Abstract
Within social signaling contexts, behavioral displays used for territorial defense and courtship may be affected by vegetation characteristics and by human disturbance. The primary aim of this study was to evaluate the relation between motor display variables of the blue-black grassquit (Volatinia jacarina) and vegetation characteristics. Secondly, we tested if human disturbance (fire and grass mowing) could induce variations in display variables. We modelled two display variables involving conspicuousness and energetic motor investment (i.e., leap duration and rate) to examine their relation to habitat characteristics that reflect vegetation complexity (i.e., grass seed abundance, shadow intensity, vegetation density) and evaluated whether confounding factors (e.g., time of day, territory location and breeding status) influenced this relationship. In a second set of analyses, we assessed the influence of fire and grass mowing upon the bird’s display. We found that leap duration increased in contexts of high seed abundance and shadow intensity, and leap rate decreased along the day. Distance from display perches to vegetation patch edge or streets and the presence of an active nest did not predict displays variables. We also show that following a fire event, birds exhibited a lower display rate. Our results indicate that vegetation structure helps to shape the blue-black grassquit display, consistent with the interpretation that courtship exhibitions can signal territory quality. Our findings also show that anthropogenic disturbance can impact a bird’s sexual display and underscores the urgency of further studies about the effects of human activities on animals’ reproductive behaviors.
Significance statement
Vegetation characteristics influence resource abundance and provide the backdrop for most animal activities. The degree of vegetation density can either facilitate or confound individuals’ daily activities, since vegetation density influences detection by mates, competitors, and predators. Human-induced habitat changes can influence animal communication by modifying vegetation structure and resource distribution. Our objective was to evaluate the relation between motor display variables of a tropical bird and vegetation characteristics and test if human disturbance could induce variations in display variables. We found that displays are influenced by seed abundance and shadow intensity, leap rate is highest at dawn, and fire reduces display rate. Our results indicate that vegetation structure helps in shaping this species’ sexual display. We highlight the lack of studies evaluating the influence of human activities on animals’ reproductive behaviors.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Aguilar TM, Dias RI, Oliveira AC, Macedo RH (2008) Nest-site selection by Blue-black Grassquits in a Neotropical savanna: do choices influence nest success? J Field Ornithol 79:24–31. https://doi.org/10.1111/j.1557-9263.2008.00142.x
Alderton CC (1963) The breeding behavior of the Blue-black Grassquit. Condor 65:154–162. https://doi.org/10.2307/1365492
Almeida JB, Macedo RH (2001) Lek-like mating system of the monogamous Blue-black Grassquit. Auk 118:404–411. https://doi.org/10.1642/0004-8038(2001)118[0404:LLMSOT]2.0.CO;2
Alquezar RD, Macedo RH, Sierro J, Gil D (2020) Lack of consistent responses to aircraft noise in dawn song timing of bird populations near tropical airports. Behav Ecol Sociobiol 74:88. https://doi.org/10.1007/s00265-020-02865-6
Assunção SL, Felfili JM (2004) Fitossociologia de um fragmento de cerrado sensu stricto na APA do Paranoá, DF, Brasil. Acta Bot Bras 18:903–909
Bejarano V, Jahn AE (2018) Relationship between arrival timing and breeding success of intra-tropical migratory Fork-tailed Flycatchers (Tyrannus savana). J Field Ornithol 89:109–116. https://doi.org/10.1111/jofo.12251
Biagolini C Jr, Macedo RH (2019) bwimage: A package to describe image patterns in natural structures. F1000Res 8:1168. https://doi.org/10.12688/f1000research.19801.3
Biagolini C Jr, Macedo RH (2021) Philornis infection in Blue-black grassquits: impact on nestlings and risk factors involved. J Avian Biol (published online. https://doi.org/10.1111/jav.02592)
Biagolini C Jr, Silva EF Jr, Silva CHA, Macedo RH (2020) Food, shadow and fire influence a tropical bird´s display. https://doi.org/10.17632/t7tkrwynt7.1 Accessed 19 March 2021.
