1 Plumage convergence in tyrant flycatchers: A
2 tetrachromatic view
3
4 A thesis submitted to the Department of Biological Science of the
5 Universidad de los Andes in partial fulfillment of the requirements for the
6 degree of Bachelor of Science in Biology
7
8
9 María Alejandra Meneses-Giorgi
10 Laboratorio de Biología Evolutiva de Vertebrados
11 Departamento de Ciencias Biológicas
12 Universidad de los Andes
13
14 Advisor:
15 Daniel Cadena, PhD
16 Full Professor
17 Departamento de Ciencias Biológicas
18 Universidad de los Andes
19
20 21 ABSTRACT
22 Convergent evolution is the process through which different evolutionary lineages
23 independently evolve similar features. Phenotypic convergence has been linked
24 with selective pressures including predation and competitive interactions. Social
25 mimicry may lead to convergent evolution when interactions with conspecifics and
26 heterospecifics drive evolution towards similar phenotypes. Several hypotheses
27 accounting for convergence based on mechanisms of social mimicry exist, but
28 evaluations of how similar species are given the visual system of receptors has
29 been ostensibly missing from tests of such hypotheses. We used phylogenetic
30 methods, plumage reflectance measurements of six species of tyrant flycatchers
31 (Passeriformes, Tyrannidae) with strikingly similar plumage patterns, and models
32 of avian vision to evaluate the efficacy of visual deception and therefore the
33 plausibility of hypotheses potentially accounting for plumage convergence involving
34 mimicry. We found plumage similarity resulted from convergence and may have
35 been favored by selective pressures exerted by predation because putative models
36 and mimics species were indistinguishable by visually oriented raptors. We reject
37 social mimicry hypotheses as an explanation for the aparent similarity between one
38 of the putative model species and putative mimics because deception seems
39 unlikely given the visual system of passerines visual system. Nonetheless,
40 plumage convergence may have been favored by competitive interactions with
41 other putative model species or with other smaller species of passerines.
42 Experiments and behavioral observations are necessary to better characterize
43 social interactions among our study species and to test predictions of alternative
44 hypotheses posed to account for mimicry. 45
46 RESUMEN
47 La evolución convergente es el proceso mediante el cual diferentes linajes
48 evolutivos independientemente evolucionan características similares. La evolución
49 convergente ha sido relacionada con presiones de selección como la depredación
50 y las interacciones de competencia. El mimetismo social puede llevar a evolución
51 convergente cuando las interacciones competitivas con individuos coespecíficos y
52 heteroespecíficos impulsan la evolución hacia fenotipos similares. Existen varias
53 hipótesis que dan cuenta de la convergencia dado el mimetismo social, pero
54 estimaciones de qué tanto se parecen las especies involucradas dado el sistema
55 visual de especie receptoras han estado ausentes de los trabajos que evalúan
56 dichas hipótesis. En este estudio usamos métodos filogenéticos, medidas de
57 reflectancia de seis especies de tiránidos (Passeriformes, Tyrannidae) que
58 presentan plumajes similares y modelos visuales de aves para evaluar la eficacia
59 del engaño visual y, por ende, la plausibilidad de hipótesis que plantean que la
60 convergencia en el plumaje ha surgido por mimetismo social. Encontramos que la
61 similitud en el plumaje es producto de convergencia, que pudo ser favorecida por
62 la presión de selección ejercida por los depredadores pues las especies modelo e
63 imitadoras hipotéticas son indistinguibles para aves rapaces que se orientan
64 visualmente. Rechazamos las hipótesis de mimetismo social como una explicación
65 de la aparente similitud entre una de las especies modelo y los imitadores
66 hipotéticos debido a que el engaño es poco probable dado el modelo visual de los
67 Passeriformes. Sin embargo, la convergencia en el plumaje pudo haber sido
68 favorecida por interacciones competitivas con la otra especie modelo putativa o 69 con otras especies passeriformes más pequeñas. Es necesario hacer
70 experimentos y observaciones de comportamiento para caracterizar mejor las
71 interacciones sociales entre nuestras especies de estudio y para probar
72 predicciones de hipótesis alternativas planteadas para explicar el mimetismo.
73
74 Keywords: Convergence, coloration, social mimicry, visual models, interespecific
75 social dominance mimicry.
76
77 INTRODUCTION
78 Convergent evolution, the process through which two or more distinct lineages
79 independently acquire similar traits, reveals that the paths of evolution are not
80 infinite, but may be rather restricted. Convergence may happen rapidly or over the
81 course of millions of years either by random drift or more likely because a given
82 phenotypic trait is repeatedly favored by natural selection in a particular
83 environment (Endler, 1986; Losos et al., 1998). Likewise, convergence may also
84 occur due to biases in the production of phenotypic variation such as shared
85 developmental constraints (Brakefield, 2006; Losos et al., 1998; Price & Pavelka,
86 1996). A well-studied form of convergent evolution is mimicry, in which one species
87 (the mimic) evolves to resemble another species (the model), often to deceive a
88 third species (the receptor; McGhee, 2012).
89
90 There are numerous examples of phenotypic convergence among birds (Cody &
91 Brown, 1970; Davies & Welbergen, 2008; Jønsson et al., 2016; Laiolo, 2017;
92 Leighton et al., 2018; Lopes et al., 2017; Prum, 2014; Stoddard, 2012), and several 93 scientists have proposed hypothesis to explain this phenomenon in the context of
94 mimicry (Barnard, 1979, 1982; Diamond, 1982; Moynihan, 1968; Prum, 2014;
95 Prum & Samuelson, 2012, 2016). Among leading ideas proposed to account for
96 phenotypic convergence in birds, the social mimicry hypothesis (Moynihan, 1968)
97 posits that convergent similarity in traits like coloration and plumage patterns may
98 evolve to promote efficient communication maintaining cohesion both among
99 conspecifics and heterospecifics in mixed-species flocks. A variant of this
100 hypothesis posits that rather than maintaining cohesion of mixed flocks, social
101 mimicry serves mainly as an antipredatory adaptation because predation
102 eliminates conspicuous or atypical individuals from populations, thereby promoting
103 phenotypic uniformity (Barnard, 1979). How atypical an animal is in this context
104 must be examined relative to the background (Gomez & Théry, 2007); if a predator
105 considers a whole mixed-species flock as the background, then any species
106 forming a distinct minority within it may be a preferred prey, resulting in a selective
107 pressure favoring homogeneity (Mueller, 1971). Therefore, the efficacy of social
108 mimicry to reduce predation (Barnard, 1979) depends on the extent to which
109 predators may perceive mixed flocks as homogeneous, which ultimately relies on
110 the acuity of their visual system.
