Seasonal changes in ovarian steroid hormone concentrations in the large hairy armadillo (Chaetophractus villosus) and the crying armadillo (Chaetophractus vellerosus)

First assessment of hoary fox (Lycalopex vetulus) seasonal ovarian cyclicity by non-invasive hormonal monitoring technique

Reproduction is key to species survival, and reproductive physiology represents a high priority investigative area for conservation biology, as it provides a basic understanding of critical life-history traits, information that is helpful for the establishment of management strategies. Here, we generated knowledge about the reproductive endocrinology of the hoary fox (Lycalopex vetulus), a small canid (2.5-4 kg) endemic to open areas of the Brazilian Cerrado and listed in the Brazilian National List of Endangered species. Specifically, we utilized non-invasive hormone monitoring methods to assess oestrogen and progestagen metabolites from eight female hoary foxes housed in five zoological institutions in the state of São Paulo-Brazil. We observed the elevations of oestrogen and progestagen metabolites between July and September in six of the eight females. No significant evidence of ovarian activity was observed during other months. Two females, who shared the same enclosure, did not show a pattern of reproductive cyclicity. Based on these characteristics, we concluded that captive hoary foxes are seasonal monoestric, with the beginning of the oestrus cycle occurring mainly in July followed by 2 months of the luteal phase when conception does not occur. We suggest the dosage of faecal metabolites of estradiol and progesterone could be used to differentiate the reproductive period from a non-reproductive period in Lycalopex vetulus females, providing relevant information about their reproductive biology that may contribute to species conservation and management strategies, such as increased ex situ reproductive success.

Cytogenetic damage in peripheral blood cultures of Chaetophractus villosus exposed in vivo to a glyphosate formulation (Roundup)

Different concentrations of a glyphosate formulation, Roundup® Full II (66.2% glyphosate) were tested in culture peripheral blood of armadillo Chaetophractus villosus with cytogenetic biomarkers like mitotic index (MI), chromosomal aberrations (CA), sister chromatid exchange (SCE) and cell proliferation kinetics (CPK) by means of replication index. Adults animals of both sexes were exposed to RU at four concentrations ranging from 0.026 mL RU solution to 0.379 mL RU daily in oral treatment with the same volume (0.2 mL) during 7 days. We analyzed the induced damage at different times considering T0 as control value, one (T1), seven (T7) and 30 days (T30). One day after, only the higher concentration shows MI significant differences (p < 0.05), at T7 the frequency increases and at T30 it decreases reaching T0 values. The analysis of CA frequencies shows that only 0.106 mL RU/day exhibit significant differences vs T0 values. A great variability is expressed in the values of standard deviation (SD) and in the wide confidence intervals of the media. One day after treatments (T1) all four concentrations shows significant differences in SCE vs T0 values. Replication Index (RI) does not show significant differences. The dose-response behavior was not observed in either CA or SCE. The consistency of the findings obtained with the same biomarkers in vitro support the idea of expanding studies in order to characterize the risk doses for these mammals.

Characterization of the ovarian cycle in the two-toed sloths (Choloepus didactylus): an innovative, reliable, and noninvasive method using fecal hormone analyses

Little is known about reproductive physiology in the two-toed sloth (Choloepus didactylus). Therefore, the aim of this study was to obtain detailed information about the ovarian cycle. Measurements of reliable gonadal steroids in the feces of this species were undertaken. For this purpose, fecal samples were collected one to three times per week from nonpregnant captive females (n = 2) over a 16-month period. Before assay analysis, the fecal samples were extracted with methanol. Radioimmunoassays and enzyme immunoassays for fecal progesterone, estradiol-17β, pregnanediol-glucuronide (PdG), and estrone sulfate were tested for their ability to detect the ovarian activity. Using the lowest and highest progesterone values, the ovarian cycle length was comparatively analyzed. The ovarian cycle (n = 26) averaged between 31.4 ± 9.1 days (lowest progesterone) and 32.5 ± 7.5 days (highest progesterone) throughout the whole year. The length of the follicular phase, as indicated by low progesterone levels, was 18.1 ± 4.4 days (range 12-25 days), and the length of the luteal phase, as characterized by elevated progesterone levels, was 13.2 ± 1.8 days (range 11-16 days). In contrast, estradiol-17β and estrone sulfate were not suitable to detect the cycle due to irregular collection intervals. Fecal progesterone and PdG, as well as estradiol-17β and estrone sulfate, significantly correlated (r = 0.621, P < 0.01 and r = 0.606, P < 0.01). PdG concentrations (dilution factor (DF) 1:40) were considerably higher than progesterone concentrations (DF 1:10), PdG amounted in the range of 1326.7 ± 320.2 ng/g wet feces (animal S1) and 1373.8 ± 468.3 ng/g wet feces (animal S2) compared with progesterone concentrations in the range of 98.0 ± 17.0 ng/g (S1) and 105.9 ± 30.0 ng/g (S2). The estrone sulfate levels (DF 1:2) were similar to estradiol-17β (DF 1:22). The mean fecal estradiol-17β concentrations were 6.7 ± 0.9 ng/g for animal S1 and 7.5 ± 1.6 ng/g for animal S2. In conclusion, the ovarian activity of the two-toed sloth was studied using the noninvasive method by means of the fecal steroid monitoring. Progesterone was the most reliable fecal steroid hormone to determine the duration of the ovarian cycle independent of the weekly defecation rate. The course of progesterone concentrations resulted in a cycle length of 4-5 weeks length in the two-toed sloth. Thus, the reproductive activity of the two-toed sloth does not show any seasonality like the three-toed sloth.

Using non-invasive methods to characterize gonadal hormonal patterns of southern three-banded armadillos (Tolypeutes matacus) housed in North American zoos

Understanding the basic reproductive biology and limitations to successful breeding of the southern three-banded armadillo (Tolypeutes matacus) is necessary to maintain viable zoo populations. Our objectives were to: 1) describe the reproductive biology using non-invasive, fecal hormone analysis; 2) assess influence of season on gonadal hormonal patterns in both the sexes; 3) characterize reproductive cyclicity and pregnancy in the female; and 4) characterize the onset of sexual maturity in males. Nineteen armadillos were monitored including: 13 (7 males, 6 females) from Lincoln Park Zoo and six (3 males, 3 females) from San Antonio Zoological Garden. Fecal samples (n=5220; 275/animal/yr) were collected 5 to 7 times a week for 1 year. Hormones were extracted from feces and analyzed for progestagen (females) and androgen (males) metabolite concentrations using enzyme immunoassays. Mean estrous cycle length (26.4±1.3 days) did not vary (P<0.05) among individuals (n=9). Mean gestation length (n=3) was 114.0±0.6 days long with mean fecal progestagen metabolites increasing 10-fold during pregnancy. Seasons did not influence (P<0.05) fecal androgen or progestagen metabolites. These data can assist with management decisions, which will directly affect the success of this species in zoos.