Boyd RJ, Kelly TR, MacDougall-Shackleton SA, MacDougall-Shackleton EA (2018) Alternative reproductive strategies in white-throated sparrows are associated with differences in parasite load following experimental infection. Biol Lett 14:20180194. https://doi.org/10.1098/rsbl.2018.0194
Brumm H, Zollinger SA (2013) Avian vocal production in noise. In: Brumm H (ed) Animal communication and noise. Springer, Berlin, pp 187–227. https://doi.org/10.1007/978-3-642-41494-7
Cantarero A, Pilastro A, Griggio M (2018) Nestling sex ratio is associated with both male and female attractiveness in rock sparrows. J Avian Biol 49:e01666. https://doi.org/10.1111/jav.01666
Carvalho CBV, Macedo RH, Graves JA (2006) Breeding strategies of a socially monogamous neotropical passerine: Extra-pair fertilizations, behavior, and morphology. Condor 108:579–590. https://doi.org/10.1093/condor/108.3.579
Carvalho CBV, Macedo RHF, Graves JA (2007) Reproduction of Blue-black Grassquits in central Brazil. Braz J Biol 67:275–281. https://doi.org/10.1590/S1519-69842007000200012
Coutinho LM (1990) Fire in the ecology of the Brazilian cerrado. In: Goldammer JG (ed) Fire in the Tropical Biota. Ecological Studies (Analysis and Synthesis). Springer, Berlin, pp 82–105. https://doi.org/10.1007/978-3-642-75395-4_6
Da Silva A, Samplonius JM, Schlicht E, Valcu M, Kempenaers B (2014) Artificial night lighting rather than traffic noise affects the daily timing of dawn and dusk singing in common European songbirds. Behav Ecol 25:1037–1047. https://doi.org/10.1093/beheco/aru103
Darolová A, Krištofík J, Hoi H (2014) Vegetation type variation in marsh habitats: does it affect nest site selection, reproductive success, and maternal investment in Reed Warblers? J Ornithol 155:997–1008. https://doi.org/10.1007/s10336-014-1086-0
de Moraes PZ, Diniz P, Macedo RH (2019) Flirting with danger: predation risk affects male aerial display in a Neotropical songbird. Behav Ecol 30:1265–1272. https://doi.org/10.1093/beheco/arz073
de Moraes PZ, Diniz P, Macedo RH (2020) Sex-specific effects of predation risk on parental care in a sexually dichromatic Neotropical songbird. J Avian Biol (published online). https://doi.org/10.1111/jav.02483)
Dias RI, Macedo RH (2011) Nest predation versus resources in a Neotropical passerine: Constraints of the food limitation hypothesis. Ornis Fennica 88:30–39
Dias RI, Kuhlmann M, Lourenço LR, Macedo RH (2009) Territorial clustering in the Blue-black Grassquit: reproductive strategy in response to habitat and food requirements? Condor 111:706–714. https://doi.org/10.1525/cond.2009.090142
Dias RI, Castilho L, Macedo RH (2010) Experimental evidence that sexual displays are costly for nest survival. Ethology 116:1011–1019. https://doi.org/10.1111/j.1439-0310.2010.01817.x
Dillard JR, Westneat DF (2016) Disentangling the correlated evolution of monogamy and cooperation. Trends Ecol Evol 31:503–513. https://doi.org/10.1016/j.tree.2016.03.009
Dominoni DM, Greif S, Nemeth E, Brumm H (2016) Airport noise predicts song timing of European birds. Ecol Evol 6:6151–6159. https://doi.org/10.1002/ece3.2357
Double M, Cockburn A (2000) Pre–dawn infidelity: females control extra-pair mating in superb fairy–wrens. Proc R Soc Lond B 267:465–470. https://doi.org/10.1098/rspb.2000.1023
Fernández-Juricic E, Deisher M, Stark AC, Randolet J (2012) Predator detection is limited in microhabitats with high light intensity: an experiment with Brown-headed Cowbirds. Ethology 118:341–350. https://doi.org/10.1111/j.1439-0310.2012.02020.x
Fox J, Weisberg S (2018) An R companion to applied regression. Sage, Thousand Oaks
Francis CD, Ortega CP, Cruz A (2009) Noise pollution changes avian communities and species interactions. Curr Biol 19:1415–1419. https://doi.org/10.1016/j.cub.2009.06.052
Fuller RA, Warren PH, Gaston KJ (2007) Daytime noise predicts nocturnal singing in urban robins. Biol Lett 3:368–370. https://doi.org/10.1098/rsbl.2007.0134