111
112 An alternative explanation for mimicry not focusing on predation but still
113 considering social interactions suggests that mimicry may serve two purposes: (1)
114 mimics may escape attack from model species of larger body size, and (2) mimics
115 may deceive species of smaller size and scare them off without further effort
116 (Diamond, 1982). Along the same lines, Prum & Samuelson (2012) further 117 proposed the Interspecific Social Dominance Mimicry (ISDM) hypothesis, which
118 posits that, given interference competition, smaller species evolve to mimic larger,
119 ecologically dominant competitors, to deceive them and thereby avoid attacks. For
120 this mechanism to be plausible, individuals of the mimic species must be confused
121 by individuals of the model species as if they were conspecific based on pictorial
122 cues like shape, color and plumage patterns regardless of differences in body size
123 (Leighton et al., 2018; Prum, 2014; Prum & Samuelson, 2012, 2016). Therefore,
124 the efficacy of this form of mimicry critically depends on the visual system of model
125 species.
126
127 Explicit consideration of the efficacy of visual deception given avian visual models
128 has been ostensibly missing from analyses, limiting our ability to assess the
129 plausibility of various hypotheses posed to account for mimicry. Birds have visual
130 pigments enabling them to acquire information from red, green and blue
131 wavelengths (like humans), but they are also capable of acquiring information from
132 ultraviolet wavelengths with an additional pigment. Also, each of the avian
133 pigments is paired with a particular pigmented oil droplet type, which results in
134 better spectral discrimination relative to other vertebrates (Cuthill et al., 2000). The
135 ability to distinguish colors varies among birds, however, with a pronounced
136 difference in the absorbance peak of the ultraviolet sensitive (UVS-type) cones
137 present in Passeriformes and Psittaciformes, and the violet sensitive (VS-type)
138 cones present in all other non-passerines including raptors (Håstad et al., 2005).
139 Thus, a crucial question one must answer to gauge support for hypotheses
140 attempting to account for mimicry is whether phenotypic similarities between 141 species perceived by humans are sufficient to deceive birds including predators,
142 competitors, and putative models given properties of their visual systems.
143
144 We used plumage reflectance measurements of six species of tyrant flycatchers
145 (Passeriformes, Tyrannidae) with strikingly similar plumage patterns to evaluate
146 the efficacy of visual deception and therefore the plausibility of mimicry hypotheses
147 potentially accounting for phenotypic convergence. The species we studied are
148 part of a hypothetical mimicry complex posited to be an example of ISDM
149 consisting of two model species of large body size and a variety of putatively mimic
150 species of smaller size (Prum 2014). We first reconstructed ancestral character
151 states on a molecular phylogeny to evaluate whether plumage similarity is indeed a
152 result of convergence and not of common ancestry in tyrant-flycatchers. We then
153 compared plumage coloration for each pair of hypothetical models and mimics both
154 from the perspective of raptorial predators (using a VS vision model) and of the
155 study species themselves and smaller competitors (using an UVS vision model for
156 passerine birds) to evaluate the plausibility of deception of different observers.
157 Because raptors are likely the main diurnal predators of passerine birds (Acosta-
158 Chaves et al., 2012; Amar et al., 2008; Gotmark, 1995; Thomson et al., 2010)
159 detecting them by sight (Mueller, 1975; Mueller, 1971; Slagsvold et al., 1995), the
160 hypothesis of social mimicry that species converge phenotypically to deceive
161 predators (Barnard 1979) predicts that species of flycatchers involved in the
162 mimicry complex should be very similar to each other or indistinguishable given
163 raptor vision in ecologically relevant plumage patches. On the other hand,
164 hypotheses positing that species evolve to deceive heterospecifics with which they 165 may compete for resources (Diamond 1982, Prum & Samuelson 2012, Prum 2014)
166 predict that tyrant flycatcher species involved in the mimicry complex should have
167 indistinguishable plumage coloration given their own passerine visual model.
168
169 METHODS
170 Study system
171 We studied Boat-billed Flycatcher (Megarynchus pitangua, mean body mass 73.5
172 g) and Great Kiskadee (Pitangus sulphuratus, 63.8 g) as hypothetical models, and
173 Lesser Kiskadee (Pitangus lictor, 25.5 g), White-bearded Flycatcher (Phelpsia
174 inornata, 29.4 g), Social Flycatcher (Myiozetetes similis, 28 g), and Rusty-margined
175 Flycatcher (Myiozetetes cayanensis, 25.9 g) as hypothetical mimics following Prum
176 (2014; mean body masses from Dunning, 2008). All these species are members of
177 the Tyrannidae family showing strikingly similar plumage patterns which we refer to
178 as “kiskadee-like”: black facial mask, white throat, bright yellow underparts,
179 brownish upperparts, and tail and wings with rufous edges (John Fitzpatrick et al.,
180 2004; Hilty & Brown, 1986). They are all lowland species (500m-1700m) with wide
181 distribution ranges except for P. inornata, which is restricted to areas in the llanos
182 of Colombia and Venezuela (Fitzpatrick et al., 2004). The distribution ranges of
183 putative models and mimics overlap extensively and species share habitats in
184 mostly semi-open areas. Despite having very similar plumage patterns and
185 coloration to the human eye, the species have distinctive voices (Hilty & Brown,
186 1986).
187
188 Is plumage similarity product of convergent evolution? 189 To assess whether the similarity in phenotype among species of flycatchers is
190 product of convergent evolution or if it is a result of common ancestry, we
191 reconstructed ancestral states of a binary character (kiskadee-like or nonkiskadee-
192 like) using stochastic mapping, a Bayesian approach in which character histories
193 are sampled from their posterior probability distribution (Huelsenbeck et al., 2003;
194 Ree, 2005; Revell, 2013b, 2013a). To conduct this analysis we used a subset of a
195 complete phylogeny of the Tyrannidae (Gomez-Bahamon, 2014), corresponding to
196 a clade defined by the most recent common ancestor of all study species except P.
197 inornata because no molecular data for this species are available. Using R
198 packages “ape” (Paradis et al., 2004, 2017) and “phytools” (Revell, 2012, 2017) we
199 generated 100 stochastically mapped trees using the “make.simmap” function
200 (Revell, 2017). Subsequently, we summarized them to estimate the number of
201 changes of each type and the proportion of time spent in each state, and using the
202 “densityMap” function we visualized the posterior probability of being in each state
203 across all the edges and nodes of the tree (Revell, 2013b). Although we were not
204 able to take spectrophotometric measurements of Conopias albovittatus we
205 included this species in the ancestral states reconstruction because it shares the
206 kiskadee-like plumage (Prum, 2014).
