Trends in cheetah Acinonyx jubatus density in north-central Namibia

Assessing trends in abundance and density of species of conservation concern is vital to inform conservation and management strategies. The remaining population of the cheetah (Acinonyx jubatus) largely exists outside of protected areas, where they are often in conflict with humans. Despite this, the population status and dynamics of cheetah outside of protected areas have received relatively limited attention across its range. We analyzed remote camera trapping data of nine surveys conducted from 2005 to 2014 in the Waterberg Conservancy, north-central Namibia, which included detections of 74 individuals (52 adult males, 7 adult females and 15 dependents). Using spatial capture–recapture methods, we assessed annual and seasonal trends in cheetah density. We found evidence of a stable trend in cheetah density over the study period, with an average density of 1.94/100 km² (95% confidence interval 1.33–2.84). This apparent stability of cheetah density is likely the result of stable and abundant prey availability, a high tolerance to carnivores by farmers and low turnover rates in home range tenure. This study highlights the importance of promoting long-term surveys that capture a broad range of environmental variation that may influence species density and the importance of nonprotected areas for cheetah conservation.     

Blood platelets of the cheetah (Acinonyx jubatus)

The blood platelet count and platelet morphology of 22 adult cheetahs was investigated. The platelet counts of the animals displayed a normal distribution, with a mean count of 344×10⁹/l and a mean platelet volume of 11 fl. Morphological and ultrastructural features of the cheetah platelets revealed the typical platelet morphology of anuclear cells, with granules scattered throughout the cytoplasm. The characteristic surface canalicular system and microtubules were present. True cross‐sections of the platelets had a mean area of 2.146 µm², circumference of 6.805 µm, and mean minimum and maximum projections of 1.000 µm and 2.933 µm, respectively. Zoo Biol 23:263–271, 2004. © 2004 Wiley‐Liss, Inc.     

The composition of cheetah (Acinonyx jubatus) milk

Milk was obtained from two captive bred cheetahs. The nutrient content was 99.6 g protein; 64.8 g fat; and 40.21 g lactose per kg milk. Small amounts of oligosaccharides, glucose, galactose and fucose were noted. The protein fraction respectively consisted of 34.2 g caseins per kg milk and of 65.3 g whey proteins per kg milk. Very little variation in milk composition among the individual cheetahs was noted. Electrophoresis and identification of protein bands showed a similar migrating sequence of proteins as seen in lion's and cat's milk, with small differences in the β-caseins. The lipid fraction contains 290.4 g saturated and 337.3 g mono-unsaturated fatty acids per kg milk fat respectively. The high content of 279.5 g kg^− 1 milk fat of polyunsaturated fatty acids is due to a high content in α-linolenic acid. No short chain fatty acids, but substantial levels of uneven carbon chain fatty acids were observed.     

Anthrax in cheetahs (Acinonyx jubatus) in Namibia

Bacillus anthracis caused the death of five cheetahs (Acinonyx jubatus) on a farm in the Gobabis district in Namibia. The mode of infection was believed to be a freshly shot baboon (Papio ursinus) with a cutaneous anthrax lesion.     

Lifetime semen production in a cheetah (Acinonyx jubatus)

Lifetime semen production data provide valuable insight into a species’ natural history and biology as well as information about the potential fertility of males at various life stages. An understanding of the ages of sexual maturity, peak sperm production, and gonadal senescence will contribute to the design of species management plans for captive, free‐ranging, and reintroduced populations of exotic animals. To describe these life stages in the cheetah, semen was collected biweekly for 13 years from a solitary male beginning at 3 years of age. The 338 ejaculates were obtained noninvasively by artificial vagina. Ejaculate volume and sperm motility score, concentration, and normal morphology were recorded. A sperm quality index incorporating all five semen parameters was calculated to facilitate ejaculate comparisons. Polynomial regression analysis revealed a significant effect of age on volume, which increased throughout the animal’s lifetime except for a reduction between ages 10 and 12. Concentration was also significantly affected by age and increased from the age of 3 to the age of 10, then decreased. The sperm quality index revealed a significant effect of age as it increased from age 3 to age 8, then declined as the male grew older. The cheetah did not reach peak semen production until age 8 and continued to produce good quality semen for several more years. These data were somewhat unexpected, given the average cheetah life expectancy of approximately 7 years. Zoo Biol 20:359–366, 2001. © 2001 Wiley‐Liss, Inc.     

Timed running speed of a cheetah (Acinonyx jubatus)

The speed of an adult cheetah was timed at 29ms^-1 (mean of three trials over a 201.2 m course, with a running start). This is the highest running speed that has been recorded reliably for any animal.     

