Phylloscopus Research Articles

ムシクイ類３種の秋の渡り時期の違い

The difference of migration timing during the autumn migratory period of three leaf warblers of the genus Phylloscopus, breeding widely in Japan, was studied at two areas of Honshu Island, Japan; Nobeyama plateau in Nagano Prefecture, central Honshu and Mt. Rokko in Hyogo Prefecture, about 340 km west-southwest from Nobeyama plateau. The three species of leaf warbler were captured by mist-net from late July to early or late November over a five year period (2003-2007). The Eastern Pale-legged Leaf Warbler Phylloscopus borealoides and the Eastern Crowned Leaf Warbler P. coronatus were captured almost exclusively from late July to early September, whereas the Arctic Warbler P. borealis was captured from early September to late November. The trapping period of the former two warblers overlapped greatly, but the median period of the Eastern Pale-legged Leaf Warbler was earlier than that of the Eastern Crowned Leaf Warbler at Mt. Rokko. The slight overlap of fall migration timing between the Arctic Warbler and the other two warblers may be related to the latitude of breeding ranges of the respective warbler species.

Leaf Warblers (Phylloscopus spp.) As a Model Group in Migration Ecology Studies

Leaf Warblers (Phylloscopus spp.) As a Model Group in Migration Ecology Studies The aim of this paper is to review information on systematic position, distribution ranges, habitat requirements, morphology, and ecology of the leaf warblers (Phylloscopus spp.). Closely related species of this group present different migration strategies. Exhibiting many inter-specific similarities in morphology and ecological requirements, leaf warblers reveal high intra-specific variability. The morphological differentiation of individual species, subspecies, populations, and age-sex groups, affords considerable possibilities for migration studies, especially those concerning the basis of migration strategy. Leaf warblers make a group of model species, being a good subject for ecological studies. The knowledge of their migration strategies may be a good reference point for understanding a general pattern of the migration of European passerines.

Intraspecific differentiation of Sino-Himalayan bush-dwelling Phylloscopus leaf warblers, with description of two new taxa (P. fuscatus, P. fuligiventer, P. affinis, P. armandii, P. subaffinis)

We investigated external morphology, molecular genetics and bioacoustics of the Chinese leaf warblers Phylloscopus fuscatus, P. fuligiventer, P. affinis, P. armandii and P. subaffinis, a set of predominantly high-altitude species of open bushy habitats. Phylloscopus fuscatus and P. fuligiventer were found to be sister taxa; the current subspecies of P. fuscatus appeared to be paraphyletic. P. fuscatus weigoldi (Qinghai) is excluded from P. fuscatus and transferred to P. fuligiventer as a subspecies (formerly E Himalayas/SE Tibet only). Several individuals of nominate fuscatus carrying private haplotypes were found in China during the breeding season and may locally breed there (Shaanxi, Gansu). Genotyping of type specimens of P. fuscatus robustus yielded a composite type series including nominate fuscatus. A lectotype of taxon robustus is designated since the holotype was lost in World War II. – Phylloscopus affinis falls into three distinct population groups which differ by exhibiting marked molecular genetic distance values, in coloration and in vocalisations. Central Asian Phylloscopus griseolus is firmly nested in the P. affinis clade. The Himalayan (incl. SE Tibet) populations of P. affinis on the one hand and the Chinese populations (Yunnan, Sichuan, Qinghai, Gansu) on the other are differentiated on the species level. For the latter populations a new name is introduced (P. occisinensis nov. sp.). The Himalayan population group itself is subdivided into a western (P. affinis perfl avus nov. ssp.) and an eastern group (nominate affinis). – Phylloscopus armandii generally is subdivided into a larger northern (nominate armandii) and a smaller southern Chinese population (ssp. perplexus). Their cytb and 16S distance values are remarkably high but subspecies status is retained because of only subtle morphological differences and a lack of acoustic divergence. – Phylloscopus subaffinis is unstructured with respect to cytb and 16S genes throughout China.

