Comparison of serum hormone levels of captive and free-living maned wolves Chrysocyon brachyurus

Abstract

Serum hormone levels were compared between captive and free-living maned wolves and seasonal variations of sex hormones were studied. Blood samples were collected from 16 male and 26 female adult animals from Brazilian zoos, and from 30 male and 24 female free-living adults to determine serum progesterone and testosterone by radioimmunoassay. Serum testosterone concentrations varied (P < 0.05) across seasons for 16 captive males, being higher in autumn (2184.7 ± 355.1 pg/mL) than in summer (1080.7 ± 205.4 pg/mL), winter (1270.1 ± 276.6 pg/mL) and spring (963.9 ± 248.1 pg/mL), although they did not differ between summer, winter and spring. Testosterone concentration of 30 free-living males differed (P < 0.05) between autumn (824.1 ± 512.2 pg/mL), winter (14.4 ± 8.0 pg/mL) and spring (151.9 ± 90.5 pg/mL). Comparison between captive and free-living animals showed no difference in autumn (P > 0.05). Sixteen captive males showed higher testosterone concentration during winter and spring compared with 30 free-living animals (P < 0.05). Progesterone concentration varied among seasons in 26 captive females (P < 0.05), being higher in autumn (15.3 ± 3.1 ng/mL) than in summer (6.6 ± 1.5 ng/mL), winter (5.3 ± 3.1 ng/mL) and spring (4.3 ± 0.7 ng/mL). Progesterone concentration of 24 free-living females varied between autumn (17.1 ± 6.0 ng/mL) and winter (1.7 ± 0.3 ng/mL) (P < 0.05), but we could not obtain data for spring or summer. No difference in progesterone levels was observed between captive and free-living females in autumn and winter.

Intraocular pressure and Schirmer tear test values in maned wolf (Chrysocyon brachyurus)

“…Several studies have been published in the literature on the habitat, behavior, anatomy and physiology of maned wolves. Work at CBMM's breeding center with maned wolves has reported the presence of urolithiasis in four animals (Fernandes & Marcolino 2007), a comparison of serum hormone levels (Maia et al 2008), seasonal aspects of male reproductive physiology 2 and aspects of reproductive physiology and stress in captivity (Spercoscki 2013).…”

Reproduction in the endangered African wild dog: Basic physiology, reproductive suppression and possible benefits of artificial insemination

“…In most seasonally breeding Canidae including maned wolves (Chrysocyon brachyurus; Velloso et al, 1998;Maia et al, 2008), red and blue foxes (Vulpes vulpes and Alopex lagopus; Farstad, 1998;Andersenberg et al, 2001) and coyotes (Canis latrans; Minter and DeLiberto, 2008), testosterone levels, testis size and semen production increase in males during the breeding season. In the African wild dog, the measurement of testosterone levels has given conflicting results Monfort et al, 1997;Johnston et al, 2007), but testis size appears to increase in the breeding season and semen could not always be collected at other times of the year (Johnston et al, 2007).…”

Adrenal activity in maned wolves is higher on farmlands and park boundaries than within protected areas

“…Although breeding pairs are known to share a large home range (averaging 50.9 km 2 ), individuals are not often seen together [17,46]. The species is facultatively monogamous and seasonally monestrous, that is, mating occurs once from March through June (autumn and part of winter) [17,27,47] when there is decreasing' daylight, rainfall and ambient temperatures. Most maned wolf births occur in winter (June through August; after a 65 day gestation), although some extend into early spring (September) [17,26].…”