Gelman A, Hill J (2007) Data analysis using regression and multilevel/hierarchical models. Cambridge University Press, Cambridge
Gigliotti LC, Slotow R, Hunter LTB, Fattebert J, Sholto-Douglas C, Jachowski DS (2020) Habitat complexity and lifetime predation risk influence mesopredator survival in a multi-predator system. Sci Rep 10:17841. https://doi.org/10.1038/s41598-020-73318-3
Gosler AG, Greenwood JJD, Perrins C (1995) Predation risk and the cost of being fat. Nature 377:621–623. https://doi.org/10.1038/377621a0
Götmark F, Hohlfält A (1995) Bright male plumage and predation risk in passerine birds: are males easier to detect than females? Oikos 74:475–484. https://doi.org/10.2307/3545993
Gravolin I, Key M, Lill A (2014) Boldness of urban Australian magpies and local traffic volume. Avian Biol Res 7:244–250. https://doi.org/10.3184/175815514X14151981691872
Hansen IJK, Otter KA, van Oort H, Holschuh CI (2005) Communication breakdown? Habitat influences on black-capped chickadee dawn choruses. Acta Ethol 8:111–120. https://doi.org/10.1007/s10211-005-0007-x
Herényi M, Garamszegi LZ, Hargitai R, Hegyi G, Rosivall B, Szöllősi E, Török J (2014) Laying date and polygyny as determinants of annual reproductive success in male collared flycatchers (Ficedula albicollis): a long-term study. Naturwissenschaften 101:305–312. https://doi.org/10.1007/s00114-014-1157-3
Hopkins GR, Gaston KJ, Visser ME, Elgar MA, Jones TM (2018) Artificial light at night as a driver of evolution across urban-rural landscapes. Front Ecol Environ 16:472–479. https://doi.org/10.1002/fee.1828
Howell DC (2012) Statistical methods for psychology. Wadsworth, Cengage Learning
Johnson MD, Sherry TW (2001) Effects of food availability on the distribution of migratory warblers among habitats in Jamaica. J Anim Ecol 70:546–560. https://doi.org/10.1046/j.1365-2656.2001.00522.x
Jones RE, Hungerford KE (1972) Evaluation of nesting cover as protection from magpie predation. J Wildlife Manage 36:727–732. https://doi.org/10.2307/3799423
Keiser CN, Ingley SJ, Toscano BJ, Scharf I, Pruitt JN (2018) Habitat complexity dampens selection on prey activity level. Ethology 124:25–32. https://doi.org/10.1111/eth.12700
Kullberg C, Fransson T, Jakobsson S (1996) Impaired predator evasion in fat blackcaps (Sylvia atricapilla). Proc R Soc Lond B 263:1671–1675. https://doi.org/10.1098/rspb.1996.0244
Langmore NE (1998) Functions of duet and solo songs of female birds. Trends Ecol Evol 13:136–140. https://doi.org/10.1016/s0169-5347(97)01241-x
Lantz SM, Karubian J (2017) Environmental disturbance increases social connectivity in a passerine bird. PLoS ONE 12:e0183144. https://doi.org/10.1371/journal.pone.0183144
Legendre P, Legendre L (2012) Interpretation of ecological structures. In: Developments in Environmental Modelling. Elsevier, Amsterdam, pp 521–624. https://doi.org/10.1016/B978-0-444-53868-0.50010-1
Longcore T, Rich C (2004) Ecological light pollution. Front Ecol Environ 2:191–198. https://doi.org/10.1890/1540-9295(2004)002[0191:ELP]2.0.CO;2
Macedo RH, Manica LT (2019) Sexual selection and mating systems: contributions from a Neotropical passerine model. In: Reboreda J, Fiorini V, Tuero D (eds) Behavioral Ecology of Neotropical Birds. Springer, Cham, pp 61–86. https://doi.org/10.1007/978-3-030-14280-3_4
Macedo RH, Manica L, Dias RI (2012) Conspicuous sexual signals in a socially monogamous passerine: the case of neotropical Blue-black Grassquits. J Ornithol 153:15–22. https://doi.org/10.1007/s10336-012-0815-5
Manica LT, Maia R, Dias A, Podos J, Macedo RH (2014) Vocal output predicts territory quality in a Neotropical songbird. Behav Process 109:21–26. https://doi.org/10.1016/j.beproc.2014.07.004
Manica LT, Graves JA, Podos J, Macedo RH (2016) Multimodal flight display of a neotropical songbird predicts social pairing but not extrapair mating success. Behav Ecol Sociobiol 70:2039–2052. https://doi.org/10.1007/s00265-016-2208-x
