Introduction
Wild birds are significantly affected by permanent ectoparasites, including mites, ticks, louse flies, fleas and chewing lice (Calvete et al., Reference Calvete, Estrada, Lucientes and Estrada2003; Sychra et al., Reference Sychra, Literák, Podzemný, Harmat and Hrabák2011; Oslejskova et al., Reference Oslejskova, Kounkova, Gustafsson, Resendes, Rodrigues, Literak and Sychra2020). These parasites may directly affect bird condition and fitness by causing stress and injuries that compromise its well-being, such as body condition, anaemia, reduction of flight ability, thermoregulation issues and behaviour changes (Lehmann, Reference Lehmann1993; Martínez-de La Puente et al., Reference Martínez-de La Puente, Merino, Tomás, Moreno, Morales, Lobato and Martínez2011; Defaye et al., Reference Defaye, Moutailler, Vollot, Galon, Gonzalez, Moraes, Leoncini, Rataud, Le Guillou, Pasqualini and Quilichini2023; Espí et al., Reference Espí, Del Cerro, Peón-Torre, González-Escudero and Somoano2023). Such effects have lasting implications for the growth and reproductive success, especially on passerine birds (Fitze et al., Reference Fitze, Tschirren and Richner2004), but also on other avian groups like prey birds (Lesko and Smallwood Reference Lesko and Smallwood2012; Reed et al., Reference Reed, Daunt, Kiploks, Burthe, Granroth-Wilding, Takahashi, Newell, Wanless and Cunningham2012). In addition to their ecological relevance, ectoparasites play a central role in shaping host behaviour, life history, and population dynamics (Poulin, Reference Poulin2007).
Despite this importance, systematic surveys of avian ectoparasites remain scarce, particularly in southern Europe and island ecosystems. In the Iberian Peninsula, most studies have focused on specific host groups or parasite taxa (e.g. Moreno-Rueda and Hoi Reference Moreno-Rueda and Hoi2012; Tomás et al., Reference Tomás, Palma, Rebelo and Da Fonseca2016), leaving significant knowledge gaps on broader host–parasite associations. In the Balearic Islands, no comprehensive studies have yet described the diversity or prevalence of ectoparasites in wild birds. In this sense, Menorca is an island with the UNESCO status of Reserve of the Biosphere since 1993 (UNESCO 1993). The island belongs to the Balearic Island archipelago (Spain) located in the western Mediterranean basin, and has typical Mediterranean climate following the Köppen climate classification, by warm temperatures in summer, with an average annual temperature of 17.2 ºC and average annual precipitation of 545 mm (AEMET 2022). Its landscape comprises diverse natural habitats, ranging from wetlands and coastal areas to Mediterranean forests, which sustain rich avian biodiversity. The island is strategically located along East Atlantic flyway and serves as a key stopover site for migratory birds traveling between northern Europe and Africa. This convergence of migratory and resident species within the same habitats creates opportunities for ectoparasite spillover, co-infestation, and the establishment of novel host–parasite associations (Altizer et al., Reference Altizer, Bartel and Han2011; Tomás et al., Reference Tomás, Palma, Rebelo and Da Fonseca2016). Such conditions make Menorca a natural laboratory for studying ectoparasite dynamics in insular ecosystems, where local ecological constraints and the mixing of host populations can shape parasite prevalence and community composition in unique ways (Poulin, Reference Poulin2007; Krasnov et al., Reference Krasnov, Mouillot, Khokhlova, Shenbrot and Poulin2012). Therefore, establishing baseline data in such region is essential for understanding parasite biogeography, assessing host–parasite network structure, and providing a reference for future ecological and epidemiological research (Krasnov et al., Reference Krasnov, Mouillot, Khokhlova, Shenbrot and Poulin2012; Bush and Clayton Reference Bush and Clayton2018).
