Broad scale population estimates of declining species are desired for conservation efforts. However, for many secretive species including large carnivores, such estimates are often difficult. Based on published density estimates obtained through camera trapping, presence/absence data, and globally available predictive variables derived from satellite imagery, we modelled density and occurrence of a large carnivore, the jaguar, across the species’ entire range. We then combined these models in a hierarchical framework to estimate the total population. Our models indicate that potential jaguar density is best predicted by measures of primary productivity, with the highest densities in the most productive tropical habitats and a clear declining gradient with distance from the equator. Jaguar distribution, in contrast, is determined by the combined effects of human impacts and environmental factors: probability of jaguar occurrence increased with forest cover, mean temperature, and annual precipitation and declined with increases in human foot print index and human density. Probability of occurrence was also significantly higher for protected areas than outside of them. We estimated the world’s jaguar population at 173,000 (95% CI: 138,000–208,000) individuals, mostly concentrated in the Amazon Basin; elsewhere, populations tend to be small and fragmented. The high number of jaguars results from the large total area still occupied (almost 9 million km2) and low human densities (< 1 person/km2) coinciding with high primary productivity in the core area of jaguar range. Our results show the importance of protected areas for jaguar persistence. We conclude that combining modelling of density and distribution can reveal ecological patterns and processes at global scales, can provide robust estimates for use in species assessments, and can guide broad-scale conservation actions.

Density is crucial for understanding large carnivore ecology and conservation, but estimating it has proven methodologically difficult. We conducted 1 year of camera trapping to estimate jaguar (Panthera onca) density and population structure in the Los Llanos region of Venezuela on the Hato Piñero ranch, where hunting is prohibited and livestock are excluded from half of ranch lands. We identified 42 different jaguars and determined their sex, age class, and reproductive status. We estimated adult jaguar densities with spatial capture-recapture models, using sex/reproductive state and session as covariates. Models without temporal variation received more support than models that allowed variation between sessions. Males, reproductive females, and nonreproductive females differed in their density, baseline detectability, and movement. The best estimate of total adult jaguar population density was 4.44 individuals/100 km 2 . Based on reproductive female density and mean number of offspring per female, we estimated cub density at 3.23 individuals/ 100 km 2 and an overall density of 7.67 jaguars/100 km 2 . Estimated jaguar population structure was 21% males, 11% nonreproductive females, 26% reproductive females, and 42% cubs. We conclude that extending the sampling period to 1 year increases the detectability of females and cubs and makes density estimates more robust as compared to the more common short studies. Our results demonstrate that the Venezuelan Llanos represent important jaguar habitat, and further, they emphasize the importance of protected areas and hunting restrictions for carnivore conservation.

River dolphins are especially susceptible to negative human impacts. For their conservation, attempts of relocation or procreation ex situ may become important in the future to avoid their extinction. Additional knowledge and medical experiences of river dolphin management in captivity may aid such conservation efforts. The medical records and necropsy and histopathology reports on 123 captive Amazon River dolphins (Inia geoffrensis) were re-viewed. Of these 123 animals, 105 were necropsied and 70 necropsies were supported with histopathology. Eighteen animals were not necropsied. Among wild-born animals, mortality was highest in the first 2 mo immediately postcapture and transport, accounting for 32 of 123 deaths. Pneumonia and skin lesions (cutaneous and subcutaneous ulcerations and abscesses) were the most common findings, found in 44 of 105 (42%) and 38 of 105 (36%) of gross diagnoses, respectively. At least 10 of 44 cases of pneumonia diagnosed grossly included a verminous component. Cachexia, from a variety of causes, was a major gross finding in 21 animals. Fifteen animals had histologic evidence of significant renal pathology, and this was the primary cause of death in 13 cases. Hepatic pathology was found in 18 cases, and bacterial sepsis was confirmed via histology in 16 cases. Based on these findings, it may be concluded that keys to successful maintenance of this species include 1) prophylactic anthelminthic and antibiotic therapy immediately post-capture; 2) maintenance of animals in larger enclosures than in past attempts, in compatible groups, and in facilities capable of separating aggressive animals; 3) maintenance in microbiologically hygienic water quality at all times; and 4) a proactive program of preventive medicine during the immediate postcapture, quarantine, and maintenance period of captivity.

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The Amazon River dolphin Inia geoffensis is distributed throughout the Amazon and Orinoco River basins. The species is rare in captivity and as at 31 December 1996 there were only 3.0 reported to ISlS and 1.4 maintained at Valencia Aquarium, Venezuela. This paper describes the husbandry, diet and veterinary care of 14 dolphins maintained at Valencia Aquarium between 1975 and 1995, and the rearing and development of a ♀ born at the institution in 1994.

The Orinoco river dolphin Inia geoffrensis humboldtiana is included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The International Union for Conservation of Nature Red List used to categorize the Orinoco river dolphin as Vulnerable; however, it is now considered Data Deficient because current information about threats, ecology and the population are limited and out of date. The Red Book of Venezuelan Wildlife categorizes the species as ‘vulnerable’, and the Venezuelan National Biodiversity Strategy and Action Plan identifies ex situ conservation actions for threatened species. The distribution of this river dolphin in Venezuela extends from the Casiquiare canal, upper/mid‐/lower Orinoco River, tributaries, through the delta, where its populations are threatened by the deterioration of habitat, illegal hunting and accidental capture in fishing nets. Captive‐breeding programmes for cetacean river species worldwide, including the Orinoco river dolphin, have led to an increase in knowledge about reproductive parameters and biological data, which is helpful for future conservation planning. Detailed husbandry manuals and management procedures, which were insufficient at the time the data were collected, are of vital importance for the sustained survival and reproduction of this species ex situ, especially if the conservation status should change from Vulnerable to Critically Endangered. Valencia Aquarium, Venezuela, housed Orinoco river dolphins for 41 years, from 1975 onwards. In 1994 a reproductive group was established with one male and two females. Over the next 22 years (1994–2016) eight calves were born. The following report details the prenatal management, birthing events, lactation periods, and sizes, weights and survival of the young.

Given the importance of the rescue and rehabilitation of confiscated manatees from illegal traffic or accidental fishery entanglements, the handling and transport of two Antillean manatees Trichechus manatus manatus in the ‘Llanos’ of Apure state in Venezuela is described. In 1992, two ♀ calves were confiscated in the region of Arichuna in the Apure River and transported to a lagoon at the Fondo Nacional de Investigaciones Agropecuarias, Biruaca, for rehabilitation. Data about age, size, weight and haematological values were recorded. In 1994, one of the manatees was transferred to the Parque Zoologico y Botanico Bararida, Barquisimeto, in order to form a breeding pair and start a captive‐breeding programme. Successful reproduction was achieved in 2007, 2011 and 2013. In 1995, the second ♀ Antillean manatee was released into a natural environment in Santa Luisa Cattle Ranch, Apure state. The confiscation, rescue, rehabilitation and transport (by land and air) of these two ♀ Antillean manatees were carried out satisfactorily.