The research was conducted at Vale Natural Reserve, a 22,711-hectare protected area between the municipalities of Linhares and Jaguaré in northern Espírito Santo. The reserve forms part of the Linhares-Sooretama Forest Block, which covers more than 53,000 hectares and represents about 11% of the forest remaining in the state. Most of Vale Natural Reserve consists of dense lowland forest on flat terrain, classified as perennial seasonal forest. The landscape also includes a locally named sandy-soil forest type called Mussununga, native grasslands, flooded swamps and areas affected by human uses. The climate is tropical with a dry winter, with a mean annual temperature of 24.3 °C and mean annual rainfall of 1,214 millimetres, although rainfall varied considerably among years.

Researchers collected data at eight ocelot latrines distributed across the reserve. These sites were identified through active searches and characterized by the repeated accumulation of feces and urine in the same location. One Bushnell Trophy Cam HD Agressor digital camera trap was installed on a tree stem facing each latrine. The cameras operated continuously for 24 hours a day from March 2018 to February 2019. At each trigger, they recorded two photographs and a 20-second video, with a 10-second interval between consecutive capture events. The design concentrated observations on sites that ocelots used for scent marking and that the source identifies as places of direct and indirect interaction within and between the sexes.

Ocelots were identified individually from their distinctive coat patterns, including spots and stripes. External sexual characteristics visible in males, together with relative body size, allowed the researchers to classify individuals by sex and age category. The records included eight adult males, 12 adult females and two cubs whose sex was not determined. Both flanks were recorded for six adult males, while only the right flank was available for two; all adult females were recorded on both flanks. Adult males appeared at every latrine, whereas females appeared at all but one. Seven of the eight latrines registered individuals of both sexes, and the two cubs were recorded at one of the eight sites.

Repeated detections at multiple latrines distinguished the spatial records of males from those of females. Six of the eight adult males were recorded at more than one latrine, and three males were each recorded at three sites, qualifying them for home-range estimation. All adult females were recorded at only one site, including the female observed with her two cubs. Males also shared latrines more frequently: the mean number of males recorded per latrine was 2.1, compared with 1.5 females, and five latrines contained more males than females. The observed adult sex ratio was 1.0 male to 1.5 females, unlike an earlier survey at the same reserve that registered more males. The authors suggested that the difference may partly reflect sampling design, because latrines are used for interactions and may have favored the recording of females, but the study did not directly establish the population’s true sex ratio.

Home-range size was estimated in two ways so the results could be compared with published studies that used different analytical approaches. The 100% minimum convex polygon, abbreviated MCP, produced estimates of 6.19 square kilometres for male Lp26, 20.76 square kilometres for Lp44 and 9.28 square kilometres for Lp65. The 95% adaptive kernel density estimator, abbreviated 95%K and calculated with a standard biweight or quartic kernel, produced respective estimates of 10.10, 10.83 and 38.92 square kilometres. The mean 95%K estimate was 1.6 times the mean MCP estimate. The 38.92-square-kilometre kernel estimate for Lp65 was also the largest individual value, showing that the range across the three males and the two methods extended from 6.19 to 38.92 square kilometres rather than being confined to the narrower interval between the smallest and largest polygon estimates.

Vale Natural Reserve’s estimates fell within the range reported for ocelots elsewhere. The source describes published home ranges across the species’ distribution as varying from 2 to 39 square kilometres and cites a meta-analysis with a species-wide mean of 17.4 ± 3.7 square kilometres and a male mean of 20.7 ± 6.1 square kilometres. Previous Atlantic Forest studies using MCP produced mean male estimates of 7.5 ± 4.8 square kilometres in Caraguatá Ecological Reserve in Santa Catarina, 13.4 ± 8.0 square kilometres in the Green Corridor of Misiones in Argentina, and 32.9 ± 10.9 square kilometres in Iguaçu National Park in Paraná. One previous study using 95%K reported a male mean of 45.2 ± 4.9 square kilometres at Iguaçu National Park. The Vale polygon estimate was near the middle of the MCP values reported for the biome, while its kernel estimate was almost half the previously reported kernel mean for male ocelots in Atlantic Forest.

Home-range estimates can vary with sex, age, population density, season, food availability and habitat conditions, but the present study did not measure all of these variables directly. The authors placed the perennial seasonal forest at Vale Natural Reserve between dense ombrophilous forest and dense subtropical semideciduous forest in a vegetation gradient, noting that the reserve’s polygon estimate was intermediate between the lower values reported for ombrophilous forest and the higher value reported for semideciduous forest. They suggested that vegetation structure could affect productivity and prey availability, with smaller ranges potentially associated with greater food availability. That interpretation was based on the reserve’s result together with published values from other sites; the study did not measure prey abundance or establish a general inverse relationship between food availability and ocelot home-range size.

