A nationwide collapse of a priority grassland bird related to livestock conversion and intensification.

Grassland birds are among the most threatened and fastest declining terrestrial vertebrate species in Europe, principally due to agricultural intensification and transformation. The little bustard is a priority grassland bird under the European Directive (2009/147/CE) that led to the classification of a network of Special Protected Areas (SPAs) in Portugal. A third national survey carried out in 2022 reveals a worsening of an ongoing population collapse at a national scale. The population declined by 77% and 56% compared to the previous surveys in 2006 and 2016, respectively. We found that the little bustard has greatly disappeared outside SPAs, while the remaining breeding population concentrated within the protected area network is showing a steep decline at a rate of 9% a year. This decline is now twice as fast when compared to the period 2006-2016. Analysis of the variation of the breeding densities between 2006 and 2022 at 49 survey sites revealed that those that initially had higher bustard densities and shifted toward a higher proportion of cattle among the total stocking rate experienced steeper declines. Areas where the density of roads increased also experienced declines over the course of the study period. Agricultural areas converted to or dominated by beef production likely relate to low breeding success and mortality of nesting females in fodder crops. Still, major habitat conversion outside SPAs to permanent crops led to overall habitat destruction, which contributed to the species decline and range contraction. Other threats are likely acting synergistically such as fragmentation, climate change and anthropogenic mortality. The extinction of the little bustard in Portugal is expected in the short term if no conservation actions are put in place.

Iatrogenic atrial septal defect after percutaneous left atrial appendage closure: a single-center study.

There is conflicting evidence regarding the significance of iatrogenic atrial septal defects (iASDs) after transseptal puncture during percutaneous cardiac interventions. To study the clinical outcome of iASD after percutaneous left atrial appendage occlusion (LAAo). Single-center, retrospective study of 70 consecutive patients who underwent percutaneous LAAo between May 2010 and August 2017, and subsequent transesophageal echocardiography (TEE) at 1 month. The sample population was divided into two groups: A (with iASD, 22 (37%) patients) and B (no iASD, 44 (63%) patients). Procedures were guided either by TEE (36 patients (54%)) or intracardiac echocardiography (ICE) from the left atrium (30 patients (46%)). The primary end point was presence of iASD at 1 month, and secondary end points included mortality, hospital admission due to heart failure (HF), and right atrium (RA) size during follow-up. 70 patients were included in this study and the prevalence of iASD at 1 month was 37%. The use of ICE was associated with iASD (adjusted odds ratio, 3.79; 95% CI 1.27-11.34). The presence of iASD was not associated with adverse events (mortality, 15.4% vs 20.5%; P = 0.60; HF hospitalizations, 7.7% vs 13.6%, P = 0.45; and RA area, 24.8 ± 7.0 cm2 vs 22.2 ± 6.8 cm2, P = 0.192). At 1-month follow-up after LAAo, iASD was present in one third of patients, but was not associated with clinical outcomes. The use of ICE was associated with a higher risk of short-term iASD.

Influence of colony traits on ectoparasite infestation in birds breeding in mixed-species colonies.

Coloniality in birds is often associated with an increase in parasite burden, but whether the co-occurrence of several host species influences the prevalence and abundance of ectoparasites and their relationship with colony size or density remains poorly known. Here, we studied mixed-species breeding colonies formed after the provision of artificial breeding structures for restoring the lesser kestrel (Falco naumanni) population in Portugal, to investigate the influence of colony traits on ectoparasite infestation. We sampled four groups of ectoparasites (carnid flies, haematophagous mites, louse flies and chewing lice) in four hosts: lesser kestrels, European rollers (Coracias garrulus), feral pigeons (Columba livia) and spotless starlings (Sturnus unicolor). Each host species had a distinct infracommunity of ectoparasites, regardless of colony traits such as size, density or host richness. The abundance of the most common ectoparasite, Carnus hemapterus, was influenced by colony composition ­ number of nests of each host species ­ rather than by colony size or density, with its abundance being diluted with increasing numbers of less suitable hosts such as starlings. The increased contact between multiple species of hosts in breeding colonies may complexify host­parasite interactions and challenge our current knowledge on the ecological relationships between host sociality and parasitism.