2007 American Society of Naturalists Awards

2007 American Society of Naturalists Awards

Breeding ecology of an Old World high-altitude warbler, Phylloscopus affinis

Reproduction of Tickell’s Leaf Warblers Phylloscopus affinis was studied in an alpine valley (29°27′N, 91°40′E, 3,980–5,600 m) in the Lhasa mountains, Tibet, at the upper elevational limit of the species’ breeding range. This species is a summer breeder, and is the only breeding Phylloscopus species in the valley. It nested in all types of shrubby vegetation across the altitudinal range of the valley. Most nests were placed close to the ground (<1 m) in low thorn bushes. Egg-laying dates fell between late May and early July, most within the first 3 weeks after the commencement of breeding. Mean clutch size was 4.0 (3–5) and mean brood size at fledging 3.4 (2–5). Incubation was by the females and lasted 13–14 days, and both parents cared for the young for 14–17 days. Nestlings ready to leave the nest were 13% heavier than the adults. Overall, 76% of nesting attempts produced at least one fledged young. Some aspects of the breeding biology of this high-altitude warbler were compared with those of lower-altitude Phylloscopus species.

Is earlier spring migration of Tatarstan warblers expected under climate warming?

We analysed data on the arrival dates of four species of leaf warbler (genus Phylloscopus) collected in Tatarstan between 1957 and 2004. There was no evidence over the whole period that the warblers returned to their breeding sites significantly earlier, mainly because local temperatures for April and May, months when the majority of birds arrived from their wintering grounds, did not increase significantly. However, arrival dates of two species (Chiffchaff P. collybita and Willow warbler P.trochilus) were strongly related to local temperature in April, and that of Greenish warbler P. trochiloides to that in May. As expected, arrival dates for the three species wintering in Africa (Chiffchaff, Willow and Wood warblers P. sibilatrix) correlated positively with one another (P < 0.01 in all cases), but were not correlated with arrival dates of Greenish warbler (P > 0.5 in all cases), a species wintering in the Indian sub-continent.

Bridging the Gap between Theory and Ecology in Evolutionary Models

Bridging the Gap between Theory and Ecology in Evolutionary Models

Isolation and characterization of microsatellite markers in Ijima's leaf warbler, Phylloscopus ijimae (Aves: Sylviidae)

AbstractMicrosatellite markers were isolated from Ijima's leaf warbler, Phylloscopus ijimae. From an enriched genomic library and using the fast isolation by AFLP of sequences containing repeats (FIASCO) method, 10 polymorphic loci were obtained. Four to 12 alleles were identified in an analysis of 23 Ijima's leaf warblers, with the degree of heterozygosity ranging from 0.35 to 0.87. The markers were tested in four species of Phylloscopus and two other non‐Phylloscopus species of Sylviidae. Some loci were successfully amplified and showed polymorphism in Phylloscopus species, whereas amplification in the non‐Phylloscopus species was less successful.

Sjeldne fugler i Norge i 2004 - Rapport fra Norsk sjeldenhetskomité for fugl (NSKF)

This is the 28th annual report and the 29th announcement from the Norwegian Rarities Committee (NSKF). Most of the records treated here are from 2003, but older records are also included. The systematic list of accepted records is set out in the following system: (1) The bird’s Norwegian name, (2) scientific name, (3) the numbers in brackets, e.g. (30/32 - 1), refers respectively to the total number of records/total number of individuals up to and including 2002, and in 2003, (4) any limitations given of (3), (5) any breeding, (6) year, (7) county, (8) number of individuals, age (1K = first calendar year etc.), sex (if known) and sometimes circumstances («ringmerket» means that the bird was ringed), (9) site and municipality, (10) date, (11) * indicates if the record was complemented by positive evidence, and type of the evidence (F = photo, V = video-recorded, L = tape-recorded, D = found dead), (12) observers names in brackets, main observer is specified first and emphasized with *, (13) roughly gives the species general distribution and (14) comments concerning the records. General trends: This year was the second best in the history of NSKF concerning number of accepted records. Several species reached record numbers. Most significant were the influxes of Water Pipit Anthus spinoletta (17 records) and Hume’s Warbler Phylloscopus humei (10 records) during autumn. Five records of Black-necked Grebe Podiceps nigricollis , two records of Black-browed Albatross Thalassarche melanopris , four records of Balearic Shearwater Puffinus mauretanicus , six records of Bittern Botaurus stellaris , nine records of Red Kite Milvus milvus , two records of Sharp-tailed Sandpiper Calidris acuminata, six records of Mediterranean Gull Larus melanocephalus , two records of Caspian Gull Larus cachinnans and five records of Red-rumped Swallow Hirundo daurica were all maximum records for one single year. Four records of White-rumped Sandpiper Calidris fuscicollis and two records of Isabelline Shrike Lanius isabellinus were equal to previous maximum number of records. New accepted records from 2002 resulted in an increase in the maximum number of records for Great Reed Warbler Acrocephalus arundinaceus (9 records) and Blyth’s Reed Warbler Acrocephalus dumetorum (7 records). Pallid Harrier Circus macrourus (6 records), M ontagu’s Harrier Circus pygargus (6 records), Pectoral Sandpiper Calidris melanotos (12 records), Olive-backed Pipit Anthus hodgsoni (4 records) and Pallas’s Leaf Warbler Phylloscopus proregulus (20 records) were also recorded in relatively high numbers. Species and subspecies new to the Norwegian list: Two species were added to the Norwegian category A list: Yellow-legged Gull Larus michahellis and Ovenbird Seiurus aurocapillus . A record of Masked Wagtail Motacilla alba personata added a new subspecies to the Norwegian list. A record of Lammergeier Gypaetus barbatus was placed in category D and a record of Turkey Vulture Cathartes aura from 2002 was placed in category E. With these new records the official Norwegian bird list consists of 466 species. In 2003, Black-necked Grebe Podiceps nigricollis was recorded breeding in Norway for the first time with one brood successfully raised, and Pink-footed Goose Anser brachyrhynchus was recorded breeding for the first time on the Norwegian mainland excluding Svalbard).

