Irreproducible text-book “knowledge”: The effects of color bands on zebra finch fitness

Abstract

Many fields of science-including behavioral ecology-currently experience a heated debate about the extent to which publication bias against null findings results in a misrepresentative scientific literature. Here, we show a case of an extreme mismatch between strong positive support for an effect in the literature and a failure to detect this effect across multiple attempts at replication. For decades, researchers working with birds have individually marked their study species with colored leg bands. For the zebra finch Taeniopygia guttata, a model organism in behavioral ecology, many studies over the past 35 years have reported effects of bands of certain colors on male or female attractiveness and further on behavior, physiology, life history, and fitness. Only eight of 39 publications presented exclusively null findings. Here, we analyze the results of eight experiments in which we quantified the fitness of a total of 730 color-banded individuals from four captive populations (two domesticated and two recently wild derived). This sample size exceeds the combined sample size of all 23 publications that clearly support the "color-band effect" hypothesis. We found that band color explains no variance in either male or female fitness. We also found no heterogeneity in color-band effects, arguing against both context and population specificity. Analysis of unpublished data from three other laboratories strengthens the generality of our null finding. Finally, a meta-analysis of previously published results is indicative of selective reporting and suggests that the effect size approaches zero when sample size is large. We argue that our field-and science in general-would benefit from more effective means to counter confirmation bias and publication bias.

Meta-analysis challenges a textbook example of status signalling and demonstrates publication bias

“…An exhaustive review and meta-analysis on plumage coloration of blue tits ( Cyanistes caeruleus ) revealed that, after dozens of publications studying the function of plumage ornamentation in this species, the only robust conclusion is that females’ plumage differs from that of males ( Parker, 2013 ). Another example is the long-believed effect of leg bands of particular colours on the perceived attractiveness of male zebra finches ( Taeniopygia guttata ), which has been also experimentally and meta-analytically refuted ( Seguin and Forstmeier, 2012 ; Wang et al, 2018 ). Finally, the existence of a badge of status in a non-bird model species, the paper wasp ( Polistes dominulus ; Tibbetts and Dale, 2004 ) has also been challenged multiple times (e.g.…”

Meta-analysis challenges a textbook example of status signalling: evidence for publication bias

“…An exhaustive review and meta-analysis on plumage coloration of blue tits (Cyanistes caeruleus) revealed that, after dozens of publications studying the function of plumage ornamentation in this species, the only robust conclusion is that females' plumage differs from that of males (Parker, 2013). Another example is the longbelieved effect of leg bands of particular colours on the perceived attractiveness of male zebra finches (Taeniopygia guttata), which has been also experimentally and meta-analytically refuted (Seguin & Forstmeier, 2012;Wang et al, 2018). Finally, the existence of a badge of status in a non-bird model species, the paper wasp (Polistes dominulus; Tibbetts & Dale 2004) has also been challenged multiple times (e.g.…”

The role of replication studies in ecology

“…"S" means that the study element in the replication study is similar enough to the original study that it would be considered a fair test of the original hypothesis, and "D" means that the study element is distinctly different in original and replication studies, testing beyond the original hypothesis So far, there have been no equivalent, large-scale replication projects in ecology or related fields. However, meta-analytic studies have shown that several classic behavioral ecology findings do not reliably replicate (Sánchez-Tójar et al, 2018;Seguin & Forstmeier, 2012;Wang et al, 2018). In addition, all of the conditions expected to drive low rates of replication mentioned above appear common in ecology and evolution (Fidler et al, 2017;Parker et al, 2016): low power (Jennions & Moller, 2000), publication bias (Cassey, Ewen, Blackburn, & Moller, 2004;Fanelli, 2012;Franco et al, 2014;Jennions & Moller, 2002;Murtaugh, 2002), and prevalence of questionable research practices (Fraser et al, 2018).…”