The effects of saltwater intrusion on germination success of standard and alternative crops

Estimates of animal abundance provide essential information for population ecological studies. However, the recording of individuals in the field can be challenging, and accurate estimates require analytical techniques which account for imperfect detection. Here, we quantify local abundances and overall population size of Morelet’s crocodiles (Crocodylus moreletii) in the region of Calakmul (Campeche, Mexico), comparing traditional approaches for crocodylians (Minimum Population Size—MPS; King’s Visible Fraction Method—VFM) with binomial N-mixture models based on Poisson, zero-inflated Poisson (ZIP) and negative binomial (NB) distributions. A total of 191 nocturnal spotlight surveys were conducted across 40 representative locations (hydrologically highly dynamic aquatic sites locally known as aguadas) over a period of 3 years (2017–2019). Local abundance estimates revealed a median of 1 both through MPS (min–max: 0–89; first and third quartiles, Q1–Q3: 0–7) and VFM (0–112; Q1–Q3: 0–9) non-hatchling C. moreletii for each aguada, respectively. The ZIP based N-mixture approach shown overall superior confidence over Poisson and NB, and revealed a median of 6 ± 3 individuals (min = 0; max = 120 ± 18; Q1 = 0; Q3 = 18 ± 4) jointly with higher detectabilities in drying aguadas with low and intermediate vegetation cover. Extrapolating these inferences across all waterbodies in the study area yielded an estimated ~10,000 (7,000–11,000) C. moreletii present, highlighting Calakmul as an important region for this species. Because covariates enable insights into population responses to local environmental conditions, N-mixture models applied to spotlight count data result in particularly insightful estimates of crocodylian detection and abundance.

N-mixture models provide informative crocodile (Crocodylus moreletii) abundance estimates in dynamic environments

The implementation of water developments for wildlife is a common management practice in regions with seasonal water shortages. The water developments are installed to benefit species of human interest, nevertheless, they can be used by other species. In this note we report observations of small rodents visiting the water developments in a locality in the Tehuacan-Cuicatlan Biosphere Reserve. The water developments were monitored using 12 camera traps during the 2018 dry season in the locality of San Gabriel Casa Blanca, Oaxaca. We calculate the visit rate of rodents and compared it between two types of water developments. We observe 154 visits of rodents of at least four genera: Peromyscus, Liomys, Sigmodon and Dipodomys. The mean visit rate for both types of water developments was 18.8 ± 37.7 visits/100 days. We don´t find significant differences in the visits among the water development types. Using camera-traps we demonstrate the visits and use of water developments by some species of cricetids. Likewise, we suggest that the lack of ramps or concave walls in the troughs represents a risk for small species. Other studies are necessary to evaluate the effect of the water developments on the biomass, survival, abundance of rodents in dry forests.

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Uso de bebederos artificiales por pequeños roedores en un bosque tropical seco en Oaxaca, México

We aimed to evaluate the temporal and spatial use of waterholes by ocelots in Calakmul Biosphere Reserve (CBR), Mexico. From 2014 to 2017, we monitored 11 waterholes with camera traps. We compared diel activity patterns with circular statistics depending on waterholes’ level of human intensity and distance to the Calakmul road, seasonality, and sex. We identified 40 different ocelots. Four waterholes were the most important ones, being 2 of them close to the road. Individuals took on average 19 days to return to waterholes. The diel activity of ocelots was 63.67% nocturnal, 20.70% crepuscular and 15.60% diurnal, and they were more diurnal in waterholes distant from the road. Their activity pattern was bimodal and it did not change between any of the categories tested. This is the first study to determine the spatial and temporal activity of ocelots in waterholes of Mexico. Ocelots are mainly nocturnal, and this pattern is conserved throughout CBR, however, they are able to adjust slightly their activity depending on extrinsic factors, such as an increased human presence. In the Calakmul region, all waterholes are crucial, and we particularly emphasize the conservation of the most important waterholes for ocelots, especially the ones close to the road.

Waterhole use and diel activity pattern of ocelots in Calakmul rainforest, Mexico

“A record of the coyote (Carnivora: Canidae) in the Calakmul Biosphere Reserve, Mexico”. In recent years the coyote (Canis latrans) has expanded its range in the tropical areas of Mexico and Central America. We report the first record of a coyote in the Calakmul Biosphere Reserve in the southeastern, Mexico. Using photo trapping, from December 2018 to June 2019, tree photographs of coyotes were obtained from a site located in the center of the southern core area of the reserve.