Fecal corticoid metabolite measurement in the cheetah (Acinonyx jubatus)

This longitudinal study addresses the relationship of cortisol excretion to ovarian activity in captive female cheetahs. A radioimmunoassay was developed and validated to measure corticoid metabolite concentrations in feces. A restraint experiment was used to demonstrate that fecal cortisol is detectable following stressful episodes. In studies of 7 females, fecal cortisol output indicated that they could be placed into 3 different categories. Females of the high-in-cortisol category (∼200 ng/g feces, n = 2) were independently rated by caretakers as the most nervous individuals in the collection (n = 24). These females appeared to be compromised in their ovarian cycling, as indicated by fecal estrogen measurements. In contrast, reproducing females fell into the low and intermediate cortisol excretion categories. A non-cycling high-cortisol female had an episodic cycle following a period of relatively low (intermediate) cortisol levels, followed by resumption of acyclicity and high cortisol excretion. Stress and reproductive failure may, therefore, be associated in the female cheetah. The close proximity of conspecifics as a potential source of stress and, consequently, suppressed ovarian activity in some females is suggested by these results. Zoo Biol 16:133–147. 1997 © 1997 Wiley-Liss, Inc.     

Habitat selection and feeding ecology of the cheetah (Acinonyx jubatus) in thicket vegetation: is the cheetah a savanna specialist?

Habitat selection and feeding ecology of a reintroduced population of cheetahs Acinonyx jubatus were studied in a 16 000 ha game reserve in the Eastern Cape Province (South Africa). Seventy per cent of the reserve is characterized by very dense thicket vegetation (valley bushveld) and the remainder is open and savanna-like. The results illustrated a strong effect of sex and group size on the behaviour of cheetahs. The coalition (three adult males) killed significantly larger animals (55% of kills weighed more than 65 kg) than single female cheetahs (less than 2% of kills weighed more than 65 kg). Female cheetahs showed temporal and spatial avoidance of lions by hunting at dawn and dusk and positioning their home ranges [95% utilization distribution (UDs)] significantly farther from the pride of lions than did the coalition. The coalition hunted earlier and later than female cheetahs, and 46% of their kills were made in darkness. In addition, their home range overlapped that of the lions and they showed neither temporal nor spatial avoidance of the lions. The rates of kleptoparasitism were lower and the kill retention times were longer than those reported elsewhere in Africa, and it is suggested that this is a consequence of the cover provided by the thicket vegetation and prey size. The home ranges (95% UDs) of female cheetahs incorporated more thicket vegetation than that of the coalition, indicating that the coalition is less susceptible to predation than single females. These data suggest that cheetahs possess greater behavioural flexibility than previously reported, that they can hunt successfully in thicket vegetation, sometimes in darkness, that they are not restricted to killing small to medium-sized prey, and that they may not be savanna specialists.     

Naturally acquired anthrax antibodies in a cheetah (Acinonyx jubatus) in Botswana

An outbreak of anthrax in the Jwana Game Reserve in Jwaneng, Botswana, was first observed when three cheetahs (Acinonyx jubatus) died of the disease in November 2004. In the aftermath of this event, banked serum samples collected from 23 wild-caught cheetahs were examined, by the inhibition enzyme-linked immunoassay (ELISA), for antibodies to the protective antigen (PA) of Bacillus anthracis. Of the 23 cheetahs, 16 regularly accessed the reserve. Antibodies to PA were detected in one cheetah collected in May 2004, indicating the disease was occurring well before it was first noticed. This appears to be the first demonstration of naturally acquired anthrax antibodies in cheetahs. The finding of one antibody-positive animal amongst at least 16 potentially exposed individuals is consistent with existing reports that it is uncommon for cheetahs to develop natural immunity to anthrax.     

Distribution of muscle fibers in skeletal muscles of the cheetah (Acinonyx jubatus)

We examine the muscle fiber population of skeletal muscles from whole body in the cheetah (Acinonyx jubatus). In the present experiments, we showed the characteristics of fiber composition in the cheetah by comparative studies among the cheetah, domestic cat, and the beagle dog. Fiber population was determined on muscle fibers stained with monoclonal antibody to each myosin heavy chain isoform. Histochemical analysis demonstrated that many muscles in the cheetah and domestic cat had a low percentage of Type I fibers and a high percentage of Type IIx fibers, while those in the beagle dog showed a high percentage of Type IIa. The hindlimb muscles in the cheetah had a higher percentage of Type II (Type IIa + IIx) fiber than the forelimb muscles. This fact suggests that the propulsive role of the hindlimb is greater than the forelimb in the cheetah. The longissimus in the cheetah had a high percentage of Type IIx fibers over a wide range from the thoracic to lumbar parts, while the population of muscle fibers in this muscle was different depending on the parts in the domestic cat and beagle dog. This indicates that the cheetah can produce a strong and quick extension of the spinal column and increase its stiffness during locomotion. Furthermore, we found the notable difference of muscle fiber type population between flexors and extensors of digits in the cheetah. The present experiments show the characteristics of muscle fibers in the cheetah, corresponded to its ability to perform high-speed running.     

