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This article reports on the discovery of a complete male skull of the marsh deer in Uruguay, marking the southernmost limit of its range. The skull was found in the departments of Canelones and Maldonado and was estimated to be around 294 years old through radiocarbon dating. Genetic analysis revealed significant genetic diversity and past population dynamics of marsh deer in the region. These findings highlight the need for habitat restoration and future rewilding strategies to protect this species. [Extracted from the article]

Historical accounts documenting the presence of a species, despite several known spatial and temporal weaknesses, are useful to understand distribution patterns, to establish conservation baselines, and to develop effective conservation strategies. An article by Flueck et al. (2022), based on historical records, proposes to reinterpret the past distribution, population dynamics, and migratory behaviour of the huemul (Hippocamelus bisulcus), an endangered deer endemic of the southern Andes. Our analysis of the same historical data revealed a range of questionable interpretations of the sources. Because of this, we argue that the conservation strategies for huemul proposed by Flueck et al. (2022) may be counterproductive and even potentially harmful.

Data on the reproductive physiology of the Brazilian dwarf brocket deer (Mazama nana) is still scarce in many aspects, such as its reproductive cycle and endocrine pattern. Therefore, this study aimed to characterize the estrous cycle (length and fecal progestagen metabolites -FPM- profile) in captive females of M. nana, by non-invasive hormonal monitoring. The study was performed with females (n = 4), housed at two different facilities: 1) in a collective enclosure at the Danilo José Galafassi Municipal Zoo, in Cascavel, Paraná, Brazil, (n = 3). 2) in an individual pen at the Deer Research and Conservation Center (n = 1), from UNESP, Jaboticabal, São Paulo, Brazil. Fecal samples were collected three times a week during two complete estrous cycles, based on behavioral observations. FPM profiles were analyzed by enzyme immunoassay (EIA). The estrous cycle length was defined as the intervals between behavioral estrus observations and fecal hormonal monitoring. The mean duration (± SEM) of the estrous cycle was 23.9 ± 0.6 days, and the mean duration of behavioral estrus was 1.6 ± 0.3 days. Mean concentrations (± SEM) of FPM for the luteal phase and inter-luteal phase were 6183.0 ± 2268.7 ng/g and 754.5 ± 216.1 ng/g, respectively.

This study aimed to evaluate minimally invasive protocols for estrus synchronization in the brown brocket deer (Subulo gouazoubira). Females were submitted to Latin square design, in different treatments. All females received 0.25 mg of estradiol benzoate on the first day of treatment, concomitant with one of the following sources of progesterone: (1) DIP: an intravaginal progesterone releasing device for eight days, (2) MGA1x: once a day (in the morning) oral dose of 1 mg melengestrol acetate for eight days, (3) MGA2x: twice a day (morning and afternoon) oral doses of 0.5 mg of MGA for eight days, (4) P4LA: a single i.m. administration of 75 mg of long-acting progesterone (P4LA). Eight days after the beginning of each treatment, females received an i.m. administration of 265 µg of prostaglandin (PGF 2α ; cloprostenol). Treatment efficacy was evaluated by manifestation of behavioral estrus after treatment and concentration of fecal progesterone metabolites (FPM). The time to onset of estrus in treatment P4LA was significantly longer (180 ± 38.9 h) compared to DIP (63 ± 6.6 h), MGA1x (53 ± 14.4 h) and MGA2x (41 ± 10.1 h) (P = 0.008). According to individual baseline FPM and FPM concentration during the days after estrus, the corpus luteum formation was suggested in all females which responded to the treatments (93.75 %). Low synchrony, longer interval between PGF 2α administration and onset of estrus suggest that the P4LA dose (75 mg) is too high and not effective for S. gouazoubira. DIP, MGA 1x and MGA 2x, were effective in estrus synchronization. • First report of long-acting progesterone in a deer estrus synchronization protocol. • FPM concentrations suggest ovulation after estrus synchronization in all treatments. • Treatment MGA2x promoted great estrus synchrony similar to treatment DIP. [ABSTRACT FROM AUTHOR]

• Dietetic fiber affects fecal androgen metabolites detection. • High dietetic fiber enhances fecal androgen metabolites detection. • A rich-fiber diet increases fecal production. • Defecation rate, and passage and retention times are similar in experimental diets. Non-invasive endocrinology is an important tool for animal conservation, but its success depends on many factors (e.g. adequate hormonal extraction, diet, antibody used in the assay). Dietary fiber is one of the main sources that can lead to erroneous interpretation of the endocrine status provided by EIA analysis. This study aimed to evaluate the dietary fiber effect on the fecal androgen metabolites (FAM) detection, on the daily defecation rate and fecal production, as well as to analyze the gastrointestinal passage and retention time of the experimental diets. Eight brown brocket deer (Mazama gouazoubira) males were randomly assigned to two groups and submitted to both isocaloric and isoproteic experimental diets for 10 days, in a crossover system: low fiber percentage feed (LF, 7% fiber) and high fiber percentage feed (HF, 19% fiber). Such groups were alternated in the middle of this period, with an interval of 10 days between them. In addition, there was a five-day adaptation phase at the beginning of each diet. Fecal collection for FAM measurement was performed during 10 days of treatment, whereas, the defecation rate and fecal production were performed every two hours, for 6 days. The mean FAM level in the HF group was 5038.0 ± 1529.1 ng/g, while for LF, 2178.7 ± 824.9 ng/g (p < 0.05). The mean HF fecal production was 182.6 ± 36.2 g DM/day and 117.5 ± 12.6 g DM/day for LF (p < 0.05). There were no differences in terms of mean defecation rate, passage, and retention times between groups. The results suggest that dietary fiber affects the FAM detection, and this should be taken into consideration before conducting experiments using fecal samples as a source of reproductive hormones profiling. [ABSTRACT FROM AUTHOR]