Environmental and ecological factors affecting tick infestation in wild birds of the Americas.

The Americas hold the greatest bird diversity worldwide. Likewise, ectoparasite diversity is remarkable, including ticks of the Argasidae and Ixodidae families - commonly associated with birds. Considering that ticks have potential health implications for humans, animals, and ecosystems, we conducted a systematic review to evaluate the effects of bioclimatic, geographic variables, and bird species richness on tick infestation on wild birds across the Americas. We identified 72 articles that met our inclusion criteria and provided data on tick prevalence in wild birds. Using Generalized Additive Models, we assessed the effect of environmental factors, such as habitat type, climatic conditions, bird species richness, and geographic location, on tick infestation. Our findings show that most bird infestation case studies involved immature ticks, such as larvae or nymphs, while adult ticks represented only 13% of case studies. We found birds infested by ticks of the genera Amblyomma (68%), Ixodes (22%), Haemaphysalis (5%), Dermacentor (1%), and Rhipicephalus (0.8%) in twelve countries across the Americas. Our findings revealed that temperature variation and bird species richness were negatively associated with tick infestation, which also varied with geographic location, increasing in mid-latitudes but declining in extreme latitudes. Our results highlight the importance of understanding how environmental and bird community factors influence tick infestation in wild birds across the Americas and the dynamics of tick-borne diseases and their impact on biodiversity.

Ticks (Acari: Ixodidae) on resident and migratory wild birds in Orinoquia region, Colombia.

Several species of hard ticks, including those of the genera Ixodes, Haemaphysalis, Amblyomma, and Rhipicephalus, are of medical and veterinary importance and have been reported in association with Neotropical wild birds. Colombia, known for its great bird diversity, has 57 confirmed tick species. However, there are few studies on the association between wild birds and ticks in Colombia. The Orinoquia region, a migratory center in Colombia, provides a unique opportunity to study wild bird-tick associations and their implications for tick-borne disease dynamics. Our study, conducted between October and December 2021, aimed to identify hard ticks infesting resident and migratory wild birds in the department of Arauca and to assess the presence of bacteria from the genera Anaplasma, Borrelia, Ehrlichia, Rickettsia, and piroplasms. A total of 383 birds were examined, of which 21 were infested. We collected 147 ticks, including Amblyomma dissimile (larvae), Amblyomma longirostre (nymphs), Amblyomma mixtum (adults), and Amblyomma nodosum (larvae and nymphs). We did not detect bacterial DNA in the tested ticks; however, piroplasm DNA was detected in ticks from three of the infested birds. Of the 21 bird-tick associations, six are new to the Americas, and interesting documentation of piroplasm DNA in A. longirostre, A. nodosum, and A. dissimile ticks from wild birds in the region. This study provides valuable insights into the ticks associated with wild birds and their role in the dispersal of ticks and pathogens in Colombia, enhancing our understanding of tick life cycles and tick-borne disease dynamics.

Infestation, histology, and molecular confirmation of Sarcoptes scabiei in an Andean porcupine (Coendou quichua) from the Central Andes of Colombia.

Sarcoptic mange is a highly contagious, worldwide disease that affects the skin of mammals, including humans. It is caused by the mite Sarcoptes scabiei, however, the information available in wild mammal populations in the world, and particularly in Colombia is limited. Here, we document a new case of sarcoptic mange in an Andean porcupine (Coendou quichua) from the Andean region of Colombia. We morphologically and molecularly confirmed the mite as S. scabiei and documented the histopathology associated with scabies, and show the different stages of the life cycle of S. scabiei from the Andean porcupine skin samples. Our review of reports of additional cases of scabies in wild mammal species in South America showed 15 species, mostly carnivores, artiodactyls, and rodents. Considering the limited information in Colombia, it is urgent to evaluate the risk of this condition on mammals which would contribute to the epidemiological knowledge and the potential implications of sarcoptic mange in the ecology and conservation of wild mammals in the country.

Breeding biology in a population of Rufous-collared Sparrow (Zonotrichia capensis, Statius Müller, 1776) at different elevations in the Tropical Andes / Biología reproductiva en una población de Gorrión Copetón (Zonotrichia capensis, Statius Müller, 1776) a diferente elevación en los Andes tropicales

Abstract: Breeding biology in a population of Rufous-collared Sparrow (Zonotrichia capensis, Statius Müller, 1776) at different elevations in the Tropical Andes. Elevation strongly influences the evolution of life history traits associated with bird physiology and reproduction. Since life history traits in birds are modulated by environmental factors that vary with elevation, we expected to find changes in breeding biology traits of Z. capensis at different elevations. In this study, we compared the breeding biology (clutch size, egg volume, and reproductive activity) of a non-migratory population of Z. capensis in two localities at different elevations (low and high elevations, 1 800 m a.s.l., and 3 800 m a.s.l., respectively) and same latitude in the Colombian Tropical Andes for a one-year period. We found no differences in clutch size between the localities; however, egg volume was higher at high elevation. Furthermore, the reproductive activity differed significantly between localities. We propose that clutch size is likely conserved throughout the altitudinal distribution of Z. capensis since the species evolved in Tropical lowlands. On the other hand, the larger egg volume at high elevation could obey local environmental factors that may favor the reproductive success of the population.

