Gray Brocket Deer Research Articles

Faecal Standing Crop with real time correction using scat detection dogs to estimate population density

Abstract Population density is fundamental information for assessing the conservation status of species and support management and conservation actions for in situ populations, but is unknown for many forest species due to their difficulty in detection. The Faecal Standing Crop (FSC) method using detection dogs is an alternative for cryptic or elusive species. An intrinsic difficulty of FSC is the ability to find faecal samples in the field and to estimate the probability of which faeces detection is influenced by degradation due to climatic conditions. Our goal was to propose a concurrent FSC parameter estimation using a scat detection dog under different climatic conditions and apply those parameters in a wild deer population. Ten faecal samples of grey brocket deer (Subulo gouazoubira) were placed weekly in a transect (24 × 1440 m) in both dry and wet seasons (12 weeks each). A scat detection dog was then employed to find experimental faecal samples to determine the FSC parameters that were subsequently used with naturally occurring faecal samples (also dog‐detected) to estimate population density. The oldest dog found samples were 21 (Dry) and seven (Wet) days after placement, resulting in dog efficiency of 22.5% (Dry) and 30% (Wet). Adjusting the model to account for efficiency and scat durability, we estimated similar, seasonal, densities of 4.51 individuals km−2 (SD = 2.21, Dry) and 5.37 individuals km−2 (SD = 3.71, Wet). Synthesis and applications: Our results demonstrate that our concurrent methodology corrected the effects of weather and habitat on FSC parameters thereby allowing for accurate population density estimation. Additionally, this method can provide reasonably precise density estimates with a logistically feasible sample size, as demonstrated by simulation. Following our recommendations, this method allows a reliable estimate of population density because it incorporates any influence of study area, dog ability and climate in faecal sample detection, providing fundamental information for the conservation of many cryptic and elusive species.

Identifying medium- and large-sized mammal species sensitive to anthropogenic impacts for monitoring in subtropical montane forests

SummaryMedium- and large-sized mammals play important roles in maintaining forest ecosystem functions, and these functions often diminish when mammal species are depleted by human activities. Understanding the sensitivity or tolerance of mammal species to human pressure and detecting species changes through monitoring programmes can inform appropriate management decisions. The objective of our study was to identify medium- and large-sized mammal species that can be included in a monitoring programme in the Southern Yungas of Argentina. We used occupancy modelling to estimate the probability of habitat use (ψ) of 13 of 25 mammal species detected by 165 camera traps placed in forests across a range of human footprint index (HFI) values. As defined by the HFI, 54% of the study area is wilderness. The probabilities of habitat use of two mammal species were significantly associated with the HFI: the lowland tapir (Tapirus terrestris; ψ = 0.33, range = 0.22–0.50) was inversely associated with HFI values, whereas the grey brocket deer (Mazama gouazoubira; ψ = 0.79, range = 0.67–0.87) was positively associated with the HFI. Monitoring the probability of habitat use of the sensitive species (lowland tapir) could help us to detect changes in areas experiencing anthropogenic impacts before they cause extirpation, whereas the high probability of the habitat use values of the tolerant species (grey brocket deer) might indicate that anthropogenic impacts are strongly influencing habitat, signalling that mitigation strategies might be warranted. The Southern Yungas retains an intact mammal fauna, and we showed that the HFI is useful for monitoring anthropogenic impacts on these mammals. There are still opportunities to develop conservation strategies to minimize threats to mammal species in the region by implementing a monitoring programme with the proposed species.

Applicability of DNA barcoding-based analyses on the diet of the gray brocket deer (Subulo gouazoubira) in xeric hillside forests

