In‐house monitoring of steroid hormone metabolites in urine informs breeding management of a giant anteater (Myrmechophaga tridactyla)

Abstract

Although numbers of giant anteaters within North American facilities have been steadily increasing for the last 15 years, the population now exhibits an unstable age distribution with genetically valuable individuals nearing reproductive senescence. Contributing to this issue is the Association of Zoos and Aquariums (AZA) described lack of standardization of breeding introduction practices and high risk of female injury occurring during such pairings. This report describes the development of a successful breeding protocol at Cleveland Metroparks Zoo based on hormone monitoring and efficient communication between science and animal management teams that minimizes risk of female injury. By training a female giant anteater for urine sample and body weight data collection, staff members accurately predicted estrus, and timed breeding introductions to facilitate positive interactions between the male and female. Such training also allowed for careful monitoring of two pregnancies through parturition (169-184 days from breeding) and post-partum return to estrus (114-129 days from parturition). Urinary hormone monitoring revealed a sharp progestogen increase averaging >five-fold over basal levels (0.52 ± 0.05 ng/mg creatinine) which was sustained throughout the second half of pregnancy. Mean regular estrous cycle length (n = 14 cycles), was calculated as 46.17 ± 1.39 days, measured as days between estrogen peaks of mean concentration 2.27 ± 0.19 ng/mg creatinine. This report summarizes impressive collaborative efforts among multiple zoological departments to achieve extensive hormonal and body weight monitoring from a female giant anteater, adding valuable information on reproductive parameters, and specifics for novel hormone assay techniques.

An Investigation of Ovarian and Adrenal Hormone Activity in Post-Ovulatory Cheetahs (Acinonyx jubatus)

“…There was no evidence of matrix interference as adding diluted fecal extract to synthetic standards did not alter the amount observed (y = 0.942x − 0.141, R 2 = 0.999, p < 0.001). Normalization of hormone concentrations for variations in urine water content was done by quantitatively measuring urinary creatinine (CRT) and dividing the sample hormone values by CRT concentration, as has been described previously [ 48 , 49 ].…”

Correcting for enzyme immunoassay changes in long term monitoring studies

“…Recently, these techniques have been applied to the non-invasive monitoring of steroid hormones in wildlife for conservation and management purposes [24] . Steroid hormones are typically measured in urine and/or feces, as these samples can be collected non-invasively, and have been quantified in such matrices across a wide array of taxa, including giant anteater ( Myrmecophaga tridactyla ) [25] , blue whale ( Balaenoptera musculus ) [26] , and tiger ( Panthera tigris ) [27] . The quantification of steroid hormones has become a critical method for monitoring physiological function and responses in wildlife.…”

Spermatic profile of captive giant anteaters (Myrmecophaga tridactyla): Knowing more to preserve better

“…(Knott et al, 2013; Leiva & Marques, 2010; Shaw et al, 1987). Although reproductive senescence is not well known in the species, Amendolagine et al (2018) reports the birth of offspring from an approximate 16 years old female and the oldest known reproductive captive dams were 20–24 years old (Miranda et al, 2014). It is a solitary species in the wild, except for females with cub (Shaw et al, 1987).…”