An additional question of ecological interest is whether ectoparasite prevalence differs between migratory and sedentary species. Migratory birds may be exposed to more parasites through contact with multiple host populations along their flyways, potentially increasing prevalence (Altizer et al., Reference Altizer, Bartel and Han2011). Conversely, sedentary birds may accumulate higher infestations due to continuous exposure within local habitats, acting as ‘sitting ducks’ for parasite transmission (Poulin, Reference Poulin2007). Previous studies have reported mixed results, for instance some authors described higher prevalence in migrant birds (Sychra et al., Reference Sychra, Literák, Podzemný, Harmat and Hrabák2011), while others observed similar or even higher prevalence in resident species (Sychra et al., Reference Sychra, Literák, Podzemný and Benedikt2008; Tomás et al., Reference Tomás, Palma, Rebelo and Da Fonseca2016; Gustafsson et al., Reference Gustafsson, Lei, Luo, Chu, Zhao, Zhang and Zou2019). These inconsistencies suggest that host traits, ecology, and environmental conditions strongly modulate parasite dynamics.
An example of those ectoparasites is the feather mites (Acari: Astigmata), these are specialized arthropods that inhabit bird plumage and skin, feeding primarily on uropygial oil. While typically non-parasitic, they may cause skin irritation, especially in birds kept in captivity (Blanco et al., Reference Blanco, Tella, Potti and Baz2001; Labrador et al., Reference Labrador, Doña, Serrano and Jovani2022). Social birds are at greater risk acquiring mites due to close contact with conspecifics. In fact, group-living passerines are more likely to harbour feather mites than solitary species (Poulin Reference Poulin1991). Similarly, seasonal variations in feather mite infestations between migratory and resident birds have been reported (Galván et al., Reference Galván, Barba, Piculo, Cantó, Cortés, Monrós, Atiénzar and Proctor2008).
Here, we present the first survey of ectoparasites, including ticks, louse flies, chewing lice, and feather mites in wild birds from Menorca (Balearic Islands). Our primary objective is to describe the ectoparasite and feather mite communities present in this insular system and establish baseline host–parasite associations. In addition, we explore whether prevalence differs between migratory and sedentary species, as well as across seasonal sampling periods, to provide insights into the ecological factors shaping ectoparasite distributions.
Material and methods
Field sampling
Fieldwork was carried out in four locations of Menorca Island (Balearic Islands, Spain): (a) Illa de s’Aire (39° 48′ 02″ N, 4° 17′ 25″ E), a natural area that consists of an uninhabited islet (34 ha) located in the south-eastern part of Menorca; two natural areas within inland Menorca, (b) Alfurí de Dalt, (40º 02′ 14″ N, 3º 58′ 42″ E), (c) Albufera des Grau (39° 58′ 35″ N, 4° 14′ 23″ E) and d) the recovery centre for autonomous wild animals of Menorca (CRFSM) (40º 00′ 16″ N, 3º 52′ 03″ E), a facility for injured wildlife. Sampling on Illa de s’Aire was conducted during the prenuptial (30 April–1 May 2022) and postnuptial (4 October 2022) bird migration periods. Sampling on inland sites took place on eight occasions between 8 May and 31 July 2022. Birds were captured using mist nets during regular ringing campaigns by the Society of Ornithologists of Menorca (SOM). All selected sites are well known stopovers during bird migration. The captured birds were identified to species level using identification keys (Svensson et al., Reference Svensson, Mullarney, Zetterström, Grant and Pijoan Rotgé2010) and Avibase (https://avibase.bsc-eoc.org). We also broadly classify the bird species into sedentary (year-round residents in Menorca) or migratory (long-distance migrants) based on Svensson (2010) and ‘Estatus de l’avifauna Balear’ (López-Jurado, Reference López-Jurado2022). Those species that could belong to both migratory and sedentary populations, were considered as migratory or sedentary based on regional distribution and phenological data. Birds were examined for ectoparasites (ticks, louse flies and chewing lice) and feather mites by visual inspection of the head and body plumage, primary and secondary wing feathers, and tail feathers. Each bird was inspected for approximately 5–10 min to minimize handling time and stress. Inspections were always conducted by at least two people. Birds were placed over a white paper to facilitate the detection of any dislodged parasites. In addition, wings were examined against the light to enhance the visibility of feather mites. A 10× magnifier lens were also used to magnify and confirm the presence of small ectoparasites. The duration of inspection was kept consistent across individuals, independent of their size, health, or stress level. Ectoparasites were extracted using tweezers, brushes, or a swab and stored in 1.5 mL Eppendorf tubes containing 96% ethanol for further morphological identification. The presence of ectoparasites in birds at the CRFSM was assessed upon their arrival by the centre’s staff following the same protocol between February and November 2022.
