Lark Species Research Articles

Drinking dependency shapes behavioural thermoregulatory trade-offs in four arid-zone larks

Desert birds obtain water either solely from diet and metabolic water (drinking independent), or by drinking scarce surface water (drinking dependent). However, the implications of drinking dependency for behavioural trade-offs made by birds in the context of thermoregulation is not fully understood. We hypothesized that drinking dependency would influence foraging and thermoregulatory behaviours in birds with otherwise similar ecologies, because species that drink may be able to use evaporative cooling more readily than non-drinking species. We predicted that drinking birds would a) utilize respiratory evaporative cooling (panting) earlier than non-drinking species and b) continue to forage in the sun at hotter temperatures than non-drinking species. We tested these predictions using scan samples and focal observations of four species of lark (Alaudidae; two drinking species and two non-drinking species) across a range of air temperatures (Tair, 16.2–43.2 °C) in the arid Tankwa Karoo National Park, South Africa. Our results indicate that drinking species forage in the sun at hotter air temperatures and begin panting at cooler air temperatures than non-drinking species. Foraging intensity was higher in the sun than the shade for all species, so this potentially allows drinking species to maintain higher food intake rates during hot weather. Drinking species may therefore be less vulnerable to behavioural thermoregulatory trade-offs and more resilient to increased temperatures under climate change. However, drinking species rely on free surface water and as a result could be more vulnerable than non-drinking species if water resources diminish as climate change progresses.

Features of the population dynamics of larks (Alaudidae, Aves) in the semi-desert zone of the Saratov Trans-Volga region

The paper presents the results of our long-term monitoring of the family of larks (Alauda arvensis L., Melanocorypha calandra L., M. leucoptera Pallas, M. yeltoniensis J. R. Forster and Calandrella rufescens Vieillot) in the semi-desert zone of the Saratov Trans-Volga region. Bird censuses were carried out at 4 key sites on permanent routes during the nesting period, the total length of the census transects was 792 km. Statistical indicators of population dynamics were calculated, namely: the growth rates (Tnp.) and average density values (ind. / 100 ha) of each lark species. A statistical multivariate factor analysis (F-test) was carried out, with the help of which we were able to reveal the influence of a whole range of factors on the lark density dynamics. Changes in habitat conditions at the key areas (Fcrit. = 1.30, p = 0.003), as well as weather factors (Fcrit. = 1.39, p = 0.004) of particular years, have a significant impact on the density dynamics of larks. Evaluation of the variance showed heterogeneity of the sample (St = 0.119, p = 0.006), therefore, the average densities of larks differs significantly from each other. Thus, the structure of the lark community and the annual density of each species are the result of the environmental conditions of the habitats at each key site, and the weather conditions of particular years.

Disjunct resident population of Melodious Lark Mirafra cheniana discovered in East Africa

We describe the discovery of a previously unknown population of Melodious Lark Mirafra cheniana from northern Tanzania and southern Kenya, some 2000 km north of what was previously thought to be its northern limit in central Zimbabwe. The identification of this population as M. cheniana is based primarily on analyses of mitochondrial DNA and song. We also clarify relationships within this genus by sequencing material of White-tailed Lark Mirafra albicauda for the first time; although its relationships with other species in the group remain unclear, our analyses clearly show it to be different from M. cheniana in the newly discovered population. The discovery of a population of M. cheniana in East Africa conforms to a known pattern for closely related lark species to have disjunct distributions in southern and eastern Africa.

Analysis of the long-term lark population dynamics (Alaudidae, Aves) in the semi-desert in the Northwestern Caspian lowland

The dynamics of the numbers of larks inhabiting several areas differing in physical and geographical (landscape) conditions and the level of anthropogenic impact (pasture) on the natural environment is considered. Four key sites (“Akhmat”, “Zhdanov”, “Baiguzha”, and “Vetelki”) are located on the Priuzenskaya plain in the Aleksandrovo-Gaysky district of the Saratov region. The described territory is characterized by a high mosaicity of the facial structure of landscapes and, consequently, plant communities. This habitat diversity forms the structure of the communities as well as the population density of the individual lark species at the key sites surveyed. Our study of the dynamics of the numbers of species inhabiting the named key areas was carried out using calculations of logarithmic trends in the bird densities by the years of our study. In total, there were five species of larks (Alauda arvensis, Calandrella rufescens, Melanocorypha calandra, M. leucoptera, and M. yeltoniensis). As a result of our statistical processing of the obtained materials, significant differences were found in the dynamics of the numbers of individual lark species nesting in the key areas differing in landscape-ecological conditions and the level of anthropogenic load on ecosystems. In all likelihood, the dynamics of the density of the nesting lark population in the semi-desert of the Trans-Volga region is associated with both changes in the structure of habitats and, apparently, with the dynamics of the abundance of these species in the main part of their habitats, and with a number of other factors.