Manica LT, Macedo RH, Graves JA, Podos J (2017) Vigor and skill in the acrobatic mating displays of a Neotropical songbird. Behav Ecol 28:164–173. https://doi.org/10.1093/beheco/arw143
Marcondes-Machado LO (1987) Comportamento reprodutivo de Volatinia jacarina jacarina (Linnaeus, 1766) em cativeiro (Passeres, Emberizidae). Rev Bras Zool 4:319–330. https://doi.org/10.1590/S0101-81751987000400004
Martin TE (1993) Nest predation among vegetation layers and habitat types: revising the dogmas. Am Nat 141:897–913. https://doi.org/10.1086/285515
McDonnell MJ, Stiles EW (1983) The structural complexity of old field vegetation and the recruitment of bird-dispersed plant species. Oecologia 56:109–116. https://doi.org/10.1007/BF00378225
McLaren JD, Buler JJ, Schreckengost T, Smolinsky JA, Boone M, Emiel van Loon E, Dawson DK, Walters EL (2018) Artificial light at night confounds broad-scale habitat use by migrating birds. Ecol Lett 21:356–364. https://doi.org/10.1111/ele.12902
McLeod BT, Ritchison G (2018) Effects of supplemental food on the behaviour and paternity status of male Indigo Buntings (Passerina cyanea). Avian Biol Res 11:67–73. https://doi.org/10.3184/175815618X15203297120204
Menezes JCT, Marini MÂ (2017) Predators of bird nests in the Neotropics: a review. J Field Ornithol 88:99–114. https://doi.org/10.1111/jofo.12203
Menezes JCT, Santos ESA (2020) Habitat structure drives the evolution of aerial displays in birds. J Anim Ecol 89:482–493. https://doi.org/10.1111/1365-2656.13132
Mikami OK, Katsuno Y, Yamashita DM, Noske R, Eguchi K (2010) Bowers of the great bowerbird (Chlamydera nuchalis) remained unburned after fire: is this an adaptation to fire? J Ethol 28:15–20. https://doi.org/10.1007/s10164-009-0149-9
Mills GS, Dunning JB Jr, Bates JM (1991) The relationship between breeding bird density and vegetation volume. Wilson Bull 103:468–479
Miranda HS, Sato MN, Neto WN, Aires FS (2009) Fires in the cerrado, the Brazilian savanna. In: Cochrane MA (ed) Tropical fire ecology. Springer, Berlin, pp 427–450. https://doi.org/10.1007/978-3-540-77381-8_15
Moreno-Palacios M, Losada-Prado S, Echeverry-Galvis MA (2013) Breeding and molt cycles in the Blue-black Grassquit (Volatinia jacarina) and the Gray Seedeater (Sporophila intermedia) (Passeriformes: Thraupidae) in secondary scrub of northern Tolima, Colombia. Ornitol Neotrop 24:421–431
Norris DR, Stutchbury BJM (2002) Sexual differences in gap-crossing ability of a forest songbird in a fragmented landscape revealed through radiotracking. Auk 119:528–532. https://doi.org/10.1093/auk/119.2.528
Penn DJ, Számadó S (2020) The Handicap Principle: how an erroneous hypothesis became a scientific principle. Biol Rev 95:267–290. https://doi.org/10.1111/brv.12563
R Development Core Team (2019) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria, http://www.R-project.org
Randlkofer B, Obermaier E, Hilker M, Meiners T (2010) Vegetation complexity— The influence of plant species diversity and plant structures on plant chemical complexity and arthropods. Basic Appl Ecol 11:383–395. https://doi.org/10.1016/j.baae.2010.03.003
Rodrigues RC, Hasui É, Assis JC, Pena JCC, Muylaert RL, Tonetti VR, Martello F, Regolin AL, Costa TVV, Pichorim M, Carrano E, Lopes LE, Vasconcelos MF, Fontana CS, Roos AL, Gonçalves F, Banks-Leite C, Cavarzere V, Efe MA, Alves MAS, Uezu A, Metzger JP, Antas PTZ, Ferraz KMPM, Calsavara LC, Bispo AA, Araujo HFP, Duca C, Piratelli AJ, Naka LN, Dias RA, Gatto CAFR, Vallejos MAV, Menezes GR, Bugoni L, Rajão H, Zocche JJ, Willrich G, Silva ES, Manica LT, Guaraldo AC, Althmann G, Serafini PP, Francisco MR, Lugarini C, Machado CG, Marques-Santos F, Bobato R, Souza EA, Donatelli RJ, Ferreira CD, Morante-Filho JC, Paes-Macarrão ND, Macarrão A, Lima MR, Jacoboski LI, Candia-Gallardo C, Alegre VB, Jahn AE, Barbosa KVC, Cestari C, Silva JN, Silveira NSD, Crestani ACV, Petronetto AP, Bovo AAA, Viana AD, Araujo AC, Santos AH, Amaral ACA, Ferreira