In this study, we explore the applicability of DNA barcoding, specifically targeting the chloroplast DNA (cpDNA) sequences, particularly the trnL (UAA) intron region, to analyze the diet of gray brocket deer. This approach offers improved taxonomic resolution and the ability to identify species with greater precision compared to traditional methods. The study was conducted in the "Reserva Natural Salus" in Uruguay, covering a range of vegetation types, where gray brocket deer coexist with other exotic ungulates. A local reference database of trnL (UAA) sequences was established, incorporating both GenBank data and sequences obtained from native species in the study area. Fecal samples were collected in summer and winter, and DNA was extracted and amplified for metabarcoding analysis in pooled samples for each season. For each sample 28,229 and 33,588 reads were obtained respectively, which together corresponded to 25 Operational Taxonomic Units (OTUs). The species Rubus ulmifolius and Schinus engleri were the most represented in the diet with 69.6 % of the summer reads, whereas in winter, 68.7 % of the reads corresponded only to Schinus engleri. These findings indicate that gray brocket deer consume species that have higher nutritional value, which may be linked to their capacity to thrive in young and productive ecosystems. This study demonstrates the feasibility of DNA barcoding for dietary analysis in gray brocket deer and provides valuable insights into their food habits in the "Reserva Natural Salus". Further improvements to increase the reference databases of native species and the exploration of additional genetic markers are recommended for enhanced species-level discrimination in dietary analysis studies. This methodology is promising for future research as diet studies have an impact on species management, habitat conservation and biodiversity conservation efforts.

Following the trail of the grey brocket deer (Mazama gouazoubira) in Argentina: new locality records, activity patterns and habitat use

The brown brocket deer (Mazama gouazoubira) is a species of neotropical ungulate that inhabits several countries in South America. In Argentina, it is distributed in the northern portion of the country, while historical records do not mention it in the province of Mendoza. However, in the Categorization of Mammals of Argentina (2019), the NE of Mendoza is proposed as a potential distribution area of the species. In this work we confirm the presence of the brown brocket deer in the province of Mendoza (locality of Desaguadero - RAMSAR Site), and we also evaluate its activity patterns and habitat preferences. We established 1 km2 grids in three environments: salt flats, shrublands, and forests. A camera trap (n = 38) was placed in each grid, active for 55 days between October 2022 and April 2023 for fauna survey. In addition, NDVI values (Normalized Difference Vegetation Index) were calculated from LANDSAT-8 images as an estimator of vegetation cover for each grid. We obtained 25 independent records of 11 individuals (5 males and 6 females) from a sampling effort of 51,072 hours of camera operation (2,090 night/trap = 55 night * 38 camera). The males were individually identified based on the presence of antlers, their size, dimension and texture, while the females by their body size and gestation condition. In terms of activity patterns, we observed that these animals are most active in the afternoon (16 to 19 hs) and morning (8 to 9 hs), avoiding the moments of greatest solar radiation (Rayleigh-test r = 0.99, p < 0.001). NDVI was significantly different among the three environments (Chisq = 32.98; p < 0.001), with the forest having the highest vegetation cover. Finally, generalized linear models with binomial distribution were used to evaluate the effect of vegetation on the presence of brown brocket deer. We found that the higher the NDVI value, the higher the probability of presence of the deer (z = 2.27; p < 0.05). These results expand the distribution of the species and increase the diversity of mammals for Mendoza province, which generates added value to the planning of the proposed protected area for Desaguadero in the RAMSAR site Lagunas de Guanacache, Desaguadero y del Bebedero.

Phylogenetic congruence of Plasmodium spp. and wild ungulate hosts in the Peruvian Amazon

Malaria parasites are known to infect a variety of vertebrate hosts, including ungulates. However, ungulates of Amazonia have not been investigated. We report for the first time, the presence of parasite lineages closely related to Plasmodium odocoilei clade 1 and clade 2 in free-ranging South American red-brocket deer (Mazama americana; 44.4%, 4/9) and gray-brocket deer (Mazama nemorivaga; 50.0%, 1/2). We performed PCR-based analysis of blood samples from 47 ungulates of five different species collected during subsistence hunting by an indigenous community in the Peruvian Amazon. We detected Plasmodium malariae/brasilianum lineage in a sample from red-brocket deer. However, no parasite DNA was detected in collared peccary (Pecari tajacu; 0.0%, 0/10), white-lipped peccary (Tayassu pecari; 0.0%, 0/15), and tapir (Tapirus terrestris; 0.0%, 0/11). Concordant phylogenetic analyses suggested a possible co-evolutionary relationship between the Plasmodium lineages found in American deer and their hosts.

