Africa Wild

Hockey, P.A.R. & Ryan, P. 2014. All together now: why do birds form groups? African Birdlife 2(2):32-38.

Ryan, P. 2014. Moult: The cost of annual renewal African Birdlife 2(3):36-42.

Great reads Toko. Thanks for the links.

The evolution of modern bird species revised by major new study

The genomes of modern birds reveal how they emerged and evolved after the mass extinction that wiped out dinosaurs 66 million years ago, reports Smithsonian Science.

The family tree of modern birds has long been the subject of debate and the evolution of our more than 10,000 species has not been known.


Great Spotted Woodpeckers are one species said to have descended from an apex predator

Now a four-year international collaboration involving more than 200 scientists from 80 institutions in 20 countries has sequenced, assembled and compared full genomes of 48 bird species.

The first findings of the Avian Phylogenomics Consortium led by Guojie Zhang of the National Genebank at BGI in China and the University of Copenhagen, Erich D Jarvis of Duke University and the Howard Hughes Medical Institute and Thomas P Gilbert of the Natural History Museum of Denmark, suggests some remarkable new ideas about bird evolution.

The consortium focused on species representing all major branches of modern birds including the crow, duck, falcon, parakeet, crane, ibis, woodpecker and eagle.

The first flagship paper published in Science presents a new family tree for birds, based on whole-genome data.

The new family tree resolves the early branches of Neoaves (new birds) and supports conclusions about some relationships that have been long-debated.

For example, the findings support three independent origins of water birds. They also indicate that the common ancestor of core land birds, which include songbirds, parrots, woodpeckers, owls, eagles and falcons, was an apex predator, which also gave rise to the giant terror birds that once roamed the Americas.

The whole-genome analysis dates the evolutionary expansion of Neoaves to the time of the mass extinction event 66 million years ago that killed off all dinosaurs except some birds.

This contradicts the hypothesis in previous research that Neoaves arose 10 to 80 million years earlier than that.

Using this new genomic data, the conclusion is that only a few bird lineages survived the mass extinction.

These gave rise to the more than 10,000 Neoaves species that now comprise 95 per cent of all the bird species we have today.

The researchers believe that the ecological niches left by the mass extinction event may have allowed birds’ rapid species radiation, in less than 15 million years, which explains modern avian biodiversity.

The second flagship paper produced by the consortium describes the big picture of genome evolution in birds.

Six other papers describe how vocal learning may have independently evolved in a few bird groups and in the human brain’s speech regions; how the sex chromosomes of birds came to be; how birds lost their teeth; how crocodile genomes evolved; ways in which singing behaviour regulates genes in the brain; and a new method for phylogenic analysis with large-scale genomic data.

The impacts of the Pied Crow Corvus albus on other species need to be determined
John E Fincham, Ronelle Visagie, Les G Underhill, Michael Brooks and Miles B Markus

http://oo.adu.org.za/pdf/OO_2015_06_232-239.pdf

How many species can a Southern Fiscal mimic?

Harebottle DM 2016. Notes on the vocalisation and additional mimicry in the Common Fiscal Lanius collaris. Biodiversity Observations, Vol 7.5: 1-5

http://www.journals.uchicago.edu/doi/fu ... 086/684681

Abstract
Many long-distance migratory birds sing extensively on their tropical African wintering grounds, but the function of this costly behavior remains unknown. In this study, we carry out a first empirical test of three competing hypotheses, combining a field study of great reed warblers (Acrocephalus arundinaceus) wintering in Africa with a comparative analysis across Palearctic-African migratory songbird species. We asked whether winter song (i) functions to defend nonbreeding territories, (ii) functions as practice to improve complex songs for subsequent breeding, or (iii) is a nonadaptive consequence of elevated testosterone carryover. We found support for neither the long-assumed territory-defense hypothesis (great reed warblers had widely overlapping home ranges and showed no conspecific aggression) nor the testosterone-carryover hypothesis (winter singing in great reed warblers was unrelated to plasma testosterone concentration). Instead, we found strongest support for the song-improvement hypothesis, since great reed warblers sang a mate attraction song type rather than a territorial song type in Africa, and species that sing most intensely in Africa were those in which sexual selection acts most strongly on song characteristics; they had more complex songs and were more likely to be sexually monochromatic. This study underlines how sexual selection can have far-reaching effects on animal ecology throughout the annual cycle.

Here an article explaining the study: https://theconversation.com/theres-a-re ... ason-59009

Interesting!

Arctic Warming Is Shrinking Red Knot

http://news.nationalgeographic.com/2016 ... -red-knot/