Julia Zurdo, Paula Gómez-López, Adrián Barrero, Daniel Bustillo-de la Rosa, Julia Gómez-Catasús, Margarita Reverter, Cristian Pérez-Granados, Manuel B. Morales, Juan Traba. 2023: Selecting the best: Interspecific and age-related diet differences among sympatric steppe passerines. Avian Research, 14(1): 100151. DOI: 10.1016/j.avrs.2023.100151
Citation: Julia Zurdo, Paula Gómez-López, Adrián Barrero, Daniel Bustillo-de la Rosa, Julia Gómez-Catasús, Margarita Reverter, Cristian Pérez-Granados, Manuel B. Morales, Juan Traba. 2023: Selecting the best: Interspecific and age-related diet differences among sympatric steppe passerines. Avian Research, 14(1): 100151. DOI: 10.1016/j.avrs.2023.100151

Selecting the best: Interspecific and age-related diet differences among sympatric steppe passerines

More Information
  • Corresponding author:

    Terrestrial Ecology Group, Department of Ecology, Universidad Autónoma de Madrid (TEG-UAM), Madrid, Spain. E-mail address: julia.zurdo@uam.es (J. Zurdo)

  • Received Date: 18 Sep 2023
  • Rev Recd Date: 13 Nov 2023
  • Accepted Date: 13 Nov 2023
  • Available Online: 10 Jan 2024
  • Publish Date: 20 Nov 2023
  • Parental food provisioning is crucial for the growth and survival of offspring. Growth rate depends on food quality and food supplied to offspring may differ from what adults use for their own. In the case of steppe passerine birds, detailed characterization on nestling dietary composition, as well as prey choice and resource partitioning among species, is a pending subject. Dietary differences between nestlings and adults remain also largely unexplored. By using faecal DNA metabarcoding, we described the diet of nestlings and adults of five shrub-steppe passerine species over the 2017–2019 breeding seasons in central Spain. We also monitored arthropod availability in the field to assess dietary selection. We expected interspecific dietary differences to limit competition for food resources among sympatric species, as well as parental selection of high quality prey for nestlings. We also predicted age-related differences, with nestlings being fed nutrient-rich prey more frequently than adults. The main arthropod orders provisioned to nestlings were Orthoptera, Julida, Araneae and Lepidoptera. Nestlings of the different species showed high interspecific diet overlap, indicating both a coincidence in growth needs among bird species and no or little limitation of the most profitable resources during the breeding season. Adults of all species showed higher diet richness than nestlings, and age-related differences in prey composition were mainly driven by the selection of the most easily digestible, larger protein- and calcium-rich prey for nestlings, which may favour their rapid growth, and avoiding highly sclerotized and less nutritional prey such as ants. Our study sheds light on the basic ecology and conservation of these declining steppe birds, indicating that interspecific competition may not be a major factor during the breeding season. Given the current global decline of arthropods, further long-term research would be necessary, along with the implementation of effective conservation measures that ensure a sufficient availability of resources identified as key prey in the diet of steppe bird nestlings.

  • Rejection of parasite eggs is an effective defense mechanism of bird hosts against brood parasitism (Davies, 2000; Soler, 2014; Ma and Liang, 2021; Ye et al., 2022a, 2022b). Accurate rejection of parasitic eggs requires recognition of the host eggs. Visual cues (Ruiz-Raya and Soler, 2020; Samaš et al., 2021), tactile cues (Meshcheryagina et al., 2016; Ye et al., 2022b) and olfactory cues (Soler et al., 2014; Golüke et al., 2016; Leclaire et al., 2017) are all used by hosts to identify foreign eggs. Recognition may occur through two different mechanisms (Feeney et al., 2014; Manna et al., 2017): true recognition, that is, the ability to compare the eggs in the nest to an internal template of the appearance of the host's own eggs, and discordancy, that is, the ability to identify an odd egg, or eggs, in the clutch. If the egg recognition mechanism of the hosts is true recognition, they reject the foreign eggs whether these are as numerous as their own eggs, outnumber their own eggs, or are the only egg type present (Rothstein, 1975; Lyon, 2007; Yi et al., 2020; Yang et al., 2022). If the egg recognition mechanism of the hosts is discordancy recognition, the small number of eggs that are different from the most eggs are rejected (Moskát et al., 2010, 2014; Bán et al., 2013; Yang et al., 2014; Tosi-Germán et al., 2020). However, only some hosts can readily recognize their own eggs.

    Differences in selection pressures in the coevolutionary process between hosts and cuckoos in the same region have resulted in varied egg recognition abilities among host species (Begum et al., 2012; Liu et al., 2020). For example, there were significant differences in the egg recognition ability among the four hosts of different cuckoo species: Common Mynas (Acridotheres tristis), Jungle Babblers (Turdoides striata), Long-tailed Shrikes (Lanius schach) and House Crows (Corvus splendens). Common Mynas and Jungle Babblers do not possess egg recognition ability and accept all mimetic eggs. House Crows show low egg recognition ability, rejecting 9.1% of the mimetic eggs, while Long-tailed Shrikes have egg recognition ability and reject 75% of the mimetic eggs (Begum et al., 2012). The differences in coevolution and interaction pressure between a host species and its parasitic cuckoos may also lead to significant differences in egg rejection among geographic populations of the same host species (Yang et al., 2015; Liang et al., 2016). In southern Spain where there is a high risk of parasitism by Great Spotted Cuckoos (Clamator glandarius), the rejection rate of the Eurasian Magpie (Pica pica) toward non-mimetic eggs is close to 90% (Soler et al., 2015). In contrast, in China, where the Eurasian Magpie is not parasitized by any cuckoo species, the acceptance rate of experimental non-mimetic parasite eggs was 100% (Yang et al., 2021). Great Tits (Parus major) in Europe do not have a coevolutionary relationship with cuckoos (Davies, 2000), and they do not have the ability to recognize eggs. In China, Great Tits and Green-backed Tits (Parus monticolus) may have a strong coevolutionary interaction with cuckoos, because they all have a high egg recognition capability (Liang et al., 2016; Liu et al., 2019, 2020).