Resumen: Biología reproductiva en una población de Gorrión Copetón (Zonotrichia capensis, Statius Müller, 1776) a diferente elevación en los Andes tropicales. La elevación influye fuertemente en la evolución de los rasgos de historia de vida asociados con la fisiología y reproducción de las aves. Dado que los rasgos de historia de vida en las aves están modulados por factores ambientales que varían con la elevación, esperábamos encontrar cambios en los rasgos de la biología reproductiva de Z. capensis a diferentes elevaciones. En este estudio, comparamos la biología reproductiva (tamaño de puesta, volumen del huevo y actividad reproductiva) de una población no migratoria de Z. capensis en dos localidades a diferente elevación (elevación baja 1 800 m snm, y elevación alta 3 800 m snm,) y a la misma latitud en los Andes tropicales colombianos por un período de un año. No encontramos diferencias en el tamaño de puesta entre las localidades; sin embargo, el volumen del huevo fue mayor en elevación alta. Además, la actividad reproductiva difirió entre las localidades. Proponemos que el tamaño de puesta probablemente se conserve en toda la distribución altitudinal de Z. capensis, ya que la especie evolucionó en las tierras bajas tropicales. Por otro lado, el mayor volumen del huevo a elevación alta podría obedecer a factores ambientales locales que pueden favorecer el éxito reproductivo de la población.

A morphological, reproductive, and molt phenology database for 379 bird species from the Colombian Tropical Andes.

The Colombian Tropical Andes are one of the regions with highest bird diversity on Earth. However, information on bird morphology, reproductive phenology, and molt is particularly scarce in this region. Also, this region is heavily impacted by deforestation, and it is vulnerable to climate change. Hence, providing baseline information on life history and morphological traits will be essential to support future research on functional diversity, climate change effects, conservation, evolution, and phenology. To fill this gap, we have compiled information on bird distribution, morphology, molt, and reproductive phenology at 52 localities of the Department of Caldas, covering an elevation range between 148 and 3845 m. This compilation comprises a wide range of habitats, including native forests, forestry plantations, croplands, and paramo. Our database presents information for 3,398 records belonging to 379 bird species (representing 23 orders, 53 families, and 258 genera). From those records, 2,843 correspond to information collected in the field between 2008 and 2019, and the remaining 555 records correspond to specimens deposited in the Natural History Museum of the Caldas University, collected between 1969 and 2014. We measured nine morphological traits from all specimens: total culmen, gape, bill width, bill depth, tarsus, wing length, tail length, total length, and mass. We also have reproductive condition information for 257 species and molt information available for 378 species. The information contained in this data set represents ~20% of the Colombian avifauna and ~11% of the bird species richness in South America. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA).

Morphological differences in a population of Rufous-collared Sparrow (Zonotrichia capensis, Statius Müller, 1776) (Passerine, Emberizidae) at different elevations in the Tropical Andes / Diferencias morfologicas en una poblacion de Copetón (Zonotrichia capensis, Emberizidae) a diferente altitud en los Andes tropicales

Abstract Populations that breed along steep elevation gradients show diverse physiological and morphological changes in response to the different environmental conditions. The latter has been discussed by Bergmann's and Allen's ecogeographic rules about body and appendage sizes and environmental temperature. We compared morphometric measures (mass, bill width, tarsus, wing, and tail length) of a Zonotrichia capensis population in two localities at different elevations with similar latitudes and photoperiods on the western slope of the Colombian Central Andes. We compared a Low Elevation locality (LE) at 1800 m a.s.l. and a High Elevation locality (HE) at 3853 m a.s.l. that have approximate wind speeds of 1.3 m/s and 8.4 m/s, respectively. During 12 months of sampling, we captured 46 adults using mist-nets; 26 in the LE and 20 in the HE. Each individual was sexed using molecular techniques at the Laboratory of Genetics of the Department of Biological Sciences of Universidad de Caldas. Individuals (males + females) from the HE had longer wings and tails than those from the LE (F1,44 = 5.93; P = 0.019). Also, wings of males in the HE were longer than those of females in both localities and tails of males in the HE were longer than those of LE males. Our results did not agree with what was expected according to Allen's and Bergmann's ecogeographic rules. Longer wings and tails increase sustainment, maneuverability, and balance in low atmospheric pressures and strong air currents and these conditions are found at high elevation habitats. Most likely, the longer wings found for HE males allow greater movement during territorial behavior. Further, these differences in morphological traits along elevational gradients could result from micro-evolutionary changes between localities or phenotypic plasticity of individuals exposed to different environmental conditions.

Resumen Las poblaciones que se reproducen en gradientes altitudinales, adoptan diversos cambios morfológicos para afrontar las condiciones ambientales. En el presente estudio se compararon las medidas morfológicas (peso corporal, longitud del tarso, ala, cola y culmen) de una población de Zonotrichia capensis, a diferente altitud en los Andes colombianos. Las localidades de tierra baja (TB) y alta (TA) se encuentran a 1800 m.s.n.m. y 3853 m.s.n.m., con velocidad aproximada del viento de 1.3 m/s y 8.4 m/s, respectivamente. Durante 12 meses se realizó la captura de 46 individuos (TB n=26, TA n=20) para la medición de los rasgos morfológicos. La longitud del ala de los individuos de TA fue mayor que en TB. Así mismo, en machos de TA la longitud del ala fue mayor que en hembras en general. Es posible que a las más grandes incrementen la eficiencia del vuelo en zonas ventosas y con baja presión atmosférica, como ocurre en TA. Probablemente la diferencia del tamaño del ala entre los machos de TA y las hembras, se deba a un mayor desplazamiento dentro de la conducta territorial. Estas diferencias podrían ser el resultado de cambios microevolutivos entre localidades o la plasticidad fenotípica de individuos expuestos a diferentes condiciones ambientales.