Transport Stress in Captive Felids in the USA
By James Carlyle
• There are 7 representative species of big cat.
• 5 out of 7 species Threatened.1
• All have a decreasing population trend.
• Main threats2-6: - Habitat loss
- Loss of prey
Below is a list of the seven representative species of big cat, alongside their IUCN Red List status:1
Lion (Panthera leo) – Vulnerable
Tiger (Panthera tigris) – Endangered
Leopard (Panthera Pardus) – Vulnerable
Cheetah (Acinonyx jubatus) – Vulnerable
Jaguar (Panthera onca) – Near Threatened
Snow leopard (Panthera uncia) – Vulnerable
Puma (Puma concolor) - Least Concern
Habitats lost to deforestation remain a major concern, causing the disruption of natural ecosystems, and reducing prey numbers.2-4
Big cats are frequently hunted due to predation on livestock, for use in the illegal wildlife trade – such as in traditional Asian medical practices, or trophy hunting.5",6
How are zoos involved?7
Zoos aid in the conservation of big cat species in multiple ways, including by:
• educating the public on current conservation issues
• funding conservation projects (in situ)
• research into threatened species
• initiating reintroduction programmes and
• involvement in captive breeding programmes (ex situ).
Including species of big cat in zoo exhibits also provides enhancement to the public experience, thus increasing the zoo’s appeal and profit.
Captive breeding programmes in zoos7",8
• In recent years, zoos have become increasingly cooperative.
• Animals are transported between zoos for breeding.
• Maintains genetic variation.
• In some cases, can aid in restoring endangered populations.
Why is this a welfare issue?
• Felids are thought to encounter high stress during transport.8
• Reports of increased susceptibility to disease post-transportation.9
• Does not permit three of the Five Freedoms for duration of time in transport cages8:
• Freedom from discomfort
• Freedom to express normal behaviour
• Freedom from fear and distress
Dembiec et al. (2004) conducted an investigation on transport stress in captive tiger species by transporting them for 30 minutes, with the animals finishing in the same enclosure as they started in; their cages met Association of Zoos and Aquariums’ (AZA) Tiger Species Survival Plan (SSP) standards. Welfare was measured through changes in faecal corticoid levels, observed respiratory rate, time spent pacing, pace rate, and ear position.8 Ear position is relatively unique to felids, with low, flat ears indicating an alert, fearful state.10 The investigation discovered a marked increase in each behavioural and physiological parameter during transport, remaining elevated for up to 12 days after release.8 Wells et al. (2004) supports this paper, with a study of the stress elicited in cheetahs during transportation by measuring faecal corticoids, with an overall significant increase in cortisol excretion during transport.11
Munson (1993) documented an increased incidence of diseases, such as feline infectious peritonitis (FIP), in cheetahs after transportation, suggesting increased susceptibility, partly due to immunosuppression from transport stress.9
Definitions of welfare
• Physical/“Function” approach Poor welfare occurs when biological systems (e.g. survival, reproduction) are impaired.12
• Mental/“Feelings” approach Poor welfare occurs when animals “feel” suffering or negative affect.13
• Natural/“Freedom” approach Poor welfare occurs when an animal is unable to perform all of the natural behaviours in their repertoire.14
Not all of these definitions pertain relevance when considering the transport of captive felids, as the biological functioning of captive felids is not impaired by movement between sanctuaries. However, during transport, it has been reported that felids are likely to “feel” stress due to the lack of stimulation in their environment, and cannot perform all natural behaviours in their repertoire, such as exploration, as they are confined to very small spaces8",11 By these definitions, a welfare issue is being encountered.