207
208 Quantifying plumage similarity
209 Reflectance measurements
210 We quantified plumage similarity between hypothetical models and mimics using
211 spectrophotometric data obtained from museum specimens deposited in the
212 Museo de Historia Natural de la Universidad de los Andes (ANDES), Instituto de 213 Ciencias Naturales de la Universidad Nacional (ICN), and Instituto de Investigación
214 de Recursos Biológicos Alexander von Humboldt (IAvH). We took reflectance
215 measurements using an Ocean Optics USB4000 spectrophotometer and a DH-
216 2000 deuterium halogen light source coupled with a QP400-2-UV-VIS optic fiber
217 with a 400 µm diameter. We measured reflectance from eight patches: crown,
218 back, rump, throat, flank, upper breast, middle breast and belly (Figure 1). We
219 measured each patch three times per individual; the spectrometer was calibrated
220 using a white standard prior to measuring any new patch. We averaged the three
221 measurements per patch per individual and removed electrical noise using
222 functions implemented in the package “pavo” for R (Maia et al., 2013).
223
224 We quantified plumage coloration in six species belonging to the putative mimicry
225 complex described by Prum (2014); we were unable to include data for
226 Myiozetetes granadensis, Conopias parva and Conopias cinchoneti. We measured
227 spectra from 10 or 11 specimens per species except for P. inornata for which there
228 where only seven specimens available and P. sulphuratus for which 19 specimens
229 were measured. We used both female and male individuals and measured
230 specimens not older than 50 years (Armenta et al., 2008) for a total of 68
231 specimens and 1,632 spectra (Supplementary Table 1).
232
233 Statistical and perceptual analysis
234 To determine whether species putatively involved in the mimicry complex are
235 indeed indistinguishable from the perspectives of predators (raptors) or competitors 236 (passerines), one needs to address two separate questions: (1) Are hypothetical
237 models and mimics statistically distinct?; and (2) Are they perceptually different?
238 We addressed both questions following the approach described by Maia & White
239 (2017). We performed paired analysis between hypothetical models and mimics
240 comparing coloration of each plumage patch using the averaged and noise-free
241 spectra in the R package “pavo” based on the receptor-noise model (Vorobyev &
242 Osorio, 1998). This model assumes thresholds for discrimination are imposed by
243 receptor noise, which is dependent on the receptor type and its abundance in the
244 retina (Vorobyev & Osorio, 1998; Vorobyev et al., 2001). The model allows one to
245 estimate the distance between groups of points in a color space in units of “just
246 noticeable differences” or JNDs (Vorobyev et al., 2001). If when comparing two
247 colors the JND value is lower than 1, then those colors are predicted to be
248 indistinguishable given the visual model employed for analyses.
249
250 To determine whether hypothetical models and mimics are statistically different in
251 plumage coloration, we used permutation-based analyses of variance
252 (PERMANOVAs) using perceptual color distances in the R package “vegan”
253 (Oksanen et al., 2008). We used 999 permutations and recorded the pseudo-f, the
254 significance of the analysis (a=0.05), and the R2 (Maia & White, 2017). To evaluate
255 whether plumage patches showing statistical differences in reflectance are also
256 perceptually distinguishable we did a bootstrap analysis to calculate a mean
257 distance and a confidence interval in JNDs (Maia & White, 2017). If two colors are
258 statistically distinct and the bootstrapped confidence interval does not include the 259 threshold of 1 JND, then one can conclude that these colors are statistically distinct
260 and perceptually different given a visual model (Maia & White, 2017).
261
262 To assess statistical and perceptual differences from the perspective of raptors and
263 tyrant-flycatchers we performed the PERMANOVAs and the bootsraps assuming
264 two alternative visual models. First, we used the “avg.v” model implemented in
265 “pavo” which represents the standard violet-sensitive visual system; because there
266 is no information available for Accipitriformes, we used the Gallinula tenebrosa
267 (Rallidae) receptor densities -1:1.69:2.10:2.19- (Olsson et al., 2017). We then
268 used the “avg.uv” model representing the standard ultraviolet-sensitive visual
269 system and used the default receptor densities -1:2:2:4- which correspond to
270 Leiothrix lutea (Leothrichidae; Maia et al., 2017). We used a Weber fraction of 0.1
271 for both models (Maia et al., 2017).
272
273
274 RESULTS
275 Is plumage similarity among kiskadee-like flycatchers product of convergent
276 evolution?
277 Our analyses suggest there have been four independent evolutionary origins of the
278 kiskadee-like phenotype in: (1) Conopias albovittatus, (2) M. pitangua, (3) the
279 Myiozetetes clade and (4) the Pitangus clade (Figure 2). These four independent
280 origins of kiskadee-like plumage suggest that phenotypic similarity among putative
281 model and mimic species is product of convergence and not of common ancestry. 282 However, similarity due to common ancestry cannot be rejected in cases involving
283 closely related species (i.e Myiozetetes similis – M. cayanensis – M. granadensis
284 and Pitangus lictor - P. sulphuratus).
285
286 Can plumage similarity among flycatchers deceive putative competitors or
287 predators?
288 As predicted by various hypotheses involving social mimicry (Barnard, 1979;
289 Diamond, 1982; Prum, 2014; Prum & Samuelson, 2012), we found some pairs of
290 hypothetical model and mimic species to be indistinguishable from each other in
291 aspects of their plumage. Most hypothetical mimic species are perceptually
292 indistinguishable from hypothetical model M. pitangua in the coloration of the upper
293 breast, middle breast, belly and flanks (JND values ≤1; Figure 4 and
294 Supplementary Table 3) in spite of some being statistically different from each
295 other (Figure 4 and Supplementary Table 2). Additionally, all hypothetical mimics
296 are indistinguishable from both hypothetical models in plumage from the crown,
297 back and rump (JND values≤1; Figure 4, Figure 5A, Figure 6A and Supplementary
298 Table 3). Statistical and perceptual evaluation of the data were almost identical for
299 the UVS and VS visual models (Figure 4, Supplementary Table 2 and
300 Supplementary Table 3), indicating that both predators and competitors might be
301 deceived by the coloration of underpart plumage patches when considering M.
302 pitangua as hypothetical model or by upperpart patches when considering either
303 M. pitangua or P. sulphuratus as hypothetical models. Resemblance between M.
304 pitangua and hypothetical mimics exists because although there are differences in
305 brilliance of all the patches, the hue reflected by each patch is highly similar 306 between species (Figure 5C). Moreover, descriptive variables of the plumage (i.e
307 usml centroids, total and relative volumes, color span, hue disparity and saturation)
308 of each species vary between the two visual models (Supplementary Table 4). As
309 a graphical example of the variation, points occupied larger volume when being
310 evaluated using the UVS model than when being evaluated with the VS model
311 (Figure 5B).
312
313 Conversely, we found some pairs of hypothetical model and mimic species are
314 distinguishable in plumage, particularly in patches of the underparts. All
315 hypothetical mimics were perceptually distinguishable from hypothetical model M.