Molecular Species Delimitation of Larks (Aves: Alaudidae), and Integrative Taxonomy of the Genus Calandrella, with the Description of a Range-Restricted African Relic Taxon

Larks constitute an avian family of exceptional cryptic diversity and striking examples of convergent evolution. Therefore, traditional morphology-based taxonomy has recurrently failed to reflect evolutionary relationships. While taxonomy ideally should integrate morphology, vocalizations, behaviour, ecology, and genetics, this can be challenging for groups that span several continents including areas that are difficult to access. Here, we combine morphometrics and mitochondrial DNA to evaluate the taxonomy of Calandrella larks, with particular focus on the African C. cinerea and the Asian C. acutirostris complexes. We describe a new range-restricted West African taxon, Calandrella cinerea rufipecta ssp. nov. (type locality: Jos, Plateau State, Nigeria), with an isolated relic population 3000 km from its closest relative in the Rift Valley. We performed molecular species delimitation, employing coalescence-based multi-rate Poisson Tree Processes (mPTP) on cytochrome b sequences across 52 currently recognized lark species, including multiple taxa currently treated as subspecies. Three species-level splits were inferred within the genus Calandrella and another 13 across other genera, primarily among fragmented sub-Saharan taxa and taxa distributed from Northwest Africa to Arabia or East Africa. Previously unknown divergences date back as far as to the Miocene, indicating the presence of currently unrecognized species. However, we stress that taxonomic decisions should not be based on single datasets, such as mitochondrial DNA, although analyses of mitochondrial DNA can be a good indicator of taxa in need of further integrative taxonomic assessment.

Sublethal fitness costs of chronic exposure to hot weather vary between sexes in a threatened desert lark

ABSTRACT Behavioural trade-offs between foraging and thermoregulation result in negative relationships between diurnal body mass (M b) gain and daily maximum air temperature (T max) in arid-zone birds. However, it remains unclear how these trade-offs are affected by habitat type or sexually dimorphic behaviour. Using the South African arid-zone endemic Red Lark (Calendulauda burra) as a model taxon and focusing solely on non-breeding adults, we evaluated predictions that a) time-activity budgets are more strongly affected by air temperature (T a) than is the case for species occurring in arid savanna habitats with greater access to shaded microsites, and b) the effects of T max on diurnal M b gain differ between males and females. Behavioural observations revealed an effect of T a on activity, and sex differences in the temperature-dependence of resting and wing-spreading. Moreover, M b data obtained from habituated larks trained to perch on an electronic balance revealed that in males, but not females, diurnal M b gain was negatively related to T max, with diurnal M b gain equivalent to average overnight M b loss when T max = 33.5°C and zero diurnal M b gain (i.e. net 24-hr M b loss of ~ 5 %) when T max = 40.0°C. Under recent climate conditions, male Red Larks rarely, if ever, experienced consecutive days with T max > 40.0°C but, under an unmitigated climate change scenario, will experience 10–15 consecutive days per summer by the end of the 21st century. Our findings suggest that this threatened lark species is unlikely to persist across much of its current range by 2100.

A Fossil Species of Eremophila and Other Larks (Aves, Alaudidae) from the upper Pliocene of the Selenga River Valley (Central Asia)

We describe lark (Alaudidae) fossils from the upper Pliocene of the Beregovaya (southern Transbaikalia) and Shaamar (northern Mongolia) localities. The presence of 4 extinct forms in these localities is established, including the new fossil horned lark Eremophila orkhonensis (Zelenkov et Kurochkin, 2012), comb. nov. This is the oldest member of Eremophila in the fossil record, indicating a possible Central Asian origin of the genus. Two other larks Alaudala aff. A. rufescens and Calandrella aff. C. brachydactyla also probably represent extinct forms. The paper describes in detail the osteology of larks and compares it with other passerines in its size class. The evolutionary history of Eremophila is discussed, and the environmental preferences of larks and their relationship to the late Pliocene landscapes of Central Asia are considered.