Indicators of poor welfare15-19
Hypothalamic-pituitary-adrenal measures8",11 Anxious/fearful8
Stress = HPA activation = Cortisol release
(Measured in blood, faeces, saliva, urine, hair and milk) • Stereotypic behaviour (e.g. pacing, overgrooming)
Autonomic measures8 Sad/depressed
• Heart rate
• Respiratory rate
• Blood pressure
• Pupil dilation • Self-maintenance (e.g. grooming)
• Lack of activity/natural behaviours
• Lack of response to stressors
When clinical disease, or visible injury, is not grossly present, welfare can be difficult to identify and quantify. Cortisol – a hormone frequently associated with stress – is commonly used as a measurement in animals after exposure to a suspected stressor.15 Upon exposure, the hypothalamus releases corticotrophin-releasing factor (CRF), stimulating the anterior pituitary gland to release adrenocorticotrophic hormone (ACTH). This binds to receptors in the adrenal cortex, causing the release of cortisol.16 In short, cortisol reduces energy used on processes such as growth and reproduction, for increased consumption in brain and muscle activity; however, long term exposure to stressors can cause health issues, including immune suppression.17 Cortisol is released in pulsatile circadian and ultradian rhythms, hence regular samples must be taken at standardised times.18 The HPA axis is limited through a negative feedback system.16
The autonomic measures listed above describe the impact of the central nervous system’s reaction to stress, wherein activation of the sympathetic nervous system triggers adrenaline/noradrenaline release, eliciting the “fight or flight” response .19 These physiological parameters have been used as measures of welfare in captive felids, along with anxiety-related behavioural measures to indicate stress. Although depression has not been used in this example, it is worth considering as a limitation of these studies, where there is potential for the data collected to not fully reflect the animal’s welfare.
Problems with these methods?
• Measures affect in terms of arousal as opposed to valence.20
• HPA changes due to sustained negative feedback make this a less viable long term measure.21",22
• Can be subjective, and is difficult to quantify.
• Lack of stereotypic behaviours does not necessarily equate to good welfare.26
• High variation between individual responses to stressors.8
HPA axis activation and the autonomic nervous system response act merely a measure of arousal, as opposed to valence.20 For example, HPA activation occurs when food is anticipated in big cats 21, as does sympathetic nervous system activation around potential mates 22; events strongly associated with positive affect.20 False negative results can also be generated, wherein “sad/depressed” animals experience poor welfare, but are not aroused. Henceforth, other supporting methods are required.
Furthermore, prolonged stress enhances the negative feedback system, causing a down-regulation in the basal cortisol levels present in the blood.23",24 Therefore, welfare may not be accurately reflected in cortisol levels during long-term studies. Having said this, the transportation of felids causes acute stress over relatively short periods8",11, and measurements will review short term physiological and behavioural changes.
Stereotypies are widely used to measure poor welfare, characterised by repetitive, invariant, non-functional behaviours.25 Despite this, it is important to note that they are a form of coping mechanism, aiming to alleviate the effects of poorly stimulating surroundings.26 Thus, within any system, those engaging in stereotypic behaviour may not be the ones suffering the most, such as when transporting captive felids. Further, stereotypic behaviours often become habitual, so can continue even once preferred environments are provided; this must be taken into account when analysing the cause of the behaviour in these feline species, with measurements being taken prior to transfer to isolate transport as the causative factor.27
What could be different?
• - Shorter journeys.
• - Use less animals.
• - Fewer journeys.
• - Transport frozen . semen for AI.29-31
• - Provide anxiolytics.35
• - Stress-reducing . pheromones.36
• - Larger cages.
• - Enrichment.37-39
Reducing the incidence of transport may result in significant trade-offs in terms of genetic variation in captive breeding.28
It is possible to transport cryopreserved semen from genetically valuable males, for artificial insemination into anaesthetised females 29; this has proven success in felids, including leopards and pumas30, 31 However, it can be unpredictable, with limited success 32",33, with a 40% loss of sperm after thawing, along with a 20% reduction in motility.32",34
Anxiolytics, such as benzodiazepines, may be of use during transport of captive big cats.35 These can be used in conjuncture with stress-reducing pheromone treatment, which reportedly have 90% effectiveness in reducing anxiety-related behaviour in felids.36 The provision of more space and familiar enrichment is proven in reducing stress and stereotypic behaviours during stressful events.37-39
What is the U.S. legislation?
