The Estrous Cycle of Coyotes

摘要: The estrous cycle in coyotes (Canis latrans) is characterized by a long proestrus (2-3 months). Vaginal smear patterns associated with proestrus, estrus, and metestrus are described. Data from 41 adults indicated estrus begins about 13 March persists for 10 days. Neither onset date nor duration of differed body weight or age; however, the number corpora lutea increased age. Of 22 juveniles, 19 showed sexual activity but no more than 11 ovulated. In adults, ovulation apparently occurred as early 1st late 9th day estrus. Left right ovaries were similar lutea. J. WILDL. MANAGE. 40(2):272-277 Reproduction has not been studied extensively coyotes. Hamlett (1938) defined breeding season, estimated gestation period, provided some data on testicular ovarian changes peculiar to this seasonal breeder. Whiteman (1940) reported habits several captive was first call attention proestrum period experience. Gier (1968) information morphological physiological reproductive cycle. Kennelly (1972) described coyote spermatogenic sperm transit time epididymis. Studies dog-coyote hybrids have further limited source reproduction (Kennelly Roberts 1969, Silver Mengel 1971). here related events gathered part larger program define clearly those aspects that need be understood if populations managed rationally. Our primary objective gather describe reflected vaginal smears. examining females coyotes, we accumulated observations topics, these included. MATERIALS AND METHODS Sixty-four female either born captivity captured near San Antonio, Texas, Denver, Colorado, when 3-5 weeks age raised maintained at Denver under routine dog colony procedures. Food (Wayne Dry Dog Food) water ad libitum. Each immunized against distemper, hepatitis, leptospirosis treated parasites needed. animals housed one, two, three pen outdoor concrete-lined runs containing weatherproofed unheated shelters; illumination natural daylight only. Gross microscopic observed both juveniles (less year old) adults. Gier's (1960) technique making smears, slightly modified, used throughout study. A plastic ca heter approximately 20 cm rubber bulb one end inserted into vagina far cervix, fluid aspirated catheter 1Present address: Massachusetts Cooperative Wildlife Research Unit, University Massachusetts, Amherst 01002. 272 Wildl. Manage. 40 (2):1976 This content downloaded 207.46.13.10 Mon, 12 Sep 2016 04:35:11 UTC All use subject http://about.jstor.org/terms EsTRous CYCLE OF COYOTES " Johns 273 slowly withdrawn. When fluids insufficient, small volume saline (1.0 cc) introduced. drop sample mixed an equal aqueous solution 0.1 percent toluidine blue. After coverslips placed them, smears examined within 30 minutes 400x. Routine aseptic surgical procedures followed all operations. Pentobarbitol sodium given (I.V.) effect organs exposed through midline incision. cases extent operation incision closed; others, unilateral ovary, oviduct, uterus removed before closed. contra-lateral collected different intervals following surgery. instance, bitch killed overdose pentobarbitol (I.V.). ovary dissected free tissue, weighed, sectioned transversely razor 1.5-mm grossly determine present. oviduct cut just proximal tubo-uterine junction flushed saline; flushing medium checked low power microscope (35x) presence ova zygotes. basis defining primarily cellular pattern smear. appropriate, decisions relative augmented evidence acceptance male; copulation present