Morphological identification of ectoparasites and mites
Ticks (Ixodidae) were identified to species level (when possible) following the keys by Krantz and Walter (Reference Krantz and Walter2009) and Estrada-Peña et al. (Reference Estrada-Peña, Mihalca and Petney2017). Louse flies (Hippoboscidae) were identified using standard taxonomic keys (Hutson, Reference Hutson1984). Chewing lice (Phthiraptera) and feather mites (Astigmata) were mounted on Hoyer’s medium on microslides and sealed with Glpt insulating varnish. Lice were identified to the species level using specific taxonomic keys (Martín Mateo, Reference Martín Mateo2002, Reference Martín Mateo2009), except for the two newly recorded species in Spain. To identify these species, host associations were first confirmed following Price et al. (Reference Price, Hellenthal, Palma, Johnson and Clayton2003), and subsequently verified using the descriptions, as no dichotomous keys currently exist for these taxa. Ardeicola expadillus was identified based on the original description by Blagoveshtchensky (Reference Blagoveshtchensky1940); nevertheless, this identification remains tentative and awaits a formal redescription of the species. For the identification of Kurodaia haliaeeti, the description provided by Price and Beer (Reference Price and Beer1963) was used. Feather mites were identified to species level under optical microscopy following specific literature (Atyeo and Braasch, Reference Atyeo and Braasch1966; Karg, Reference Karg1971; Kolarova and Mmitov, Reference Kolarova and Mmitov2008; Kolarova, Reference Kolarova2021).
Voucher specimens of lice, mites, ticks, and louse flies were deposited at the laboratory of the Applied Zoology and Animal Conservation research group, University of Balearic Islands, Spain.
Statistical analysis
We compared the prevalence (presence or absence) of ectoparasites and feather mites between sedentary and migratory birds using Fisher test. Differences in ectoparasite prevalence were assessed by ticks, louse flies, and lice together and independently due their different behaviour.
Additionally, we tested for differences in feather mite prevalence among migratory birds of the four species captured in both migration periods in Illa de s’Aire (Erithacus rubecula, Ficedula hypoleuca, Phoenicurus phoenicurus, and Phylloscopus trochilus) during pre- (May) and postnuptial (October) migration. Only birds captured in Illa de s’Aire and inland Menorca sites were included in the analyses, while samples from CRFSM were excluded since these individuals were usually injured or stressed.
All analyses were performed using R version 4.3.2 (R Core Development Team, 2016). A significance level of ≤0.05 was used to determine statistical significance.
Results
A total of 344 wild birds from 44 species were examined for ectoparasites and feather mites. Ectoparasites were detected in 70 birds (20.4%), comprising 18 different taxa: 13 species of lice, two of ticks, two of louse flies and one of mites. Among these, Ardeicola expallidus (Blagoveshtchensky, Reference Blagoveshtchensky1940) (Figure 1), and Kurodaia haliaeeti (Denny, 1842) (Figure 2), represent new records for the chewing louse fauna of Spain, while ten additional lice species are recorded here for the first time in the Balearic Islands (Table 1). Notably, the association between the lice Ciconiphilus decimfasciatus (Boisduval and Lacordaire, 1835) and the grey heron Ardea cinerea (Linnaeus, 1758) constitutes the first host–parasite record for Spain.
Figure 1. Ardeicola expallidus. (a) female body, (b) head and (c) terminal tergites of the abdomen. Scale: 1 mm.
Figure 2. Kurodaia haliaeeti (a) male body, (b) terminal tergites of the abdomen from a female and (c) genitalia. Scale: 1 mm.
Table 1. Chewing lice on birds analysed in the CRFSM
* First record for Spain.
