Monarchidae (1 Viewer)

[albertonykus]

Ó Marcaigh, F., D.P. O'Connell, K. Analuddin, A. Karya, N. Lawless, C.M. McKeon, N. Doyle, N.M. Marples, and D.J. Kelly (2022)
Tramps in transition: genetic differentiation between populations of an iconic "supertramp" taxon in the Central Indo-Pacific
Frontiers of Biogeography 14: e54512
doi: 10.21425/F5FBG54512

The island monarch (Monarcha cinerascens) was an original example of the “supertramp strategy”. This involves well-developed dispersal specialisation, enabling a species to colonise remote islands but leaving it competitively inferior. Supertramps are hypothesised to be excluded from larger islands by superior competitors. It is the only original Melanesian supertramp to occur in Wallacea, home also to the sedentary pale-blue monarch (Hypothymis puella). We interrogate the supertramp strategy and its biogeographical underpinnings by assessing the population structure of these two monarchs. We sampled island and pale-blue monarchs in Wallacea, collecting DNA and morphological data. We investigated monarch population structure by applying ABGD and Bayesian and Maximum Likelihood methods to their ND2 and ND3 genes. We constructed linear models to investigate the relationships between genetic divergence, dispersal ability, and island area, elevation, and isolation. Wallacea’s deep waters restrict gene flow even in a supertramp, as the Wallacean and Melanesian island monarchs are likely separate species (mean genetic distance: 2.7%). This mirrors the split of the pale-blue monarch from Asia’s black-naped monarch (Hypothymis azurea). We found further population structure within Wallacean and Melanesian island monarch populations. Their genetic divergence was related to elevation, area, and isolation of islands, as well as dispersal ability of birds. However, dispersal ability was independent of island elevation and area. Rather than being r-selected on small, disturbance-prone islands, our results support the view that the island monarch’s supertramp lifestyle is a temporary stage of the taxon cycle, i.e. supertramps may transition into resident species after colonisation. Our models suggest that more dispersive monarchs reach more distant islands, and divergence is promoted on islands that are more distant or larger or more permanent, without selection against dispersal ability per se. We suggest that supertramp lifestyle helps determine the distribution of species across islands, not necessarily the divergence occurring thereafter.

 

[albertonykus]

Campagna, L., Z. Mo, A. Siepel, and J.A.C. Uy (2022)
Selective sweeps on different pigmentation genes mediate convergent evolution of island melanism in two incipient bird species
PLoS Genetics 18: e1010474
doi: 10.1371/journal.pgen.1010474

Insular organisms often evolve predictable phenotypes, like flightlessness, extreme body sizes, or increased melanin deposition. The evolutionary forces and molecular targets mediating these patterns remain mostly unknown. Here we study the Chestnut-bellied Monarch (Monarcha castaneiventris) from the Solomon Islands, a complex of closely related subspecies in the early stages of speciation. On the large island of Makira M. c. megarhynchus has a chestnut belly, whereas on the small satellite islands of Ugi, and Santa Ana and Santa Catalina (SA/SC) M. c. ugiensis is entirely iridescent blue-black (i.e., melanic). Melanism has likely evolved twice, as the Ugi and SA/SC populations were established independently. To investigate the genetic basis of melanism on each island we generated whole genome sequence data from all three populations. Non-synonymous mutations at the MC1R pigmentation gene are associated with melanism on SA/SC, while ASIP, an antagonistic ligand of MC1R, is associated with melanism on Ugi. Both genes show evidence of selective sweeps in traditional summary statistics and statistics derived from the ancestral recombination graph (ARG). Using the ARG in combination with machine learning, we inferred selection strength, timing of onset and allele frequency trajectories. MC1R shows evidence of a recent, strong, soft selective sweep. The region including ASIP shows more complex signatures; however, we find evidence for sweeps in mutations near ASIP, which are comparatively older than those on MC1R and have been under relatively strong selection. Overall, our study shows convergent melanism results from selective sweeps at independent molecular targets, evolving in taxa where coloration likely mediates reproductive isolation with the neighboring chestnut-bellied subspecies.

 

[Jim LeNomenclatoriste]

Leo Joseph, Julian Teh, Paul Sweet, Phil Gregory,
The black-winged Monarch (Monarcha frater): Geographic variation, taxonomy, a new population, and an enduring mystery in migration, Avian Research, 2023, 100122.

The black-winged Monarch (Monarcha frater): Geographic variation, taxonomy, a new population, and an enduring mystery in migration

The Black-winged Monarch (Monarcha frater) inhabits low-mid elevation forests across New Guinea and far north-eastern Australia. Of its four recognize…

www.sciencedirect.com

Abstract: The Black-winged Monarch (Monarcha frater) inhabits low-mid elevation forests across New Guinea and far north-eastern Australia. Of its four recognized subspecies, M. f. canescens is migratory, breeding in tropical north-eastern Australia from approximately November–March. The non-breeding range of M. f. canescens, apart from some individuals overwintering in Australia, has been unknown for >100 years. Data from 194 New Guinean and Australian specimens and a literature review have not solved this mystery; the narrow latitudinal range of the intratropical migration may inhibit use of GPS loggers in resolving the migration route. Field work in central and western parts of southern New Guinea is needed. Specimen data, however, revealed an essentially overlooked population in north-western New Guinea east of the Bird's Head Peninsula phenotypically indistinguishable from nominate M. f. frater of that Peninsula. Future genomic analysis of the complex will be largely done from toepad skin because frozen tissue samples for DNA analysis exist only of four individuals of what we suggest should be elevated to species rank as M. periophthalmicus. We discuss how genomic analysis might distinguish among alternative taxonomic hypotheses of one, two or three species. We suggest English names for what we consider to be three diagnosable taxa worth recognizing at species rank in this group: Doberai Monarch corresponding to M. frater (Bird's Head Peninsula and the “new†population of north-western New Guinea); Pearly Monarch for M. canescens (Australia and still unknown non-breeding range), and Masked Monarch for M. periophthalmicus (including kunupi, elsewhere in New Guinea).

 

[sicklebill]

Another Cape York endemic, but only seen in the wet season.

 

[Jim LeNomenclatoriste]

Aves—A Taxonomy in Flux: Recent Changes

Avian Taxonomy

jboyd.net

Maupiti Monarch: Historically, Pomarea pomarea has been used for both birds from Tahiti and Maupiti. Dickinson et al. (2019) argued that the Maupiti Monarch, Monarcha pomareus, Lesson and Garnot, 1828, should be restricted to the Tahitian birds, and that Monarcha maupitiensis, Garnot, 1829, should be used for the Maupiti birds. Finally, the Muscicapa nigra Sparrman, 1785 has priority over Muscicapa pomarea so the Tahitian birds are called Monarcha niger.
[Monarchidae, Corvida III (Corvoidea), 3.05a]