    The Azure-winged Magpie (Cyanopica cyanus) is a passerine species (Zheng, 2021) commonly found in the eastern Palearctic (Madge, 2020; Madge and Juana, 2020). Other than Great Spotted Cuckoos of Spain (Erritzøe et al., 2012), the Common Cuckoo (Cuculus canorus) is the only parasite species in most regions of Europe. In the past, Azure-winged Magpies in Iberia and China were thought to be the same species, but because they have had an independent evolutionary history for a long time, they are now considered as two species, Azure-winged Magpie (Cyanopica cyanus) and Iberian Magpie (C. cooki) (Zheng, 2021). Although Iberian Magpies are not parasitized by Great Spotted Cuckoos in Europe, it has developed strong egg recognition ability. This suggests that the egg recognition ability of Iberian Magpies has evolved from intra-specific (con-specific) and not inter-specific brood parasitism (Avilés, 2004). In Japan, no egg recognition ability has been observed in Azure-winged Magpies when they are not parasitized by Common Cuckoos. Within 10–20 years of the Common Cuckoo parasitism, they rapidly evolved the ability to recognize and reject foreign eggs (Takasu et al., 1993; Nakamura et al., 1998). In South Korea, Azure-winged Magpies are rarely hosts of Indian Cuckoos (Cuculus micropterus) but they possess strong egg recognition ability. Son et al. (2015) believe that Korean Azure-winged Magpies migrated from China, and retained the egg recognition ability of their founders. In China, Azure-winged Magpies are parasitized by both Indian Cuckoos and Asian Koels (Eudynamyss scolopaceus) (Yang et al., 2012; J. Liu, own observations), but it is unclear if the Azure-winged Magpie populations in a multiple cuckoo system in China have egg recognition ability and, if so, how they identify parasitic eggs. One earlier research suggested that Azure-winged Magpies are more sensitive to the number of eggs than to their size (Shang et al., 1994). Therefore, we wondered if changes in egg numbers would affect egg rejection behavior in Azure-winged Magpies. To address these questions, egg discrimination ability and recognition mechanism of the Azure-winged Magpie in China were investigated. We predicted that Fusong Azure-winged Magpies also have a high egg recognition ability. If the Azure-winged Magpies are more sensitive to egg numbers, directly increasing the number of eggs by adding two experimental eggs will result in an increased rejection rate of the experimental eggs compared to replacing two Azure-winged Magpie's eggs with two experimental eggs.

    This study was conducted in Fusong County, southeastern Jilin, China (42°19ʹ N, 127°15ʹ E), an area of secondary forest fragmented by Corn (Zea mays) crop farmlands and scattered plantations (dominated by larch Larix spp.), from May to June 2013. This region is in the temperate zone at an elevation of 481 ​m, with a continental monsoon climate characterized by cold and snowy winters with an average annual temperature of 4 ​℃ (Yang et al., 2019).

    Field studies were conducted during the breeding season of Azure-winged Magpies in 2013. Breeding nests in the study area were searched and egg discriminate experiments were conducted on nests in the early stage of incubation, that were assigned to one of these four treatments. Experiment 1, in which two Japanese Quail (Coturnix japonica) eggs were introduced (Fig. 1A). Experiment 2, in which two host eggs were removed and two quail eggs were added (Fig. 1B). In Experiment 1 and Experiment 2, we wondered if Azure-winged Magpies were able to recognize foreign eggs and whether the increase in clutch size caused Azure-winged Magpies to become more sensitive to experimental eggs and reject the experimental eggs more often. Experiment 3, two Azure-winged Magpie eggs (conspecific eggs) were added to the host magpie nest. Experiment 4, two host eggs were removed and two conspecific eggs were added (Fig. 1C). In Experiment 3 and Experiment 4, we wondered if Azure-winged Magpies were able to recognize conspecific eggs and whether the increase in clutch size caused Azure-winged Magpies to become more sensitive to conspecific eggs and reject the conspecific eggs more often. Experiment 5, namely the "control group", refers to a group in which nests were visited using the same procedure as the experimental group, but without any experimental eggs added to control for human disturbance (n ​= ​10). Most Azure-winged Magpies can recognize foreign eggs and will reject quail eggs within three days after the experiment (own unpublished data). Therefore, after confirming that the Azure-winged Magpies recognized and discarded the experimental parasitic eggs, the egg recognition mechanism was further tested. For Azure-winged Magpies that could correctly recognize and reject the experimental parasitic eggs, Experiment 6, a '4 ​+ ​4' experiment, was subsequently performed as described by Wang et al. (2013) and Yi et al. (2020). In Experiment 6, four Azure-winged Magpie eggs and four quail eggs were simultaneously placed in a nest (Fig. 1D). If the egg recognition mechanism of the Azure-winged Magpie is true recognition mechanism, then all the individual Azure-winged Magpies will reject the quail eggs added to their nests. For all of the experimental nests, host response to the experimental eggs was observed for six days (Moksnes et al., 1991; Yang et al., 2019). If no egg rejection was observed within this period, the eggs were considered accepted. If the experimental eggs were rejected and the host eggs were not damaged, disappeared, or the host abandoned the nest, the eggs were considered rejected. If the host rejected its own eggs, it was considered as the cost of rejection. Experimental nests that were predated or destroyed by humans during the six-day period were eliminated from the experimental results.

    Figure  1.  Egg recognition experiments in nests of the Azure-winged Magpie. (A) refers to adding two Japanese Quail eggs to the nest; (B) refers to replacing two host eggs with two quail eggs; (C) refers to replacing two host eggs with two conspecific eggs and (D) refers to experimental nests with four experimental eggs and four host eggs.

    Statistical analysis was performed with IBM SPSS 20.0 (IBM Inc., USA) for Windows. Fisher's exact test or Pearson's Chi-squared test was used to compare the probabilities obtained in different experimental groups. All tests were two-tailed. The significance level was P ​ < ​0.05, and summary data are presented as mean ​± ​SD.