A, Vieira-Filho AH, Ribeiro BC, Missagia CCC, Bosenbecker C, Medolago CAB, Espínola CRR, Faxina C, Nunes CEC, Prates C, Luz DTA, Moreno DJ, Mariz D, Faria D, Meyer D, Doná EA, Alexandrino ER, Fischer E, Girardi F, Giese FB, Shibuya FLS, Faria FA, Farias FB, Favaro FL, Freitas FJF, Chaves FG, Las-Casas FMG, Rosa GLM, Torre GMDL, Bochio GM, Bonetti GE, Kohler G, Toledo-Lima GS, Plucenio GP, Menezes Í, Torres IMD, Provinciato ICC, Viana IR, Roper JJ, Persegona JE, Barcik JJ, Martins-Silva J, Just JPG, Tavares-Damasceno JP, Ferreira JRA, Rosoni JRR, Falcon JET, Schaedler LM, Mathias LB, Deconto LR, Rodrigues LC, Meyer MAP, Repenning M, Melo MA, Carvalho MAS, Rodrigues M, Nunes MFC, Ogrzewalska MH, Gonçalves ML, Vecchi MB, Bettio M, Baptista MNM, Arantes MS, Ruiz NL, Andrade PGB, Ribeiro PHL, Junior PMG, Macario P, Oliveira Fratoni R, Meurer R, Saint-Clair RS, Romagna RS, Lacerda RCA, Cerboncini RAS, Lyra RB, Lau R, Rodrigues RC, Faria RR, Laps RR, Althoff SL, Jesus S, Namba S, Braga TV, Molin T, Câmara TPF, Enedino TR, Wischhoff U, Oliveira VC, Leandro-Silva V, Araújo-Lima V, Lunardi VO, Gusmão RF, Correia JMS, Gaspar LP, Fonseca RCB, Neto PAFP, Aquino ACMM, Camargo BB, Cezila BA, Costa LM, Paolino RM, Kanda CZ, Monteiro ECS, Oshima JEF, Alves-Eigenheer M, Pizo MA, Silveira LF, Galetti M, Ribeiro MC (2019) Atlantic bird traits: a data set of bird morphological traits from the Atlantic forests of South America. Ecology 100:e02647. https://doi.org/10.1002/ecy.2647
Saino N, Primmer CR, Ellegren H, Moller AP (1997) An experimental study of paternity and tail ornamentation in the barn swallow (Hirundo Rustica). Evolution 51:562–570. https://doi.org/10.1111/j.1558-5646.1997.tb02443.x
Schlicht L, Valcu M, Kempenaers B (2015) Male extraterritorial behavior predicts extrapair paternity pattern in blue tits, Cyanistes caeruleus. Behav Ecol 26:1404–1413. https://doi.org/10.1093/beheco/arv076
Shannon G, McKenna MF, Angeloni LM et al (2016) A synthesis of two decades of research documenting the effects of noise on wildlife. Biol Rev 91:982–1005. https://doi.org/10.1111/brv.12207
Sick H (1997) Ornitologia Brasileira. Nova Fronteira, Rio de Janeiro
Sicsú P, Manica LT, Maia R, Macedo RH (2013) Here comes the sun: multimodal displays are associated with sunlight incidence. Behav Ecol Sociobiol 67:1633–1642. https://doi.org/10.1007/s00265-013-1574-x
Swaddle JP, Page LC (2007) High levels of environmental noise erode pair preferences in zebra finches: implications for noise pollution. Anim Behav 74:363–368. https://doi.org/10.1016/j.anbehav.2007.01.004
Tomotani BM, Caglar E, de la Hera I, Mateman AC, Visser ME (2017) Early arrival is not associated with more extra-pair fertilizations in a long-distance migratory bird. J Avian Biol 48:854–886. https://doi.org/10.1111/jav.01317
Ward MP, Alessi M, Benson TJ, Chiavacci SJ (2014) The active nightlife of diurnal birds: extraterritorial forays and nocturnal activity patterns. Anim Behav 88:175–184. https://doi.org/10.1016/j.anbehav.2013.11.024
Whittaker DJ, Gerlach NM, Soini HA, Novotny MV, Ketterson ED (2013) Bird odour predicts reproductive success. Anim Behav 86:697–703. https://doi.org/10.1016/j.anbehav.2013.07.025
Whittingham LA, Dunn PO (2016) Experimental evidence that brighter males sire more extra-pair young in tree swallows. Mol Ecol 25:3706–3715. https://doi.org/10.1111/mec.13665
Zahavi A (1975) Mate selection—a selection for a handicap. J Theor Biol 53:205–214. https://doi.org/10.1016/0022-5193(75)90111-3
Zehm A, Nobis M, Schwabe A (2003) Multiparameter analysis of vertical vegetation structure based on digital image processing. Flora 198:142–160. https://doi.org/10.1078/0367-2530-00086
Zuur AF, Ieno EN, Walker NJ, Savelive AA, Smith GM (2009) Mixed effects models and extensions in ecology with R. Springer, New York. https://doi.org/10.1007/978-0-387-87458-6
Zuur AF, Ieno EN, Elphick CS (2010) A protocol for data exploration to avoid common statistical problems. Methods Ecol Evol 1:3–14. https://doi.org/10.1111/j.2041-210X.2009.00001.x