Registro del coyote (Carnivora: Canidae) en la Reserva la Biosfera de Calakmul, México

Objective: To describe the use of artificial drinking fountains by the central American Agouti (Dasyprocta punctata) in the Calakmul Biosphere Reserve.
Design/methodology/approach: Eight artificial drinking fountains were monitored each one with a trap camera with the aim to estimate the relative abundance index and activity patterns of visits to the drinking fountains. The monitoring was during the dry season of 2019. The analyzes were carried out with the InfoStat and R programs.
Results: From January to May 2019, with a sampling effort of 1121 days/camera, average abundance of 160.08±85.44. The pattern of visits to the drinking troughs was mainly diurnal.
Limitations of the study/implications: The use of trap cameras in the artificial drinking fountains allows us to know the extent of habitat modification in the Calakmul Biosphere Reserve.
Findings/conclusions: The implementation of artificial drinking fountains in the RBC during the dry season was a successful action to mitigate the effects of water scarcity. The use of the water resource by the Central American Agouti in artificial drinking fountains was constant, other species of mammals and birds were also observed making use of artificial drinking fountains.

Uso de bebederos artificiales por el sereque centroamericano (Dasyprocta punctata) en la reserva de la biosfera de Calakmul, México

Panthera onca is the largest feline in America. Its diet has been studied in several countries, and reptiles have been identified as part of it. Despite being one of the most studied felines in Mexico, the depredation of P. onca towards crocodiles had not been documented with photographic evidence until now. This note documents for the first time with a photograph, a Crocodylus moreletti depredated by a P. onca, in southeastern Mexico.

http://mastozoologiamexicana.com/ojs/index.php/theryanotes/article/download/10/5

Morelet’s crocodile predation by jaguar in the Calakmul Biosphere Reserve in southeastern México

The ocelot faces conservation problems throughout its distribution, mainly due to illegal hunting and habitat transformation. It has been documented that the ocelot diet consists mainly of small nocturnal terrestrial mammals, especially rodents, although it has also been recorded that they can feed on possums, squirrels, rabbits, primates, iguanas, frogs, birds, fish, insects and terrestrial crabs.This note is relevant to the feeding behavior of ocelots in Mexico because it describes a photographic event of an ocelot feeding on a bat, the record was obtained with camera traps placed in the southern core zone of the Calakmul Biosphere Reserve. These cameras were installed to record that species of fauna visitrificiales drinkers (water sources constantly supplied by members of the project) that were placed as part of a pilot project in the years 2018 and 2019 and aim to supply water in the RBC for use of wildlife. As a result of this effort, this photographic record was obtained of an ocelot individual feeding on a bat associated with an artificial drinker.

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Registro fotográfico de un murciélago capturado por Leopardus pardalis (Carnivora: Felidae) en la Reserva de la Biosfera de Calakmul, México

Objective: We describe the use of artificial drinking fountains by the Central American agouti (Dasyprocta punctata) in the Calakmul Biosphere Reserve, Mexico. Design/methodology/approach: Eight artificial drinking fountains were monitored each one with a camera trap with the aim to estimate the relative abundance index and activity patterns of visits to the drinking fountains. The monitoring was during the dry season of 2019. The analyzes were carried out with the InfoStat and R programs. Results: From January to May 2019, with a sampling effort of 1121 days/camera, average abundance of 160.0885.44. The pattern of visits to the drinking troughs was mainly diurnal. Limitations/Implications: The water shortage in the Calakmul region limits this monitoring system, as water for drinking supply must be transported from distant distances. Findings/conclusions: The implementation of artificial drinking fountains in the RBC during the dry season was a successful action to mitigate the effects of water scarcity. The use of the water resource by the Central American agouti in artificial drinking fountains was constant, other species of mammals and birds were also observed making use of artificial

David E. Sima-Pantí

Papers

Uso de bebederos artificiales por el sereque centroamericano (Dasyprocta punctata) en la reserva de la biosfera de Calakmul, México

Morelet’s crocodile predation by jaguar in the Calakmul Biosphere Reserve in southeastern México

Registro fotográfico de un murciélago capturado por Leopardus pardalis (Carnivora: Felidae) en la Reserva de la Biosfera de Calakmul, México

Use of artificial drinking fountains by the Central American agouti (Dasyprocta punctata) in the Calakmul biosphere reserve in Mexico.

Registro del coyote (Carnivora: Canidae) en la Reserva la Biosfera de Calakmul, México