Data from: Vigor and skill in the acrobatic mating displays of a Neotropical songbird

Animal social behaviors are often mediated by signals that provide information about signaler attributes. Although some signals are structurally simple, others are temporally dynamic and multifaceted. In such cases, exaggeration of some display components is likely to curtail the expression of others. We quantified features of the acrobatic, multimodal “leap display” of blue-black grassquits (Volatinia jacarina), which appears to entail moderate-to-high performance levels in terms of vigor and skill. We video recorded and quantified leap parameters (height, duration, rotation angle, launch velocity, and number of wing beats) and assessed how these parameters covaried with each other and with vocal parameters, display rates, and body mass index. Our analyses revealed correlations among multiple performance variables: leap height, duration, launch velocity, and number of wing beats. Leap height also correlated positively with song duration. By contrast, no leap parameters covaried with rotation angle. Our analyses also revealed a trade-off in vigor and skill-based leap attributes: birds with a lower body mass index showed a negative relationship between leap heights and the proportion of displays that included leaps (vs. perched vocalizations only). Our results identify directions of display evolution subject to mechanical or timing constraints and provide evidence that display attributes that emphasize vigor and skill may limit one another. Our results also support a key expectation of handicap models of display evolution, which is that costs of display execution should be borne disproportionately by signalers of lower quality

Multimodal flight display of a neotropical songbird predicts social pairing but not extrapair mating success

Models of sexual selection predict that socially monogamous females may gain direct or indirect (genetic) benefits by mating with multiple males. We addressed current hypotheses by investigating how, in the socially monogamous blue-black grassquit (Volatinia jacarina), male courtship and territory quality varied with social and extrapair paternity. Males of this tropical granivorous passerine exhibit multimodal displays integrating motor (leap displays) and acoustic components. Across 3 years, we found that extrapair paternity ranged from 8 to 34 % of all nestlings and from 11 to 47 % of all broods. Extrapair and socially paired male territories had similar seed densities. Females preferred to pair socially with males executing higher leaps, but no other male display characteristic associated with paternity loss and extrapair fertilizations. Extrapair and social mates did not differ in genetic similarity to female partners nor in inbreeding levels. Additionally, inbreeding and body condition of extrapair and within-pair nestlings did not differ. Thus, not only did we reject the direct benefits hypothesis for extrapair copulations, but our results also did not support the additive and nonadditive genetic benefits hypotheses. Instead, we found support for benefits through selection of potentially “good fathers,” specifically for females that chose to pair socially with males exhibiting enhanced performance in their displays.</p

Leaf habit does not predict leaf functional traits in cerrado woody species

Plant species with a high leaf life span (LLS) commonly have a low specific leaf area (SLA), leaf nitrogen per unit mass (N), and phosphorous concentration (P), whereas species with low LLS have a high SLA, N and P. However, LLS tends to be longer in species growing in low-nutrient soils and, therefore, differences in LLS and other leaf traits may not be consistent with a plant classification according to leaf habit. Here we investigated whether leaf habit is consistent with leaf economic spectrum trade-offs in cerrado (a Neotropical savanna) woody species. We analyzed the SLA, N and P of 125 woody species with a distinct leaf habit (deciduous, semideciduous, brevideciduous or evergreen). We also gathered data on the LLS (33 species), maximum net photosynthesis per leaf area (Aarea, 56 species) and per leaf mass (Amass, 31 species), comprising the most extensive database analyzed so far for the cerrado. Differences among leaf habit groups were tested using generalized linear mixed models and ANOVA. We did not find differences in SLA and N among species with a distinct leaf habit, but deciduous species had a higher leaf P concentration than evergreens. Species did not differ in LLS and Amass, but Aarea varied among groups. Semideciduous species had higher Aarea values than deciduous and brevideciduous species, but all other groups had similar Aarea values. Because of the small difference in the LLS, SLA, leaf N, leaf P and maximum net photosynthesis, we argue that deciduous, brevideciduous, semideciduous and evergreen species may not constitute different functional groups in cerrado woody species.Pflanzenarten mit einer hohen Blattlebensdauer (LLS) haben gemeinhin eine geringe spezifische Blattfläche (SLA), sowie geringe Stickstoff- (N) und Phosphorkonzentrationen (P), während Arten mit geringer LLS hohe SLA-, N- und P-Werte aufweisen. Indessen tendiert die LLS dahin, bei Arten, die in nährstoffarmen Böden wachsen, länger zu sein, und deshalb könnten Unterschiede hinsichtlich der LLS und anderer Blatteigenschaften nicht mit einer Einteilung der Pflanzen nach Blattwurftypen übereinstimmen. Wir untersuchten an den Gehölzarten neotropischer Savannen (cerrado), ob der Blattwurftyp mit den Zielkonflikten im Ökonomiespektrum der Blätter in Einklang steht. Wir analysierten SLA, N und P von 125 Gehölzarten aus unterschiedlichen Blattwurftypen (laubwerfend, halblaubwerfend, kurzlaubwerfend oder immergrün). Wir berücksichtigten auch LLS-Daten (33 Arten), sowie die maximale Netto-Photosynthese je Blattfläche (Aarea, 56 Arten) und je Blattmasse (Amass, 31 Arten). Unterschiede zwischen den Blattwurftypen wurden mit GLMM und ANOVA getestet. Wir fanden keine Unterschiede hinsichtlich SLA und N zwischen den Blattwurftypen, aber die Blätter blattwerfender Arten hatten eine höhere P-Konzentration als die von immergrünen Arten. Es gab keine Unterschiede hinsichtlich LLS und Amass, aber Aarea variierte zwischen den Blattwurftypen. Halblaubwerfende Arten wiesen höhere Aarea-Werte als laubwerfende und kurzlaubwerfende Arten, aber alle anderen paarweisen Unterschiede waren nicht signifikant. Angesichts der geringen Unterschiede hinsichtlich LLS, SLA, N, P und Netto-Photosynthese postulieren wir, dass laubwerfende, halblaubwerfende, kurzlaubwerfende und immergrüne Arten keine funktionellen Gruppen von neotropischen Savannengehölzen begründen

Manica et al BE 2016_DryadSubmission

This data file describes motor and acoustic display parameters and body mass index of male blue-black grassquits (Volatinia jacarina)

Data from: Vigor and skill in the acrobatic mating displays of a Neotropical songbird

This data file describes motor and acoustic display parameters and body mass index of male blue-black grassquits (Volatinia jacarina)

Passeriformes: nest predators and prey in a Neotropical Savannah in Central Brazil

The identification of predators of birds' nests, crucial to a better understanding of predator-prey interactions, remains poorly known. Here we provide evidence that birds, and especially passerines, may depredate birds' nests in the Cerrado (Neotropical Savannah) of Central Brazil. Data was collected primarily in a Conservation Unit (Estação Ecológica de Águas Emendadas) during the breeding season, between 2003 and 2007. We report and discuss details on 14 events of nest predation, 12 of which by passerines, mostly by curl-crested jays - Cyanocorax cristatellus (Temminck, 1823). The results of our study suggest that the role of birds as nest predators in the Cerrado has been underestimated and needs to be further investigated