Geographical variation in the vocalizations of the suboscine Thorn‐tailed Rayadito Aphrastura spinicauda

Structural variation in acoustic signals may be related either to the factors affecting sound production such as bird morphology, or to vocal adaptations to improve sound transmission in different environments. Thus, variation in acoustic signals can influence intraspecific communication processes. This will ultimately influence divergence in allopatric populations. The study of geographical variation in vocalizations of suboscines provides an opportunity to compare acoustic signals from different populations, without additional biases caused by song learning and cultural evolution typical of oscines. The aim of this study was to compare vocalizations of distinct populations of a suboscine species, the Thorn‐tailed Rayadito. Four types of vocalizations were recorded in five populations, including all three currently accepted subspecies. Comparisons of each type of vocalization among the five populations showed that some variation existed in the repetitive trill, whereas no differences were found among alarm calls and loud trills. Variation in repetitive trills among populations and forest types suggests that sound transmission is involved in vocal differences in suboscines. Acoustic differences are also consistent with distinguishing subspecies bullocki from spinicauda and fulva, but not the two latter subspecies from each other. Our results suggest that the geographical differentiation in vocalizations observed among Thorn‐tailed Rayadito populations is likely to be a consequence of different ecological pressures. Therefore, incipient genetic isolation of these populations is suggested, based on the innate origin of suboscine vocalizations.     

Fleas associated with non‐flying small mammal communities from northern and central Chile: with new host and locality records

Fleas associated with small mammals from seven localities from northern and central Chile were assessed. We captured 352 small mammals belonging to 12 species from which we obtained 675 fleas belonging to 15 different species. The most frequently captured flea species were Neotyphloceras crassispina crassispina (n = 198) and N. chilensis (n = 175). High values of flea species richness and diversity were found in Fray Jorge National Park (NP), a north‐central Chilean site, whereas the highest values of mean abundance (MA) and prevalence were found in three diverse sites that include Los Molles River, a high altitude site located in north‐central Chile, Fray Jorge NP and Dichato, in south‐central Chile. On the other hand, high values of flea richness and diversity were found on two rodent species, Abrothrix olivacea and A. longipilis, whereas the highest values of MA and prevalence were found on Oligoryzomys longicaudatus, A. longipilis and Phyllotis xanthopygus. A total of three new host recordings, nine new localities and nine new host species and locality recordings are reported. Also, this study represents the first known record of Tetrapsyllus (Tetrapsyllus) comis in Chile and the first ecological analysis of Neotyphloceras chilensis.