Biological Earth observation with animal sensors

Space-based tracking technology using low-cost miniature tags is now delivering data on fine-scale animal movement at near-global scale. Linked with remotely sensed environmental data, this offers a biological lens on habitat integrity and connectivity for conservation and human health; a global network of animal sentinels of environmen-tal change

Spring migration phenology of Eurasian Woodcocks tagged with GPS-Argos transmitters in Central Europe

Eurasian Woodcock (Scolopax rusticola) plays a special role in the cultural heritage of most nations in Europe. In the last decade, ringing revealed the main migratory patterns of some well studied and intensively harvested Woodcock populations wintering in Western and Southern Europe. The same study sites and populations were in focus when the recently revolutionized satellite tracking technologies allowed the study of individual migrations. In contribution to these efforts, we present here the pre-nuptial migration data of Woodcocks captured and tagged with GPS-Argos transmitters in Central Europe, in 2020. Woodcocks migrated from the tagging site in Hungary to Ukraine, European Russia and Central Siberia by an average of 2,678 km (range 677–5,002 km). The duration of the migration ranged between 1–52 days, the overall migration speed was 382 km/day, the absolute maximum distance covered in a day was 866 km. The individual number of stopovers varied during the migration from 0 to 5. The average time spent at each stopover site was 5.6 days. Within the stopover sites, the daily displacements ranged between 11–3,329 m. The Carpathian Basin may be more important in the wintering of Woodcocks than previously assumed, as tagged birds stayed significantly longer compared to any later en route migratory stopover. In accordance with the results of previous DNA analysis, identified breeding grounds of tagged individuals represented a large part of the distribution area

The relationship of louse infestation and clutch size in the Common Kestrel (Falco tinnunculus)

SUMMARY Background: Lice are common ectoparasites of birds, completing their entire life cycle in the plumage. Transmission – in most cases – requires physical contact between hosts. Lice may benefit from choosing host individuals with better survival prospects and dispersal chances. Bodily contacts between parents and offsprings provide a good opportunity for host selection. The Common Kestrel is a widespread, small-bodied raptor of the Palearctic region, with well-known breeding biology and ectoparasite fauna, making it suitable to study the ecological correlates of vertical transmission of lice. Objectives: The aim of our study was to investigate how the sex, maturity and clutch size of Common Kestrel nestlings affect the abundance of their lice. Materials and Methods: Field work was carried out in Körös-Maros National Park Directorate (Hungary). The ectoparasites were collected from nestlings (n = 54) with dust-ruffling. The effect of the host’s sex, wing length and clutch size on the abundance of their lice was analysed using negative binomial mixed models. Results and Discussion: In case of Colpocephalum subzerafae, none of the investigated variables had a significant effect. Contrarily, clutch size had a significant effect on Degeeriella rufa abundance. In small clutches (3–4 nestlings) the mean abundance of D. rufa (15.5 95% C.I.: 8–30) is 3.7 times higher, than in large (5–6 nestlings) clutches (4.2 95% C.I.: 2.3–7.4). We discuss two non-exclusive explanations of this pattern. First, parental quality is known to affect the clutch size. If low quality parents are also more heavily infested with lice, this could explain the higher louse load of their nestlings. Alternatively, according to the dilution hypothesis, long life-cycle ectoparasites (such as lice), that are incapable to significantly raise their subpopulation size till the fledging of the chicks, disperse among the nestlings, resulting in lower per nestling louse counts in larger clutches. According to our results both the breeding parameters and the quality of the parents may affect their offsprings’ ectoparasite load