316 pitangua in plumage of the upper breast, middle breast, belly and flank patches
317 (JND values>1; Figure 3 and Figure 6A). Underpart patches were statistically
318 (Figure 4) and perceptually different in all comparisons. Additionally, we found two
319 species to be distinguishable from M. pitangua in some plumage patches: P. lictor
320 is distinguishable from M. pitangua in the middle breast and flank patches (lower
321 JND values 1.85 and 2.06 respectively; Supplementary Table 3) and M.
322 cayanensis was found to be distinguishable in the rump patch (lower JND value of
323 1.28; Supplementary Table 3). Color dissimilarity between P. sulphuratus and
324 hypothetical mimics is shown by the difference in the wavelengths reflected
325 between 450nm and 500nm in underpart patches (Figure 6C). Color dissimilarity in
326 underparts patches is also illustrated by variance in the values of the s centroid
327 when comparing hypothetical mimics and hypothetical models (Supplementary
328 Table 5). Statistical and perceptual evaluation of the data were almost identical
329 both for the UVS and VS models indicating that species are distinguishable by 330 models, smaller passerine species, and predatory raptors. Nevertheless,
331 descriptive variables of the plumage of each species varied when using UVS and
332 VS models (Supplementary Table 4), illustrated by points occupying a larger
333 volume when being evaluated using the UVS model than when being evaluated
334 with the VS model (Figure 6B).
335
336
337 DISCUSSION
338 Although plumage convergence is widespread (Barnard, 1979, 1982; Cody &
339 Brown, 1970; Davies & Welbergen, 2008; Laiolo, 2017; Leighton et al., 2018;
340 Moynihan, 1968; Prum, 2014; Prum & Samuelson, 2016, 2012; Stoddard, 2012),
341 few studies have assessed the mechanisms underlying this phenomenon. For
342 example, convergence has been documented in previous studies of birds which
343 may engage in mimicry including toucans (Weckstein, 2005), friarbirds and orioles
344 (Jønsson et al., 2016), and woodpeckers (Leighton et al., 2018; Miller et al., 2018)
345 but the extent to which alternative hypotheses involving mimicry may account for
346 convergence is unknown. A first step to examine the plausibility of alternative
347 hypotheses posed to account for mimicry is to determine whether two or more
348 sympatric and phenotypically similar species indeed acquired their resemblance
349 due to convergence and not as a consequence of common ancestry. We found
350 that phenotypic similarity among Neotropical flycatcher species with kiskadee-like
351 plumage pattern is indeed a product of convergence among hypothetical mimics in
352 the genera Myiozetetes, Pitangus and Phelpsia, and hypothetical models in
353 Megarynchus and Pitangus. 354
355 The hypothesis that mimicry in birds arises as an antipredatory strategy (Barnard
356 1979) predicts that plumages should be indistinguishable to predators given their
357 visual system. Moreover, mimicry should be more precise in plumage patches
358 used by predators as cues to select prey (Barnard, 1979). The main predators of
359 adult songbirds, including tyrant flycatchers, are likely diurnal raptors (Amar et al.,
360 2008; Acosta-Chaves et al., 2012; Motta-Junior, 2007; Selas, 1993), which often
361 observe prey from long distances while perched on treetops (Clark & Wheeler,
362 2001) and may choose odd individuals relative to their background (Mueller, 1971,
363 1975). Consequently, similarity in upperpart coloration in species that forage
364 together or use different strata of the same trees may create a sense of
365 homogeneity and thereby be adaptive to avoid attacks from predators approaching
366 from above. In agreement with this hypothesis, our analyses of kiskadee-like
367 flycatchers revealed that all hypothetical mimics are indistinguishable from
368 hypothetical models in the coloration of upperpart plumage patches, which would
369 arguably be the most relevant ones considering the perspective of predatory
370 diurnal raptors perched on treetops.
371
372 Wallace (1863, 1869) and later Diamond (1982) were amazed by the striking
373 similarity in plumage between orioles (genus Oriolus, family Oriolidae) and
374 friarbirds (genus Philemon, family Meliphagidae). Wallace first claimed such
375 similarity was a case of visual mimicry, but no study on the subject was done until
376 Diamond (1982) posited that visual mimicry may serve to escape attack from larger
377 model species or to deceive smaller species and scare them off only by 378 appearance. Prum & Samuelson (2012) and Prum (2014) further expanded on the
379 first idea by positing the ISDM hypothesis and outlining its predictions. A recent
380 analysis assessing ISDM on orioles and friarbirds using phylogenetic methods
381 suggested that orioles indeed appear to mimic larger-bodied friarbirds (Jønsson et
382 al., 2016), but there is no information about the species being deceived in this
383 system. In principle, ISDM may also apply to kiskadee-like flycatchers because
384 existing data support the prediction that hypothetical model species are larger in
385 body mass (i.e. at least 30g heavier) than hypothetical mimic species. The
386 additional prediction that models are socially dominant over mimics has not been
387 tested quantitatively, but several observations exist of both hypothetical model
388 species scaring off hypothetical mimics from foraging grounds (personal
389 communications with other ornithologists). Also, we found that shared phenotypic
390 similarities between model and mimic species are not product of common ancestry:
391 our ancestral state character reconstructions revealed that because the kiskadee-
392 like phenotype has evolved at least four times independently it is product of
393 convergence.
394
395 A critical additional prediction of the ISDM hypothesis is that visual deception
396 based on covergent coloration should be physiologically plausible at ecologically
397 relevant visual distances between individuals (Prum, 2014). We found partial
398 support for this prediction in kiskadee-like tyrant flycatchers. On one hand,
399 because all hypothetical mimics were perceptually distinguishable from
400 hypothetical model P. sulphuratus in the coloration of the upper breast, middle
401 breast, abdomen and flank patches using the UVS model, and considering that 402 underpart patches are visually relevant when two species engage physically in
403 interference competition (Schoener, 1983), our analyses reject the proposition that
404 visual deception is physiologically possible when having P. sulphuratus as
405 hypothetical model. This result is consistent with previous work in other birds
406 showing that despite striking similarity to the human eye, putatively mimic Downy
407 Woodpeckers (Picoides pubescens) do not experience reduced aggression from
408 hypothetical model Hairy Woodpeckers (Picoides villosus), implying lack of
409 deception (Leighton et al., 2018). Because Downy Woodpeckers were more
410 dominant over other bird species than expected based on their body size,
411 convergence in plumage with Hairy Woodpeckers may instead have evolved to
412 deceive smaller third-party species (Diamond, 1982; Leighton et al., 2018), a
413 hypothesis to be tested in kiskadee-like flycathers resembiing P. sulphuratus.