Density of Larks (Alaudidae, Aves) of the Semi-desert of the Trans-Volga Region in Connection with the Landscape Wetting Dynamics

The dynamics of the density of nesting pairs of five lark species (Alaudidae) living on the territories of the Mezhuzenskii and Uzeno-Dyurinskii Plains, on the northwestern tip of the Caspian Lowland, and in the semi-desert of the Aleksandrovo-Gayskii district of Saratov oblast, and its relationship with Selyaninov’s hydrothermal coefficient (HTC) are considered. This research was carried out annually on 40 fixed routes of 1 km each in the breeding period of the annual lark cycle from 2011 to 2019. It was established that the abundance dynamics trends were negative in four lark species, namely, the Calandra Lark (Melanocorypha calandra), the White-winged Lark (M. leucoptera), the Black Lark (M. yeltoniensis), and the Lesser Short-toed Lark (Calandrella rufescens); and were positive in the Skylark (Alauda arvensis). The calculated trend of HTC indicators for these territories demonstrates a 5.4% annual increase in the moistening of the semi-desert zone of our survey area. To assess the relationship of the density of different lark species to the values of the HTC, we calculated the Spearman correlation coefficients. When analyzing the data obtained, it was found that a high positive correlation of density with the HTC was observed for the Skylark, Calandra Lark, and Black Lark; no such relationship was found in the White-winged Lark, and a high negative correlation of the density of nesting pairs with the HTC was found in the Lesser Short-toed Lark. Based on our research, it can be assumed that moistening of the semi-desert territory is one of the main factors determining the abundance dynamics of larks. The heat–moisture ratio determines the level of vegetation and, accordingly, the quality of habitats for these land-nesting birds.

Long-Term Dynamics of the Community Structure of Larks (Alaudidae, Aves) in the Northwestern Caspian Lowland

Abstract—We studied the population structure and the number of larks in the steppe and semidesert zones of the Caspian Lowland (within the territories of the Alexandrov-Gai district of Saratov region, Russian Federation, and Dzhanybek and Bokey-Ordyn districts of the Western Kazakhstan region, Republic of Kazakhstan) in six key areas in 2011–2018. From the data obtained, dynamic series of the density dynamics were calculated for each lark species (Tgr, growth rate). The group statistical indicators were R, which is the fluctuation magnitude of the lark density, and u, the coefficient of variation, etc.; using Pearson’s χ2 statistics, the normal type of lark distribution was checked in their habitats. A correlation analysis between the density of larks and values of the vegetation index (NDVI) was performed. It has been established that four species of lark (calandra lark, white-winged, black and lesser short-toed larks) show a tendency toward a decrease in their density in the Alexandrov-Gai district. The maximum decrease in abundance was observed for the white-winged lark (Tgr = –28.4%, R2 = 0.785). In the Western Kazakhstan part of the habitat, the highest negative growth rate was recorded for the skylark (Tgr = –99.9%), while the maximum positive one was observed for the white-winged lark (Tgr = +25.2). It has been revealed that the lark density dynamics and the structure of their nesting population are influenced by the vegetation level in the previous year, as well as the vegetation structure associated with the soil and ground conditions of this mosaic landscape and the anthropogenic press, such as cattle pasture.

Estudio preliminar de especies de aves presentes en zona urbana el municipio de Tunja, Boyacá

Se presentan los resultados del trabajo de observación y caracterización de las especies de aves residentes, migratorias y endémicas, que permanecen y transitan en la zona urbana del municipio de Tunja en el departamento de Boyacá, durante cuatro años. Inicialmente, se hace una introducción en donde se atribuye a las aves una importancia significativa en la conservación de los ecosistemas, resaltando su nicho ecológico. Asimismo, se describe el modelo metodológico con el que se desarrolla la investigación, denominado observación directa a través de puntos de conteo, que contempla la selección de los sitios de muestreos en diferentes lugares circundantes o aledaños a los ríos, parques y zonas verdes; se destaca el uso de la herramienta de análisis de confiabilidad de la información recolectada a través de curvas de acumulación de especies, se determina la riqueza específica y abundancia de las especies encontradas. De acuerdo con los resultados, se reporta la descripción de 68 especies de aves presentes en la zona urbana y en donde, de manera particular, se caracterizan dos casos: el primero, relacionado con la especie alondra (Eremophila alpestris) y segundo, el Chamon (Molothrus bonarensis). En cuanto al primero, se reporta avistamiento de seis individuos en una zona donde se consideraba extintas por la desaparición de su hábitat; en el segundo, se alerta sobre la relación parásita que establecen el chamón con el copetón (Zonotrichia capensis). Finalmente, se evidencia la necesidad de la creación de un programa de conservación de los hábitats de las especies de aves que se identificaron.