The yellow armadillo as a potential predator of medium-sized vertebrates

Studies on the predation of vertebrates by armadillos are scarce, and most of them refer to the consumption of small reptiles and rodents, attributing the remains of larger prey to the ingestion of carrion. However, there is evidence that some species of the Chlamyphoridae family may have predatory habits, killing and consuming even larger prey. In this study, we document predation of a black-and-white tegu (Salvator merianae) and a gray brocket deer (Mazama gouazoubira) by a yellow armadillo (Euphractus sexcinctus) in the northeast of Argentina, and we review attacks and captures of other medium- to large-sized vertebrates by this armadillo. The results suggest that the yellow armadillo could play a hitherto underestimated role in the food webs of the communities of which they are a part.

Comparative studies of X chromosomes in Cervidae family

The family Cervidae is the second most diverse in the infraorder Pecora and is characterized by variability in the diploid chromosome numbers among species. X chromosomes in Cervidae evolved through complex chromosomal rearrangements of conserved segments within the chromosome, changes in centromere position, heterochromatic variation, and X-autosomal translocations. The family Cervidae consists of two subfamilies: Cervinae and Capreolinae. Here we build a detailed X chromosome map with 29 cattle bacterial artificial chromosomes of representatives of both subfamilies: reindeer (Rangifer tarandus), gray brocket deer (Mazama gouazoubira), Chinese water deer (Hydropotes inermis) (Capreolinae); black muntjac (Muntiacus crinifrons), tufted deer (Elaphodus cephalophus), sika deer (Cervus nippon) and red deer (Cervus elaphus) (Cervinae). To track chromosomal rearrangements during Cervidae evolution, we summarized new data, and compared them with available X chromosomal maps and chromosome level assemblies of other species. We demonstrate the types of rearrangements that may have underlined the variability of Cervidae X chromosomes. We detected two types of cervine X chromosome—acrocentric and submetacentric. The acrocentric type is found in three independent deer lineages (subfamily Cervinae and in two Capreolinae tribes—Odocoileini and Capreolini). We show that chromosomal rearrangements on the X-chromosome in Cervidae occur at a higher frequency than in the entire Ruminantia lineage: the rate of rearrangements is 2 per 10 million years.

Revalidation of Passalites Gloger, 1841 for the Amazon brown brocket deer P.nemorivagus (Cuvier, 1817) (Mammalia, Artiodactyla, Cervidae).

Mazamanemorivaga (Cuvier, 1817) is a gray brocket deer that inhabits the Amazon region. An assessment of previous studies revealed inconsistencies in its current taxonomic classification, suggesting the need for an update in its genus classification. A taxonomic repositioning of this species is proposed through the collection of a specimen from its type locality (French Guiana) with subsequent morphological (coloring pattern, body measurements, and craniometry), cytogenetics (G Band, C Band, conventional Giemsa, Ag-NOR staining, and BAC probe mapping), and molecular phylogenetic analysis (mitochondrial genes Cyt B of 920 bp, COI I of 658 bp, D-loop 610 bp), and comparisons with other specimens of the same taxon, as well as other Neotropical deer species. The morphological and cytogenetic differences between this and other Neotropical Cervidae confirm the taxon as a unique and valid species. The phylogenetic analysis evidenced the basal position of the M.nemorivaga specimens within the Blastocerina clade. This shows early diversification and wide divergence from the other species, suggesting that the taxon should be transferred to a different genus. A taxonomic update of the genus name is proposed through the validation of Passalites Gloger, 1841, with Passalitesnemorivagus (Cuvier, 1817) as the type species. Future research should focus on evaluating the potential existence of other species within the genus Passalites, as suggested in the literature.

Comparing GPS collar and fecal sampling using detection dogs for habitat selection analysis in brocket deer (Mazama)

