Matching times of leading and following suggest cooperation through direct reciprocity during V-formation flight in ibis

One conspicuous feature of several larger bird species is their annual migration in V-shaped or echelon formation. When birds are flying in these formations, energy savings can be achieved by using the aerodynamic up-wash produced by the preceding bird. As the leading bird in a formation cannot profit from this up-wash, a social dilemma arises around the question of who is going to fly in front? To investigate how this dilemma is solved, we studied the flight behavior of a flock of juvenile Northern bald ibis (Geronticus eremita) during a human-guided autumn migration. We could show that the amount of time a bird is leading a formation is strongly correlated with the time it can itself profit from flying in the wake of another bird. On the dyadic level, birds match the time they spend in the wake of each other by frequent pairwise switches of the leading position. Taken together, these results suggest that bald ibis cooperate by directly taking turns in leading a formation. On the proximate level, we propose that it is mainly the high number of iterations and the immediacy of reciprocation opportunities that favor direct reciprocation. Finally, we found evidence that the animals' propensity to reciprocate in leading has a substantial influence on the size and cohesion of the flight formations

Transapical mitral valve implantation for treatment of symptomatic mitral valve disease: a real-world multicentre experience.

AIMS Transcatheter mitral valve implantation (TMVI) is a new treatment option for patients with symptomatic mitral valve (MV) disease. Real-world data have not yet been reported. This study aimed to assess procedural and 30-day outcomes of TMVI in a real-world patient cohort. METHOD AND RESULTS All consecutive patients undergoing implantation of a transapically delivered self-expanding valve at 26 European centres from January 2020 to April 2021 were included in this retrospective observational registry. Among 108 surgical high-risk patients included (43% female, mean age 75 ± 7 years, mean STS-PROM 7.2 ± 5.3%), 25% was treated for an off-label indication (e.g. previous MV intervention or surgery, mitral stenosis, mitral annular calcification). Patients were highly symptomatic (New York Heart Association [NYHA] functional class III/IV in 86%) and mitral regurgitation (MR) was graded 3+/4+ in 95% (38% primary, 37% secondary, and 25% mixed aetiology). Technical success rate was 96%, and MR reduction to ≤1+ was achieved in all patients with successful implantation. There were two procedural deaths and 30-day all-cause mortality was 12%. At early clinical follow-up, MR reduction was sustained and there were significant reductions of pulmonary pressure (systolic pulmonary artery pressure 52 vs. 42 mmHg, p < 0.001), and tricuspid regurgitation severity (p = 0.013). Heart failure symptoms improved significantly (73% in NYHA class I/II, p < 0.001). Procedural success rate according to MVARC criteria was 80% and was not different in patients treated for an off-label indication (74% vs. 81% for off- vs. on-label, p = 0.41). CONCLUSION In a real-world patient population, TMVI has a high technical and procedural success rate with efficient and durable MR reduction and symptomatic improvement

A new species of the genus Aulobia Kethley (Acariformes: Syringophilidae) parasitizing Daphoenositta chrysoptera (Passeriformes: Neosittidae) in Australia

International audienceThe small passerine family Neosittidae has never been checked under the presence of ectoparasitic mites of the family Syringophilidae (Acariformes: Prostigmata). Herein, we describe a new species, Aulobia sittellae n. sp., collected from the Varied Sittella Daphoenositta chrysoptera (Latham). In addition to the first record of the syringophilid mites on a host representative of the family Neosittidae, it is also the first record of the genus Aulobia in the Australian region. Additionally, a key to all described Aulobia species is constructed, and the genus distribution on the hosts is briefly discussed

Host-Parasite Relationships of Quill Mites (Syringophilidae) and Parrots (Psittaciformes)

The family Syringophilidae (Acari: Prostigmata) includes obligatory ectoparasites, which occupy feather quills from various parts of avian plumage, where they feed and reproduce. Our study was concerned with the global fauna of syringophilid mites associated with Psittaciformes, as well as host-parasite specificity and evolution. We assumed that the system composed of quill mites and parrots represents a model group that can be used in a broader study of the relationships between parasites and hosts. In total, we examined 1524 host individuals of parrots belonging to 195 species, 73 genera, and 4 families (which constitute ca. 50% of global parrot fauna) from all zoogeographical regions where Psittaciformes occur. Among them, 89 individuals representing 81 species have been infested by quill mites belonging to 45 species and 8 genera. The prevalence of host infestations by syringophilid mites varied from 2.8% to 100% (95% confidence interval (CI Sterne method) = 0.1–100). We applied a bipartite analysis to determine the parasite-host interaction, network indices, and host specificity at the species and whole network levels. The Syringophilidae-Psittaciformes network was composed of 24 mite species and 47 host species. The bipartite network was characterized by a high network level specialization H2′ = 0.98, connectance C = 0.89, and high modularity Q = 0.90, with 23 modules, but low nestedness N = 0.0333. Moreover, we reconstructed the phylogeny of the quill mites on the generic level, and this analysis shows two distinct clades: Psittaciphilus (Peristerophila + Terratosyringophilus) (among Syringophilinae subfamily) and Lawrencipicobia (Pipicobia + Rafapicobia) (among Picobiinae). Finally, the distributions and host-parasite relationships in the system composed of syringophilid mites and parrots are discussed

The Occurrence of Quill Mites (Arachnida: Acariformes: Syringophilidae) on Bee-Eaters (Aves: Coraciiformes: Meropidae: Merops) of Two Sister Clades

We studied the quill mite fauna of the family Syringophilidae, associated with bee-eaters. We examined 273 bird specimens belonging to nine closely related species of the genus Merops, representing two phylogenetic sister clades of a monophyletic group. Our examination reveals the presence of two species of the genus Peristerophila, as follows: (1) a new species Peristerophila mayri sp. n. from Merops viridis in the Philippines, M. leschenaulti in Nepal and Sri Lanka, and M. orientalis in Sri Lanka; and (2) P. meropis from M. superciliosus in Tanzania and Egypt, M. persicus in Sudan, Tanzania, Liberia, Senegal, Kenya, and D.R. Congo, M. ornatus in Papua New Guinea, M. philippinus in Thailand, Indonesia and Sri Lanka, and M. americanus in the Philippines. The prevalence of host infestations by syringophilid mites varied from 3.1 to 38.2%. The distribution of syringophilid mites corresponds with the sister clade phylogenetic relationships of the hosts, except for P. meropis associated with Merops americanus. Possible hypotheses for the host lineage shift are proposed