Analysis of Soil and Vegetation Cover from Satellite Imagery to Assess its Relation to Lark Habitats (Alaudidae, Aves) in the Trans-Volga Semi-Desert

Abstract—This work was carried out in the Dzhanibek and Bokey Orda districts of the West Kazakhstan region of the Republic of Kazakhstan in two key areas. The possibility to study the relationship between the distribution of the abundance of various lark species and their nesting habitats detected using high-resolution satellite images, ground geobotanical descriptions, and bird counts on routes with a variable width of the accounting band was evaluated. The image heterogeneity in a snapshot was analyzed by cluster analysis in the ILWIS software (Heckbert quantization algorithm) using three rasters as variables: infrared and red channel images and NDVI. The correlation between the number of some lark species and the share of some plant associations in the band of accounting routes was established using correlation analysis and approximation of empirical distributions by theoretical ones. A reliable relationship was established between the distribution of three lark species living in the Trans-Volga semi-desert of the Caspian lowland with certain plant associations which they prefer to use as nesting stations.

Microbiome assembly of avian eggshells and their potential as transgenerational carriers of maternal microbiota.

The microbiome is essential for development, health and homeostasis throughout an animal's life. Yet, the origins and transmission processes governing animal microbiomes remain elusive for non-human vertebrates, oviparous vertebrates in particular. Eggs may function as transgenerational carriers of the maternal microbiome, warranting characterisation of egg microbiome assembly. Here, we investigated maternal and environmental contributions to avian eggshell microbiota in wild passerine birds: woodlark Lullula arborea and skylark Alauda arvensis. Using 16S rRNA gene sequencing, we demonstrated in both lark species, at the population and within-nest levels, that bacterial communities of freshly laid eggs were distinct from the female cloacal microbiome. Instead, soil-borne bacteria appeared to thrive on freshly laid eggs, and eggshell microbiota composition strongly resembled maternal skin, body feather and nest material communities, sources in direct contact with laid eggs. Finally, phylogenetic structure analysis and microbial source tracking underscored species sorting from directly contacting sources rather than in vivo-transferred symbionts. The female-egg-nest system allowed an integrative assessment of avian egg microbiome assembly, revealing mixed modes of symbiont acquisition not previously documented for vertebrate eggs. Our findings illuminated egg microbiome origins, which suggested a limited potential of eggshells for transgenerational transmission, encouraging further investigation of eggshell microbiome functions in vertebrates.

Многолетняя динамика структуры сообщества жаворонков (Alaudidae, Aves) на северо-западе Прикаспийской низменности

We studied the population structure and the number of larks in the steppe and semi-desert zones of the Caspian Lowland (within the territories of Alexandrov-Gay district of the Saratov region, Russian Federation, Dzhanybek and Bokey-Ordyn districts of the Western-Kazakhstan region, Republic of Kazakhstan) in six key areas in 2011 – 2018. From the data obtained, dynamic series of the density dynamics were calculated for each lark species (T gr , growth rate), the group statistical indicators: R is the fluctuation magnitude of larks, u the coefficient of variation, etc., using Pearson’s χ 2 , the normal type of lark distribution was checked in their habitats. A correlation analysis between the density of larks and the vegetation index ( NDVI ) values was done. It has been established that four lark species (the steppe, white-winged, black and gray larks) show a tendency of decreasing their density in Alexandrov-Gay district. The maximum abundance decrease was observed for the White-winged Lark (T gr = -28.4%, R 2 = 0.785). In the Western Kazakhstan part of the habitat, the highest negative growth rate (T gr = -99.9%) was recorded for the field lark, while the maximum positive one was for the white-winged lark (T gr = +25.2). It has been revealed that the lark density dynamics and the structure of their nesting population are influenced by the vegetation level in the previous year, and the vegetation structure associated with the soil and ground conditions of this mosaic landscape and the anthropogenic press such as cattle pasture.