Abstract Habitat use data are key to understanding species ecology and extinction risk. However, such information is lacking for the elusive deer species of Neotropical region. In this context, fecal sampling has emerged as an alternative tool, in which development and evaluation are essential to obtaining unbiased ecological data. We aimed to compare data from GPS-tracked animals and fecal sampling using scat detection dogs to evaluate the noninvasive performance of this method in habitat selection analysis. We carried out the study in the Brazilian Pantanal, where we monitored six free-living Gray Brocket Deer (Mazama gouazoubira) with GPS collars for 1 year (average of 584 GPS locations/animal) and collected fecal samples (n = 649) simultaneously along a set of transects designed for a scat detection dog survey. We evaluated habitat selection using the chi-square test in an availability/utilization analysis and submitted both data to a bootstrap procedure to assess its precision and accuracy with increasing sample size. GPS data indicated habitat selection at a fine utilization scale, in which savanna and cerrado were preferred and open grassland habitat was avoided. Exclusive fecal sampling also indicated habitat selection, revealing the preference for cerrado and avoidance of open grassland. The GPS and fecal habitat utilization estimates did not differ significantly and fecal sampling increased precision and accuracy with increased sample size, reaching minimal values once n = 200 which should be considered a sufficient survey effort. The similarity between the two methods suggested the reliability of fecal sampling, as long as a standardized sampling design is used. This noninvasive sampling framework can provide previously unavailable ecological data for threatened Neotropical deer as well as other elusive species.

Mazama gouazoubira(Cetartiodactyla: Cervidae)

AbstractMazama gouazoubira (Fischer [von Waldheim], 1814) is an ungulate commonly called gray brocket deer. Six morphological forms have been described, but it is currently considered as monotypic. It is a widespread medium-sized cervid, sexually dimorphic with males having antlers. The geographic distribution of M. gouazoubira extends from the southern Amazon region to northern Argentina and Uruguay and stretches from east of the dry Andean range in Argentina and Bolivia, to the Atlantic Coast. It is the most abundant species of brocket deer in South America. Habitat loss and hunting are considered the major threats and it is listed as “Least Concern” (LC) by the International Union for Conservation of Nature (IUCN).

Resurrection of the genus Subulo for the gray brocket deer, with designation of a neotype

Abstract The gray brocket deer, Mazama gouazoubiraG. Fischer, 1814, occurs in South America and presents an extensive degree of morphological and genetic variability. Previous phylogenetic research showed that the genus Mazama is polyphyletic and imposed the designation of a different genus-group name for M. gouazoubira. We aimed to review and clarify the taxonomy of M. gouazoubira through the proposal of updating the nomenclature for this taxon and by the characterization of specimens collected close to the original type locality (topotypes). The topotypes were characterized by morphological (general characterization and morphometry), cytogenetic (conventional staining, Ag-NOR, G- and C-banding, and fluorescence in situ hybridization), and phylogenetic (mitogenomes) approaches. We revealed chromosome homologies between cattle and M. gouazoubira using an entire set of cattle whole chromosome painting probes and propose an updated G-band idiogram for the species. The morphometric analysis did not discriminate the individuals of M. gouazoubira, including the topotypes, from other small brocket deer species. However, the phylogenetic analysis, based on a Bayesian inference tree of the mitogenomes, confirmed the polyphyly of the genus Mazama and supported the need to change the gray brocket deer genus-group name. Based on our revision, we validated the genus SubuloSmith, 1827, and fixed a type species for the genus. In the absence of the holotype, we denominated a neotype described by the collection of a male topotype in Paraguay. The nomenclature rearrangement presented here is a starting point that will assist in the taxonomic resolution of Neotropical deer.

Seminoma in a gray brocket deer (Mazama gouazoubira) with unilateral cryptorchidism

Cryptorchidism is the incomplete descent of the testes and associated structures, and cryptorchid testes are more likely to develop testicular neoplasms, such as seminoma. This is the first report of a seminoma in a cryptorchid wild-caught gray brocket deer (Mazama gouazoubira). The animal developed a unilateral seminoma with classical histopathological findings and benign behavior. Six months after the orchiectomy the cervid presented a metatarsal opened fracture, dying during the orthopedic surgery. No macro or micrometric metastasis was observed at the necropsy.

Suppurative meningoencephalitis secondary to a Trueperella pyogenes-induced mandibular abscess in a free-ranging gray brocket deer (Mazama gouazoubira)

Trueperella pyogenes is an opportunistic pathogen, most commonly affecting ruminants and pigs. A female free-ranging gray brocket deer (Mazama gouazoubira) had an abscess in the masseter muscle associated with an osteolysis and osteomyelitis in the adjacent right mandibule, with a fistulous tract to the orbit and through the optic foramen into the skull, causing a suppurative meningitis. Histologically, the abscess was characterized by a neutrophilic and histiocytic inflammatory infiltrate with myriad of Gram-positive rod-shaped bacteria, and a focally extensive suppurative and histiocytic leptomeningitis of the ventral portions of the brain. Aerobic microbiologic culture, MALDI-ToF, and PCR identified T. pyogenes.