** First record for the Balearic Islands.
*** First interaction record in lice-host bird for Spain.
Ectoparasites and feather mites in captured wild birds
Of the 312 will birds examined from Illa de s’Aire and inland Menorca, 42 individuals (13.5%) were parasitized by at least one ectoparasites or feather mites. A total of 149 birds were captured from Illa de s’Aire, including 13 individuals of six species of sedentary birds and 136 individuals of 18 species of migratory birds (Table 2). Among the migratory birds on Illa de s’Aire, 63 and 73 individuals were captured during their prenuptial and postnuptial migration, respectively (Table 2). Additionally, 163 birds were captured in two inland sites in Menorca, including 153 individuals of 12 sedentary species and ten individuals of three migratory species (Table 2). Among the 163 wild birds captured in inland Menorca, eight birds (4.9%) from seven different species showed ectoparasites (Table 2). No birds captured on Illa de s’Aire (N = 149) were parasitized by ectoparasites. The prevalence of ectoparasites did not differ significantly between sedentary and migratory birds (P = 0.29; odds ratio = 2.69; 95% CI: 0.47–27.69).
Table 2. List of bird species captured in Illa de s’Aire and inland Menorca with their associated ectoparasites (number in brackets indicate the number of birds with these ectoparasites)
Ticks were observed in four birds. All of them captured inland Menorca on sedentary birds. All were immature stages identified as Hyalomma sp. (Linnaeus, 1758) (Table 2).
Louse flies were found on four birds from inland Menorca, including sedentary (N = 2), and migratory birds (N = 2). Two species were identified: Ornithoica turdi (Olivier in Latreille, 1811) (N = 3) and Ornithophila metallica (Schiner, 1864) (N = 1) (Table 2). The prevalence of louse flies did not differ significantly between sedentary and migratory birds (P = 1; odds ratio = 0.88; 95% CI: 0.06–12.2).
No chewing lice were found on birds captured either inland in Menorca or on Illa de s’Aire. All lice were recorded from birds received at the wildlife recovery centre.
Feather mites were recorded in 34 birds (10.4 %) captured in Illa de s’Aire and inland Menorca. On Illa de s’Aire, 15.4% (23/149) of birds carried mites, whereas 6.7% (11/163) of inland birds presented feather mites. Among sedentary species, 11.4% (N = 19/166) harboured mites (13 species), while 10.3 % (N = 15/146) of migratory birds were infested (18 species) (Table 3). Two mite species were identified: Proctophyllodes sylviae (Gaud, 1957), was found in 26 birds from 14 species, and Trouessartia bifurcata (Trouessart, 1884) was found in eight birds from three species. No significant difference in overall mite prevalence was found between sedentary and migratory birds (P = 0.86; odds ratio = 1.13; 95% CI: 0.52–2.49). We did not find significant differences in mite prevalence between migratory birds from the four species (Erithacus rubecula, Ficedula hypoleuca, Phoenicurus phoenicurus, and Phylloscopus trochilus) captured in both pre- (5.1%; N = 2/39) and postnuptial (15.2 %; N = 10/66) migration periods in Illa de s’Aire (P = 0.2; odds ratio = 0.3; 95% CI: 0.03–1.55).