A case of relapsing cutaneous larva migrans transmitted by a cheetah (Acinonyx jubatus)

A case of relapsing "creeping eruption" connected with parasites of the cheetah is reported in the man. The parasitological examination, carried out in two cheetahs liable of this syndrome, has shown two different helmintic species: Ancylostoma caninum and Ancylostoma tubaeforme.     

Extrinsic factors significantly affect patterns of disease in free-ranging and captive cheetah (Acinonyx jubatus) populations

The cheetah (Acinonyx jubatus) has been considered a paradigm for disease vulnerability due to loss of genetic diversity. This species monomorphism has been suspected to be the basis for their general poor health and dwindling populations in captivity. North American and South African captive populations have high prevalences of hepatic veno-occlusive disease, glomerulosclerosis, gastritis, and systemic amyloidosis, diseases that are rare in other species. Unusually severe inflammatory reactions to common infectious agents have also been documented in captive cheetahs. The current study compared disease prevalences in free-ranging Namibian cheetahs with those in two captive populations of similar ages. The occurrence of diseases in the free-ranging population was determined from 49 necropsies and 27 gastric biopsies obtained between 1986 and 2003 and compared with prevalences in 147 North American and 80 South African captive cheetahs. Except for two cheetahs, the free-ranging population was in robust health with only mild lesions present, in contrast with significantly higher prevalences in the captive populations. Despite widespread heavy Helicobacter colonization in wild cheetahs, only 3% of the free-ranging population had moderate to severe gastritis, in contrast with 64% of captive cheetahs. No severe inflammatory reactions to viral infections were detected in the free-ranging animals. Because free-ranging Namibian cheetahs are as genetically impoverished as captive cheetahs, these findings caution against attributing loss of fitness solely to genetic factors and attest to the fundamental importance of extrinsic factors in wildlife health.     

Regional variation in the cheetah (Acinonyx jubatus) revisited: Morphology of wild and captive populations

The cheetah (Acinonyx jubatus) is listed as a vulnerable species by the International union for the conservation of nature (IUCN), including two critically endangered subspecies, the Saharan cheetah, and the Iranian cheetah, so it is imperative that we understand variation in cheetah morphology to make good decisions regarding the conservation of this species. Here, we aim to determine whether northeastern African cheetahs have smaller body sizes than southern African cheetahs. This study also adds to our knowledge of cheetah morphology from two cheetah populations that do not yet have comprehensive published data: Kenya, and northeastern Africa, including captive individuals. We calculated means and standard deviations on cranial and body measurements of live or in few cases, freshly dead, cheetahs from the aforementioned populations, plus previously published data on Namibian and Botswanan cheetahs and compared them to one another using multivariate analysis of variance. Results show that northeastern African cheetahs have smaller body sizes than southern and eastern African populations. We also found that captive cheetahs retain the morphological characteristics of their ancestral population- captive cheetahs from southern Africa have similar body sizes to wild southern African cheetahs and larger body sizes than captives from northeastern Africa. Other analyses regarding cheetah growth agree with previous studies on Namibian and Botswanan cheetah populations rates. As such, this study can serve as a baseline for the care of captive cheetah populations to maintain healthy weights and body proportions.     

Different patterns of metabolic cryo-damage in domestic cat (Felis catus) and cheetah (Acinonyx jubatus) spermatozoa

Felid spermatozoa are sensitive to cryopreservation-induced damage, but functional losses can be mitigated by post-thaw swim-up or density gradient processing methods that selectively recover motile or structurally-normal spermatozoa, respectively. Despite the importance of sperm energy production to achieving fertilization, there is little knowledge about the influence of cryopreservation or post-thaw processing on felid sperm metabolism. We conducted a comparative study of domestic cat and cheetah sperm metabolism after cryopreservation and post-thaw processing. We hypothesized that freezing/thawing impairs sperm metabolism and that swim-up, but not density gradient centrifugation, recovers metabolically-normal spermatozoa. Ejaculates were cryopreserved, thawed, and processed by swim-up, Accudenz gradient centrifugation, or conventional washing (representing the 'control'). Sperm glucose and pyruvate uptake, lactate production, motility, and acrosomal integrity were assessed. Mitochondrial membrane potential (MMP) was measured in cat spermatozoa. In both species, lactate production, motility, and acrosomal integrity were reduced in post-thaw, washed samples compared to freshly-collected ejaculates. Glucose uptake was minimal pre- and post-cryopreservation, whereas pyruvate uptake was similar between treatments due to high coefficients of variation. In the cat, swim-up, but not Accudenz processing, recovered spermatozoa with increased lactate production, pyruvate uptake, and motility compared to controls. Although confounded by differences in non-specific fluorescence among processing methods, MMP values within treatments were positively correlated to sperm motility and acrosomal integrity. Cheetah spermatozoa isolated by either selection method exhibited improved motility and/or acrosomal integrity, but remained metabolically compromised. Collectively, findings revealed a metabolically-robust subpopulation of cryopreserved cat, but not cheetah, spermatozoa, recovered by selecting for motility rather than morphology.