414
415 On the other hand, we found that most hypothetical mimics are perceptually
416 indistinguishable from M. pitangua in underpart plumage patches. Perceptual
417 similarity given the UVS model indicates that M. pitangua might be deceived by
418 hypothetical mimics, misidentify them as conspecifics, and thus split resources with
419 them owing to reduced agression. Alternatively, other passerines might be
420 deceived by hypothetical mimics, misidentify them as M. pitangua individuals, and
421 therefore withdraw from any interaction which may potentially result in attack.
422 Consequently, our results are consistent with mimicry hypotheses that imply
423 deception of either putative models or smaller passerine competitors (Diamond,
424 1982; Prum, 2014; Prum & Samuelson, 2012, 2016) when considering M. pitangua
425 as the putative model. We are unable to fully support either hypotheses given our 426 results but we agree with Leighton et al. (2018) in that because individuals are
427 expected to be very good at identifying conspecifics given its importance for
428 competition and successful breeding, visual deception of hypothetical models
429 seems unlikely. Alternatively, because selective pressures to identify individuals
430 which are not predators, prey or strong competitors are likely reduced, visual
431 deception of species that are neither hypothetical mimics or models may be more
432 likely (Diamond, 1982; Leighton et al., 2018).
433
434 Ours is the first study to assess the plausibility of mimicry hypotheses in birds
435 using spectrophotometric measurements of plumage, and evaluating the data with
436 statistical and perceptual analysis (Maia & White, 2017) given two avian visual
437 models. Additional work is required to further evaluate hypotheses accounting for
438 plumage convergence. For instance, although our study species overlap in
439 geographic range, diet and foraging strategies (Fitzpatrick, 1980; Fitzpatrick, 1981;
440 Fitzpatrick et al., 2004), very little is known about interactions between them; the
441 extent to which hypothetical models are indeed deceived by hypothetical mimics
442 should be evaluated through behavioral observations and experiments. Likewise,
443 field studies are required to assess whether predators such as raptors are indeed
444 deceived by putative models and mimics to escape predation. In addition, there is
445 no knowledge of how perception of color may vary with distance between
446 individuals or of how to account for distances over which individuals interact in the
447 field when analyzing spectrophotometric data. Hence, we do not know precisely
448 how likely deception is at ecologically relevant distances, an important condition for
449 ISDM (Prum, 2014). For example, while some hypothetical models may be 450 distinguishable by hypothetical mimcs upon inspection at close distances,
451 hypothetical mimic species may be able to deceive hypothetical models from
452 greater distances (Leighton et al., 2018). Finally, we accounted for passerines’ and
453 raptors’ visual systems using available standard UVS and VS models however,
454 specific visual models of putative models, mimics and third-party receptors are
455 necessary for a more accurate assessment of social mimicry hypotheses.
456
457 In conclusion, perceptual similarity of the crown, back and rump patches among
458 species is consistent with the hypothesis that predation by visually oriented
459 predators approaching their prey from above may have favored convergence in
460 plumage in kiskadee-like tyrant flycatchers (Barnard, 1979). Perceptual similarity
461 suggests that deception involved in competitive interactions with M. pitangua, but
462 not with P. sulphuratus, may also have favored convergence (Diamond, 1982;
463 Prum, 2014; Prum & Samuelson, 2012, 2016). Future studies should focus on
464 gathering behavioral data to characterize competitive and predator-prey
465 interactions among species involved in social mimicry. Moreover, assessing how
466 other factors like climate, habitat and development shape the evolution of plumage
467 would allow for a comprehensive understanding of the mechanisms underlying
468 convergence in plumage.
469
470 Acknowledgments:
471 We thank Museo de Historia Natural de la Universidad de los Andes (ANDES),
472 Instituto de Ciencias Naturales de la Universidad Nacional (ICN), and Instituto de 473 Investigación de Recursos Biológicos Alexander von Humboldt (IAvH) for
474 permitting us take spectrophotometric measurements of museum specimens.
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Figure 1. Plumage patches measured to characterize coloration and compare plumage among species of “kiskadee-like” flycatchers.
Figure 2. Stochastic mapping of the binary discrete character kiskadee-like shown in yellow and non-kiskadee like shown in brown indicating that plumage similarity reflects convergence due to repeated evolution of the same plumage pattern.
Asterisks point edges corresponding to kiskadee-like clades or species. Pictures show examples of the diversity of phenotypes in the clade including the species studied. Photo credits: Nick Bayly and Laura Céspedes.
Figure 3. Overview of the results of perceptual analysis considering upper breast, lower breast, belly and flank plumage patches. While all four hypothetical models are distinguishable from P. sulphuratus, three out of four species are indistinguishable from M. pitangua.
UVS VS Patch/ Upper Lower Upper Lower Belly Crown Back Flank Throat Rump Belly Crown Back Flank Throat Rump Species breast breast breast breast M. pitangua/ M. cayanensis * * M. pitangua/ M. similis M. pitangua/ P. inornata M. pitangua/ P. lictor * * * * P. sulphuratus/ M. cayanensis * * * * * * * * P. sulphuratus/ M. similis * * * * * * * * P. sulphuratus/ P. inornata * * * * * * * * P. sulphuratus/ P. lictor * * * * * * * * Figure 4. Statistical and perceptual distinction of patches using the UVS and VS model. Patches that are statistically
different are shown in yellow (a≥0.05 for the PERMANOVA). Patches that are perceptually different (JNDS>1) are shown
with an asterisk.
A
B C
Figure 5. A pair of hypothetical model and mimic species that are
indistinguishable. A) Comparison of the chromatic contrast of the centroids for
each patch using the UVS (yellow) and the VS (black) models. B) Distribution of
the color volume of each species in the tetrahedral colorspace using UVS and VS
models. C) Comparison of the reflectance curves of all patches of both species.
A
B C
Figure 6. A pair of hypothetical model and mimic species that are distinguishable.
A) Comparison of the chromatic contrast of the centroids for each patch using the
UVS (yellow) and the VS (black) models. B) Distribution of the color volume of
each species in the tetrahedral colorspace using UVS and VS models. C)
Comparison of the reflectance curves of all patches of both species.
A
B C
Supplementary Figure 1. Comparison between M. pitangua and M. cayanensis, a
pair of hypothetical model and mimic that are indistinguishable except for the rump
patch A) Comparison of the chromatic contrast of the centroids for each patch
using the UVS (yellow) and the VS (black) models. B) Distribution of the color
volume of each species in the tetrahedral colorspace using UVS and VS models.
C) Comparison of the reflectance curves of all patches of both species. A
B C
Supplementary Figure 2. Comparison between M. pitangua and P. lictor, a pair of
hypothetical model and mimic that are distinguishable given middle breast and
flank patches A) Comparison of the chromatic contrast of the centroids for each
patch using the UVS (yellow) and the VS (black) models. B) Distribution of the
color volume of each species in the tetrahedral colorspace using UVS and VS
models. C) Comparison of the reflectance curves of all patches of both species.