Table 3. Mites found on birds captured on Illa de s’Aire during the prenuptial and postnuptial migrations, and inland Menorca. Numbers in brackets indicate the number of birds carrying these mite species. Species names underlined are considered migratory
Ectoparasites and feather mites in birds from the wildlife recovery centre
Among the 32 birds from 16 species examined at the CRFSM, 28 individuals (87.5%) from 14 species were parasitized by at least one type of ectoparasite (chewing lice, louse fly or tick) (Table 4). The louse fly O. metallica was found on the Eurasian hoopoe Upupa epops (Linnaeus, 1758). An adult Hyalomma lusitanicum (Koch 1844) was identified on a yellow-legged gull Larus michahellis (Naumann, 1840), and immature stage of Hyalomma sp. were found on two stone-curlews Burhinus oedicnemus (Linnaeus, 1758). The tick Rhipicephalus sanguineus s.l. (Latreille, 1806) was found on a red kite Milvus milvus (Linnaeus, 1758), and an immature stage of Ixodes sp. were found on a barn owl Tyto alba (Scopoli, 1769). A soft-bodied tick, Ornithodorus maritimus (Vermeil and Marguet, 1967) (Argasidae) was found on a cattle egret Bubulcus ibis (Linnaeus, 1758). Thirteen species of lice (Phthiraptera) were found on 67.7% (N = 21) of the CRFSM birds (Table 4). In addition to the new national and regional lice records described above, the mite Parasitus fimetorum (Berlese, 1904) was identified on Larus michahellis. The feather-mites Ornithonyssus sylviarium (Canestrini and Fanzago, 1877) was detected on the Eurasian scops owl Otus scops (Linnaeus, 1758), Ornithonyssus sp. on a house sparrow Passer domesticus (Linnaeus, 1758) and Eurasian scops owl, and Nothoapis sp. on a cattle egret.
Table 4. Ectoparasites identified on the birds analysed in the CRFSM. The prevalence corresponds to the total number of ectoparasites collected from each host species
Discussion
This study provides the first comprehensive analysis of ectoparasites and feather mites in wild sedentary and migrant passerines from Menorca (Balearic Islands). We reported 13 species of chewing lice, two of louse flies, two of ticks, and one of mites, with A. expallidus and K. haliaeeti as new records for Spain, and ten lice species newly recorded from the Balearic Islands. Most of these new records originated from birds admitted to the wildlife recovery centre (CRFSM). These findings represent interesting geographical records but not new host–parasite associations, as all lice species had been previously reported from the same or closely related host species. Ardeicola expallidus has been previously recorded on birds of the Ardeidae family, such as cattle egret, great egret Ardea alba (Linnaeus, 1758), and snowy egret Egretta thula (Molina, 1782) (Price et al., Reference Price, Hellenthal, Palma, Johnson and Clayton2003). This ectoparasite was also recorded in other European countries like Bulgaria (Balát Reference Balát1958; Ilieva, Reference Ilieva2009, Touleshkov Reference Touleshkov1974), Slovakia (Balát, Reference Balát1953, Reference Balát1956, Reference Balát1977), Hungary (Rékási, Reference Rékási and Mahunka2002), Faroae Islands (Palma and Jensen, Reference Palma and Jensen2005) and Romania in great egret and the little egret Egretta garzetta (Linnaeus 1766) (Rékási et al., Reference Rékási, Kiss and Sándor2017). The other new record for Spain is K. haliaeeti, which exclusively parasitizes Ospreys (Price et al., Reference Price, Hellenthal, Palma, Johnson and Clayton2003). Our study confirms the high specificity of most of the species sampled. The different species of lice found parasitizing birds in this study have been previously found on the same bird species, including C. decimfasciatus on grey heron (Touleshkov, Reference Touleshkov1958, Reference Touleshkov1974; Palma and Jensen, Reference Palma and Jensen2005; Gustafsson et al., Reference Gustafsson, Lei, Luo, Chu, Zhao, Zhang and Zou2019; Vas et al., Reference Vas, Privigyei, Judit Prohászka, Csörgő and Rózsa2012). This lice species was previously recorded in Spain on a bird species of the same genus: the purple heron Ardea purpurea (Linnaeus, 1766) (Millán et al., Reference Millán, Martínez and Martín-Mateo2008).