    In Fusong, no Azure-winged Magpies were found to be parasitized by Indian Cuckoos and Asian Koels in 2013. There were no differences in rejection rate of quail eggs between treatments 1 and 2 (45.5%, n ​= ​22 vs. 71.4%, n ​= ​14, Pearson's Chi-squared test, χ2 ​= ​2.414, df ​= ​2, P ​= ​0.299, Table 1). There were no differences in rejection rate of conspecific eggs between treatments 3 and 4: Azure-winged Magpies did not reject any eggs (0%, n ​= ​16 vs. 0%, n ​= ​12). In Experiment 6, Azure-winged Magpies accurately rejected all experimental eggs without incurring any rejection cost (100%, n ​= ​13). Video recordings showed that in Experiment 6, most Azure-winged Magpies rejected the experimental eggs within 2 ​h by pecking the eggs first and then seizing them and throwing them out of the nest (Appendix Video S1 and S2). Some individuals simply seized and threw the experimental eggs out of the nest without pecking. In all the experiments, we found no nest desertion in Azure-winged Magpies.

    Table  1.  Rejection frequencies (%) of experimental Japanese Quail eggs by Azure-winged Magpies.
    Experiment Number of exp. nests Rejecting two exp. eggs Accepting two exp. eggs Rejecting one exp. egg Rejection cost
    Adding two quail eggs 22 8 (36.4) 8 (36.4) 2 (9.0) 4 (18.2)
    Replacing two host eggs with two quail eggs 14 9 (64.4) 3 (21.4) 1 (7.1) 1 (7.1)
     | Show Table
    DownLoad: CSV

    Supplementary video related to this article can be found at https://doi.org/10.1016/j.avrs.2023.100112

    The present study showed that the Azure-winged Magpie population of Fusong, Jilin, China, had a moderate egg rejection rate toward non-mimetic quail eggs but was unable to recognize conspecific eggs that were highly mimetic to its own eggs. Some individuals displayed recognition errors in their rejection of experimental eggs. For example, three nests of Azure-winged Magpies mistakenly rejected one or two of their own eggs but accepted quail eggs. In addition, the species showed a true recognition mechanism (template-based recognition) and rejected foreign eggs by accurate recognition of their own eggs.

    Although Azure-winged Magpies were found to be parasitized by Indian Cuckoos in another population 320 ​km away from Fusong, no Azure-winged Magpies were found to be parasitized by Indian Cuckoos and Asian Koels in our study area in 2013. The Fusong Azure-winged Magpie population studied showed a rejection rate of 55.6% toward non-mimetic quail eggs. This rejection rate is lower than the rejection rate displayed by a Korean population (96%) (Son et al., 2015), and the Iberian Magpies (73.7%) (Avilés, 2004). The difference in the egg rejection rate in the three studies may result from the differences in coevolutionary interactions between Azure-winged Magpies and cuckoos in these regions (Yang et al., 2015; Liang et al., 2016), or the differences among the experimental eggs used. The experimental eggs used by Avilés (2004) were highly similar to the eggs of Great Spotted Cuckoos, and Son et al. (2015) used blue model eggs made from soft clay, while our study used non-mimetic quail eggs, which was a bit larger than host eggs (quail eggs: 29.42–37.25 ​mm length ​× ​24.11–27.3 ​mm breadth vs. magpie eggs: 24.06–28.28 ​mm length ​× ​19.12–21.42 ​mm breadth). The three types of experimental eggs differ in material, color, and size and this possibly contributed to the different egg rejection rates observed in these studies (Roncalli et al., 2017; Luro et al., 2018). The Azure-winged Magpie population studied here showed a relatively low egg rejection rate, which could be due to the addition of two experimental eggs because some studies suggest a reduced host rejection probability toward parasitic eggs in the presence of multiple parasitism (Moskát et al., 2009; Stevens et al., 2013). Similar to the observations of Son et al. (2015), we also found no nest desertion in Azure-winged Magpies, suggesting that nest desertion would not be a behavioral strategy against cuckoo parasitism.

    In this study, recognition errors and rejection costs were sometimes involved in the rejection of experimental eggs by the Azure-winged Magpie. Two nests of Azure-winged Magpies also rejected one of their own eggs at the same time when they rejected a quail egg. Three nests of Azure-winged Magpies accepted quail eggs and rejected one or two of their own eggs. This is similar to an Azure-winged Magpie population in Beijing (Shang et al., 1994), but differs from the results of Son et al. (2015), as the magpie population they studied did not suffer any rejection cost when they rejected blue model eggs. Avilés (2004) painted quail eggs with acrylic paint to simulate Great Spotted Cuckoo eggs and studied the egg rejection behavior of Azure-winged Magpies. They observed rejection costs in that population with many (28.6%) of the nests losing one or two of their own eggs when rejecting the parasite eggs. The rejection cost incurred by Azure-winged Magpies in rejecting quail eggs could be related to the thicker eggshell of the latter. Our video recordings show that Azure-winged Magpies usually puncture a hole in the experimental eggs before seizing them and throwing them out of the nest. Quail eggs, with a thicker eggshell, are not easily punctured (Swynnerton, 1918; Krüger, 2011). Azure-winged Magpies, in their effort to puncture quail eggs, could also destroy some of their own eggs and therefore incur a rejection cost.