Supplementary Table 1. Complete specimen information.
Species Museum Catalogue number Year collected Mass (g) Sex 1 Pitangus sulphuratus IAvH 4609 1984 58 Female 2 Pitangus sulphuratus IAvH 6198 1986 N Male 3 Pitangus sulphuratus IAvH 5996 1975 N N 4 Pitangus sulphuratus IAvH 1785 1976 53,9 Female 5 Pitangus sulphuratus IAvH 1877 1976 53,5 Male 6 Pitangus sulphuratus IAvH 4608 1984 64 Male 7 Pitangus sulphuratus IAvH 14281 2007 49 Female 8 Pitangus sulphuratus IAvH 2916 N N N 9 Pitangus sulphuratus IAvH 2888 1979 N N 10 Pitangus sulphuratus IAvH 6197 1986 N Female 11 Pitangus sulphuratus IAvH 6010 1986 60 Male 12 Pitangus sulphuratus IAvH 6009 1987 51 Female 13 Pitangus sulphuratus IAvH 7514 1994 45,9 Male 14 Pitangus sulphuratus IAvH 2189 1975 N Female 15 Pitangus sulphuratus IAvH 0772 1969 53,7 N 16 Pitangus sulphuratus IAvH 0330 1970 N Male 17 Pitangus sulphuratus IAvH 12916 2004 58 Female 18 Pitangus sulphuratus IAvH 14759 2008 60,6 Male 19 Pitangus sulphuratus ANDES 00079 1974 N N 20 Pitangus lictor IAvH 5068 1977 24,4 Male 21 Pitangus lictor IAvH 2841 1979 N Female 22 Pitangus lictor IAvH 5067 1977 22 Female 23 Pitangus lictor IAvH 5066 1977 23,6 Male 24 Pitangus lictor IAvH 1816 1976 19,1 Female 25 Pitangus lictor IAvH 1856 1976 23,8 Male 26 Pitangus lictor ICN 5315 1974 22,548 Male 27 Pitangus lictor ICN 30825 1989 N Male 28 Pitangus lictor ICN 31383 1990 N Female 29 Pitangus lictor ICN 38414 2011 25 Male 30 Myiozetetes similis IAvH 1738 1977 27 Male 31 Myiozetetes similis IAvH 5993 1975 N N 32 Myiozetetes similis ICN 39344 2015 27 Male 33 Myiozetetes similis ICN 39359 2011 28,9 Female 34 Myiozetetes similis ICN 34869 2004 26 Female 35 Myiozetetes similis ICN 2552 1977 24,672 Male 36 Myiozetetes similis ICN 38415 2011 25,5 Male 37 Myiozetetes similis ICN 32435 1978 N Female 38 Myiozetetes similis ICN 7094 1960 N Male 39 Myiozetetes similis ICN 28523 1984 23,5 Female 40 Myiozetetes cayanensis IAvH 1114 1975 N Male 41 Myiozetetes cayanensis IAvH 4620 1984 28 Male 42 Myiozetetes cayanensis IAvH 4621 1984 27 Female 43 Myiozetetes cayanensis IAvH 11483 2000 24 Male 44 Myiozetetes cayanensis IAvH 6047 N N N 45 Myiozetetes cayanensis IAvH 5037 1977 28 Male 46 Myiozetetes cayanensis IAvH 3687 1976 26,4 Male 47 Myiozetetes cayanensis IAvH 5117 1976 28,9 Female 48 Myiozetetes cayanensis IAvH 5295 1974 N Male 49 Myiozetetes cayanensis IAvH 13754 2004 24 Male 50 Myiozetetes cayanensis IAvH 13755 2004 22 Female 51 Phelpsia inornata IAvH 14737 2008 25,5 Female 52 Phelpsia inornata ICN 31033 1991 30 Male 53 Phelpsia inornata ICN 31003 1991 27 Female 54 Phelpsia inornata ICN 31032 1991 27 Male 55 Phelpsia inornata ICN 31026 1991 31 Female 56 Phelpsia inornata ICN 38372 2011 22,5 Female 57 Phelpsia inornata ICN 31040 1991 23 Female 58 Megarhynchus pitangua IAvH 13685 2004 56 Male 59 Megarhynchus pitangua IAvH 1855 1975 70,1 Male 60 Megarhynchus pitangua IAvH 15109 2009 51 Male 61 Megarhynchus pitangua IAvH 15919 2017 69 Male 62 Megarhynchus pitangua ANDES 0192 1972 N Male 63 Megarhynchus pitangua ANDES 00076 1975 N N 64 Megarhynchus pitangua ICN 38860 2013 68 Female 65 Megarhynchus pitangua ICN 34202 2002 56,8 Male 66 Megarhynchus pitangua ICN 35274 2005 62 Female 67 Megarhynchus pitangua ICN 38418 2011 54,4 Female 68 Megarhynchus pitangua ICN 31589 1991 48,6 Female
Supplementary Table 2. Pseudo-f, R2 and significance (a=0.05) for the PERMANOVA using the UVS and VS models.
Patches that are statistically different are bolded and highlighted in gray.
