, naturalistic enclosure. Within-facility tests were conducted by comparing data from behavioral observations of the apes’ position in the enclosures to measurements of the space and the availability of individual environmental elements. Between-facility comparisons utilized electivity index calculations to assess both the degree of use for specific features and the degree to which these selections strengthened or weakened in the new facility. Both gorillas and chimpanzees showed significant structural preferences in the older, hardscape environment: positioning themselves by mesh barriers (chimpanzees: P = 0.005; gorillas: P < 0.001) and corners (P = 0.005; gorillas: P < 0.001) more than would be expected by random spatial utilization, and avoiding open spaces (chimpanzees: P = 0.005; gorillas: P < 0.001) not adjacent to any physical structure. A new, naturalistic enclosure was constructed using preference data from the previous facility. In the new facility, both species of ape substantially altered the way in which they chose to position themselves in the enclosure. Chimpanzees used most of the environmental elements at rates more similar to the proportions they were available. While gorilla's preference corners was maintained in the new facility, preferences for doorways and mesh barriers disappeared. Comparing electivity indices facilitated an empirical comparison of space use preferences. Chimpanzees showed significant differences in how they used structural elements (P = 0.021), mesh barriers (P = 0.009) and corners (P = 0.016) in the new facility. Gorillas’ environmental selections were similarly altered in the new facility, as selections of areas adjacent to doorways (P = 0.003), glass barriers (P = 0.005), structural elements (P < 0.001), and mesh barriers (P = 0.012) were all significantly affected by the transfer. This approach is useful for understanding how captive animals utilize their enclosures and we advocate that electivity indices can be added to a growing list of tools to assess the effect of captive environments on animal welfare.     

Acid‐insoluble ash as a measure of dry matter digestibility in captive African elephants (Loxodonta africana)

There are limited data on the diet dry matter digestibility (DMD) of captive African elephants. Although the total fecal collection method is the standard for determining DMD, it is labor‐intensive, time‐consuming, and expensive. The acid‐insoluble ash (AIA) marker technique has been used successfully to determine DMD in ruminants and monogastrics. The objective of this study was to assess how accurately the AIA marker technique could estimate the DMD of captive African elephants (Loxodonta africana). Three mature male African elephants at Disney's Animal Kingdom in Florida were used in this study. The animals were offered a Bermuda grass hay‐based ration, and the total dry matter intake (DMI) and total fecal output were measured daily over a 7‐day period to determine the total collection DMD. The feed ingredients and fecal samples were also analyzed for AIA. Although there were differences (P<0.05) in total DMI and total fecal outputs, the DMD values did not (P>0.05) differ (35.1±0.72 vs. 37.1±0.72 for total collection and AIA, respectively). There was a linear (y=0.9461x; R²=0.74) relationship between the total collection and AIA marker technique DMD values. These results suggest that AIA can be used to accurately estimate the DMD of captive African elephants. Zoo Biol 0:1–5, 2005. © 2005 Wiley‐Liss, Inc.     

Visitor reaction to pacing behavior: influence on the perception of animal care and interest in supporting zoological institutions

Many publications within the field of zoo animal welfare have stated the importance of decreasing stereotypic behavior (e.g., pacing) to help ensure a positive visitor experience. The idea behind these statements is that visitors want to see animals engaged in natural behavior. Additionally, it is thought that watching an animal exhibit species-appropriate behavior could help increase a visitor's connection to wildlife and ultimately their interest in conservation. However, until recently, no information was available to validate such statements. The purpose of this research was to examine people's reaction to viewing an animal engaged in pacing behavior. Participants were randomly selected to fill out a survey after watching a short video of either a tiger pacing or resting (control). Results indicate that having viewed a tiger pacing significantly decreases people's perception of the level of care animals receive at that facility. In addition, people's interest in supporting zoos decreased as a result of viewing this behavior. Results are discussed from an animal welfare, business, and conservation perspective.     

Determining adrenocortical activity as a measure of stress in African elephants (Loxodonta africana) in relation to human activities in Serengeti ecosystem

African elephants (Loxodonta africana) play a vital role in most African ecosystems, with their opportunity to alter the entire ecosystem by their sheer numbers. Defining and measuring animal welfare has been much discussed. One potential way of determining an animal's welfare is to record the absence or presence of stress. Little research on elephant welfare has so far been performed in the Serengeti ecosystem. The aim of this study was to record the faecal glucocorticoid metabolite levels of African elephants in areas with high or with minimum human interference. A total of 117 faecal samples were collected from randomly located single elephants as well as family herds in the northern, central and western Serengeti National Park (SNP) as well as in Grumeti Game Reserve and Ikoma Open Area, northern Tanzania in 2010. Elephants had higher levels of faecal glucocorticoid metabolites in the areas outside, compared with areas inside SNP. No single males were observed outside SNP, and in general, higher abundance of elephants was observed inside SNP. This suggests that elephants may prefer to reside in the potential safer areas inside the national park, demonstrating the importance of protected areas to improve the welfare of elephants.     

