Migratory birds typically fly long distances in response to large-scale seasonal climate variation. However, most migratory species are partial migrants, and some fly only short distances, for example to take advantage of suitable feeding conditions during the non-breeding season. In spite of their short distance, such migrations may also be fixed in populations as a result of evolutionarily adaptive responses to local habitat conditions, but the causes and details of these partial, short-distance migrations have been scarcely investigated. Here we analyse the migratory patterns of the insular endemic subspecies of Houbara Bustard Chlamydotis undulata fuertaventurae in a small island of the Canary archipelago. We tagged 41 individuals with GSM/GPRS loggers and tracked them over two annual cycles (2017)(2018)(2019). We found that Canarian Houbara Bustards are short-distance, partial migrants. Once the mating season was over, more than one-third of all males and females moved from their breeding territories to non-breeding areas where they spent the hottest months of the year. No bird changed its migratory status between years, and most individuals showed interannual fidelity to their breeding and non-breeding areas. There were differences in the productivity of green vegetation between breeding and non-breeding areas, as estimated from remote-sensing-based indicators of vegetation productivity (Normalized Difference Vegetation Index and Soil-Adjusted Vegetation Index). During the non-breeding period, values of both indices were higher at the non-breeding than at the breeding areas in migratory birds, providing a plausible explanation of why these individuals moved to nonbreeding areas rather than remaining in their territories. Moreover, during the nonbreeding period, Soil-Adjusted Vegetation Index values were lower at breeding areas abandoned by migratory birds than at breeding areas occupied year-round, although values at the latter did not differ from those at non-breeding areas, suggesting that partial migration arises from variability in food availability during summer across different areas. One of the four non-breeding areas was selected by over half of migrant individuals. This area had a mosaic of cultivated and non-cultivated patches, with more fallow fields and irrigated farmland than the other areas. Finally, most migratory flights were performed at night. The Houbara Bustard is globally threatened, and given its vulnerability to collision with electric and telephone lines during migration, we recommend burying electric and telephone lines in high-traffic areas underground. Finally, we urge protection of the known non-breeding areas, and recommend that current farming condition practices and natural shrubland at these areas continue to provide suitable habitat for Houbara Bustards.

Excretory/secretory products released by helminth parasites have been widely studied for their diagnostic utility, immunomodulatory properties, as well as for their use as vaccines. Due to their location at the host/parasite interface, the characterization of parasite secretions is important to unravel the molecular interactions governing the relationships between helminth parasites and their hosts. In this study, the excretory/secretory products from adult worms of the trematode Fasciola hepatica (FhES) were employed in a combination of two-dimensional electrophoresis, immunoblot and mass spectrometry, to analyze the immune response elicited in sheep during the course of an experimental infection. Ten different immunogenic proteins from FhES recognized by serum samples from infected sheep at 4, 8, and/or 12 weeks post-infection were identified. Among these, different isoforms of cathepsin L and B, peroxiredoxin, calmodulin, or glutathione S-transferase were recognized from the beginning to the end of the experimental infection, suggesting their potential role as immunomodulatory antigens. Furthermore, four FhES proteins (C2H2-type domain-containing protein, ferritin, superoxide dismutase, and globin-3) were identified for the first time as non-immunogenic proteins. These results may help to further understand host/parasite relationships in fasciolosis, and to identify potential diagnostic molecules and drug target candidates of F. hepatica.

Background The home range of an animal is determined by its ecological requirements, and these may vary depending on many intrinsic and extrinsic factors, which are ultimately driven by food resources. Investigating the effects of these factors, and specifically how individuals use food resources within their home ranges is essential to understand the ecology and dynamics of animal populations, and to establish conservation measures in the case of endangered species. Here, we investigate these questions in the Canarian houbara bustard, an endangered subspecies of African houbara endemic to the Canary Islands. Methods We analysed GPS locations of 43 houbaras in 2018–2021, using solar GSM/GPRS loggers provided with accelerometers. We assessed (1) the variation in their home range and core area with kernel density estimators in relation to several intrinsic and extrinsic factors and (2) their foraging habitat selection. Results Home ranges were smallest during the breeding season (November–April), when rains triggered a rapid growth of herbaceous vegetation. Displaying males and nesting females had smaller home ranges than individuals not involved in reproduction. Both sexes used almost exclusively non-cultivated land, selecting low density Launaea arborescens shrublands, pastures and green fallows as foraging habitats. Heavier males used smaller home ranges because they spent more time displaying at a fixed display site, while heavier females moved over larger areas during the mating period, probably visiting more candidate mates. During the non-breeding season (May–October), both sexes showed larger home ranges, shifting to high density shrubland, but also partly to cultivated land. They selected sweet potato fields, green fallows, alfalfas, orchards and irrigated fields, which offered highly valuable food resources during the driest months of the year. Conclusions Our study shows how Canarian houbara, originally a desert-dwelling species that uses mostly shrublands and pastures, has developed the necessary adaptations to benefit from resources provided by current low intensity farming practices in the study area. Maintaining appropriate habitat conditions in the eastern Canary islands should constitute a key conservation measure to prevent the extinction of this endangered houbara subspecies.

We studied the effects of visibility, female and male distribution, microhabitat and distance to human infrastructure on display site selection in a ground-dwelling bird, the Canarian houbara bustard. Using a very high-resolution digital elevation model based on LIDAR technology, and a complete census of the breeding population, we compared 98 display sites with randomly generated sites through generalized linear models. Univariate analyses showed that males displayed at locations that increased their visibility, both at short and long distances. Interestingly, although numbers of females and males around sites did not differ between display and random locations, from display locations males could see more females and males at both distance ranges. The absence of vegetation and stones was also critical as it allowed males to perform display runs on a ground free of obstacles. The amount of trophic resources did not correlate with the selection of the display site itself, though an appropriate vegetation cover seemed to be important at a wider habitat scale. Finally, display sites were farther away than random sites from sources of human disturbance, such as urban nuclei, buildings and tracks. Logistic regression analyses confirmed the importance of viewshed, low stone and vegetation cover, and distance to urban centres and tracks, and model averaging identified short-range visibility and females visible in the long range as the most important visibility variables. These results are compatible with the sexual advertisement and predator avoidance hypotheses. We provide recommendations to ensure an appropriate management of the breeding habitat of this endangered subspecies.