Behavioral interpretations were likewise presented in the context of previous ocelot research. The broader overlap among male records and the lower overlap among female records were consistent with studies in which males occupy larger ranges, although access to females can also influence male movement. The authors cited observations that pregnant and lactating females may increase patrolling and scent marking, potentially making them less tolerant of territorial overlap with other females. Relaxed territoriality among familiar females outside breeding periods, or possible family relationships, were proposed as possible explanations for four adult females using the same latrine, including the female with cubs. These explanations were not tested directly, so they remain interpretations rather than measured causes of the observed distribution.

The study’s central contribution is a paired set of home-range estimates for three adult male ocelots in Lowland Atlantic Forest, accompanied by population and spatial records for 22 identified animals at eight latrines. Its limitations are substantial: only males appearing at more than two latrines received range estimates, the sample comprised three individuals, and the eight monitoring points did not cover the full landscape available to them. The authors therefore described the calculated areas as portions of the total ranges used by the males. Within that scope, the results show that estimates from the same three animals varied markedly with method and place Vale Natural Reserve within the range of previously published ocelot home-range measurements. They also identify latrines as effective monitoring locations for gathering information on ocelot population and spatial ecology, providing reference values for this reserve, the wider Linhares-Sooretama block and comparable lowland forest.

Subject of Research: Camera-trap estimation of male ocelot home ranges in southeastern Brazil’s Lowland Atlantic Forest

Article Title: Ocelot, Leopardus pardalis ( Mammalia , Carnivora , Felidae ), home range in the Lowland Atlantic Forest of Southeastern Brazil

Article References: Magalhães, L. M., & Srbek-Araujo, A. C. (2022). Ocelot, Leopardus pardalis (Mammalia, Carnivora, Felidae), home range in the Lowland Atlantic Forest of Southeastern Brazil. Neotropical Biology and Conservation, 17(4), 229-237. https://doi.org/10.3897/neotropical.17.e93828

Image Credits: AI Generated

DOI: 10.3897/neotropical.17.e93828

Keywords: ocelot, Leopardus pardalis, home range, camera traps, Atlantic Forest, spatial ecology, wildlife monitoring, Espírito Santo, latrines, kernel density estimation, Leopardus, pardalis

The scale of the prostate cancer problem in Brazil is considerable. According to estimates from the country’s National Cancer Institute, prostate cancer is the most frequently diagnosed malignancy among Brazilian men when non-melanoma skin cancers are excluded, with nearly 78,000 new cases expected annually in the coming years. Globally, roughly 1.4 million new cases and more than 375,000 deaths were estimated in 2020, ranking prostate cancer as the second most frequently diagnosed cancer and the fifth leading cause of cancer death among men. Yet while high-income countries have accumulated extensive survival data, low- and middle-income countries such as Brazil have historically lacked robust, registry-based studies linking patient characteristics to long-term outcomes, a gap the new research set out to close.

To build the cohort, the team tapped the Hospital Cancer Registry of Espírito Santo, an institutional system recognized by the International Agency for Research on Cancer, and linked its records with the national Mortality Information System. Record linkage relied on key identifying variables including patient name, mother’s name, date of birth, sex and municipality of residence, with phonetic Soundex encoding applied to name fields to improve matching accuracy. Only records showing exact agreement across the selected identifiers were retained, and every matched pair was manually reviewed using complementary information such as residential address and dates of diagnosis and death. Patients were followed from diagnosis until death from any cause or administrative censoring at the end of 2021, producing a follow-up window that spans more than two decades of clinical care.

The demographic and clinical profile of the cohort reveals much about the population the Brazilian public health system serves. The average age at diagnosis was 69.2 years, and 70.39 percent of patients were 65 or older. Nearly two-thirds of the men identified as non-White, 65.92 percent were married, and almost two-thirds had no formal education or only basic schooling. The overwhelming majority of tumors, 98.52 percent, were adenocarcinomas, and 91.65 percent of patients had no distant metastases at diagnosis. First treatments were distributed across surgery in 23.71 percent of cases, hormone therapy in 21.97 percent, radiotherapy in 19.47 percent and combined radiotherapy and hormone therapy in 15.15 percent. By the end of follow-up, 18.34 percent of patients had died from prostate cancer and 21.14 percent had died from other causes, a pattern that underscores the importance of accounting for competing causes of death in elderly cancer populations.