Characterization of "Candidatus Ehrlichia Pampeana" in Haemaphysalis juxtakochi Ticks and Gray Brocket Deer (Mazama gouazoubira) from Uruguay.

Human ehrlichiosis are scantily documented in Uruguay. The aim of this study was to investigate the presence of Ehrlichia spp. in Haemaphysalis juxtakochi and in a gray brocket deer (Mazama gouazoubira) from Uruguay. The presence of Ehrlichia DNA was investigated in free-living H. juxtakochi in five localities of southeast and northeast Uruguay, as well as blood, spleen, and ticks retrieved from a M. gouazoubira. Ehrlichia spp. DNA was detected in six out of 99 tick pools from vegetation, in the spleen of M. gouazoubira, and in one out of five pools of ticks feeding on this cervid. Bayesian inference analyses for three loci (16S rRNA, dsb, and groEL) revealed the presence of a new rickettsial organism, named herein as “Candidatus Ehrlichia pampeana”. This new detected Ehrlichia is phylogenetically related to those found in ticks from Asia, as well as Ehrlichia ewingii from USA and Cameroon. Although the potential pathogenicity of “Ca. E. pampeana” for humans is currently unknown, some eco-epidemiological factors may be relevant to its possible pathogenic role, namely: (i) the phylogenetic closeness with the zoonotic agent E. ewingii, (ii) the evidence of H. juxtakochi parasitizing humans, and (iii) the importance of cervids as reservoirs for zoonotic Ehrlichia spp. The molecular detection of “Ca. E. pampeana” represents the third Ehrlichia genotype described in Uruguay.

Detection of anti-Toxoplasma gondii antibodies in wild free-living birds and mammals from the northwest region of São Paulo state, Brazil

Toxoplasmosis is a protozoonosis caused by an obligate intracellular parasite named Toxoplasma gondii, which can infect humans and a large number of homeothermic animal species with worldwide distribution. The present study aimed to detect anti T. gondii antibodies from serological samples of free living wild animals from the northwest region of São Paulo state, Brazil. Thirty-two samples (eight from birds and 24 from mammals) were analyzed by the modified agglutination test (MAT) using 5 cut-off points for birds and 25 for mammals. Seropositivity was observed in 25% (2/8) of birds, including the species Rupornis magnirostris (roadside hawk) and Caracara plancus (southern caracara), and 29.2% (7/24) animals were seropositive among mammals, including one hoary fox (Lycalopex vetulus), two maned wolves (Chrysocyon brachyurus), one black howler monkey (Alouatta caraya), two crab-eating foxes (Cerdocyon thous) and one gray brocket deer (Mazama gouazoubira). The results obtained with the present study indicate the exposure to T. gondii of free-living wild animals from the northwest region of São Paulo state and, therefore, that they probably play a role in the transmission and maintenance of T. gondii in the environment they inhabit. Thus, identification of the infection in several animal species in the region indicates the environmental contamination of the area. Studies of this nature may help to understand the importance of the prevention and control of this disease in Brazil.

Abortion in Captive Gray Brocket Deer (Mazama gouazoubira) Associated with Colloid Goiter, Hemonchosis and Necrotizing Rumenitis