The radiation of the Seicercus burkii complex and its congeners (Aves: Sylviidae): molecular genetics and bioacoustics

Cryptic species of passerine birds lack notable morphological differentiation and can best be identified by molecular and bioacoustic markers. Here we investigate seven cryptic species of the golden-spectacled warbler ( Seicercus burkii complex) with respect to territorial song and cytochrome- b (cyt- b) sequences. Their phylogenetic relations to other Seicercus species and to members of the genus Phylloscopus are inferred by the same methods. Three separate lineages of Seicercus are nested within different branches of the molecular Phylloscopus tree. The S. burkii complex is a monophyletic unit comprising seven species ( S. burkii s. str., S. whistleri, S. valentini, S. soror, S. omeiensis, S. tephrocephalus and S. affinis). S. xanthoschistos turned out to be a close relative of Phylloscopus davisoni within the P. reguloides group. Two isolated sister taxa, S. grammiceps and S. castaniceps, also branch together with the P. reguloides group. Within the S. burkii complex the overall haplotype and nucleotide diversity is highest in taxa from the Chinese middle and upper mountain belt ( S. valentini, S. omeiensis and S. soror), indicating at least partially restricted gene flow in these species. This is explained by the fragmentation of high-altitude habitats in China while in the Himalayas the vicariant species S. whistleri inhabits a more continuous mountain belt at the same altitude. For the Chinese species from medium and high altitudes, past range expansion is indicated by significantly negative Tajima Ds. According to pairwise genetic distances, most species of the S. burkii complex have diverged 5 myr ago, the most recent split between S. burkii and S. tephrocephalus is dated 2 myr ago. Coalescence times for haplotype lineages of the different species range from 9 up to 12 myr, and between 5 and 6 myr for S. burkii and S. tephrocephalus. Within Seicercus divergence of song features such as frequency parameters and syntax structures correlate with genetic distances between taxa. The three cyt- b lineages of Seicercus correspond to different clusters in a discriminant analysis by acoustic parameters. Common syntax structures of territorial song in the Phylloscopus/ Seicercus assemblage are: (1) an introductory element derived from specific calls and (2) a syntax of trills and repeated element groups or a combination of both. There are clear indications that these song structures have repeatedly emerged, were lost or were altered in different branches of the phylogenetic tree at different times. Absolute differences between taxa in frequency parameters or in an acoustic divergence index increase significantly with growing genetic distances. However, due to multiple parallel evolution phylogenetic information provided by single acoustic traits decreases with increasing numbers of taxa involved in the investigation.

Unmelanized plumage patterns in Old World leaf warblers do not correspond to sequence variation at the melanocortin-1 receptor locus (MC1R).

Evolutionary changes in patterns and coloration of plumage are likely to represent a major mechanism for speciation among birds, yet the molecular basis for such changes remains poorly understood. Recently much attention has focused on the melanocortin-1 receptor (MC1R) as a candidate locus for determining the level and extent of epidermal melanin deposition. We tested the hypothesis that MC1R sequence variation is associated with interspecific variation in unmelanized plumage pattern elements in Old World leaf warblers (genus Phylloscopus). This genus is characterized by a variety of plumage patterns that nonetheless vary along similar lines. Species vary in the presence or absence of pale (unmelanized) pattern elements against a dark background, and these patterns are used in species recognition and courtship. We sequenced most of the MC1R coding region for eight Phylloscopus species, representing the full range of plumage patterns found in this genus. Although MC1R sequence varied among species, this variation was not related to melanin-based plumage variation. Rather, evolution of this locus in these birds appears to be conservative. Ratios of nonsynonymous to synonymous substitutions (dN/dS) were consistently low, suggesting that strong purifying selection has operated at this locus, and likelihood ratio testing revealed no evidence of variable selective pressures among lineages or across codons. Adaptive evolution at MC1R may be constrained by the adaptive importance of plumage pattern elements in this genus.