    Avilés (2004); Avilés and Parejo (2012), and Son et al. (2022) observed the ability of magpies to recognize conspecific eggs, with 42.8% in Avilés (2004), 35.5% in Avilés and Parejo (2012) and 30% in Son et al. (2022). Both Avilés and Parejo (2012) and Son et al. (2022) found that the recognition and rejection of conspecific eggs by Iberian Magpies and Azure-winged Magpies were strongly related to variation in egg size within the nests and less related to variation in egg color. However, in our study, Azure-winged Magpies accepted all the conspecific eggs whether two such eggs were added to the nests or the eggs were added as a replacement for two removed host eggs. This indicates that the Azure-winged Magpie of Fusong population is unable to recognize conspecific eggs. This difference may be related to differences in the coevolutionary history and the interactions between Azure-winged Magpies, Iberian Magpies and different cuckoo species in China, Korea and Iberia. For example, in Iberia, records show that Great Spotted Cuckoos and Common Cuckoos once co-evolved with Iberian Magpies but there are few field observations indicating the recent occurrence of inter-specific brood parasitism in the Iberian Magpie (Alonso et al., 1991; Valencia et al., 2003, 2005; Avilés, 2004). For this reason, Avilés (2004) suggested that the Iberian Magpies evolved egg recognition not as a defense against interspecific brood parasitism, but as a defense against conspecific brood parastisim. Indian Cuckoo parasitism is also rarely reported on Azure-winged Magpies in South Korea (Lee, 2014), and Son et al. (2015) suggested that the high egg recognition ability of Azure-winged Magpies may be due to the coevolutionary relationship between Azure-winged Magpies and Indian Cuckoo in the past, because interspecific brood parasite is the main selection pressure leading to the evolution of egg recognition ability in birds (Ruiz-Raya et al., 2016). However, Azure-winged Magpies are parasitized by both Indian Cuckoos and Asian Koels in China.

    Interestingly, different from Wang et al. (2013), in which increase of clutch size triggered clutch destruction behavior in Common Moorhens (Gallinula chloropus), Azure-winged Magpies in this study accepted all additional two or four experimental eggs added to their nests in Experiment 1, Experiment 3, and Experiment 6 without nest desertion. In Experiment 6, all the individuals rejected quail eggs, and no one rejected their own eggs. Although we did not design an additional experiment by adding an extra set of experimental treatment in which the quail eggs were more numerous than the Azure-winged Magpie's own eggs, the egg recognition mechanism of Fusong Azure-winged Magpies is more likely to be true recognition mechanism, as the discordancy mechanism predicts that hosts typically eject the egg types that are most dissimilar (and thus, necessarily, in the minority) in clutches, irrespective of whether these are their own eggs or parasitic eggs. If egg discrimination in the Azure-winged Magpie occurs by the discordancy recognition mechanism, then there are two possible outcomes in Experiment 6. The first outcome is that all the individuals do not reject the eggs in nests, and the second outcome is that all the individuals randomly reject the eggs in the nests. If all the individuals randomly reject the eggs in the nests, it is highly unlikely that in Experiment 6 all individuals will reject only quail eggs.

    In conclusion, our study shows that Azure-winged Magpies in a north Chinese population possess moderate egg recognition ability as some populations do in other geographical regions, and show a true recognition mechanism of rejecting foreign eggs by accurate recognition of their own eggs. However, they cannot recognize mimetic conspecific eggs. In the '4 ​+ ​4' experiment, all Azure-winged Magpies accurately rejected quail eggs added to their nests. However, more experiments may be necessary in order to completely eliminate the mechanism of recognition by discordancy. The egg characteristics used as recognition clues remain to be identified. There may be differences in parasitic cuckoo species and cuckoo parasitism across China (Yang et al., 2012). For example, in northern China (Palearctic realm), Azure-winged Magpies are parasitized by only one cuckoo species, while in southern China (Indomalayan realm), Azure-winged Magpies could be parasitized by several cuckoo species, including Common Cuckoos, Indian Cuckoos and Asian Koels. Geographical variations in egg recognition ability of Azure-winged Magpies under different cuckoo and/or even conspecific parasitism remain to be determined.

    The experiments comply with the current laws of China, where they were performed. Experimental procedures were in agreement with the Animal Research Ethics Committee of Hainan Provincial Education Centre for Ecology and Environment, Hainan Normal University (No. HNECEE-2014-005).

    WL designed the study, LW carried out field experiments, JL performed the analyses and wrote the draft manuscript, WL edited and improved the manuscript. All authors read and approved the final manuscript.

    The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

    We are grateful to two anonymous reviewers' constructive comments which help improve this manuscript.