• International All big cats are listed under Appendix I of CITES, restricting international trade to non- commercial uses.40
• Zoo animals are to be handled and treated humanely . during transport – facilities subject to inspection.41",42
• Enclosure must be well-ventilated, with space for the . animal to freely turn.41
• Threatened felids can only be traded between states for . non-commercial uses (e.g. captive breeding, scientific . research).42
• State Variation in specific laws, but all
states have legislation enforcing
federal law, with varying degrees
of enforcement and punishment.43
The Animal Welfare Act (1966) is a federal legislation stating that zoo animals are to be handled and treated humanely during transportation. This includes an easily accessible, well-ventilated enclosure with enough space to allow the animal to freely turn; the Act allows for the Secretary of Agriculture to consult with experts on minimum requirements for these species. It is enforced by the United States Department of Agriculture, with regular inspections of facilities to check that federal standards of care are being met.41
The U.S. Fish and Wildlife Service enforce the Endangered Species Act (1973), which restricts the transport of threatened species to non-commercial uses.42
Different public attitudes and a lack of resources in some local agencies has resulted in variations between state laws and their enforcement. For example, California charge up to one-year imprisonment and a $20",000 fine in response to cruelty towards zoo animals. However, states such as Georgia, Idaho, Michigan, Missouri, New Jersey, and Washington exclude zoo animals from their anti-cruelty laws, making transport standards more lenient.43
The Association of Zoos and Aquariums (AZA) provide accreditation to establishments meeting their standards for animal management and care. For transportation of big cats, this includes:43
• Pre-shipment training.
• Food and water fixed off ground (>24hr journeys) to avoid soiling.
• Provide comfortable, absorbent bedding such as straw.
• Flooring of narrow slats for excreta.
• Moved individually Solitary species.
• Felid must be able to stand with its head erect.
• Should be kept in darkness, away from noise where possible to reduce stress
• Protection from extreme temperatures.
AZA recommend feeding animals in their transportation crate prior to movement, to build positive associations. Furthermore, felids must be moved separately, aside from cubs in the same litter.
Respect . for:
Stakeholders Wellbeing Autonomy Justice
Animals • High stress during (and after) transport.8",11
• However, possibility of alleviation.29-31, 36-39 • Cannot consent to transport, or its conditions.
• Behavioural freedom severely limited.11
• Infringement of “rights”? • Does not take into account what the individual animal wants; undermines intrinsic value.
Zoos • Increased profit for zoos from public interest in animals.7 • Able to decide conditions and times of transport, provided it complies with legal and AZA standards.40-43 • Concern is of long-term benefits in conservation Maintain population and varied gene pool.7
• Belief that stress of one individual is outweighed by the “bigger picture” in species conservation.
Public • Enhanced experience at zoo from introduction of popular animal spectacle.7 • Likely unaware of the transport process prior to visit, so cannot choose on this basis.7 • May only be informed of conservation value.
• Potential to feel deceived if information on the animal’s histories is withheld.7
Environment • Part of an ultimate goal in long-term conservation.8 • Eventual increase in biodiversity in previously harmed ecosystems which contain wild feline populations.8 • Sustainability of end goals not yet known.7
Here, a utilitarian approach is adopted to ethically analyse the transporting of felids for captive breeding.
The wider issue
This issue is not exclusive to transport stress in captive felids, rather a facet in a much larger welfare issue involving:
• Other zoo animals whom experience stress during transportation (e.g. red deer, black rhinoceroses, nonhuman primates).43-45
• Implications upon arrival of a felid into novel environments (different staff, surroundings, husbandry practices etc).8",11
Transport stress has been reported in many zoo animal species, including red deer (Cervus elaphus), black rhinoceroses (Diceros bicornis), and nonhuman primates.43-45
Wells et al. (2004) documented the extension of this welfare issue into introduction to novel environments, with continued elevated cortisol being recorded for over 3 months in some cheetahs8",11.
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