To cull or not to cull – the Red Junglefowl?

posted in: Species | 8

Red Junglefowl (Gallus gallus) is the ancestor of our domestic chicken. A small breeding population was established in the offshore island of Pulau Ubin around 1985 (Hails 1988). Subsequently they were seen in various parts of mainland Singapore. Then around 1999 the Sungei Buloh Wetland Reserve saw an influx of these birds, most probably introduced by the Jurong Bird Park. And since 2011 these birds have been breeding freely in the Reserve (Wang & Hails, 2007).

Male Red Junglefowl (Photo credit: Johnny Wee)
Male Red Junglefowl (Photo credit: Johnny Wee)

Originally classified as an uncommon resident, it is now commonly found in most parts of mainland Singapore. However, there have been extensive hybridisation with the domestic chickens such that in most urban areas the Red Junglefowls are hybrids. One reason for the increase in the urban population is feeding by people. This in turn has led to complaints of their loud crows in the early mornings.

Female Red Junglefowl (Photo credit: Johnny Wee)
Female Red Junglefowl (Photo credit: Johnny Wee)

The crow of the adult Red Junglefowl is the best known of all bird calls. This is a territorial call, crowing from an elevated roost before dawn. The call is also made during the day as the bird patrols its territorial boundaries. Or just before mating… or to show dominance over the others in the flock.

The video of a male junglefowl crowing (below) is courtesy of Sun Chong Hon.

Here is a video of the call by the hen, also courtesy of Chong Hong. It is not as loud or as impressive as that of the male, but it contributes to the so-called “noise pollution”.

There have been many complaints of noise pollution, especially in quiet neighbourhoods in the urban areas of Singapore.

The older generation has apparently forgotten that once the morning crows were a wake up call to Singaporeans. ON the other hand the younger generation was not born when Singapore was less urbanised, when there were many farms around with their chickens and ducks.

According to wildlife consultant Subaraj Rajathurai, most of the urban Red Junglefowls are hybrids and should be culled as they are starting to invade our Central Catchment Nature Reserve.

YC Wee, Subaraj Rajathurai, Sun Chong Hong & Johnny Wee
5th January 2017

Hails, C.J., 1988. An annotated checklist of the birds of Singapore.. Unpublished.
2. Wang, L.K. & C. J. Hails, 2007. An annotated checklist of birds of Singapore. Raffles Bulletin of Zoology, Supplement 15: 1-179.

8 Responses

  1. Kimosabe

    I would say cull the hybrids to keep the wild breed pure, if possible. I would also suggest cull and domesticate the hybrids and recycle them as food! Waste not, want not!

  2. Lee Chiu San

    What do you mean keep the wild breed pure? If domestic chickens are genetically predominantly Gallus gallus, then they are, technically speaking, purebred jungle fowls.
    Several experiments in back-breeding domestic breeds to revert to the wild type show that wild genes tend to be dominant. In Europe, there was an experiment to re-create the European Wild Ox, the Aurochs. By breeding a number of domestic breeds together, very soon, calves were showing up that resembled the Aurochs as described in ancient ballads.
    In the USA, there was an experiment to cross breed beagles with coyotes. Within a few generations, all the pups were indistinguishable from coyotes.
    And, as any cat fancier will tell you, if you breed all the cats in the world together indiscriminately, you will end up with grey tabbies, which are closest in colour to the original wild cat.
    From personal experience, where I live in Seletar, there are many abandoned farms, quite a number of domestic chickens run wild, and a few jungle fowl. The problem will take care of itself naturally.
    Those chicks that are physically more like domestic chickens will be slower and clumsier. The racers, rat snakes, pythons and monitor lizards which are relatively abundant here will cull them naturally.
    The chicks which have more jungle fowl abilities, namely, the ability to fly over a house, will survive.
    In a few years, through natural selective breeding, we will have birds that are physically like jungle fowl. And genetically, they are predominantly jungle fowl.

  3. Lee Chiu San

    Birds that look very much like purebred Jungle Fowl are now showing up in unexpected places in Singapore. I see them striding quite confidently in the Leedon Park and Kingsmead Road area.
    They also elicit very contrasting responses from human residents. One owner of a Good Class Bungalow in Bukit Timah was so delighted to have a Jungle Fowl cock show up at his place that he rushed to a pet shop to buy some Jungle Fowl hens in the hope that they will attract the visitor to stay.
    On the other hand, a prominent local family, whose members live in a number of adjacent bungalows, have been irritated by the morning crowing of a flock of Jungle Fowls, and have asked for advice on how they can be culled or removed.

