About bush chats

Note: this is a revised version of an old text.

One of my fondest memories and greatest achievements as a bird ringer, was the first time I held a rufus bush chat (Cercotrichas galactotes) in my hand, after being captured in South Portugal. Then, and still now, is one of the birds I most enjoyed watching, photograph and sketch. That ringing session prompted me to look a bit deeper on this species.

The rufus bush chat (Cercotrichas (Erythropygia) galactotes) is a medium sized insectivorous Muscicapid, with an overal rufus-brown plumage. Although having some distinctive marks on its head, the most strinking feature is the long, reddish tail with a typical pattern of terminal black and white bars. The birds happily display this as they regularly open and lift their tails as a flashing sign.

 

C. galactotes has a wide distribution area, spending the reproductive period along the Mediterranian bassin, Middle East, Southern Kazakhstan and Pakistan, being found in scrubland and olive groves but mostly small creeks and streams with good riparian vegetation. The Winter is spent South of Sahara, from Mauritania to Kenya and Ethyopia.

Five subspecies are currently recognized: C. galactotes galactotes in Western Europe and North Africa; C. g. syriaca in Balkan area, Turkey and Middle East; C. g. familiaris, occupying the most eastern part of the species distribution area; C. g. hamertoni in Somalia and Ethiopia; and C. g. minor, from Mauritania to Ethiopia and Somali. These last two sedentary subspecies, are sometimes classified as a separate species, the African bush chat (Cercotrichas minor).

Regarding the Genus phylogeny, Cercotrichas appears to be non-monophyletic, althoug being part of a clade (Copsychini) including chat/robin and flycatcher genera, such as Alethe, Muscicapa and Copsychus. Some Cercotrichas species, including C. galactotes, are closer to Saxicoloides, Copsychus and Trichixos than to other members of the Genus. So, adittional analysis is needed to clarify the relationship within bush chats.

In Iberia, some studies have been conducted on their reproductive biology and intricate reationship with cuckoos (Cuculus canorus)

The male´s tail (Left) seems to work as an breeding successn indicator, since individuals with longer tails, with more symmetrical patterns and broader terminl bands tend to raise larger clutches and with higher survival rates. The frequent tail flicking movements are a form of intra-specific signaling and, along with singing, are used to create and defend territories.

 

The nest is built by both male and female, using little twigs and coated with sheep or rabbit fur, usually in a bush or small tree. This nest-builing activity also works as a courtship display, since the males that carry more nesting material or help build larger nests, seem to show better parental skills, such as feeding larger and more numerous prey to chicks. This allows females to adjust their breeding efforts, producing larger or smaller broods, depending on nest size (and the parenting skills of the male). Breeding succes also depends on female fitness and the couple age/experience. On average, 3 to 4 eggs are layed, which are incubated for 13 days. By the 10th day, the chicks start to venture outside the nest protection.

Deeply connected to all this breeding activity is the relationship between bush chats and cuckoos. The latter is believed to be the most important predator of bush chats and in certain areas, almost 30% of their nests are parasitized by cuckoos. Bush chats developed some strategies to minimize the cuckoos parasitism, such as the hability to raise a second clutch, laying smaller eggs (cuckoos tend to favour nests with larger eggs) and showing an array of predator distraction behaviours. These adaptions seem to occur only in areas where chats and cuckoos co-exist.

Very few details are known about disease dynamics in this species; bush chats can be reservoirs of West Nile virus and infected birds can carry the virus during their migrations; Plasmodium relictum, one of the many causative agents of avian malaria, is also found infecting some bush chat populations.

A lot more could probably be written about rufus bush chats and much more needs to be studied on Cercotrichas in general but for now, I can only finish by stating what amazing birds they are.

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