Free amino acid and acylcarnitine values in Ursus americanus Pallas 1780 (black bear) from Northeastern Mexico.

INTRODUCTION: Ursus americanus Pallas 1780 is the largest carnivore and the only ursid in Mexico. It is considered an endangered species in the country because its distribution and population have been reduced by up to 80% because of habitat loss or furtive hunting. These problems can lead to a diet change, which could result in metabolic disorders, such as fatty acid ß-oxidation defects or organic acid metabolism disorders. In our study, a free amino acid and acylcarnitine profile was characterized. METHODS: Peripheral blood samples were drawn from nine free-ranging black bears in a period of five months, from June to October of 2019 in Northeastern Mexico, and 12 amino acids and 30 acylcarnitines were determined and quantified. Age differences were observed in the samples through ANOVA and post-hoc Tukey test. RESULTS: Only three metabolites showed a significant difference with age: alanine (Ala) [cubs vs juvenile], free-carnitine (C0) [juvenile vs cubs] and acetylcarnitine (C2) [cubs vs adults and juvenile vs cubs]. CONCLUSION: Metabolites with variability due to age were identified, making them potential biomarkers to monitor metabolic status as early diagnosis in endangered species. This is the first study of black bear amino acid and acylcarnitine profiles, and the values found could be used as reference for free amino acid and acylcarnitine concentrations in further studies of the species.

Winter diet of Burrowing Owls in the Llano La Soledad, Galeana, Nuevo León, México.

The dietary niche breadth of the Burrowing Owl was determined (Athene cunicularia Molina, 1782) in Llano La Soledad, Galeana, Nuevo Leon in northern Mexico, by considering prey type, numerical percentage, weight, weight percentage, frequency of occurrence percentage, and IRI percentage. The study compared data from three winters (2002-2003, 2003-2004, 2004-2005) by analyzing 358 pellets, identifying 850 prey items. Invertebrates constituted 90% of prey items, which mostly included insects (85%); beetles were the most common insects found in pellets (70%). Vertebrates made up 84% of consumed weight, of which 83% were mammals. Most of the mammals were cricetid rodents (41%). Niche breadth based on the numerical and weight percentage confirmed the Burrowing Owl as a generalist species with mean values per year ranging between 0.65 and 0.82. Additionally, there was a strong association between the weight of rodent species in winter. This association was mainly driven by changes in composition and frequency of these prey species during the second winter, probably caused by high annual rainfall. The second season also showed a statistically significant narrower niche (Ro = 0.96) and the smallest overlap (0.45 vs. 0.76) among the three winters.

Great-tailed Grackles (Quiscalus mexicanus) as Biomonitors of Atmospheric Heavy Metal Pollution in Urban Areas of Monterrey, Mexico.

Heavy metals exposure has been linked to severe health problems. In Mexico, the Monterrey metropolitan area (MMA) is considered one of the most polluted industrial regions. Because birds have been used successfully as environmental biomonitors, the levels of lead, cadmium, and arsenic in feathers of Great-tailed grackles (Quiscalus mexicanus) from two sites within and one site outside the MMA were determined. One hundred birds were captured, samples were analyzed by atomic absorption spectrometry. Ciudad Universitaria had the highest mean values of lead and cadmium, 11.91 ppm d.w. and 1.66 ppm d.w., respectively. This was at least, 10- and 8-times higher than the two other sample sites. We believe that using Great-tailed grackles as bioindicators in conjunction with air pollutants sampling from meteorological stations in Monterrey City could help in making decisions when applying environmental remediation measures as well as in the selection of places for housing, school and work among others.

High Prevalence of Avian Influenza Virus Among Wild Waterbirds and Land Birds of Mexico.

Aquatic wild birds, especially waterfowl, have been long considered the main reservoirs of the avian influenza A virus; however, recent surveys have found an important prevalence of these viruses among land birds as well. Migration has been suggested as an important factor in the avian influenza virus dissemination. We aimed to estimate the prevalence of influenza A viruses in wild birds (waterbirds and land birds; resident and migratory) in eastern Mexico, where the three main North American migration flyways converge and where there was no previous information on this subject. We detected influenza with reverse transcription coupled with a PCR approach. Of the 534 birds sampled between 2010 and 2012, we detected the influenza A virus in a high proportion of birds (39%). Prevalence was particularly high in land birds (49%) when compared to aquatic birds (26%); there was no difference in overall prevalence between resident (39%) and migratory birds (39%). The high prevalence of the avian influenza virus in land birds was noteworthy in the innermost sampling areas in northern Mexico (Coahuila [82%] and Nuevo Leon [43%]).

Alta prevalencia del virus de la influenza aviar entre aves acuáticas silvestres y aves terrestres de México. Las aves silvestres acuáticas, especialmente las aves anseriformes, han sido consideradas durante mucho tiempo los principales reservorios del virus de la influenza aviar A; sin embargo, muestreos recientes también han encontrado una importante prevalencia de estos virus entre las aves terrestres. Se ha sugerido que la migración es un factor importante en la diseminación del virus de la influenza aviar. El objetivo de este estudio fue estimar la prevalencia de los virus de la influenza A en aves silvestres (aves acuáticas y terrestres; residentes y migratorias) en el este de México, donde convergen las tres rutas migratorias principales de América del Norte y donde no había información previa sobre este tema. Se detectó al virus de influenza mediante transcripción reversa acoplada a PCR. De las 534 aves muestreadas entre los años 2010 y 2012, se detectó al virus de la influenza A en una alta proporción de aves (39%). La prevalencia fue particularmente alta en las aves terrestres (49%) en comparación con las aves acuáticas (26%); no se observó diferencia en la prevalencia general entre las aves residentes (39%) y las migratorias (39%). La alta prevalencia del virus de la influenza aviar en las aves terrestres fue notable en las áreas de muestreo hacia el interior del norte de México (Coahuila [82%] y Nuevo León [43%]).

Population density of the western burrowing owl (Athene cunicularia hypugaea) in Mexican prairie dog (Cynomys mexicanus) colonies in northeastern Mexico.

BACKGROUND: The western burrowing owl (Athene cunicularia hypugaea) occurs throughout western North America in various habitats such as desert, short-grass prairie and shrub-steppe, among others, where the main threat for this species is habitat loss. Range-wide declines have prompted a need for reliable estimates of its populations in Mexico, where the size of resident and migratory populations remain unknown. RESULTS: Our objective was to estimate the abundance and density of breeding western burrowing owl populations in Mexican prairie dog (Cynomys mexicanus) colonies in two sites located within the Chihuahuan Desert ecoregion in the states of Nuevo Leon and San Luis Potosi, Mexico. Line transect surveys were conducted from February to April of 2010 and 2011. Fifty 60 ha transects were analyzed using distance sampling to estimate owl and Mexican prairie dog populations. We estimated a population of 2026 owls (95 % CI 1756-2336) in 2010 and 2015 owls (95 % CI 1573-2317) in 2011 across 50 Mexican prairie dog colonies (20,529 ha). CONCLUSIONS: The results represent the first systematic attempt to provide reliable evidence related to the size of the adult owl populations, within the largest and best preserved Mexican prairie dog colonies in Mexico.