The high prevalence of ectoparasites observed in birds at the CRFSM likely reflects their compromised health status. Similar findings were reported in Portugal, where stressed or injured birds had higher ectoparasite loads (Tomás et al., Reference Tomás, Palma, Rebelo and Da Fonseca2016). Many of the birds examined at the CRFSM were debilitated, which could have increased their susceptibility to infestation. Indeed, captive conditions can influence ectoparasite dynamics through behavioural changes in birds. For example, stress or confinement can temporarily reduce grooming, facilitating parasite proliferation, although this effect likely only appears after several parasite generations. In contrast, birds kept in captivity for longer periods may groom more frequently than wild individuals, as they spend less time foraging or monitoring for predators (Waite et al., Reference Waite, Henry and Clayton2012; Villa et al., Reference Villa, Altuna, Ruff, Beach, Mulvey, Poole, Campbell, Johnson, Shapiro, Bush and Clayton2019; Bush et al., Reference Bush, Waller, Herman, Hobbs, Clayton, Watson, Oleyar and Clayton2023). However, since ectoparasites were collected upon arrival at the recovery centre, before the birds’ shared enclosures, infestation due to the factors previously described and/or cross-infection within the centre is unlikely. Only occasional accidental transfer, particularly of feather mites, during transport would be possible.
Previous studies in Europe have reported high rates of ectoparasite infections in Accipitriformes, with a lice prevalence of 41.8% in Spanish raptors (Pérez et al., Reference Pérez, Ruiz-Martínez and Cooper1996) and 42.6 % in Turkish raptors (Inci et al., Reference Inci, Dik, Kibar, Yildirim and Duzlu2010), or Eleonora falcons Falco eleonorae Géné, 1839 from Alegranza island also show high prevalence of louse flies (Gangoso et al., Reference Gangoso, Gutiérrez-López, Martínez-de La Puente and Figuerola2019). Birds collected in the current study were mainly passerines (except in the CRFSM, where the birds inspected were birds of prey). According to Rozsa (Reference Rozsa1997), larger-bodied bird species tend to harbour more ectoparasites than smaller passerines. This is not only because of their greater surface area but also due to the relative size of the parasites. For example, a tick on a small passerine’s head is highly exposed and more likely to be removed during preening, whereas on a large raptor, it may remain unnoticed. Additionally, longevity could influence ectoparasite accumulation, as longer-lived species may provide more opportunities for colonization over time. However, the role of migration in shaping ectoparasite prevalence appears to differ among bird groups: in some non-passerines, host migration seems to have little effect on louse prevalence (Grossi et al., Reference Grossi, Lee, Tian, Zou, Choi and Gustafsson2023), whereas in passerines, higher ectoparasite loads in migratory species can have long-term fitness consequences, potentially reducing annual survival probability (Klaus et al., Reference Klaus, Gethmann, Hoffmann, Ziegler, Heller and Beer2016). This fact can greatly impact the return rate of parasite-infested birds from breeding sites to wintering grounds. Heavily infested birds often deplete their fat reserves to support an increased metabolic rate, leading to reduced body mass and lower survival rates, especially during migration (Brown and Sherry, Reference Brown and Sherry2006). The complete absence of ectoparasites in birds from Illa de s’Aire was striking. However, similar results were found by Gustafsson et al. (Reference Gustafsson, Lei, Luo, Chu, Zhao, Zhang and Zou2019), which found a low parasitized rate by lice in migratory passerine birds. Given the relatively homogeneous climate across Menorca, this pattern likely reflects differences in the bird community rather than environmental conditions. High ectoparasite loads can increase energetic costs, reduce flight efficiency, and lower survival during migration. Consequently, heavily parasitized birds may fail to reach stopover sites such as Illa de s’Aire. This ‘migratory culling’ effect could therefore explain the complete absence of ectoparasites in the individuals captured on the islet (Satterfield et al., Reference Satterfield, Marra, Sillett and Altizer2018; Gangoso et al., Reference Gangoso, Santamaría-Cervantes, Martínez-de la Puente, López and Figuerola2024).