Background: The gray brocket deer (Mazama gouazoubira) is a specie that shows great adaptability in different habitats and it is the most abundant deer specie in South America. The present work describes for the first time a case of abortion followed by death associated with colloid goiter, massive hemonchosis and necrotizing rumenitis in a captive female gray brocket deer. Case: A 4-year-old female gray brocket deer (M. gouazoubira) raised in captivity had a history of abortion during the last third of gestation. The animal was kept in an enclosure together with 3 other gray brockets deers, being 1 male of the same age and 2 juvenile brocket deer of approximately 1 and 2 years old. The animals were fed with concentrated used as cattle feed and dewormed annually with 1% Ivermectin. The animals' enclosure had vegetation cover formed by grasses and soil. The animals appeared healthy with no behavioral changes. The day after the stillbirth, the mother was found dead in the enclosure and sent to the animal pathology sector of the University of Vila Velha (UVV), Brazil. Necropsy revealed that thyroid lobules were highly increased in volume and histopathological findings were compatible with colloid goiter. A large number of nematodes were found in the abomasal content,totalizing 11,626 helminths, which were morphologically characterized as Haemonchus contortus. Grossly, the serous and ruminal mucosa exhibited an extensively reddish focal area with irregular contour, surface ulceration and a firm consistency. Microscopically, a severe necrotizing rumenitis was diagnosed. The liver showed pale multifocal areas on the subcapsular surface,friable to the touch which deepened when cut. Histopathological analysis revealed an accentuated multifocal panlobular coagulative necrosis, characterizing an acute liver necrosis.Discussion: Iodine is a mineral of great importance for thyroid hormones synthesis and your requirements are higher during pregnancy and lactation. Diets deficient in iodine causes a reduction in the basal activity of the hormones triiodothyronine (T3) and thyroxine (T4) and over-stimulation of the thyroid by thyroid stimulating hormone (TSH), resulting in goiter. In the present case, it is possible that the shortage of iodine in diet caused a goiter and, as a consequence, triggered the abortion. Haemonchus contortus is a pathogenic nematode of small ruminants, leading to decreased productivity and death in some cases as a result of anemia and hypoxia. The contact between domestic and wild animals, resulting in the emergence of infectious diseases and the spread of pathogens among species. In the present case, manual counting accounted for 11,626 H. contortus larvae, characterizing a massive infection and justifying the condition of severe anemia. The high parasitic load shown in this case points out this parasite's importance related to this species in captivity. In general, inflammatory lesions in the rumen are results of excessive intake of fermentable carbohydrates, which leads to a considerable decrease in ruminal pH and leads to a high proliferation of lactic acid bacteria. This lesion has been previously reported in cervids. This case of comorbidities demonstrates that failures in nutritional and health handling, may cause simultaneous multiple diseases leading to death. Preventive measures for helminth parasite control and a proper feeding management with an adequate diet must be provided in order to preserve the species in captivity. Keywords: colloid goiter, abortion, cervids, Haemonchus contortus.

The role of tayra (Eira barbara) as predator of medium and large‐sized mammals

AbstractInteractions between predators and prey affect their distributions and abundances, and these effects are of central importance in ecology. However, these interactions are difficult to observe in some free‐ranging species due to their elusive behaviour. We describe the video‐recorded observation of predation of a grey brocket deer (Mazama gouazoubira) by a tayra (Eira barbara), which is the largest prey reported for this mustelid. Additionally, we report three other wild species (Dasypus sp., Sylvilagus brasiliensis and Leontopithecus chrysopygus) predated by tayra and we present a review of tayra attacks on, and predation of, small primates and other medium and large‐sized mammal prey. Surprisingly, this mustelid is capable of predating a high diversity of species, both arboreal and terrestrial. At least 20 species were seen to be predated or attacked by tayras, which are capable of predating species with up to twice its own body weight, information which may be unknown due to its elusive behaviour. Additionally, we discuss the role of tayra in a community structure and raised the question of its potential key role as a predator species. This makes this mustelid a predator with greater prey diversity than previously thought and elucidate aspects of the natural history of trophic ecology of tayra, grey brocket deer and others elusive forest species.

Characterization of seminal parameters, sperm morphometry, micromorphology, and ultrastructure in gray brocket deer (Mazama gouazoubira, Fischer, 1814).

