We compiled 946 h of direct observation of 117 colour-marked individuals at 42 leks, and recorded 316 h of video. During 185 female visits to leks during observations, males increased the intensity of displays with 11 of these (6%) culminating in copulations (electronic supplementary material, video S2). Female visits approximate mating success; the time that females spent at leks was 4.4 times greater where we observed copulations than at leks where we observed no copulations (F1,58 = 19.5, p < 0.0001). The proportion of time females spent visiting leks also increased with male attentiveness (time within 15 m of log; F1,58 = 22.8, p < 0.0001), advertisement trills per hour (F1,58 = 6.7, p = 0.012) and N subordinate males (F1,58 = 22.8, p < 0.0001). Videos confirmed that observers did not affect female visitation or male behaviour. The observation and video datasets were extremely similar in the proportion of time females spent at leks (r2 = 0.48, F1,8 = 7.3, p = 0.027), and male display rates (log landings: r2 = 0.84, F1,8 = 43.8, p = 0.0002; aerial dives: r2 = 0.56, F1,8 = 10.3, p = 0.012; butterfly flights: r2 = 0.74, F1,8 = 23.2, p = 0.001).
We estimated migratory tendency of 216 individual-year combinations including 90 adult males (25 in both years) using δD
measurements from claws [16
measurements in precipitation predicted an 11.7‰ difference between breeding and non-breeding elevations [17
] (electronic supplementary material, figure S2). Supporting this, white-ruffed manakin claws collected at breeding sites were 16.0‰ (±4.9‰) more depleted in D
than those collected at low elevations in November–December 2008 (electronic supplementary material, figure S3a
= 3.2, p
= 0.005), mirroring differences in claws of other non-migratory frugivorous species sampled at both elevations (electronic supplementary material, figure S3b
). White-ruffed manakin claws grew 0.030 mm d−1
(±0.007), indicating that turnover of claw tissue takes approximately four months. Thus, samples collected early in March reflect the elevation of individuals during November–February when the greatest number of migrants are at low elevations [9
values in 2008 samples averaged 4.8‰ higher than 2009 samples (t214
= 4.1, p
< 0.0001), indicating that more individuals migrated prior to 2008 than 2009. This result is consistent with capture data showing that migratory tendency is related to storm severity [10
], as rainfall was 44 per cent higher prior to the 2008 than the 2009 breeding season. Claw δD
data in 2009 also corroborated capture data, indicating that adult males were the sex most likely to migrate [8,10] (whole model: F3,156
= 5.3, p
= 0.002; sex × year: F1,156
= 3.5, p
Alpha males with more resident δD values attracted females more frequently (F1,34 = 4.9, p = 0.035) and for longer durations (a; F1,35 = 7.1, p = 0.012). Alphas with more resident δD values also tended to spend more time at their lek (b; F1,35 = 3.5, p = 0.068), vocalize more (trills per hour: F1,35 = 3.0, p = 0.094) and have larger subordinate male groups (F1,35 = 2.4, p = 0.130). The slope and intercept of the relationship between the proportion of time females spent at leks and male δD values in video data closely paralleled the observation data (electronic supplementary material, figure S4).
Relationship between δD values in claws of alpha males and the proportion of time that (a) females visited and (b) alphas attended their leks.
In 2009, status was related to migratory tendency, with betas being less migratory than alphas or lower ranking males (status × year: F3,107 = 2.8, p = 0.041). Changes in male status between 2008 and 2009 were related to migratory tendency during the intervening non-breeding season. Out of 38 males, 17 retained a high status (alpha or beta) from 2008 to 2009, 10 remained low, six increased and five decreased in status. Males with the most migratory δD values decreased in status upon returning to breed the subsequent year, whereas males with the most resident δD values retained their high status from one year to the next (; F3,34 = 2.9, p = 0.048).
Change in male status between the 2008 and 2009 breeding seasons relative to δD values in their claws (indicating migratory tendency) in the intervening non-breeding season. Error bars represent ±1 s.e.m.