The louse fly O. turdi recorded on Curruca melanocephala, Streptopelia turtur, and Parus major, has been documented previously in various passerine families, indicating low host specificity (Gaponov and Tewelde, Reference Gaponov and Tewelde2020; Zittra et al., Reference Zittra, Schoener, Wagner, Heddergott, Duscher and Fuehrer2020). While this species is primarily distributed in Africa and southern Europe (Oboňa et al., Reference Oboňa, Sychra, Greš, Heřman, Manko, Roháček, Šestáková, Šlapák and Hromada2019; González et al., Reference González, Hidalgo, Talabante and Bernal2023), it has been also recorded across central Europe (Droz and Haenni, Reference Droz and Haenni2011). Its distribution is of special interest due to its potential role as vector for trypanosome parasites (Santolíková et al., Reference Santolíková, Brzoňová, Čepička and Svobodová2022). Keve et al. (Reference Keve, Csörgő, Kováts, Benke, Bende, Ágoston, Mórocz, Németh, Tamás, Huber, Gyurácz, Keve, Kontschán, Németh and Hornok2024) observed O. turdi more frequently on short-distance migrants, but we did not record significant differences in prevalence between migratory and sedentary birds, probably due to the low prevalence of louse flies in our sampled birds The other louse fly observed, O. metallica, found on S. turtur is a well-documented species that parasitize numerous bird species across Europe (Nartshuk and Matyukhin, Reference Nartshuk and Matyukhin2019; Lehikoinen et al., Reference Lehikoinen, Pohjola, Valkama, Mutanen and Pohjoismäki2021). Although O. metallica predominantly parasitize sedentary birds, we found it on a migratory species. Further studies are needed to assess its potential role as vector for trypanosome parasites.
The prevalence of ticks observed in our study aligns with previous studies, where only a small number of migratory birds were usually parasitized by ticks (Elfving et al., Reference Elfving, Olsen, Bergström, Waldenström, Lundkvist, Sjöstedt, Mejlon and Nilsson2010; Jameson et al., Reference Jameson, Morgan, Medlock, Watola and Vaux2012; Klaus et al., Reference Klaus, Gethmann, Hoffmann, Ziegler, Heller and Beer2016; Espí et al., Reference Espí, Del Cerro, Peón-Torre, González-Escudero and Somoano2023). For example, Espí et al. (Reference Espí, Del Cerro, Peón-Torre, González-Escudero and Somoano2023), reported that only 2.5% of wild birds captured in Northwestern coastal Spain were parasitized by ticks. While we observed a marginally higher tick prevalence in sedentary birds than in migratory ones, the difference was not statistically significant, likely due to the low number of positive cases. In contrast, Klaus et al. (Reference Klaus, Gethmann, Hoffmann, Ziegler, Heller and Beer2016), in Germany, reported significantly higher tick infestations in sedentary birds compared to migratory ones. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground (Hasle, Reference Hasle2013). Ground-feeding species, such as the common blackbird (Turdus merula), often shows higher tick prevalence than non-ground feeders (Klaus et al., Reference Klaus, Gethmann, Hoffmann, Ziegler, Heller and Beer2016). In fact, in our study, 25% of the common blackbirds analysed were parasitized by ticks. Ticks collected from birds in our study were predominantly identified as Hyalomma sp., consistent with previous reports where Hyalomma ticks have been frequently associated with migratory birds (Capek et al., Reference Capek, Literak, Kocianova, Sychra, Najer, Trnka and Kverek2014; Estrada-Peña et al., Reference Estrada-Peña, D’Amico and Fernández-Ruiz2021). In particular, Hyalomma marginatum is commonly transported into Europe along migratory routes and is a known vector of Crimean-Congo haemorrhagic fever virus (CCHFV; Lindeborg et al., Reference Lindeborg, Barboutis, Ehrenborg, Fransson, Jaenson, Lindgren, Lundkvist, Nyström, Salaneck, Waldenström and Olsen2012). Although CCHFV detection was beyond the scope of this study, the presence of Hyalomma sp. on migratory birds underlines the potential risk for the introduction and spread of zoonotic pathogens in the study area.