Interfacial properties of avian stratum corneum monolayers investigated by Brewster angle microscopy and vibrational sum frequency generation

The outermost layer of skin, the stratum corneum (SC), contains a complex mixture of lipids, which controls the rate of cutaneous water loss (CWL) in reptiles, mammals, and birds. However, the molecular structure of SC lipids and how molecular configurations influence CWL is poorly understood. Here, the organization and structure of SC lipids extracted from birds were investigated by means of Langmuir films. Properties of lipids from the SC of arid and semi-arid adapted larks, known to have a low CWL, were compared with lipids extracted from the SC of mesic lark species with higher CWL to gain insight into how structure impacts CWL. Film properties were probed with surface pressure-area isotherms, Brewster angle microscopy (BAM), and vibrational sum frequency generation (VSFG). Results indicate organization and ordering of SC lipids in the arid-adapted hoopoe lark was vastly different from all other species, forming a miscible, rigid monolayer, whereas monolayers from semi-arid and mesic species were immiscible and disordered. Probing of interfacial water structure reveals that film morphology determines organization of water molecules near the monolayer; monolayers with a porous morphology had an increased population of water molecules that are weakly hydrogen-bonded. In general, CWL appears related to the miscibility and ordering of lipid components within the SC, as well as the ability of these lipids to interact with water molecules. From a broader perspective, CWL in larks appears linked to both the SC lipid composition and the aridity of the species’ environment.

Breeding biology of the endangered Dupont’s Lark Chersophilus duponti in two separate Spanish shrub-steppes

ABSTRACTCapsule: The Dupont’s Lark Chersophilus duponti in Iberia has relatively high breeding success in both core and fragmented habitats, so population declines are more likely to be the result of low juvenile or adult survival.Aims: To measure important aspects of the reproductive biology of one of the most endangered and least known larks: the Dupont’s Lark C. duponti.Methods: We monitored 36 nests in 2 Spanish shrub-steppes, one holding one of the largest European populations (250 pairs) and one composed by fragmented habitat patches holding a smaller population (50 pairs).Results: The breeding season went from late-March to early July. Overall mean (±sd) clutch size was 3.47 ± 0.56, and the number of fledglings per successful nest was 3.0 ± 1.15. Mean nestling period was short (8.2 days). Nests showed similar daily survival rate during the incubation period (0.9750 ± 0.0110) as during the nestling period (0.9545 ± 0.0168), with a mean breeding success of 50%. Predation was the main cause of complete nest failure (83.3% of failed nests in both localities).Conclusion: Breeding parameters did show no significant variation between populations. Breeding success in both sites was generally higher than recorded in previous studies of this and most other lark species, which suggests that breeding success does not compromise long-term viability of these populations. The decline of the studied populations should be explained by other causes, such as a general decrease in habitat quality, habitat loss or habitat fragmentation.

Structural dynamics of the breeding population of larks (Alaudidae, Aves) in the semidesert of the Saratov Trans-Volga region

According to our data on the density of breeding pairs of five lark species obtained from route censuses, the dynamics of their population in the Mezhuzenskii and Uzensko-Dyurinskii landscapes of the semidesert in the Caspian lowland is considered. Our five-year census work was carried out on key sites 25 km2 in area, with mapping and description of the soils and vegetation using remote sensing techniques. Our comprehensive studies of these key areas have revealed the dynamics of the individual lark species characteristic of the northwestern part of the Trans-Volga region of the Caspian lowland and the changes in the level of vegetation of the plant component of individual landscape tracts depending on the moisture level in certain years. It is shown that, in the monotonous plain conditions, an important role in the distribution of the specific population of larks is played by the meso- and micro-relief, which determines the soil salinity, and the distribution of moisture and vegetation groups (which predetermine the features of bird habitats). The interannual variability of the population structure of larks is shown, which, in the modern conditions of consistently low anthropogenic pressure, is determined by the weather in specific years, which determines the level of vegetation and, therefore, changes in the nesting conditions of birds in specific habitats.

Nesting population structure of larks (Alaudidae, Aves) in typical semidesert habitats of the Caspian Lowland

The distribution of nesting populations of individual lark species by semidesert habitats in the Caspian Lowland is analyzed on the basis of data on the density of nesting pairs estimated by transect counts. The counts have been taken in 25-km2 key areas, in combination with mapping and description of soils and vegetation. Such an integrated approach has made it possible to reveal habitat preferences of individual Alaudidae species characteristic of the northwestern Transvolga part of the Caspian Lowland. It is shown that the distribution of lark species in a monotonous plain depends primarily on its meso-and microrelief as the main factor determining the patterns of soil salinity and vegetation groups, which, in turn, determine specific features of bird habitats.