Latitudinal trends in body size among over‐wintering leaf warblers (genus Phylloscopus)

Geographical trends in body size are commonly interpreted in the framework of Bergmann's rule, which states that larger body sizes are found at higher latitudes. Here we demonstrate a negative association of body size with latitude among over‐wintering warblers of the genus Phylloscopus as well as within a single species (Phylloscopus trochiloides) we were able to study in depth. We examine the role of resources in determining body size distributions. In mid‐winter in India there are more large prey at southern sites (occupied by large‐bodied warblers) than at a northern site (occupied by small‐bodied warblers). Phylloscopus trochiloides is a relatively large species. The timing of its autumn migration is correlated with the withdrawal of the monsoon through India and its appearance on the breeding grounds in spring is correlated with the appearance of relatively large prey. We suggest that prey size and abundance are the main determinants of the spatial distributions of Phylloscopus warblers in winter. Cross‐species associations of body size with both time of arrival on the breeding grounds and migration distance may also largely reflect the spatial and temporal distribution of prey. Resources are likely to be more important in determining both the strength and direction of latitudinal associations with body size than is currently appreciated, even in cases where Bergmann's rule is upheld.

Cryptic species in the genus Phylloscopus (Old World leaf warblers)

In almost all ecological and evolutionary research, it is important to assess the number of species under study. Cryptic species, which are morphologically similar, present a special problem because they need to be identified through studies of behavioural or genetic variation. Here we review the important factors in the recent discovery of three species and elevation of nine previously known taxa to species status within the genus Phylloscopus (Old World leaf‐warblers) and we examine the case of three morphologically similar taxa (inornatus, humei and mandellii) that until recently were considered to be members of the single species Phylloscopus inornatus. We have identified several locations at which humei and inornatus coexist at high density, and the results of playback experiments, observations of interactions, and spectrogram analysis of vocalizations at these sites all indicate that there are significant behavioural differences and a lack of recognition between humei and inornatus. Estimated relationships within the species complex based on mitochondrial control region DNA sequences show that there is little variation within the geographic ranges of either humei or inornatus compared with the deep split between the two taxa. These observations support the division of humei and inornatus into separate species. The third taxon, mandellii, which is geographically separated from both humei and inornatus, is behaviourally and genetically more similar to humei. Under the biological species concept, it is difficult to determine the species status of allopatric taxa. Alternative species concepts, such as the phylogenetic and recognition concepts, are more easily applied to allopatric taxa but lead to differing conclusions over whether mandellii and humei are separate species. This confusion arises from the fact that the two taxa are in an early stage of allopatric divergence. The review of other recently designated species reveals that song divergence is of primary importance in their designation and that song variation, playback experiments and genetic analysis lead to similar conclusions regarding species status.

Determinants of the northern and southern range limits of a warbler

AbstractAimTo understand the determinants of range limits by studying the behaviour and ecology of a single species (the Hume’s leaf warbler, Phylloscopus humei) at both its northern and southern range limits.LocationsNorth‐west India (Himachal Pradesh) and central India (Maharashtra).MethodsWe worked at seven locations primarily in the winter of 1997–98. Five locations spanned the northern range limit of the species and two were close to the southern range limit. We censused arthropod and bird abundance (including both the Hume’s leaf warbler and other ecologically similar species) at each site. We also studied the foraging behaviour of the common warbler species.ResultsAcross the whole range of P. humei the abundance of arthropods is tightly correlated with the abundance of all warbler species. The northern range limit of P. humei coincides with the disappearance of arthropod food from its habitat (tree crowns), which is attributed to leaf loss associated with cold temperatures. Two closely related species, P. proregulus and Seicercus xanthoschistos have a northerly range limit beyond that of P. humei. They occupy the understory, which retains leaves and arthropods further north than do the tree crowns. The southern range limit of P. humei is associated with high food levels in its habitat, but also increasing numbers of a potential competitor, P. trochiloides, which is very similar in habits and also occupies the tree crowns, but is about 40% heavier. We attribute the decline of P. humei in the south to competition from P. trochiloides. Because food levels are high in the south, the mechanism of competition is likely to be interference, rather than exploitative.Main conclusionCompetition for food is likely involved in setting both the northern and southern range limits, but in very different ways. The results are discussed in the light of current theories for the way range limits are ultimately determined.

