Populations of grassland birds that overwinter in the Chihuahuan Desert are declining more rapidly than other grassland birds, and survival during the non‐breeding season may have a strong influence on population trends of these species. Habitat loss and deterioration due to desertification may be contributing to these declines, and the winter ecology of grassland birds under these changing environmental conditions remains relatively unexplored. To fill this information gap, we estimated the survival of two grassland‐obligate sparrows, Baird's Sparrows (Ammodramus bairdii) and Grasshopper Sparrows (A. savannarum), on their wintering grounds in the Chihuahuan Desert, and investigated the role of habitat structure and weather on survival rates. We deployed radio‐transmitters on Baird's (N = 49) and Grasshopper (N = 126) sparrows near Janos, Chihuahua, and tracked birds from November to March during the winters of 2012–2013 and 2013–2014. Causes of mortality included avian predators, mammals, and possibly weather. We estimated an overall weekly winter survival probability of ŝ = 92.73% (95% CI[s] = 88.63–95.44%) for Baird's Sparrows in 2012–2013. We estimated a weekly winter survival probability of ŝ = 93.48% (95% CI[s] = 90.29–96.67%) and ŝ = 98.78% (95% CI[s] = 97.88–99.68%) for Grasshopper Sparrow in 2012–2013 and 2013–2014, respectively. Weekly winter survival was lower with colder daily minimum temperatures for both species and in areas with taller shrubs for Grasshopper Sparrows, with the shrubs potentially increasing predation risk by providing perches for Loggerhead Shrikes (Lanius ludovicianus). Our results highlight the need to maintain healthy grass structure in wintering areas to provide birds with food, protection from predators, and adequate cover from inclement weather. Our results also demonstrate that the presence of shrubs can lower winter survival, and suggest that shrub encroachment into the winter habitat of these sparrows may be an important driver of their population declines. Shrub removal could increase survival of wintering sparrows in the Chihuahuan Desert by reducing availability of perches for avian predators, thus reducing predation risk.

A major barrier to advancing ornithology is the systemic exclusion of professionals from the Global South. A recent special dossier, Advances in Neotropical Ornithology, and a shortfalls analysis therein, unintentionally followed a long-standing pattern of highlighting individuals, knowledge, and views from the Global North, while largely omitting the perspectives of people based within the Neotropics. Here, we review problems with assessing the state of Neotropical ornithology through a northern lens, including discovery narratives, incomplete (and biased) understanding of history and advances, and the promotion of agendas that, while currently popular in the north, may not fit the needs and realities of Neotropical research. We argue that future advances in Neotropical ornithology will critically depend on identifying and addressing the systemic barriers that hold back ornithologists who live and work in the Neotropics: unreliable and limited funding, exclusion from international research leadership, restricted dissemination of knowledge (e.g., through language hegemony and citation bias), and logistical barriers. Moving forward, we must examine and acknowledge the colonial roots of our discipline, and explicitly promote anticolonial research, training, and conservation agendas. We invite our colleagues within and beyond the Neotropics to join us in creating a new model of governance that establishes research priorities with vigorous partici-pation of ornithologists and other stakeholders within the Neotropical region. To include a diversity of perspectives, we must systemically address discrimination and bias rooted in the socioeconomic class system, anti-Blackness, anti-Brownness, anti-Indigeneity, misogyny, homophobia, tokenism, and ableism. Instead of seeking individual excellence and rewarding top-down leadership, institutions in the North and South can promote collective leadership. Authentic collaborations should value the perspectives of those directly involved and affected by policies. In adopting these approaches, we, ornithologists, will join a community of researchers across academia building new paradigms that can reconcile our relationships and transform science.

No abstract

ResumenEl gorrión altiplanero o de Worthen (Spizella wortheni) es endémico del altiplano mexicano y debido a su limitada distribución y tamaño poblacional es considerada una especie en peligro de extinción a nivel nacional e internacional. De manera general, las especies en peligro han estado expuestas, al menos históricamente, a una fuerte reducción en su tamaño poblacional y su diversidad genética, factores que en su conjunto aumentan el riesgo y susceptibilidad a infecciones. Por lo tanto, con el propósito de determinar dicha propensión en esta especie, analizamos la prevalencia de parásitos intestinales a partir de muestras fecales en 11 individuos, así como hemoparásitos, hematocrito y cuantificación diferencial de leucocitos a partir una muestra sanguínea. Los resultados mostraron que el 91% de los individuos presentaron por lo menos un taxón de parásitos intestinales, siendo el género Cryptosporidium (64%) el de mayor prevalencia, seguido por Eimeria (55%) y Ascaridia (9%). Sin embargo, los valores medios de oocistos/huevo por gramo de heces fecales indicaron una baja infección parasitaria. Además, no se observaron parásitos sanguíneos y el conteo de células blancas fue similar a lo previamente reportado para otras especies de la familia Emberizidae y Passerellidae.Palabras clave: Gorrión altiplanero, Spizella wortheni, peligro de extinción, parásitos fecales, hemoparásitos, conteo diferencial de leucocitos. AbstractThe Worthen's sparrow is an endemic bird of the Mexican Plateau that due to its limited distribution and population size is considered to be endangered, both nationally and globally. In general, species at risk have been, at least historically, under population size and genetic diversity reductions, which are factors that can act together to increase infections risk and susceptibility. Therefore, with the purpose to determine such propensity in this species, we analyzed the intestinal parasitic infection through fecal samples from 11 individuals, and hemoparasites, hematocrit and differential leukocyte quantification from one sample. Results indicated that 91% of the samples had one parasite taxon, with genus Cryptosporidium showing the highest prevalence (64%), followed by Eimeria (55%), and Ascaridia (9%). However, mean values of oocysts/eggs per gram indicated a low parasitic infection. We found no blood parasites, and the white blood cell counts were among reference values for other sparrow species.