Populations of gray brocket deer (Mazama gouazoubira) are declining; yet, knowledge on the reproductive biology of this species remains limited. Therefore, this study aimed to describe morphology, viability, membrane integrity, mitochondrial activity, morphometry, micromorphology, and ultrastructure of the gray brocket deer sperm. Three adult male gray brocket deer were used in the study. Semen collection was performed using electroejaculation. Semen were analyzed by evaluating pH, motilities, vigor, mass movement, volume, concentration, viability, membrane integrity, mitochondrial activity, morphology, and morphometry. Micromorphology and ultrastructure of sperm were analyzed using scanning and transmission electron microscopy (SEM and TEM), respectively. There was no significant difference among males regarding on pH, motilities, vigor, mass movement, volume, concentration, viability. High values for membrane integrity, mitochondrial activity, and normal sperm were observed. The most frequent defects were simple bent tail and bowed midpiece. The head length, and width, midpiece, and tail length were 8.5, 4.4, 11.5, and 41.3 μm, respectively. SEM sperm showed paddle-shaped heads, with apical ridge and serrated band on the equatorial segment. TEM revealed the nucleus, acrosome, plasma membrane, mitochondria sheath, proximal centrioles, segmented columns, axoneme, outer dense fibers, and fibrous sheath. SEM and TEM showed the presence of some abnormalities. These results are expected to provide baseline values of diverse semen parameters, contributing toward the development of reproductive biotechnologies for gray brocket deer and, other deer species at risk of extinction.

Effects of cattle on habitat use and diel activity of large native herbivores in a South American rangeland

Cattle grazing usually has negative effects on wildlife. We studied the effects of cattle on the patterns of habitat use and diel activity of three neotropical herbivores, capybara (Hydrochoerus hydrochaeris), gray brocket (Mazama gouazoubira) and marsh deer (Blastocerus dichotomus) across the savannas of northeastern Argentina. We conducted a camera-trap survey with 234 stations in three habitat types (grasslands, forests, pine plantations) with and without cattle. We used occupancy models to evaluate the effect of cattle (presence or recording rate), season (winter vs spring-summer, and its interaction with cattle), distance to water bodies, and density of vegetation, on the probability of detection (p) of the native herbivores. We also evaluated the effect of cattle, habitat type, structural complexity of the vegetation, proportion of marshlands and forests in the landscape, season, and relative accessibility by humans, on the probability of occupancy (ψ) of these species. Using kernel density functions, we estimated the overlap in diel activity pattern of native herbivores with that of cattle, comparing this overlap between stations with and without cattle. Several variables, but not cattle, affected ψ. For marsh deer p was lower when cattle were present. For brocket, p was much lower in winter when cattle were present. For the marsh deer and the capybara, ψ increased (but in brocket decreased) with increasing cost of human access, a proxy of hunting. For capybara and brocket, ψ increased with increasing structural complexity of vegetation. Cattle were more diurnal in grasslands than in forests and plantations. Native herbivores became more nocturnal, with lesser overlap with the diel pattern of cattle, in grasslands, when cattle were present. Cattle seem to exert interference competition on the native herbivores which used less frequently areas where cattle were present and avoided being simultaneously active with grazing cattle. Livestock production should strive to mitigate the negative competitive effects of cattle on wildlife by maintaining cattle free protected areas. It should also reduce some indirect effects of this activity on the native herbivores (e.g., hunting of wildlife and frequent burning of grasslands).

Camera Trap Feasibility for Ecological Studies of Elusive Forest Deer

ABSTRACTThe difficulty in observing and capturing elusive species in the wild is one of the main reasons for the limited number of studies on such species. This knowledge gap affects the development of conservation and management plans. Hence, testing the feasibility of research tools is essential for the future use and reliability of such tools. Camera traps increasingly are used as an alternative to capturing animals for wildlife research, and to generate important data for the management and conservation of many species. We identified individual free‐ranging gray brocket deer (Mazama gouazoubira) from the Brazilian Pantanal by their natural markings. From October 2011 through September 2012, we investigated the feasibility of using camera traps for home range, habitat use, and activity period studies based on individuals with natural marks compared with the concurrent data collected from Global Positioning System (GPS) collars. Home range studies based on camera traps have limitations related to the quantity of individuals with natural marks and need for population premonitoring to detect them. The irregular performance of camera traps and lower detection probability in open habitats restricted its application in the habitat use study, especially among highly heterogeneous habitats. However, the positive correlation (r = 0.98, P < 0.001) between the frequency of photographic records and distances travelled by deer with GPS locations indicated reliable use of camera traps for research into activity periods. Camera traps can be used as an alternative to telemetry, potentially expanding the perspective and scope of noninvasive ecological studies for elusive and cryptic species. © 2020 The Wildlife Society.