A survey for the Critically Endangered Liben Lark Heteromirafra archeri in Somaliland, north-western Somalia

The Critically Endangered Archer's Lark (now Liben Lark) Heteromirafra archeri was formerly considered to be endemic to north-western Somalia and known only from the Tog Wajaale Plain, where 18 specimens were collected between 1918 and 1922. Fifteen visits between 1970 and 2008 failed to relocate the species there, although popula- tions are now known from adjacent Ethiopia. We conducted three days of intensive surveys on the Tog Wajaale Plain in May 2010. Despite the three other lark species present being in full display, and H. archeri being recorded to have bred in early June, no Liben Larks were found. Vegetation structure surveys indicated that the plain has a taller and denser growth of grass than either of the other known localities for Liben Lark (the Liben and Jijiga Plains) making Tog Wajaale Plain seem superficially more suitable for the species, which prefers areas of taller grass elsewhere. However, previous large-scale agricultural activities may have altered the composition of grass species and precipitated the observed invasion of exotic weeds, notably Parthenium hysterophorus. Importantly, the Tog Wajaale Plain has a greater density of bushes than either the Liben or Jijiga Plains, possibly making ground-nesting birds more susceptible to predation by perch hunters.

Environmental proxies of antigen exposure explain variation in immune investment better than indices of pace of life.

Investment in immune defences is predicted to covary with a variety of ecologically and evolutionarily relevant axes, with pace of life and environmental antigen exposure being two examples. These axes may themselves covary directly or inversely, and such relationships can lead to conflicting predictions regarding immune investment. If pace of life shapes immune investment then, following life history theory, slow-living, arid zone and tropical species should invest more in immunity than fast-living temperate species. Alternatively, if antigen exposure drives immune investment, then species in antigen-rich tropical and temperate environments are predicted to exhibit higher immune indices than species from antigen-poor arid locations. To test these contrasting predictions we investigated how variation in pace of life and antigen exposure influence immune investment in related lark species (Alaudidae) with differing life histories and predicted risks of exposure to environmental microbes and parasites. We used clutch size and total number of eggs laid per year as indicators of pace of life, and aridity, and the climatic variables that influence aridity, as correlates of antigen abundance. We quantified immune investment by measuring four indices of innate immunity. Pace of life explained little of the variation in immune investment, and only one immune measure correlated significantly with pace of life, but not in the predicted direction. Conversely, aridity, our proxy for environmental antigen exposure, was predictive of immune investment, and larks in more mesic environments had higher immune indices than those living in arid, low-risk locations. Our study suggests that abiotic environmental variables with strong ties to environmental antigen exposure can be important correlates of immunological variation.

Predators and Predation Rates of SkylarkAlauda arvensisand WoodlarkLullula arboreaNests in a Semi-Natural Area in the Netherlands

Predation is a major cause of breeding failure in bird species with open nests. Although many studies have investigated nest predation rates, direct identification of nest predators is sporadic, especially in (semi-)natural habitats. We quantified nest success and identified nest predators in a population of Skylarks Alauda arvensis and Woodlarks Lullula arborea breeding in a protected semi-natural area dominated by heathland and different succession states of grassland on nutrient-poor soil in The Netherlands. We monitored 54 nests by means of continuous video surveillance to determine survival times and predators, and monitored another 44 nests without a camera. Fates of the 58 (40) Skylark (Woodlark) nests were: fledging 41 (27), depredation 13 (12), egg desertion 1 (0) and nestling death 3 (1). The overall nest success of all monitored nests (58 (40), Mayfield estimate) was 33% (22%; all mortality factors considered) or 43% (25%; only depredation). Predators of Skylark nests were Red Fox Vulpes vulpes (5), Carrion Crow Corvus corone (1) and European Adder Vipera berus (1). Woodlark nests were depredated by Carrion Crow (2), Eurasian Jay Garrulus glandarius (1) and Red Fox (1). Results suggest that the main nest predators might differ between the two co-occurring lark species; Skylark nests located in more open sites were preyed upon mainly by Red Fox, while the main predators of Woodlark nests, located generally closer to trees, are corvids.