Population and Conservation Status of Bighorn Sheep in the State of Baja California, Mexico.

The bighorn sheep in Mexico is classified as at-risk by the Mexican federal government. In the state of Baja California, wild sheep can be observed throughout the length of the state from the USA-Mexico border south to the Agua de Soda mountain range. This research aimed to document the historical trend of the bighorn population based on aerial surveys conducted in 1992, 1995, 1999, 2010, and 2021, and the abundance, distribution, and structure of bighorn sheep populations in Baja California, based on an aerial survey conducted from 8-14 November 2021, covering thirteen mountain ranges. The estimated sheep population in 2021 was based on the number of individuals observed; the sightability of the animals; the area sampled; and the total area of habitat available. In 30.5 flight hours, 456 bighorn sheep were observed, with an estimated population of 1697 ± 80 individuals. The observation rate was 16 sheep sighted per hour of flight, and the ram:ewe:lamb ratio was 62:100:19. When the results of the 2021 flight were compared to the results of the previous aerial surveys, there was a large variation between the data, which was related to the lack of consistency between the sampling designs used in each study. Nevertheless, a statistical test of the results of aerial surveys conducted in the state suggest that the Baja California bighorn sheep population remained stable between 1992 and 2021. This study highlights the need to standardize wild sheep aerial surveys by defining flight paths and establishing a consistent duration of flights. On the other hand, Baja California authorities should consider modifying the current conservation strategy for bighorn sheep to increase the species' population in the state by initiating community-based wildlife conservation programs in rural communities.

Community-Based Workshops to Involve Rural Communities in Wildlife Management Case Study: Bighorn Sheep in Baja California, Mexico.

The description of natural history, and information on the factors threatening conservation, the distribution area, and the status of species population are necessary for proper wildlife management. The objective of this research was to generate such information in two rural communities and to engage residents in bighorn sheep management through a program of three workshops. The first one covered training regarding natural history and management of the species. The second one consisted in the description of the habitat of the species through a dynamic of participatory mapping. The third, include a design of a one strategy to monitor the bighorn sheep population. The workshops were attended by 37 people from the two rural communities. The results suggest the economic element was the main interest of the inhabitants regarding the bighorn sheep. Eleven risk factors were identified to the bighorn sheep in the study sites, a participatory map with relevant information for the management of the species on each community was developed, and a monitoring strategy of the bighorn sheep population was prepared. The workshop program proposed in this research is a tool that can be applied in rural communities to lay the groundwork for a long-term management project of wildlife species.

Potential distributions of the parasite Trypanosoma cruzi and its vector Dipetalogaster maxima highlight areas at risk of Chagas disease transmission in Baja California Sur, Mexico, under climate change.

Dipetalogaster maxima is a primary vector of Chagas disease in the Cape region of Baja California Sur, Mexico. The geographic distribution of D. maxima is limited to this small region of the Baja California Peninsula in Mexico. Our study aimed to construct the ecological niche models (ENMs) of this understudied vector species and the parasite responsible for Chagas disease (Trypanosoma cruzi). We modelled the ecological niches of both species under current and future climate change projections in 2050 using four Representative Concentration Pathways (RCPs): RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5. We also assessed the human population at risk of exposure to D. maxima bites, the hypothesis of ecological niche equivalency and similarity between D. maxima and T. cruzi, and finally the abundance centroid hypothesis. The ENM predicted a higher overlap between both species in the Western and Southern coastal regions of the Baja California Peninsula. The climate change scenarios predicted a Northern shift in the ecological niche of both species. Our findings suggested that the highly tourist destination of Los Cabos is a high-risk zone for Chagas disease circulation. Overall, the study provides valuable data to vector surveillance and control programs.

Infection Rate of Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) in Dipetalogaster maxima (Hemiptera: Reduviidae).

Chagas disease is caused by the infection of the parasite Trypanosoma cruzi (Chagas, 1909). Mexico is estimated to be among the countries with the highest rates of human infections. The southernmost region of the Baja California peninsula is home to the endemic, highly aggressive, and largest Triatominae vector, thus far described: Dipetalogaster maxima (Uhler 1894). Previous single-year studies have attempted to estimate the natural infection rate of T. cruzi in this species, none encompassing a multiyear sampling design nor a species-specific diagnostic tool. We report the infection rate based on more than 717 individuals examined via a PCR species-specific diagnosis. The infection rate of T. cruzi was of 4.4% (n = 5/112), 0.9% (n = 4/411), and 4.6% (n = 9/194) for 2016, 2017, and 2018, respectively, resulting in an infection rate of 2% across all sites and years (n = 18/717).

Epidemiological overview of snakebites in the Baja California peninsula, Mexico (2003-2018).

INTRODUCTION: Ophidian accident is a global public health problem. In Mexico, there is a high incidence of snakebites, which cause medical complications that can leave severe sequelae. OBJECTIVE: To analyze the epidemiological overview of snake venom poisoning in the Baja California (BC) peninsula within the 2003-2018 period. METHOD: A descriptive, retrospective analysis of reported cases was carried out, based on data collection and interpretation. RESULTS: A total of 541 records were obtained, out of which 273 occurred in BC and 268 in Baja California Sur (BCS), with an annual average of 17.06 and 16.75, respectively. The incidence rate for BC was 7.62, while for BCS it was 33.09. The highest annual incidence rate in the state of BC corresponded to southern Ensenada, with a value of 42.3, while in BCS it corresponded to the municipality of Comondú, with a value of 54.04. CONCLUSIONS: Epidemiological analyses allow a better local, state and regional understanding of the problem, in order to develop efficient action protocols to face an ophidian accident, as well as to determine the training requirements of medical personnel and establish a support network for the treatment of cases.

INTRODUCCIÓN: El accidente ofídico es un problema de salud pública mundial. En México existe una alta incidencia de mordeduras por serpientes, que provocan complicaciones médicas que pueden dejar secuelas severas. OBJETIVO: Analizar el panorama epidemiológico del ofidismo en la península de Baja California (BC) en los años 2003-2018. MÉTODO: Se hizo un análisis de tipo descriptivo y retrospectivo de los casos presentados, a partir de la recopilación e interpretación de la información. RESULTADOS: Se obtuvieron 541 registros, de los cuales 273 se presentaron en BC y 268 en Baja California Sur (BCS), con un promedio anual de 17.06 y 16.75 respectivamente. La tasa de incidencia para BC fue de 7.62 y para BCS de 33.09. La tasa de incidencia anual más alta en el Estado de BC correspondió al sur de Ensenada, con un valor de 42.3, mientras que en BCS fue en Comondú, con un valor de 54.04. CONCLUSIONES: Los análisis epidemiológicos permiten tener un mejor entendimiento local, estatal y regional de la problemática, para poder desarrollar protocolos de acción eficientes para enfrentar un accidente ofídico, así como para determinar las necesidades de capacitación del personal médico y establecer una red de ayuda para el tratamiento de casos.