  4. Jim

    I agree with Kimosabe – cull the hybrids to keep the wild species pure. But the difficulty comes when people try to determine what is pure and what is not. It’s inevitable because “chicken genes” will naturally work it’s way into the pure species and it may be too late, but people will do the best they can to preserve what is left or what they think is considered “pure”.

  5. Lee Chiu San

    There is no way that any layman can tell which jungle fowl is a hybrid and which is not, if scholarly articles about chicken ancestry which are available on line are to be believed.
    For that reason, I say that culling by human beings should stop. As I stated in my earlier post above, the Jungle Fowl breed will purify itself through natural selection.
    There are four species in the genus Gallus, the Red, (Gallus gallus) the Grey (Gallus sonneratti) the Sri Lankan (Gallus lafayetti) and the Green (Gallus varius).
    The last two look so distinctively different that it is extremely unlikely that they feature in the ancestry of our domestic chickens.
    The widely-held belief is that chickens were domesticated somewhere on continental Asia, probably India, Indo China or Thailand, and that the original ancestor was the Red Junglefowl, though there may have been some traces of the Grey (which introduced the gene for yellow legs).
    As I stated earlier, I have seen many chickens which I take to be purebred jungle fowls in many parts of Singapore. Some, like those in Choa Chu Kang and Sembawang are 100% pure because they are descended from pet Red Junglefowl whose origins I know that have run wild.
    The population in Sungei Api Api at Pasir Ris is also likely to be pure jungle fowl because that place is not far from Changi, where the original population of purebred jungle fowls came to the Singapore mainland from Pulau Tekong.
    Again, I repeat, when domestic breeds that are genetically similar to their wild ancestors are subject to indiscriminate breeding, the wild characteristics re-assert themselves in very few generations.
    Therefore, the AVA’s claim that they are culling hybrids has little basis in scientific theory. In my opinion, all culling activities should stop immediately and Nature should be allowed to take its course.

  6. Jim

    Whether to cull or not will depend on whether the people or government of Singapore will want to value them aesthetically as a bird true to the pure species. Once contaminated, it may be difficult to bring back the pure traits (I’m from the States and here, there are hybrids that even after being bred back to the original pure bird multiple times (4 backcrosses so far), you just don’t get the same quality birds compared to breedings between the pure birds). If 50 years into the future and you have a grandchild ask you if the hen in the above picture is what the original red junglefowl supposed to look like, the answer would be a no. It would be great if the wild characteristics re-assert themselves in very few generations, but that would only depend on the presence and influx of wild genes if there is any left. For example, the wild chickens in Hawaii have been loose for quite some time, but their characteristics haven’t reverted to anywhere near pure birds; those birds are still feral chickens. When the percentage of wild genes in a bird is high, like in Singapore, its dominant phenotype will be more like a pure bird. But, slowly and gradually, especially if there is no connectivity to the rjf population outside of Singapore, the Singapore junglefowl may become more chicken-like (via breeding with the domestic chicken escapees). Pure red junglefowl, when all their nutritional needs are met, usually have 1 or 2 clutches per year – with each clutch having about 6 or less eggs. Domestic chickens have more clutches per year and lay much more eggs and its only a matter of time that the hybrids will outnumber and overshadow the wild genes.

    And, are you ok with a junglefowl carrying the 5-toes genes ( Chances are good that the males (there’s 2 of them according to the author) has bred with hens of the area and those genes may spread. Regardless of whether those genes may or may not be displayed in the offspring phenotype, those 5-toes genes are present in the population. If the people of Singapore are fine with that, then ok. Pure red junglefowl do not have 5 toes as you are probably aware. There are likely no pressures in Singapore to select against that trait (i.e. predators, etc.), and so those genes may be there to stay.

  7. Lee Chiu San

    Jim, your points are valid, but I still feel that here in Singapore the wild genes are dominant. There are a lot of purebred wild jungle fowl around, and more flying in from across the Causeway every now and then.

    Your comment that even after four generations of back crosses, the domestic chicken characteristics still show through, might not hold for long if there are lots of wild jungle fowls around.

    Please remember that in Singapore, unlike other places, there are hardly any backyard chickens nowadays. So newcomers are likely to be pure jungle fowls.

    Yes, I know the situation in Hawaii, having observed and photographed the chickens there. It is probable that the domestic chicken bloodlines are predominant, because there are no genuine wild jungle fowls to accelerate the reversion to the original type. Lots of people there also keep pet chickens. This is not the case in Singapore, where you don’t generally find domestic chickens running around.

    About the birds with the five-toed gene, they probably have Silky in their bloodline, since extra toes are a characteristic of this domestic breed. They are an isolated population, and I agree that they should not be bred to the original wild jungle fowls.

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