  • Alberdi, A., Aizpurua, O., Bohmann, K., Gopalakrishnan, S., Lynggaard, C., Nielsen, M., et al., 2019. Promises and pitfalls of using high-throughput sequencing for diet analysis. Mol. Ecol. Resour. 19, 327–348.
    Alonso, H., Granadeiro, J.P., Paiva, V.H., Dias, A.S., Ramos, J.A., Catry, P., 2012. Parent-offspring dietary segregation of Cory's shearwaters breeding in contrasting environments. Mar. Biol. 159, 1197–1207.
    Aradis, A., Lo Verde, G., Massa, B., 2019. Importance of millipedes (Diplopoda) in the autumn-winter diet of Scolopax rusticola. Eur. Zool. J. 86, 452–457.
    Arco, L., Martín-Vivaldi, M., Peralta-Sánchez, J.M., Juárez García-Pelayo, N., Soler, M., 2022. Provisioning challenge: self-consumption versus nestling provisioning, an experimental study. Anim. Behav. 190, 153–165.
    Arnold, K.E., Ramsay, S.L., Donaldson, C., Adam, A., 2007. Parental prey selection affects risk taking behaviour and spatial learning in avian offspring. Proc. R. Soc. A B 274, 2563–2569.
    Arnold, K.E., Ramsay, S.L., Henderson, L., Larcombe, S., 2010. Seasonal variation in diet quality: antioxidants, invertebrates and blue tits Cyanistes caeruleus. Biol. J. Linn. Soc. Lond. 99, 708–717.
    Attard, M.R.G., Portugal, S.J., 2022. Global diversity and adaptations of avian eggshell thickness índices. Ibis. .
    Barboza, P.S., Parker, K.L., Hume, I.D., 2008. Integrative Wildlife Nutrition. Springer-Verlag, Heidelberg.
    Barrero, A., Cortés Caballero, B., Reverter, M., Gómez-Catasús, J., Bustillo-de la Rosa, D., Zurdo, J., et al., 2023a. Nesting niche segregation in steppe passerines. ARDEOLA 70, 201–224.
    Barrero, A., Ovaskainen, O., Traba, J., Gómez-Catasús, J., 2023b. Co-occurrence patterns in a steppe bird community: insights into the role of dominance and competition. Oikos 2023, e09780.
    Barrett, R.T., Camphuysen, K., Anker-Nilssen, T., Chardine, J.W., Furness, R.W., Garthe, S., et al., 2007. Diet studies of seabirds: a review and recommendations. ICES J. Mar. Sci. 64, 1675–1691.
    Bates, D., Maechler, M., Bolker, B., Walker, S., 2015. lme4: linear mixed-effects models using Eigen and S4. J. Stat. Software 67, 1–48.
    Blanco, G., Frias, O., Martinez, J., Lemus, J.A., Merino, R., Jimenez, B., 2006. Sex and rank in competitive brood hierarchies influence stress levels in nestlings of a sexually dimorphic bird. Biol. J. Linn. Soc. Lond. 88, 383–390.
    Bowler, D.E., Heldbjerg, H., Fox, A.D., de Jong, M., Bøhning-Gaese, K., 2019. Long-term declines of European insectivorous bird populations and potential causes. Conserv. Biol. 33, 1120–1130.
    Boyer, F., Mercier, C., Bonin, A., Le Bras, Y., Taberlet, P., Coissac, E., 2016. OBITools: a unix-inspired software package for DNA metabarcoding. Mol. Ecol. Resour. 16, 176–182.
    Bravo, C., Cuscó, F., Morales, M.B., Mañosa, S., 2017. Diet composition of a declining steppe bird the Little Bustard (Tetrax tetrax) in relation to farming practices. Avian Conserv. Ecol. 12, 3.
    Brodmann, P.A., Reyer, H., 1999. Nestling provisioning in water pipits (Anthus spinoletta): do parents go for specific nutrients or profitable prey? Oecologia 120, 506–514.
    Bureš, S., Weidinger, K., 2003. Sources and timing of calcium intake during reproduction in flycatchers. Oecologia 137, 634–647.
    Cabodevilla, X., Gómez-Moliner, B.J., Abad, N., Madeira, M.J., 2023. Simultaneous analysis of the intestinal parasites and diet through eDNA metabarcoding. Integr. Zool. 18, 399–413.
    Cardoso, P., Barton, P.S., Birkhofer, K., Chichorro, F., Deacon, C., Fartmann, T., et al., 2020. Scientists' warning to humanity on insect extinctions. Biol. Conserv. 242, 108426.
    Chase, J.M., Leibold, M.A., 2009. Ecological Niches: Linking Classical and Contemporary Approaches. University of Chicago Press, Chicago.
    Chesson, P., 2000. Mechanisms of maintenance of species diversity. Annu. Rev. Ecol. Evol. Syst. 31, 343–366.
    Costantini, D., 2010. Effects of diet quality on growth pattern, serum oxidative status, and corticosterone in Pigeons (Columba livia). Can. J. Zool. 88, 795–802.
    Cramp, S., 1988. Handbook of the birds of Europe, Middle East and North Africa: the birds of the Western Palearctic. Volume V. In: Tyrant Flycatchers to Thrushes, vol. 1063. Oxford University Press, Oxford.
    Cuff, J.P., Windsor, F.M., Tercel, M.P.T.G., Kitson, J.J.N., Evans, D.M., 2022. Overcoming the pitfalls of merging dietary metabarcoding into ecological networks. Methods Ecol. Evol. 13, 545–559.
    da Silva, L.P., Mata, V.A., Lopes, P.B., Pereira, P., Jarman, S.N., Lopes, R.J., et al., 2019. Advancing the integration of multimarker metabarcoding data in dietary analysis of trophic generalists. Mol. Ecol. Resour. 19, 1420–1432.
    Dänhardt, A., Fresemann, T., Becker, P.H., 2011. To eat or to feed? Prey utilization of common terns Sterna hirundo in the Wadden sea. J. Ornithol. 152, 347–357.
    Davies, S.R., Vaughan, I.P., Thomas, R.J., Drake, L.E., Marchbank, A., Symondson, W.O. C., 2022. Seasonal and ontological variation in diet and age-related differences in prey choice, by an insectivorous songbird. Ecol. Evol. 12, e9180.
    Deagle, B.E., Thomas, A.C., Shaffer, A.K., Trites, A.W., Jarman, S.N., 2013. Quantifying sequence proportions in a DNA-based diet study using Ion Torrent amplicon sequencing: which counts count? Mol. Ecol. Resour. 13, 620–633.
    del Portillo, D.G., Arroyo, B., García Simón, G., Morales, M.B., 2021. Can current farmland landscapes feed declining steppe birds? Evaluating arthropod abundance for the endangered little bustard (Tetrax tetrax) in cereal farmland during the chick-rearing period: variations between habitats and localities. Ecol. Evol. 11, 3219–3238.