UVS VS Patch/ Upper Lower Upper Lower Belly Crown Back Flank Throat Rump Belly Crown Back Flank Throat Rump Species breast breast breast breast 0.4676 1.8493 1.3606 6.0436 6.2252 1.2018 0.71904 13.995 0.359 2.0894 1.3721 5.5125 6.5988 1.5874 0.1473 16.351 M. pitangua/ 0.02402 0.09317 0.07837 0.25136 0.25697 0.07418 0.03841 0.43742 0.01854 0.10401 0.07898 0.23445 0.26826 0.0957 0.00812 0.476 M. cayanensis (0.665) (0.137) 0.277 (0.012) (0.004) (0.268) (0.545) (0.001) (0.726) (0.126) (0.25) (0.021) (0.007) (0.214) (0.892) (0.001) 1.1536 1.6763 2.131 4.2569 2.303 1.2509 1.7602 1.4301 1.4012 1.535 2.6618 3.4388 2.4883 1.0049 1.7724 2.311 M. pitangua/ 0.05724 0.0852 0.1139 0.19126 0.11931 0.06177 0.09911 0.0736 0.06868 0.07858 0.13538 0.1604 0.12768 0.05023 0.0973 0.11378 M. similis (0.348) (0.191) (0.112) (0.02) (0.103) (0.288) (0.171) (0.253) (0.233) (0.193) (0.065) (0.048) (0.106) (0.36) (0.16) (0.093) 0.50355 5.3743 1.7371 0.69618 1.8724 2.4138 1.5899 5.5515 0.32459 5.6185 2.1776 0.65478 2.0913 2.3717 1.2396 6.878 M. pitangua/ 0.03051 0.26378 0.11038 0.4435 0.11097 0.13109 0.09584 0.25759 0.01988 0.2725 0.12461 0.04183 0.12236 0.12909 0.07633 0.30064 P. inornata (0.627) (0.011) (0.13) (0.62) (0.157) (0.103) (0.203) (0.002) (0.723) (0.021) (0.053) (0.659) (0.131) (0.096) (0.252) (0.001) 0.98412 13.047 1.5509 0.69368 7.8419 12.735 2.2121 0- 6.21 0.99554 12.756 4.0197 0.69357 7.6763 12.4 1.3432 6.7053 M. pitangua/ 0.04925 0.42024 0.07932 0.03711 0.30346 0.40129 11514 0.24633 0.04979 0.41475 0.18255 0.0371 0.29897 0.39491 0.07323 0.26085 P. lictor (0.359) (0.001) (0.188) (0.544) (0.001) (0.001) (0.115) (0.001) (0.354) (0.001) (0.015) (0.525) (0.004) (0.002) (0.264) (0.001) 24.051 18.568 24.434 13.104 1.1484 16.196 1.0884 1.2281 19.848 17.059 20.645 11.653 1.43 15.764 1.3302 1.4213 P. sulphuratus/ 0.47111 0.41662 0.52621 0.3351 0.0423 0.42402 0.04018 0.04683 0.42367 0.39618 0.48411 0.30948 0.05213 0.41743 0.04867 0.05379 M. cayanensis (0.001) (0.001) (0.001) (0.002) (0.343) (0.001) (0.367) (0.284) (0.001) (0.001) (0.001) (0.002) (0.243) (0.002) (0.278) (0.253) 49.262 35.999 21.038 9.651 1.0894 29.831 5.9367 4.3567 50.007 37.753 22.32 8.185 1.1592 33.882 5.9003 4.4667 P. sulphuratus/ 0.64596 0.58064 0.47772 0.27071 0.04176 0.53431 0.19831 0.1484 0.64938 0.59218 0.4925 0.23943 0.04431 0.56581 0.19733 0.15159 M. similis (0.001) (0.001) (0.001) (0.002) 0.307 (0.001) (0.003) (0.016) (0.001) (0.001) (0.001) (0.004) (0.307) (0.001) (0.007) (0.014) 26.683 49.66 17.321 1.1874 0.17224 34.964 0.68955 1.0092 28.594 46.531 18.545 1.094 0.24154 40.732 0.87835 1.0931 P. sulphuratus/ 0.52647 0.68346 0.46411 0.04909 0.00743 0.6032 0.02911 0.04203 0.54367 0.66921 0.48113 0.0454 0.01039 0.63911 0.03678 0.04537 P. inornata (0.001) (0.001) (0.001) (0.294) (0.884) (0.001) (0.549) (0.373) (0.001) (0.001) (0.001) (0.329) (0.829) (0.001) (0.439) (0.34) 33.653 92.421 57.321 0.72764 1.5972 96.641 0.33579 1.2281 33.905 86.933 63.237 0.5704 1.8885 101.21 0.15652 1.0949 P. sulphuratus/ 9.55485 0.78045 0.70487 0.02722 0.05788 0.788 0.01325 0.04511 0.55668 0.76978 0.72489 0.02147 0.06772 0.79562 0.00622 0.04041 P. lictor (0.001) (0.001) (0.001) (0.449) (0.186) (0.001) (0.732) (0.299) (0.001) (0.001) (0.001) (0.533) (0.154) (0.001) (0.883) (0.339)
Supplementary Table 3. Upper, mean and lower values of JND resulting of the bootstrap analysis using the UVS and VS
models. Patches that are perceptually different are bolded and highlighted in gray
UVS VS Patch/ Upper Lower Upper Lower Belly Crown Back Flank Throat Rump Belly Crown Back Flank Throat Rump Species breast breast breast breast 1.84782 2.77256 1.56837 2.13576 2.73130 3.50514 0.66411 2.89343 1.93170 3.07365 1.63226 2.04874 2.68273 4.36253 0.61005 2.93722 M. pitangua/ 0.68578 1.33060 0.51545 1.31581 1.74257 1.42195 0.18632 2.04907 0.73610 1.50165 0.70648 1.27193 1.76733 1.83271 0.08608 2.13473 M. cayanensis 0.25508 0.32700 0.12514 0.44122 0.86145 0.21538 0.05894 1.28297 0.39510 0.46793 0.25162 0.46927 0.80649 0.33683 0.05094 1.30281 1.93882 2.33756 1.99843 1.50689 1.85784 2.44313 1.05471 1.34028 1.89696 2.35033 2.51170 1.29852 1.76760 2.39822 1.07435 1.41686 M. pitangua/ 0.60853 1.14127 0.83440 0.91157 0.93243 1.08735 0.47050 0.714910 0.71750 1.15275 1.18425 0.75663 0.93755 0.96852 0.44536 0.76207 M. similis 0.21472 0.23330 0.27023 0.46097 0.28598 0.33553 0.18538 0.29431 0.32759 0.33534 0.42560 0.39680 0.28370 0.38626 0.15348 0.27497 1.97583 3.21930 3.68630 1.97085 2.18689 2.68352 0.73109 2.57742 1.99593 3.28193 4.27167 1.97986 2.29990 2.60943 0.73396 2.70387 M. pitangua/ 0.71140 2.03920 1.09585 0.42465 1.02144 1.36010 0.46270 1.73330 0.49674 2.09526 1.65670 0.44594 1.03450 1.38725 0.34375 1.81234 P. inornata 0.31527 1.00077 0.44695 0.13360 0.23618 0.50710 0.32513 0.94297 0.34038 0.99656 0.84323 0.12552 0.23350 0.83435 0.15773 0.99737 2.91661 4.16115 1.47045 1.39716 2.60196 4.70175 1.18237 2.62467 3.01910 4.27714 1.86265 1.45659 2.60761 4.83556 1.01570 2.76860 M. pitangua/ 1.15470 2.95553 0.78637 0.19251 1.76965 3.31084 0.71101 1.73456 1.36010 3.01592 1.32183 0.16680 1.73697 