2024, Tobółka, Marcin, Zielińska, Zuzanna, Fusani, Leonida, Huber, Nikolaus, Maggini, Ivan, Pola, Gianni, Marasco, Valeria

ABSTRACT While immunity is frequently dampened when birds engage in strenuous migratory flights, whether and how immunity changes during the rapid accumulation of energy stores in preparation for migration remains largely unknown. Here we induced pre-migratory fattening through controlled changes of daylight in common quails (Coturnix coturnix) and regularly assessed changes in three markers of constitutive innate immunity (leukocyte coping capacity or LCC, hemagglutination and hemolysis titres) and measures of body composition (lean and fat mass). All the three markers showed similar changes over the pre-migratory fattening process. LCC responses, hemagglutination titres, and hemolysis titres, were on average higher in the mid-fattening phase compared to the peak-fattening phase, when values were similar to those observed prior the start of pre-migratory fattening. At mid-fattening, we found that the birds that showed a larger accumulation of fat mass (as % of body mass) had lower LCC peak responses and hemolysis titres. Reversibly, at mid-fattening, we also found that the birds that kept a higher proportion of lean mass (as % of body mass) had the highest LCC peaks. Our results indicate that migratory birds undergo changes in immune indices (over 8 weeks) as they accumulate energy stores for migration and propose that this could be due to competing or trade-off processes between metabolic remodelling and innate immune system function.

2024, Serratosa, Juan, Oppel, Steffen, Rotics, Shay, Santangeli, Andrea, Butchart, Stuart H.M., Cano-Alonso, Luis S., Tellería, Jose Luis, Kemp, Ryno, Nicholas, Aaron, Kalvāns, Aigars, Galarza, Aitor, Franco, Aldina M.A., Andreotti, Alessandro, Kirschel, Alexander N.G., Ngari, Alex, Soutullo, Alvaro, Bermejo-Bermejo, Ana, Botha, Andre J., Ferri, Andrea, Evangelidis, Angelos, Cenerini, Anna, Stamenov, Anton, Hernández-Matías, Antonio, Aradis, Arianna, Grozdanov, Atanas P., Rodríguez, Beneharo, Şekercioğlu, Çağan H., Cerecedo-Iglesias, Catuxa, Kassara, Christina, Barboutis, Christos, Bracebridge, Claire, García-Ripollés, Clara, Kendall, Corinne J., Denac, Damijan, Schabo, Dana G., Barber, David R., Popov, Dimitar V., Dobrev, Dobromir D., Mallia, Egidio, Kmetova-Biro, Elena, Álvarez, Ernesto, Buechley, Evan R., Bragin, Evgeny A., Cordischi, Fabrizio, Zengeya, Fadzai M., Monti, Flavio, Mougeot, Francois, Tate, Gareth, Stoyanov, Georgi, Dell'Omo, Giacomo, Lucia, Giuseppe, Gradev, Gradimir, Ceccolini, Guido, Friedemann, Guilad, Bauer, Hans-Günther, Kolberg, Holger, Peshev, Hristo, Catry, Inês, Øien, Ingar J., Alanís, Isidoro Carbonell, Literák, Ivan, Pokrovsky, Ivan, Ojaste, Ivar, Østnes, Jan E., de la Puente, Javier, Real, Joan, Guilherme, João L., González, José C., Fernández-García, José M., Gil, Juan Antonio, Terraube, Julien, Poprach, Karel, Aghababyan, Karen, Klein, Katharina, Bildstein, Keith L., Wolter, Kerri, Janssens, Kjell, Kittelberger, Kyle D., Thompson, Lindy J., AlJahdhami, Mansoor H., Galán, Manuel, Tobółka, Marcin, Posillico, Mario, Cipollone, Mario, Gschweng, Marion, Strazds, Māris, Boorman, Mark, Zvidzai, Mark, Acácio, Marta, Romero, Marta, Wikelski, Martin, Schmidt, Matthias, Sarà, Maurizio, McGrady, Michael J., Dagys, Mindaugas, Mackenzie, Monique L., Al Taq, Muna, Mgumba, Msafiri P., Virani, Munir Z., Kassinis, Nicolaos I., Borgianni, Nicolò, Thie, Nikki, Tsiopelas, Nikos, Anglister, Nili, Farwig, Nina, Sapir, Nir, Kleven, Oddmund, Krone, Oliver, Duriez, Olivier, Spiegel, Orr, Al Nouri, Osama, López-López, Pascual, Byholm, Patrik, Kamath, Pauline L., Mirski, Paweł, Palatitz, Peter, Serroni, Pietro, Raab, Rainer, Buij, Ralph, Žydelis, Ramūnas, Nathan, Ran, Bowie, Rauri C.K., Tsiakiris, Rigas, Hatfield, Richard Stratton, Harel, Roi, Kroglund, Rolf T., Efrat, Ron, Limiñana, Ruben, Javed, Salim, Marinković, Saša P., Rösner, Sascha, Pekarsky, Sasha, Kapila, Shiv R., Marin, Simeon A., Krejčí, Šimon, Giokas, Sinos, Tumanyan, Siranush, Turjeman, Sondra, Krüger, Sonja C., Ewing, Steven R., Stoychev, Stoycho, Nikolov, Stoyan C., Qaneer, Tareq E., Spatz, Theresa, Hadjikyriakou, Thomas G., Mueller, Thomas, Katzner, Todd E., Aarvak, Tomas, Veselovský, Tomáš, Nygård, Torgeir, Mellone, Ugo, Väli, Ülo, Sellis, Urmas, Urios, Vicente, Nemček, Vladimír, Arkumarev, Volen, Getz, Wayne M., Fiedler, Wolfgang, Van den Bossche, Willem, Lehnardt, Yael, Jones, Victoria R.

2024, Bialas, Joanna T., Dylewski, Łukasz, Tobółka, Marcin

AbstractThe brain size of vertebrates represents a trade‐off between natural selection for enhanced cognitive abilities and the energetic constraints of brain tissue production. Processing information efficiently can confer benefits, but it also entails time costs. Breeding strategies, encompassing timing of breeding onset and nest‐site selection, may be related to brain size. In this study, we aim to elucidate the relationship between brain size, breeding timing, nest‐site choice, and breeding success in the red‐backed shrike Lanius collurio. Our findings revealed that the timing of the first egg‐laying date was associated with female head size, with larger‐headed females tending to lay eggs later in the breeding season. Additionally, we observed that breeding success was positively correlated with increased nest concealment. However, this relationship was stronger in males with smaller heads. In turn, nest concealment was not related to head size but primarily influenced breeding onset. These results suggest that the choice of breeding strategy may be moderated by brain size, with differences between sexes. Larger‐headed females may invest more time in selecting nesting sites, leading to delayed breeding onset, while larger‐headed males may compensate for suboptimal nest concealment. Our study sheds light on the intricate interplay between brain size, breeding timing, nest‐site preferences, and breeding success in passerine birds, underscoring the potential role of cognitive capacity in shaping individual decision‐making processes.