    Donald, P.F., Muirhead, L.B., Buckingham, D.L., Evans, A.D., Kirby, W.B., Gruar, D.J., 2001. Body condition, growth rates and diet of Skylark Alauda arvensis nestlings on lowland farmland. Ibis 143, 658–669.
    Drake, L.E., Cuff, J.P., Young, R.E., Marchbank, A., Chadwick, E.A., Symondson, W.O.C., 2021. An assessment of minimum sequence copy thresholds for identifying and reducing the prevalence of artefacts in dietary metabarcoding data. Methods Ecol. Evol. 13, 1–17.
    Fox, J., Weisberg, S., 2019. An R Companion to Applied Regression, third ed. Sage, Thousand Oaks CA .
    Frøslev, T.G., Kjøller, R., Bruun, H.H., Ejrnæs, R., Brunbjerg, A.K., Pietroni, C., et al., 2017. Algorithm for post-clustering curation of DNA amplicon data yields reliable biodiversity estimates. Nat. Commun. 8, 1188.
    Galante, E., Numa Valdez, C., Verdú, J.R., 2015. La conservación de los insectos en España, una cuestión no resuelta. Revista IDE@-SEA 7, 1–13.
    García-Antón, A., Traba, J., 2021. Population viability analysis of the endangered Dupont's Lark Chersophilus duponti in Spain. Sci. Rep. 11, 19947.
    Gómez-Catasús, J., Barrero, A., Garza, V., Traba, J., 2016. Alondra ricotí-Chersophilus duponti (Vieillot, 1820). Enciclopedia Virtual de los Vertebrados Españoles. In: Sociedad de Amigos del MNCN-MNCN-CSIC. .
    Gómez-Catasús, J., Pérez-Granados, C., Barrero, A., Bota, G., Giralt, D., López-Iborra, G. M., et al., 2018. European population trends and current conservation status of an endangered steppe-bird species: the Dupont's lark Chersophilus duponti. PeerJ 6, e5627.
    Gómez-Catasús, J., Barrero, A., Reverter, M., Bustillo-de la Rosa, D., Pérez-Granados, C., Traba, J., 2021. Landscape features associated to wind farms increase mammalian predator abundance and ground-nest predation. Biodivers. Conserv. 30, 2581–2604.
    Gómez-Catasús, J., Reverter, M., Bustillo-de la Rosa, D., Barrero, A., Pérez-Granados, C., Zurdo, J., et al., 2023. Moderate sheep grazing increases arthropod biomass and habitat use by steppe birds. Agric. Ecosyst. Environ. 354, 108556.
    Gotelli, N.J., Hart, E.M., Ellison, A.M., 2015. EcoSimR: null model analysis for ecological data. R package version 0.1.0. .
    Grames, E.M., Montgomery, G.A., Youngflesh, C., Tingley, M.W., Elphick, C.S., 2023. The effect of insect food availability on songbird reproductive success and chick body condition: evidence from a systematic review and meta-analysis. Ecol. Lett. 26, 658–673.
    Hails, C.J., Turner, A.K., 1985. The role of fat and protein during breeding in the White-bellied swiftlet (Coffocaia escufenta). J. Zool. 206, 469–484.
    Hallmann, C.A., Sorg, M., Jongejans, E., Siepel, H., Hofland, N., Schwan, H., et al., 2017. More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLoS One 12, e0185809.
    Hames, R.S., Lowe, J.D., Swarthout, S.B., Rosenberg, K.V., 2006. Understanding the risk to neotropical migrant bird species of multiple human-caused stressors: elucidating processes behind the patterns. Ecol. Soc. 11, 24.
    Hebda, G., Kata, K., Zmihorski, ˙ M., 2019. The last meal: large insects predominate the diet of the European Roller Coracias garrulus prior to population extinction. Bird Study 66, 173–177.
    Heiss, R.S., Clark, A.B., McGowan, K.J., 2009. Growth and nutritional state of American Crow nestlings vary between urban and rural habitats. Ecol. Appl. 19, 829–839.
    Herlugson, C.J., 1982. Food of adult and nestling western and mountain bluebirds. Murrelet 63, 59–65.
    Herranz, J., Yanes, M., Suárez, F., 1993. Primeros datos sobre la dieta de pollos de Alondra de Dupont, Chersophilus duponti, en la Península Ibérica. ARDEOLA 40, 77–79.
    Herranz, J., Yanes, M., Suárez, F., 1997. La dieta de los pollos de dos aláudidos simpátricos: Cogujada Montesina (Galerida theklae) y Terrera Marismeña(Calandrella rufescens). In: En Actas de las Ⅻ Jornadas Ornitológicas Españolas: ˜Almerimar (El Ejido-Almería), 15 a 19 de septiembre, 1994. Instituto de Estudios Almerienses, pp. 123–133.
    Hódar, J.A., 1996. The use of regression equations for estimation of arthropod biomass in ecological studies. Acta Oecol. 17, 421–433.
    Honarmand, M., Goymann, W., Naguib, M., 2010. Stressful dieting: nutritional conditions but not compensatory growth elevate corticosterone levels in Zebra Finch nestlings and fledglings. PLoS One 5, e12930.
    Jedlicka, J.A., Vo, A.E., Rodrigo, P.P., 2017. Molecular scatology and high-throughput sequencing reveal predominately herbivorous insects in the diets of adult and nestling western bluebirds (Sialia mexicana) in California vineyards. Auk 134, 116–127.
    Johnston, R.D., 1993. Effects of diet quality on the nestling growth of a wild insectivorous passerine, the House Martin Delichon urbica. Funct. Ecol. 7, 255–266.
    Jusino, M.A., Banik, M.T., Palmer, J.M., Wray, A.K., Xiao, L., Pelton, E., et al., 2019. An improved method for utilizing high-throughput amplicon sequencing to determine the diets of insectivorous animals. Mol. Ecol. Resour. 19, 176–190.
    Klasing, K.C., 1998. Comparative Avian Nutrition. CAB International, London.
    Lamb, P.D., Hunter, E., Pinnegar, J.K., Creer, S., Davies, R.G., Taylor, M.I., 2019. How quantitative is metabarcoding: a meta-analytical approach. Mol. Ecol. 28, 420–430.
    Lawlor, L.R., 1980. Structure and stability in natural and randomly constructed model ecosystems. Am. Nat. 116, 394–408.