Tail docking in horses: a review of the issues

Routinely performed painful procedures are of increasing interest and, in 2001 (Royal Order, May 17), Belgium prohibited docking in several vertebrates including horses. In 2004, opponents to this decision submitted a Bill (Doc51 0969/001) to Parliament, intending to obtain derogation for Belgian draught horses, which were traditionally docked. The Animal Welfare Council of Belgium, an official body advising the Minister of Public Health, was asked to evaluate this complex question, including biological, ethical and socio-economic aspects, on the basis of the available peer-reviewed studies. In this context, this study reviews legal aspects (overview of the European legislation), zootechnic aspects (uses of the Belgian draught horse) and biological aspects (pain potentially related to docking; horses' welfare linked to insect harassment and hygiene, communication and reproduction) of tail docking in draught horses. We conclude that (1) there is no benefit for horses in tail docking, including Belgian draught horses, (2) potential advantages of docking are essentially in favour of humans and these advantages could be scrupulously re-evaluated, taking into account practices of other countries. Therefore, there is no need to dock any horse other than for veterinary reasons.     

A novel method of quantifying root exudation in the presence of soil microflora

A microcosm is described in which root exudation may be estimated in the presence of microorganisms. Ryegrass seedlings are grown in microcosms in which roots were spatially separated from a microbial inoculant by a Millipore membrane. Seedlings grown in the microcosms were labelled with [¹⁴C]-CO₂, and the fate of the label within the plant and rhizosphere was determined. Inoculation of the microcosms with Cladosporium resinae increased net fixation of the [¹⁴C] label compared to plants grown under sterile conditions. Inoculation also increased root exudation. The use of the microcosm was illustrated and its applications discussed.     

A novel method for quantifying in-vivo regional left ventricular myocardial contractility in the border zone of a myocardial infarction

Homogeneous contractility is usually assigned to the remote region, border zone (BZ), and the infarct in existing infarcted left ventricle (LV) mathematical models. Within the LV, the contractile function is therefore discontinuous. Here, we hypothesize that the BZ may in fact define a smooth linear transition in contractility between the remote region and the infarct. To test this hypothesis, we developed a mathematical model of a sheep LV having an anteroapical infarct with linearly-varying BZ contractility. Using an existing optimization method (Sun et al., 2009, "A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm," J. Biomech. Eng., 131(11), pp. 111001), we use that model to extract active material parameter T(max) and BZ width d(n) that "best" predict in-vivo systolic strain fields measured from tagged magnetic resonance images (MRI). We confirm our hypothesis by showing that our model, compared to one that has homogeneous contractility assigned in each region, reduces the mean square errors between the predicted and the measured strain fields. Because the peak fiber stress differs significantly (~15%) between these two models, our result suggests that future mathematical LV models, particularly those used to analyze myocardial infarction treatment, should account for a smooth linear transition in contractility within the BZ.     

Providing straw to allow exploratory behaviour in a pig experimental system does not modify putative indicators of positive welfare: peripheral oxytocin and serotonin

Numerous studies have shown that providing straw to pigs can reduce undesirable behaviours such as aggression, tail biting and stereotypy. The measurement of various neuromodulators can be helpful in assessing the development of positive behaviours and overall animal welfare. The oxytocin release is frequently linked to positive emotions and positive welfare. It has been suggested that oxytocin modulates the serotoninergic system. This study aims to investigate the potential effect of straw provision in pigs on peripheral levels of oxytocin and serotonin. In total, 18 mini-pigs were involved in an exploratory study conducted in two parallel groups, Enriched (n=10) and Control (n=8) groups. Pigs were divided by group and housed in pens of two individuals. Straw was provided continuously only in Enriched group and renewed each day for 2 weeks. Two blood samples were drawn from each animal 5 to 10 min before providing the straw, and 15 min after providing straw, during the 1^st week, to analyse peripheral changes in oxytocin and serotonin before and after straw provision, and determine the existence of a putative short-term effect. The same procedure was carried out for Control group, without straw provision. Long-term effects of straw provision were also examined using blood samples drawn at the same hour from each animal in the 2^nd and 3^rd weeks. During this time, animals had the permanent possibility to explore the straw in Enriched group but not in Control group. At the end of each week, one animal-keeper completed two visual analogue scales for each mini-pig regarding the difficulty/ease to work with and handle it and its trust in humans. Results showed peripheral oxytocin increases in both groups after 2 weeks (P=0.02). Results did not demonstrate any effect of providing straw to allow exploratory behaviour on peripheral serotonin. Other results were not significant. This preliminary study explored the relationship between peripheral oxytocin and serotonin and the presence of straw that allow pigs to perform exploratory behaviour, suggesting that there was no relationship between them. Some future studies may include crossing oxytocin and serotonin with other parameters, such as behavioural measures, to obtain more information about the true state of the animal and any possible relationship with pig welfare.     

A novel method for quantifying cell migration through tissue engineering scaffolds: evaluation of modified collagen matrices

A novel method to quantify cell migration through potential tissue engineering 3-d scaffolds is described. The migration assay uses a dot-blotting apparatus into which the tissue engineering matrix is placed on top of a nitrocellulose membrane. This assay was used to evaluate human dermal fibroblast migration through four porcine collagen matrices with varying pore diameters and pitch lengths. Fibroblasts were placed on the matrix surface, at between 1 ×10³–3 × 10³ cells mm^–2, and left for 18 h to allow migration. The nitrocellulose membrane was stained with haematoxylin, the membrane digitised and the pixel intensity of the stained cells quantified. We showed that for all matrix variants, migration was more effective with a higher initial seeding density. The application of varying initial cell densities resulted in the greatest extent of cell migration through the matrix variant with pores of 30 m diameter and 400 m pitch length (i.e. 10.3% migration at 1 ×10³ cells mm^–2). This method was coupled with confocal microscopy to evaluate the depth of cell migration within the matrix. At a depth of 20 m cell numbers were similar to those on the matrix surface: at a depth of 100 m only a few cells were observed.