3.41051 0.50566 1.79276 P. lictor 0.35040 1.86160 0.43842 0.10320 0.89673 2.05997 0.54635 0.94500 0.81078 1.88757 0.96910 0.09489 0.87897 2.05276 0.37102 1.02133 4.17953 4.61246 4.86849 2.59696 2.18092 5.83154 0.98754 1.50774 4.24660 4.87178 5.00820 2.63886 2.38593 6.07556 0.97195 1.60011 P. sulphuratus/ 3.19090 3.43020 3.87286 1.81950 1.17552 4.04628 0.55568 0.69169 3.24158 3.53406 3.99124 1.77925 1.29107 4.29448 0.52192 0.74035 M. cayanensis 2.27200 2.50836 3.00945 0.90270 0.56565 2.35257 0.29010 0.50565 2.20196 2.48152 3.06008 0.90430 0.57346 2.50053 0.24353 0.54342 5.13938 4.65684 4.76579 1.95003 1.52995 4.95356 1.51430 2.41040 5.21327 4.85727 4.95482 1.82078 1.68346 5.18412 1.50028 2.28780 P. sulphuratus/ 4.23297 3.84603 3.70523 1.36178 0.94237 3.93950 1.06415 1.53307 4.38335 4.01543 3.95028 1.18211 0.99025 4.19673 0.93954 1.48238 M. similis 3.42743 3.07083 2.85261 0.81214 0.76610 2.97652 0.74402 0.95995 3.60477 3.41980 3.38276 0.57281 0.82523 3.44696 0.53602 1.04066 4.77582 5.47310 5.00762 2.44194 1.64297 5.06601 0.56807 1.59253 5.11202 5.62168 5.53453 2.64407 1.86924 5.29528 0.51196 1.58372 P. sulphuratus/ 3.73910 4.63119 3.45081 0.92861 0.67550 4.20333 0.15761 0.81647 4.08020 4.82160 4.02480 0.96210 0.78144 4.60677 0.21962 0.90471 P. inornata 2.80516 3.90392 2.09976 0.18933 0.51740 3.43885 0.08126 0.74274 3.21150 4.18121 3.17691 0.21586 0.60124 4.04456 0.14521 0.84920 6.41404 6.50857 5.32662 1.82199 2.14781 7.06043 0.91613 1.60850 6.55423 6.62168 5.76014 1.93793 2.27481 7.42043 0.73439 1.68630 P. sulphuratus/ 4.81370 5.61481 4.58320 0.69452 1.20597 6.09806 0.11853 0.84235 5.01182 5.77015 5.03370 0.68216 1.34426 6.50724 0.01071 0.91171 P. lictor 3.45111 4.79610 3.83827 0.15865 0.56369 5.12313 0.05180 0.72661 3.67403 4.97097 4.44598 0.09781 0.69570 5.63451 0.03557 0.82904
Supplementary Table 4. Comparison of descriptive variables for all species using the UVS and VS models.
UVS VS M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus Total volume 0.00058 0.00084 0.00042 0.00056 0.00080 0.00109 0.00026 0.00039 0.00019 0.00024 0.00035 0.00053 Relative volume 0.00266 0.00393 0.00194 0.00259 0.00367 0.00503 0.00125 0.00179 0.00088 0.00112 0.00166 0.00246 Mean Color Span 0.12838 0.12560 0.11621 0.12980 0.13245 0.12168 0.12157 0.11887 0.11317 0.12414 0.13019 0.10721 Variance Color Span 0.00724 0.00620 0.00625 0.00727 0.00808 0.00579 0.00714 0.00614 0.00657 0.00742 0.00857 0.00468 Mean Hue Disparity 0.47437 0.40336 0.31162 0.48567 0.56387 0.68113 0.32513 0.32007 0.23890 0.36101 0.49453 0.58716 Variance Hue Disparity 0.17914 0.11101 0.06905 0.20825 0.38809 0.41527 0.09420 0.06902 0.09217 0.12719 0.39639 0.37552 Mean Saturation 0.46350 0.47155 0.49650 0.48308 0.52034 0.38563 0.42362 0.46456 0.44662 0.43672 0.46616 0.42695 Maximum Saturation 0.79879 0.82006 0.82484 0.80652 0.84461 0.74497 0.77300 0.82104 0.78692 0.74963 0.80286 0.78610 Supplementary Table 5. Comparison of centroid values of underpart patches for all species using the UVS and VS
models.
Upper Breast UVS VS M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus u centroid 0.14033 0.13016 0.13410 0.12556 0.13642 0.12876 0.08573 0.08090 0.08397 0.08570 0.08654 0.09722 s centroid 0.07265 0.07783 0.06695 0.07238 0.06354 0.12285 0.11865 0.12706 0.10920 0.11294 0.10250 0.17621 m centroid 0.37774 0.37909 0.37540 0.37484 0.37166 0.36446 0.38203 0.37936 0.37941 0.37488 0.37705 0.35408 l centroid 0.40926 0.41291 0.42352 0.42722 0.42836 0.38393 0.41356 0.41269 0.42740 0.42644 0.43391 0.37253 Middle breast UVS VS M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus u centroid 0.13994 0.11624 0.12870 0.12137 0.12151 0.11452 0.08996 0.07394 0.08335 0.07633 0.07318 0.08572 s centroid 0.08001 0.07367 0.06924 0.06119 0.05308 0.11946 0.12644 0.12139 0.11219 0.10252 0.09210 0.17597 m centroid 0.37574 0.38461 0.37979 0.38105 0.38387 0.37097 0.37762 0.38240 0.38115 0.38316 0.38837 0.35779 l centroid 0.40429 0.42546 0.42226 0.43635 0.44155 0.39504 0.40596 0.42225 0.42329 0.43799 0.44633 0.38052 Belly UVS VS M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus u centroid 0.10875 0.10101 0.12559 0.12893 0.12142 0.10940 0.06734 0.06270 0.08140 0.08910 0.07739 0.07915 s centroid 0.06419 0.06632 0.06883 0.07521 0.05991 0.11538 0.10901 0.11497 0.11209 0.11355 0.09860 0.17425 m centroid 0.39160 0.39476 0.38168 0.36843 0.37891 0.37466 0.39020 0.39008 0.38240 0.36952 0.38166 0.36110 l centroid 0.43544 0.43789 0.42388 0.42741 0.43972 0.40056 0.43342 0.43223 0.42409 0.42781 0.44235 0.38548 Flank UVS VS M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus M. pitangua M. cayanensis M. similis P. inornata P. lictor P. sulphuratus u centroid 0.14215 0.12342 0.14417 0.13942 0.12169 0.13744 0.09236 0.07307 0.08846 0.08780 0.07200 0.09371 s centroid 0.08074 0.06985 0.06887 0.06597 0.05082 0.11966 0.12626 0.11822 0.11323 0.10765 0.08841 0.17975 m centroid 0.37521 0.38475 0.37650 0.37462 0.38166 0.3662 0.37743 0.38590 0.38211 0.37958 0.38745 0.35825 l centroid 0.40188 0.42196 0.41045 0.41999 0.44581 0.37670 0.40394 0.42279 0.41618 0.42498 0.45211 0.36826