Acknowledgments
We thank N.M. Heming for suggestions on the method to describe shadowing pattern. We also acknowledge Lilian Manica and two anonymous referees for comments in a previous version of the manuscript.
Availability of data and material
Raw data are available in a public repository (Biagolini et al. 2020).
Code availability
Codes used in statistical analyses are presented in the supplementary material.
Funding
CB received graduate fellowships from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). EFS was also supported by CAPES with a MSc scholarship. Field work was supported by a Student Research Grant from the Animal Behavior Society. RHM received a fellowship from CNPq for the duration of the study. We acknowledge the logistic and financial support provided by Programa de Pós-Graduação em Ecologia from Universidade de Brasília in association with Programa de Excelência Acadêmica PROEX/CAPES (1789/2015); and the financial support provided by CNPq (471945/2013-7).
Author information
Authors and Affiliations
Contributions
All authors contributed to the study’s ideas and design. Data collection was performed by CB, EFS, and CAS; analyses were performed by CB. The first draft of the manuscript was written by CB and all authors revised previous versions of the manuscript. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Ethics approval
This study is part of a larger project that explores the role of habitat in blue-black grassquit breeding biology. Methods used in this study are in accordance with ethical standards and were approved by the Bioethics Committee of Universidade de Brasília (license no. 66711/2016) and by Brazilian environmental agencies. The relevant licenses for this project are Bioethics Committee of Universidade de Brasília license no. 66711/2016; Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio) license no. 51639; and Centro Nacional de Pesquisas para Conservação das Aves Silvestres (CEMAVE) license no. 4255. Additionally, we adhered to international guidelines for the use of animals in research, as stipulated by the Association for the Study of Animal Behaviour and the Animal Behavior Society.
Conflict of interest
The authors declare that they have no conflicts of interest.
Additional information
Communicated by C. Macías Garcia
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Fig. S1
Image from the burned area three days after fire occurrence (JPG 9699 kb)
Fig. S2
Scatter plots and Pearson's correlation tests for three vegetation characteristics around display perches used by blue-black grassquits (Volatinia jacarina). The association between each pair of variables was evaluated in two sets: A, B, and C using data from all territories (n =55) and D, E, and F using data only from territories not affected by human disturbances (n =39) (PNG 251 kb)
Video S1
Video sample of male blue-black grassquit performing display (MP4 544 kb)
Video S2
Video sample of male blue-black grassquit leaving an active nest and performing a vocalization similar to that produced during the motor display (MP4 13458 kb)
ESM 1
Data analyses: html file created by R markdown document presenting codes used for data analysis (HTML 1797 kb)
ESM 2
Interactive graphic: Interactive graphic of the multivariate relationship between blue-black grassquit (Volatinia jacarina) leap duration and standardized territory seed density (estimated in plots of 50 × 50 cm2) with standardized estimation of shadow intensity (see description in methods section) (HTML 2679 kb)
Rights and permissions
About this article
Cite this article
Biagolini-Jr, C., Silva-Jr, E.F., de Aguiar Silva, C.H. et al. Food, shadow, and fire influence a tropical bird´s display. Behav Ecol Sociobiol 75, 79 (2021). https://doi.org/10.1007/s00265-021-03015-2
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00265-021-03015-2