Regarding feather mites, the two species of mites found in our study have been previously reported in Spain at high prevalence levels on Eurasian blackcap Sylvia atricapilla (Linnaeus, 1758) (Fernández-González et al., Reference Fernández-González, De La Hera, Pérez-Rodríguez and Pérez-Tris2013). These mites often co-occur on Eurasian blackcap (Mironov et al., Reference Mironov, Dabert and Dabert2012). However, they have also been reported on other bird species from various families. For example, P. sylviae, has been documented on the common reed warbler Acrocephalus scirpaceus (Hermann, 1804), the Cetti’s warbler Cettia cetti (Temminck, 1820), the common chiffchaff Phylloscopus collybita (Vieillot, 1817) among others from several regions of Eurasia (Mironov, Reference Mironov1996; Per and Aktaş, Reference Per and Aktaş2018). Similarly, T. bifurcata has been observed on great reed warbler Acrocephalus arundinaceus (Linnaeus, 1758), Cetti’s warbler (Per and Aktaş, Reference Per and Aktaş2018), and greater whitethroat Curruca communis (Latham, 1787) (Siepel et al., Reference Siepel, Cremers and Hiemstra2023). These previous studies confirm our results, where we found P. sylviae in 14 different species from eight families and T. bifurcata on three species from two families.
Although Marčanová and Janiga (Reference Marčanová and Janiga2021) found that mite prevalence reached its maximum after the bird’s postnuptial moult, suggesting that mites preferred newly coated feathers after a moult, when we analysed only migratory birds, we failed to find differences in the prevalence of feather mites between those individuals captured during prenuptial migration and postnuptial migration. However, our result could be due to the highly unbalanced counts between periods (Table 3). Therefore, further studies are required to assess within-species seasonal changes in feather mite prevalence.
The current study provides the first comprehensive overview of the ectoparasite community in wild sedentary and migratory passerines from Menorca. The detection two new chewing lice records for Spain (A. expallidus and K. haliaeeti) and ten lice species newly recorded for the Balearic Islands, highlights the still underexplored diversity of avian ectoparasites in the Mediterranean region. Although no significant differences in prevalence were found between sedentary and migratory birds, these findings emphasize the importance of continuous monitoring and the use of complementary sampling methods to improve ectoparasite detection. Further studies integrating pathogen screening are needed to better understand the ecological and epidemiological implications of these host–parasite associations on Mediterranean islands.
Data availability statement
The data presented in this study are available on request from the corresponding author.
Acknowledgements
We thank the Institut Menorquí d’Estudis (IME) for the financial support of the project, and thanks to the Societat Ornitologica of Menorca and Emili Garriga, Nara Triay Cañellas, Arun Triay Cañellas, Richard Barnes, and Luís Betanzos for their help during the field sessions. We would also like to thank anonymous reviewers for constructively revising this manuscript.
Author contributions
Gutiérrez López, R: Conceptualization; Funding acquisition; Project administration; Field work; Data curation and statistical analysis; Writing-original draft; Writing-review and editing. González, MA: Field work; Insect identification; Writing-review, and editing. López-Mercadal, J: Conceptualization; Fieldwork; Writing-review and editing. Escandell, R: Fieldwork; Writing-review and editing. García-Febrero, Ò: Fieldwork; Writing-review and editing. Coll, E: Fieldwork, Writing-review, and editing. Triay, R: Fieldwork, Writing-review, and editing. García, M: Fieldwork, Writing-review, and editing. Bernal, I: Insect identification; Writing-review and editing. Talabante, C: Insect identification; Writing-review and editing. Moraza, ML: Acari identification; Writing-review and editing. Miranda, MA: Conceptualization; Funding acquisition; Project administration; Fieldwork; Insect identification; Writing-review and editing. Barceló, C: Conceptualization; Funding acquisition; Project administration; Fieldwork; Insect identification; Writing-review and editing.
Financial support
This research was funded by Institut Menorquí d’Estudis (IME) (call for research grants 2021) and Applied Zoology and Animal Conservation (ZAP-UIB) own funds. RGL was initially supported by a Margalida Comas contract from the Government of the Balearic Islands and from the European Regional Development Fund (FEDER) (REF-PD/038/2019) and he is currently funded by a Sara Borrel postdoctoral contract (Ref. CD22CIII-00009) from the Carlos III Health Institute.
Competing interests
The authors declare no conflict of interest.
Ethical standards
The permits to catch and ring birds were issued by The Direcció General de Medi Natural i Gestió Forestal de la Conselleria d’Agricultura, Pesca I Medi Natural de les Illes Balears (Exp: Permís anellatge 21/2025).
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