    Leray, M., Knowlton, N., 2017. Random sampling causes the low reproducibility of rare eukaryotic OTUs in Illumina COI metabarcoding. PeerJ 5, e3006.
    López, H., Pérez, A.J., Rumeu, B., Nogales, M., 2016. Trophic strategies of Yellow-legged Gull Larus michahellis on oceanic islands surrounded by deep waters. Bird Study 63, 337–345.
    MacArthur, R.H., Levins, R., 1967. The limiting similarity, convergence and divergence of coexisting species. Am. Nat. 101, 377–385.
    Mahé, F., Rognes, T., Quince, C., de Vargas, C., Dunthorn, M., 2015. Swarm v2: highly-scalable and high-resolution amplicon clustering. PeerJ 3, e1420.
    Mainjargal, G., Buuveibaatar, B., Boldbaatar, S., 2013. Morphology, diet composition, distribution and nesting biology of four lark species in Mongolia. Mong. J. Biol. Sci. 11, 3–11.
    Martin, T.E., 1987. Food as a limit on breeding birds: a life-history perspective. Annu. Rev. Ecol. Evol. Syst. 18, 453–487.
    McLeay, L.J., Page, B., Goldsworthy, S.D., Ward, T.M., Paton, D.C., 2009. Size matters: variation in the diet of chick and adult crested terns. Mar. Biol. 156, 1765–1780.
    Murray, D.C., Bunce, M., Cannell, B.L., Oliver, R., Houston, J., White, N.E., et al., 2011. DNA-based faecal dietary analysis: a comparison of qPCR and high throughput sequencing approaches. PLoS One 6, e25776.
    Naef-Daenzer, B., Keller, L., 1999. Foraging performance of great and blue tits (Parus major, Parus caeruleus) in relation to caterpillar development and its consequences for nestling growth and fledging weight. J. Anim. Ecol. 68, 708–718.
    Naef-Daenzer, L., Naef-Daenzer, B., Nager, R.G., 2000. Prey selection and foraging performance of breeding great tits Parus major in relation to food availability. J. Avian Biol. 31, 206–214.
    Nilsson, J. -Å., Gårdmark, A., 2001. Sibling competition affects individual growth strategies in marsh tit, Parus palustris, nestlings. Anim. Behav. 61, 357–365.
    Oksanen, J., Simpson, G., Blanchet, F., Kindt, R., Legendre, P., Minchin, P., et al., 2022. vegan: community Ecology Package. R package version 2.6-4. .
    Orłowski, G., Hałupka, L., Pokorny, P., Klimczuk, E., Sztwiertnia, H., Dobicki, W., 2016. The effect of embryonic development on metal and calcium content in eggs and eggshells in a small passerine. Ibis 158, 144–154.
    Orłowski, G., Rusiecki, S., Karg, J., 2014. Partial dietary segregation between adult and nestling Bluethroats Luscinia svecica. Acta Ornithol. 49, 107–118.
    Ottens, H.J., Kuiper, M.W., Flinks, H., van Ruijven, J., Siepel, H., Koks, B.J., et al., 2014. Do field margins enrich the diet of the Eurasian Skylark Alauda arvensis on intensive farmland? Ardea 102, 161–174.
    Pérez-Granados, C., López-Iborra, G.M., Garza, V., Traba, J., 2017. Breeding biology of the endangered Dupont's Lark Chersophilus duponti in two separate Spanish shrub-steppes. Bird Study 64, 328–338.
    Perrins, C., 1987. Aves de España y de Europa. Ediciones Omega, S.A.
    Pianka, E.R., 1973. The structure of lizard communities. Annu. Rev. Ecol. Systemat. 4, 53–74.
    Piñol, J., Senar, M.A., Symondson, W.O.C., 2018. The choice of universal primers and the characteristics of the species mixture determines when DNA metabarcoding can be quantitative. Mol. Ecol. 28, 407–419.
    Pompanon, F., Deagle, B.E., Symondson, W.O.C., Brown, D.S., Jarman, S.N., Taberlet, P., 2012. Who is eating what: diet assessment using next generation sequencing. Mol. Ecol. 21, 1931–1950.
    Poulsen, J.G., Sotherton, N.W., Aebischer, N.J., 1998. Comparative nesting and feeding ecology of Skylarks Alauda arvensis on arable farmland in southern England with special reference to set-aside. J. Appl. Ecol. 35, 131–147.
    R Core Team, 2023. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna. .
    Radford, A.N., 2008. Age-related changes in nestling diet of the cooperatively breeding Green Woodhoopoe. Ethology 114, 907–915.
    Razeng, E., Watson, D.M., 2015. Nutritional composition of the preferred prey of insectivorous birds: popularity reflects quality. J. Avian Biol. 46, 89–96.
    Reed, S.A., Raja, J.S., Hoffman, M.L., Zinn, S.A., Govoni, K.E., 2014. Poor maternal nutrition inhibits muscle development in ovine offspring. J. Anim. Sci. Biotechnol. 5, 43.
    Reeves, J.T., Fuhlendorf, S.D., Davis, C.A., Wilder, S.M., 2021. Arthropod prey vary among orders in their nutrient and exoskeleton content. Ecol. Evol. 11, 17774–17785.
    Reverter, M., Gómez-Catasús, J., Barrero, A., Traba, J., 2021. Crops modify habitat quality beyond their limits. Agric. Ecosyst. Environ. 319, 107542.
    Reynolds, S.J., Perrins, C.M., 2010. Dietary calcium availability and reproduction in birds. In: Thompson, C. (Ed.), Current Ornithology, vol. 17. Springer, New York, pp. 31–74.
    Robel, R.J., Press, B.M., Henning, B.L., Johnson, K.W., Blocker, H.D., Kemp, K.E., 1995. Nutrient and energetic characteristics of sweepnet-collected invertebrates. J. Field Ornithol. 66, 44–53.
    Rognes, T., Flouri, T., Nichols, B., Quince, C., Mahé, F., 2016. VSEARCH: a versatile open source tool for metagenomics. PeerJ 4, e2584.
    Rumpold, B.A., Schlüter, O.K., 2013. Nutritional composition and safety aspects of edible insects. Mol. Nutr. Food Res. 57, 802–823.
    Sainz Ollero, H., 2013. Steppe ecosystems: biological diversity, management and restoration. In: Morales, M.B., Traba, J. (Eds.), Steppes across the World: an Overview with Emphasis on the Iberian Peninsula. Nova Science Publishers, pp. 1–26.
