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.

Potential distribution model of Ovis canadensis in northern Baja California, Mexico

Reportamos por primera vez individuos de la cotorra argentina (Myiopsitta monachus) en una colonia reproductiva en la ciudad de Torreón, Coahuila, México. observadas por primera vez en febrero de 2013. Tras las observaciones de junio de 2016, se registró un aumento importante de la población, fue evidente que su distribución se extendió a nuevas áreas dentro del campus Laguna de la Universidad Autónoma Agraria Antonio Narro. La colonia estaba establecida sobre plantas de yuca (Yucca elata), con al menos ocho entradas visibles activas, a una altura de 4 m sobre el nivel del suelo. En 2013 observamos 12 individuos en el sitio; de los cuales nueve fueron adultos y tres jóvenes, mientras que en las observaciones del 2016 detectamos 25 cotorras. A pesar de que hay una estrategia nacional para prevenir, controlar y erradicar especies exóticas invasoras en México, en la ciudad de Torreón no existe ninguna acción que controle esta especie. El área urbana donde se encuentra establecida la población de cotorras posee características y condiciones apropiadas en estructura y composición de la vegetación, según la literatura, para que continúe el crecimiento de la población.

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.