Comparative analyses of semen and endocrine characteristics of free-living versus captive jaguars (Panthera onca)

Abstract

Semen and blood samples were obtained from free-living (n = 6) and captive (n = 8) jaguars (Panthera onca) to compare reproductive characteristics between the two populations. Semen samples were analysed for volume (ml), percentage of motile spermatozoa, rate of forward progression (0-5), concentration (10(6) ml(-1)), total sperm count (10(6)) and sperm morphology. Serum testosterone concentration was determined by radioimmunoassay. Although ejaculate volume was greater in captive jaguars (n = 47 samples) than in free-living jaguars (n = 7 samples) (P < 0.05), the free-living jaguars produced more total spermatozoa (59.3 +/- 12.8 versus 152.0 +/- 88.0 x 10(6), respectively; not significant) with better viability and forward progression (2.8 +/- 0.1 versus 3.5 +/- 0.2, respectively; P < 0.05) and more spermatozoa with normal morphology (73.5 +/- 3.9 versus 5.0 +/- 1.1%, respectively; P < 0.05). Serum testosterone concentrations were similar for captive and free-living male jaguars (3.1 +/- 0.7 and 2.1 +/- 0.8 ng ml(-1), respectively). In summary, the data showed that semen may be collected successfully from free-living jaguars and evaluated under field conditions to establish normative reproductive values in this species. The results also indicate that jaguars maintained in zoos show inferior seminal characteristics compared with free-living animals.

Electroejaculation and Semen Cryopreservation of Free-Ranging Japanese Black Bears (Ursus thibetanus japonicus)

“…The data on semen characteristics may be useful to establish normative reproductive values in this species. Electroejaculation would be a safe and reliable method for collecting semen from free-ranging Japanese black bears, as has been recognized in other species [5,10,12,15,18,21,35]. Semen samples obtained under such conditions could subsequently be used in genetic analyses and tests of sexual maturity and competence.…”

“…There are several reports on semen collection by electroejaculation in other free-ranging mammalian species, such as African elephant [10], jaguar [21], seal [18], Eastern grey kangaroo [15] and koala [35], while fewer reports about cryopreservation of erectroejaculates from free-ranging mammals such as African elephant [12], impala, wart hog, elephant and lion [5]. The inherent difficulties in collecting physiological data from free-ranging bears are reflected in the small number of samples, representing the sparse number of we had capture opportunities over the 3-year period.…”

“…Endangered and threatened wild animals are now attracting attention as a genetic resource and for species conservation, and semen has been recovered from various captive non-domestic animals, including fat-tailed dunnarts, koalas, brushtail possums, long-footed potoroos, northern brown bandicoots and ring-tailed possums [32], blesboks, dorcas gazelles and onagers [11], chacma baboons [3], jaguars [21], Indian tigers and Asiatic lions [29] and cheetahs [34]. As to Ursidae, there are reports on electroejaculation and/or semen cryopreservation in giant pandas [4,20,22,24], Hokkaido brown bears [13,14] and Japanese black bears [16].…”

Changes in the fecal concentrations of cortisol and androgen metabolites in captive male jaguars (Panthera onca) in response to stress

“…Electroejaculation was performed as previously described by Morato et al (16). Briefly, a rectal probe (2.6 cm in diameter and 29 cm long) and a portable batteryoperated electrostimulator (AC, 60 Hz current; Eletrovet Electronic Equipment, São Paulo, SP, Brazil) were used to deliver an electroejaculation stimulus sequence consisting of a total of 80 stimuli applied in a series of 30, 30 and 20 stimuli.…”

The potential for gamete recovery from non-domestic canids and felids

“…Moreover, some researchers have reported successful semen collection from wild felids by using electroejaculation, such as tigers (Panthera tigris- Donoghue et al, 1992), snow leopards (Panthera uncia- Roth et al, 1994), Indian leopards (Panthera pardus- Jayaprakash et al, 2001), caracals (Caracal caracal- Pope et al, 2001), jaguars (Panthera onca- Morato et al, 2001;Silva et al, 2003), ocelots (Leopardus pardalis- Queiroz et al, 2002), margays (L. wiedii) and tigrinas (L. tigrinus- Morais et al, 2002). Graham et al (1978) reported the use of electroejaculation to collect semen from nondomestic felids.…”