    Salsamendi, E., Garin, I., Arostegui, I., Goiti, U., Aihartza, J., 2012. What mechanism of niche segregation allows the coexistence of sympatric sibling rhinolophid bats? Front. Zool. 9, 1–12.
    Santos, T., Suárez, F., 2005. Biogeography and population trends of Iberian steppe birds. In: Bota, G., Morales, M.B., Mañosa, S., Camprodón, J. (Eds.), Ecology and Conservation of Steppe-Land Birds. Lynx Edicions and Centre Tecnològic Forestal de Catalunya, Barcelona, pp. 69–102.
    Schoener, T.W., 1982. The controversy over interspecific competition. Am. J. Sci. 70, 586–590.
    Schwagmeyer, P.L., Mock, D.W., 2008. Parental provisioning and offspring fitness: size matters. Anim. Behav. 75, 291–298.
    Searcy, W., Peters, S., Nowicki, S., 2004. Effects of early nutrition on growth rate and adult size in song sparrows Melospiza melodia. J. Avian Biol. 33, 269–279.
    Smetana, N.M., Gusewa, W.S., 1981. Food habits of the Tawny Pipit in the naursum pine-forest. Ornithologija 16, 88–92.
    Soberón, J., 2007. Grinnellian and Eltonian niches and geographic distributions of species. Ecol. Lett. 10, 1115–1123.
    Spence, A.R., Wilson Rankin, E.E., Tingley, M.W., 2022. DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds. Ornithology 139, ukab074.
    Starck, J.M., Ricklefs, R.E., 1998. Avian Growth and Development: Evolution within the Altricial-Precocial Spectrum. Oxford University Press, Oxford.
    Stillman, A.N., Caiafa, M.V., Lorenz, T.J., Jusino, M.A., Tingley, M.W., 2022. DNA metabarcoding reveals broad woodpecker diets in fire-maintained forests. Ornithology 139, ukac009.
    Suárez, F., 1987. La alimentación de los pollos de dos aves esteparias simbiotópicas en la Península Ibérica: Collalba rubia y Collalba gris. In: Ena, E.V. (Ed.), Actas I Congreso Internacional de Aves Esteparias. Junta de Castilla y León, pp. 193–208.
    Suárez, F., Hervás, I., Herranz, J., 2009. Las alondras de España peninsular. Dirección General para la Biodiversidad, Ministerio de Medio Ambiente y Medio rural y Marino, Madrid.
    Sullins, D.S., Haukos, D.A., Craine, J.M., Lautenbach, J.M., Robinson, S.G., Lautenbach, J.D., et al., 2018. Identifying the diet of a declining prairie grouse using DNA metabarcoding. Auk 135, 583–608.
    Taberlet, P., Coissac, E., Pompanon, F., Brochmann, C., Willerslev, E., 2012. Towards next-generation biodiversity assessment using DNA metabarcoding. Mol. Ecol. 21, 2045–2050.
    Taberlet, P., Bonin, A., Zinger, L., Coissac, E., 2018. Environmental DNA: for Biodiversity Research and Monitoring. Oxford University Press, Oxford.
    Tournayre, O., Leuchtmann, M., Filippi-Codaccioni, O., Trillat, M., Piry, S., Pontier, D., et al., 2020. In silico and empirical evaluation of twelve metabarcoding primer sets for insectivorous diet analyses. Ecol. Evol. 10, 6310–6332.
    Traba, J., Pérez-Granados, C., 2022. Extensive sheep grazing is associated with trends in steppe birds in Spain: recommendations for the Common Agricultural Policy. PeerJ 10, e12870.
    Trevelline, B.K., Nuttle, T., Hoenig, B.D., Brouwer, N., Porter, B.A., Latta, S.C., 2018. DNA metabarcoding of nestling faeces reveals provisioning of aquatic prey and resource partitioning among Neotropical migratory songbirds in a riparian habitat. Oecologia 187, 85–98.
    Ueckert, D.N., Yang, S.P., Albin, R.C., 1972. Biological value of rangeland grasshoppers as a protein concentrate. J. Econ. Entomol. 65, 1286–1288.
    Vamos, E., Elbrecht, V., Leese, F., 2017. Short COI markers for freshwater macroinvertebrate metabarcoding. Metabarcod. Metagenom. 1, e14625.
    Vaughan, I.P., Gotelli, N.J., Memmott, J., Pearson, C.L., Woodward, G., Symondson, W. O.C., 2018. econullnetr: an R package using null modelling to analyse the structure of ecological networks and identify resource selection. Methods Ecol. Evol. 9, 728–733.
    Wagner, D.L., Grames, E.M., Forister, M.L., Berenbaum, M.R., Stopak, D., 2021. Insect decline in the Anthropocene: death by a thousand cuts. P. Natl. Acad. Sci. USA 118, e2023989118.
    Wang, Y., Naumann, U., Wright, S.T., Warton, D.I., 2012. Mvabund–an R package for model-based analysis of multivariate abundance data. Methods Ecol. Evol. 3, 471–474.
    Wang, Y., Naumann, U., Eddelbuettel, D., Wilshire, J., Warton, D., 2022. Mvabund: Statistical Methods for Analysing Multivariate Abundance Data. R package version 4.2.1. .
    White, T.C.R., 2011. The significance of unripe seeds and animal tissues in the protein nutrition of herbivores. Biol. Rev. 86, 217–224.
    Yang, C., Stokke, B.G., Antonov, A., Cai, Y., Shi, S., Moksnes, A., et al., 2013. Host selection in parasitic birds: are open-cup nesting insectivorous passerines always suitable cuckoo hosts? J. Avian Biol. 44, 216–220.
    Zeale, M.R.K., Butlin, R.K., Barker, G.L.A., Lees, D.C., Jones, G., 2011. Taxon-specific PCR for DNA barcoding arthropod prey in bat faeces. Mol. Ecol. Resour. 11, 236–244.
    Zurdo, J., Baonza, J., Traba, J., 2021. New insights on plant communities and flora of the southern paramos of the Iberian range (Spain). Phytocoenologia 50, 371–382.
    Zurdo, J., Barrero, A., da Silva, L.P., Bustillo-de la rosa, D., Gómez-Catasús, J., Morales, M.B., et al., 2023. Dietary niche overlap and resource partitioning among six steppe passerines of Central Spain using DNA metabarcoding. Ibis 165, 905–923.

Catalog

    Figures(5)  /  Tables(3)

    Article Metrics

    Article views (14) PDF downloads (13) Cited by()

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return