Pilar Carbó-Ramírez

Blood-meal preferences and avian malaria detection in mosquitoes (Diptera: Culicidae) captured at different land use types within a neotropical montane cloud forest matrix

Abstract Human activities modify environmental conditions, altering ecological interactions that can contribute to the increasing number of vector-borne pathogens affecting both human and wildlife populations. There is a dearth of knowledge about mosquitoes feeding preferences and their role as potential vectors of haemosporidian parasites, particularly in modified habitats. During 2013–2014 we sampled mosquitoes in five different land use types within a cloud forest matrix. From a total of 4107 adult mosquitoes, 90 were engorged. We extracted DNA from mosquito blood-meals, abdomens, and thoraxes, which belonged to seven different species. Seventeen specimens were positive for avian Plasmodium parasites. We were able to identify the blood-meal source of 10 mosquitoes, the identified vertebrate species were: Homo sapiens (Human), Sturnira hondurensis (Bat), and Bos taurus (Cow). Our results show that Culex restuans is positive for avian malaria and it is feeding on both humans and domestic animals at urban and peri-urban habitat types, where it is also an abundant species throughout the year. Furthermore, Aedes quadrivittatus, also positive for avian malaria, is feeding on humans in the well-preserved cloud forest, where this mosquito species is highly abundant. This study is the first in Mexico to provide reference data showing generalist mosquito feeding preferences and presence of avian Plasmodium at locations with different land use types.

Breeding Biology of the Rufous-backed Robin (Turdus rufopalliatus) in an Urban Area Outside its Original Distribution Range

ABSTRACT The Rufous-backed Robin (Turdus rufopalliatus) is a bird endemic to the Pacific slope of Mexico and the Balsas Basin, and is currently expanding its distribution range to the Mexican Central Highlands, occupying urban areas. Its breeding biology is poorly known in its original distribution range and unknown in the newly colonized areas. We present a description of its breeding biology in one of the newly colonized areas, including nest site selection, nest composition, clutch size, eggs and incubation period, hatching and nestling success, and observations on behavior of adults and nestlings. The study was conducted in 2013 in an urban area of central Mexico, specifically at the main campus of Universidad Autónoma del Estado de Hidalgo, in Pachuca, Hidalgo. Nests were built on trees at a mean height of 5.66 ± 0.51 m. The nest was generally a shallow cup made of vegetable material reinforced with mud. Mean clutch size was 2.75 ± 0.16. Eggs were light to medium blue with reddish-brown markings. Incubation period lasted around 13 days. Hatching success was on average 1.88 ± 0.35. Nestlings remained 14 days in the nest before they fledged. The nests, eggs, and behavior have some characteristics similar to those of other thrushes, including individuals of the same species in their original distribution range. We discuss the implications of including anthropogenic materials in nest construction and present the first case of fledgling entanglement with synthetic materials at the nest for T. rufopalliatus.

Using variation partitioning techniques to quantify the effects of invasive alien species on native urban bird assemblages

Quantifying the impacts that invasive alien species (IAS) cause on affected systems is not an easy task. Here, we explore the application of variation partitioning techniques to measure and control for the effects of possible confounding factors when studying the impact that feral pigeons, European starlings, and house sparrows cause on native urban bird communities in Mexico. We argue that these IAS are provoking a severe impact on whole assemblages of native passerines only if (a) their marginal effect is statistically significant, (b) it remains so after partialling out other explanatory variables, and (c) is larger than (or similar to) the conditional effect of these covariates. We censused passerine bird assemblages and measured habitat variables in a number of greenspaces in three replicate study areas. Then, by means of partial redundancy analyses, we decomposed the total variability in bird data as a function of IAS, physical variables and vegetation data. In one of the study areas the marginal effect of IAS on native assemblages was significant, but the conditional effect was not. We conclude that this IAS effect was confounded with other explanatory variables. In the other study areas, no (marginal or partial) significant effect was found. Without invoking interspecific competition, our results support the opportunistic hypothesis, according to which IAS can exploit ecological conditions in modern cities that native species cannot even tolerate. Finally, apart from the Precautionary Principle, we found no scientific justification to control the abundance of the three IAS in our study areas.