Methodologically, the study is notable for the care with which it separates two distinct statistical questions. Because many of these older patients died of causes unrelated to their cancer, the researchers used cause-specific Cox proportional hazards models to estimate the instantaneous hazard of prostate cancer death among men who remained at risk, rather than the competing-risk Fine–Gray framework the same team had previously applied to this cohort. The authors emphasize that the two approaches answer complementary questions: Fine–Gray models estimate the cumulative probability of cancer-specific death in the presence of competing mortality, while cause-specific Cox models are better suited to etiological inference and the identification of prognostic determinants. Kaplan–Meier curves, which treated other-cause deaths as censored observations, were used only descriptively, since they can overestimate cumulative cancer-specific mortality when competing events are frequent.

The univariate survival analyses told a striking story. Five-year prostate cancer-specific survival fell from 92.3 percent in men diagnosed before age 65 to 85.7 percent in those diagnosed at 65 or older. Survival dropped steeply with advancing tumor stage, from 96.5 percent for stage I disease to just 49.9 percent for stage IV, and the presence of distant metastases cut five-year survival to 42.5 percent, less than half the 91.7 percent seen in patients without metastatic spread. Patients who underwent surgery or radiotherapy as initial treatment showed five-year survival above 95 percent, while those receiving hormone therapy had markedly lower survival at 77.4 percent. Education also mattered: men with no formal education had five-year survival of 83.4 percent, compared with 90.7 percent among those with middle or high education.

When the researchers adjusted for multiple factors simultaneously in a multivariable Cox model restricted to 6,481 patients with complete data, several independent predictors of prostate cancer-specific mortality emerged. Each additional decade of age at diagnosis raised the hazard of prostate cancer death by 14 percent. Education showed a clear protective gradient, with basic education associated with an 18 percent lower risk and middle or high education a 36 percent lower risk compared with no formal schooling. Patients referred from private or insurance-based services rather than the public Unified Health System had a modestly higher risk of prostate cancer-specific death, a finding the authors note warrants careful interpretation. Surgery was associated with a substantially lower hazard of death, while hormone therapy was associated with nearly double the risk.

The authors are careful to caution that the treatment associations should not be read as causal effects. In real-world oncology, patients selected for surgery or radiotherapy typically have localized disease and preserved functional status, whereas hormone therapy is generally reserved for more advanced disease. This confounding by indication is compounded in the study by a substantial proportion of missing data: TNM staging was absent for 48.92 percent of records and disease status after first treatment was missing for 51.71 percent, which prevented these key severity variables from entering the adjusted models. A sensitivity analysis comparing the complete-case sample with excluded patients, using standardized mean differences, found negligible imbalance for core variables such as age, race, marital status and metastasis status, suggesting the complete-case analysis was unlikely to have introduced major selection bias, though residual confounding cannot be excluded.

The findings carry clear public health implications for Brazil and other middle-income countries. Lower educational attainment is associated with delayed diagnosis and treatment, reduced chances of cure and higher mortality, likely reflecting gaps in health information, access and understanding of symptoms. The study’s authors argue that strengthening early diagnosis, reducing social inequalities in access to care and improving the quality and completeness of clinical data in cancer registries are essential steps toward better outcomes. They also highlight the value of applying complementary statistical frameworks to the same population, noting that competing-risk models support population-level risk prediction while cause-specific models illuminate etiological relationships. Together, the two analyses of the Espírito Santo cohort offer a more complete picture of prostate cancer prognosis in Brazil than either method alone, and provide a template for how registry-linked data can drive evidence-based cancer policy in resource-constrained settings.

Subject of Research: Prognostic factors for prostate cancer-specific survival and mortality in a large retrospective Brazilian cohort

Article Title: Survival and Mortality Predictors in Prostate Cancer: A Retrospective Cohort of 10 556 Brazilian Patients

Article References: Grippa, W. R., Dell'Antonio, L. S., Dell'Antônio, C. S., Salaroli, L. B., & Lopes‐Júnior, L. C. (2026). Survival and Mortality Predictors in Prostate Cancer: A Retrospective Cohort of 10 556 Brazilian Patients. Cancer Reports, 9(9), Article e70667. https://doi.org/10.1002/cnr2.70667

Image Credits: AI Generated

DOI: 10.1002/cnr2.70667

Keywords: prostate cancer, survival analysis, Brazil, cancer registry, Cox regression, competing risks, health inequalities, hormone therapy, education level, mortality predictors, Espírito Santo, oncology