Egg rejection in a passerine bird: size does matter

Avian brood parasites reduce the reproductive success of their hosts, selecting for the evolution of egg discrimination by the host, and potentially creating a coevolutionary arms race between host and parasite. Host egg discrimination ability is crucial in determining whether the arms race results in extinction (of the parasite on a particular host) or stable coevolutionary equilibrium of the host–parasite pair. I examined egg discrimination behaviour in the yellow-browed leaf warbler, Phylloscopus humei, a presumed former host of parasitic cuckoos, to show how discrimination ability has become very strong. Field experiments using model eggs demonstrate that rejection decisions are based on the relative size of eggs in the clutch. Individuals do not learn the particular size of their own eggs, but will accept both large and small eggs as long as all eggs in the clutch are of similar size. Host rejection decisions are continuously modified based on assessment of variation in egg sizes currently in the clutch, making it a difficult strategy for a cuckoo to defeat.

Mitochondrial genomic rearrangements in songbirds.

The organization of the mitochondrial genome is generally very conserved among vertebrates. Because of this, examination of the rare rearrangements which do occur has been suggested as offering a powerful alternative to phylogenetic analyses of mitochondrial DNA sequences. Here, we report on an avian mitochondrial rearrangement in a group of oscine passerines (warblers of the genus Phylloscopus). This rearrangement is identical to the mitochondrial organization recently identified in representatives of four orders of birds, including subsoscine Passeriformes. The rearrangement involves the movement of three genes (tRNA(Pro), NADH6, and tRNA(Glu)) from their normal position in birds between tRNA(Thr) and the control region (CR), to a new location between the CR and a novel, supposedly noncoding (NC), region. Our results suggest that this derived arrangement cannot be used to distinguish between suboscine and oscine passerines, as it has multiple origins both within Passeriformes and within birds as a whole. We found short stretches of DNA with high degrees of similarity between the CR and each NC region, respectively, all of which could be located in the same area of the CR. This suggests that the CR and the NC region are homologous and that the mechanism behind this mitochondrial rearrangement is a tandem duplication followed by multiple deletions. However, the similarities between the control and NC regions of each species were less pronounced than those between the control or NC regions from the different species, supporting the hypothesis of a single basal rearrangement in the Phylloscopus warblers.

Annual variation in fat storage by a migrant warbler overwintering in the Indian tropics

1. We studied fat storage in a population of greenish leaf warblers (Phylloscopus trochiloides) in southern India over four winters (1993–97). This species breeds in temperate regions and overwinters in India from October to April. 2. Diurnal variation in fat scores was comparable to that seen among temperate wintering passerines. Seasonal variation was slight, except for premigratory fattening. There was significant annual variation: in drier winters, which were also winters of low food supplies, fat scores were higher. 3. Energy metabolized overnight is unlikely to vary across winters, and annual variation in fat scores is considered a response to uncertainty of food intake on a given day. Fat scores varied inversely with short‐term rainfall, which drives the abundance of arthropod prey. 4. Annual variation in fat scores was not accompanied by changes in total body mass. This suggests that protein reserves were being compromised by increased fat deposition in dry years and offers an explanation for the observed delay in moult during drier winters. These results suggest that strategies for maximizing short‐term probability of survival translate into future fitness costs, and may shape long‐term life‐history strategies through simple physiological processes.

Different timing of the adaptive radiations of North American and Asian warblers

The timing of speciation events among warblers (small insectivorous woodland birds) in the Himalayas of India and in the White Mountains of New Hampshire, USA, is compared. Sequence divergence in the mitochondrial cytochrome b gene for 13 New World species in six genera averages 2.6%, which according to standard calibrations places most of the diversification in the early Pleistocene. In contrast, eight Himalayan species in the single genus Phylloscopus differ by an average of 10.7% in the same gene sequence. The New Hampshire warblers appear to have undergone a relatively recent burst of speciation and morphological evolution, but there is a detectable slowing of speciation rates (or increase in extinction rates) within the community towards the present. Other North American passerine groups that have been studied show no signs of explosive diversification in the Pleistocene. In these groups, pairs of sister species are often older than the entire warbler radiation. Boreal forest migrated south from very high latitudes towards the end of the Pliocene and this apparently created conditions ripe for explosive diversification among the warblers, but not for many other groups.

The evolution of multiple male traits in the yellow-browed leaf warbler

I examined how male competition and female choice influence the evolution of multiple male traits in the yellow-browed leaf warbler,Phylloscopus inornatus, by investigating the roles of colour patches, territory size, body weight and song rate in sexual selection. Comparison of 3 years of observational studies and 3 years of experimental studies, in which the colour patches on the wings of males were experimentally altered, suggest several mechanisms that may explain the evolution of multiple characters in males. First, females based their choice of mates on several male characters, not a single character. Second, the male characters preferred by females were different in observational and experimental studies. Females apparently preferred high-quality males as mates, and were able to vary the characters used in mate choice to distinguish these individuals under both experimental and observational conditions. Third, the characters important in male competition differed from those that formed the basis of female choice: the manipulation of colour patch size directly affected male territory size but was not associated with female choice. These results may provide an explanation for the diversity of sexual ornaments shown by males of many species.

The Adaptive Significance of Colour Patterns in the Old World Leaf Warblers, Genus Phylloscopus

The great diversity of colour patterns in birds remains largely unexplained (Burtt 1986, Butcher and Rohwer 1989). Experimental and comparative studies have been used to identify some adaptive correlates, including intra-specific communication (Hill 1990, 1994, Slagsvold and Saetre 1991, Saetre and Slagsvold 1992, Marchetti 1993), camouflage (Gaston 1974, Burtt 1986), abrasion resistance (Burtt 1986), inter-specific signalling (Baker and Parker 1979, Gbtmark 1993, 1995, Saetre et al. 1993) and flushing out prey (Jablonski 1996). While we might expect plumage patterns to represent a compromise between all these and other selection pressures, two hypotheses have been recently proposed to explain the diversity of colour patterns within the genus Phylloscopus (Old World leaf warblers). Marchetti (1993) ascribes a role for intra-specific communication (i.e., signalling to potential mates or competitors) in the evolution of colour patterns, whereas Jablonski (1996) suggests that conspicuous coloration might be important for flushing prey. In this note we assess the role of prey-flushing in the Phylloscopus warblers using quantitative data on foraging and colour patterns. Jablonski (1996) proposed that wing, rump and tail patches could be important in prey-flushing in the Phylloscopus warblers. To support this idea he used qualitative reports on foraging behaviour culled from the literature, and a cross-species comparative study to demonstrate an association of conspicuousness with the use of the wings during foraging. However, Burtt (1986) in a comparative study of the New World warblers also found an association between plumage brightness and foraging movements, but interpreted it as being a consequence of intra-specific communication. For example, species which flycatch are prominently displaying their wings, and therefore the wings are suitable locations to place patterns used in intra-specific communication. From Jablonski's prey-flushing hypothesis we predict positive correlations between plumage brightness and only those flying movements that lead to chases after flushed prey, but from Burtt's intra-specific communication hypothesis we expect a positive correlation between plumage brightness and the number of all types of flying movements performed by the bird when feeding. There are therefore two purposes to this paper. First, we demonstrate a correlation between plumage brightness and foraging among the Phylloscopus warblers using more quantitative data than were used by Jablonski (1996). Second, we use our results to compare the predictions of the intra-specific communication and prey-flushing hypotheses. Phylloscopus species differ in the number of colour patches they have. In all species, colour patches occur as bright, unpigmented areas on the tips of certain feather tracts of the body. Some species are essentially unpatterned and have uniform dark upperparts except for an eye-stripe. Others have one or two patches on the wings, a crown stripe, a rump patch and/or white tail patches in nested combinations, so that, for example, every species with crown or rump patches always has a wing patch (see Marchetti 1993, Price and Pavelka 1996). We used three different measures of plumage brightness for a species: 1. the total number of colour patches, varying from 0-5 (Marchetti 1993). 2. the total brightness (% reflectance relative to a standard, as measured by reflectance spectroradiometry), of the colour patch at the tip of the feather taken from the tract of feathers which form the largest wing patch on those species which have a wing patch (Marchetti 1993). 3. the size of the unpigmented patch on this same feather (area without melanin; Price and Pavelka 1996). The three variables are correlated (Fig. 1, Table 1). Quantitative data on foraging are available for eight Phylloscopus species from Kashmir, India (Price 1991). Feeding methods were classified into four main types: standpick (a prey capture not involving flight), flypick (prey resting on a leaf or branch, observed while hopping, but taken in flight), flycatch (capture of prey, which was nearly always flushed), and hoverpick (prey