Egyptian Goose

Introduction

 

 Contrary to the impression given to golf course members and facility greenkeepers and staff, Egyptian Geese are not generally regarded as “pest birds” in southern Africa – unlike Red-billed Queleas, where the population numbers literally millions of birds, which cause severe damage to cereal crops throughout the subregion, many of which crops are staples for the local human populations in areas where these queleas occur.  Egyptian Goose populations increased dramatically during the 1900s due mainly to the proliferation of manmade dams and impoundments in rural areas.  Population estimates are around 30 000 birds in the north-eastern Highveld of South Africa and between 200 000 – 500 000 birds in East and southern Africa combined (Roberts Birds of South Africa, VII ed).  In wild areas such as nature reserves and national parks and even on farms, however, the geese rarely congregate in the type of numbers found on golf courses but tend to be spread over very large areas.  So why do golf courses in particular find that Egyptian Geese are the equivalent of “bird pests”, congregating in large numbers?

Golf courses are often havens for Egyptian Geese for several reasons

Egyptian Geese on golf courses

 

 Birds – and animals for that matter – tend to migrate to areas where their particular habitat and requirements in terms of food and nesting/roosting sites can be adequately met.  Birds are highly mobile and, should conditions in one area become less favourable, they will rapidly move to and colonise another area.  Egyptian Geese in particular may move anything from 70 – 800 km to find suitable habitat.

 Golf courses are ideal habitat for Egyptian Geese.  Unlike many other duck and goose species, which feed largely on aquatic vegetation and/or aquatic invertebrates, Egyptian Geese are grazing specialists, feeding on Cynodon dactylon and certain sedges.  They are also grass seed strippers and will often settle in water bodies adjacent to croplands, where they can glean fallen grain and also strip grass crops and the indigenous grasses surrounding them.  On golf courses, these geese have adapted their diets to include grasses such as kikuyu and bentgrass, which are kept short on golf courses and are easily accessible due to the wide area of open ground surrounding fairways, tees, greens and even rough and semi-rough.  Golf courses which have large expanses of kikuyu grass in out-of-play areas compound the problem as there is more food for these geese.

 Egyptian Geese highly favour manmade impoundments such as dams in addition to other wetland types.  Golf courses are full of dams and similar wetland areas.  Egyptian Geese are strong swimmers, very much at home in the water, and rapidly take to water as soon as any perceived danger threatens.  If they have young with them, the female will shepherd the goslings to water too.  Easily accessible water bodies (i.e. with no dense vegetation surrounding them) are particularly sought-after.

 The geese are mainly terrestrial but will also roost and nest on elevated structures from tall trees to buildings.  They have even been known to nest on top of old nests originally belonging to birds such as Hamerkop, Black-shouldered Kite, crows and even Sociable Weavers (in the arid regions of the Western Cape).  They are very adaptable and naturally gregarious, although pairs will tend to stick together.

 Egyptian Geese are generally very successful breeders.  They are monogamous and may lay as many as 22 eggs.  Some 81% of broods survive to adulthood.  They are usually single-brooded but may be double-brooded in optimum conditions (i.e. having more than one breeding cycle in a season).  On golf courses, where conditions for survival are generally excellent, the mortality rate of Egyptian Geese is lower than in the wild.  We have personally noticed that on golf courses the average number of chicks per pair is around 10, of which nearly all will survive even if predators such as African Harrier Hawks, owls or mongoose are present on the course or in the general area. 

 In the wild, young birds leave the area once they reach adulthood (about 3 months after hatching), a process known as emigration.  In the case of Egyptian Geese, if the young do not leave voluntarily, the dominant males actively chase them.  This usually happens in late summer/early autumn when the breeding season is over.  (We observed this recently with an Egyptian Goose pair at Mankwe Dam in Pilanesberg National Park.)  This needs to occur as resources in natural areas are often limited due to a variety of factors and, if the young birds do not disperse to populate other areas, food scarcity, insufficient suitable nesting and roosting sites, and competition for scarce resources leading to fights and injury often results.

 However, on golf courses, this does not happen to the same degree.  Often there is not a dominant pair on the course due to human intervention and tampering with the Egyptian Goose population in an effort to remove the birds from the area.  There is also a more than adequate food supply, some protection from predators (usually because many predators found in natural areas are largely absent on golf courses), and plenty of suitable habitat including ample nesting and roosting sites.

Herons and birds of prey will eat Egyptian Goose ducklings, helping to keep populations under control

 Suggested methods for controlling Egyptian Goose populations on golf courses

 Many golf courses wish to and some have actually gone the route of obtaining permits from their local Nature Conservation branches enabling them to cull Egyptian Geese.  This can be a lengthy process.  Golf courses and individuals found removing indigenous birds without a permit can expect a visit from the “Green Scorpions”, a watchdog body created by the Wildlife & Environmental Society of South Africa (WESSA).  It is illegal to remove indigenous birds without a permit.

And it does not work.  Roberts Birds of South Africa (VII ed) and BirdLife SA both record that control measures such as culling have no effect whatsoever on Egyptian Goose populations in a given area as their survival rate is very high.  As there is no sexual dimorphism (i.e. no physical difference) between males and females and it is very difficult to tell which sex you are culling, persecution can lead to the populations of the birds being skewed in favour of one or other sex, leading to the immigration of yet more birds.  Dominant males, which are key in driving off other Egyptian Geese which may arrive and stake a claim for existing goose territories, may be removed inadvertently, in which case your golf course becomes a free zone for every goose that may happen upon it.  This is a particular problem in the non-breeding season, when birds tend not to pair up and defend territories.  The average territory per pair of Egyptian Geese is about 1 hectare in size but their home ranges may be much larger.

 To summarize the problems – golf courses:

•  provide extremely suitable habitat for Egyptian Geese, which tend to migrate to areas of this nature, sometimes travelling long distances to reach them;
• have environments providing Egyptian Geese with usually several large open water bodies, which they use as retreats when threatened, as well as an excellent supply of food in the form of short grass, which forms a major part of the birds’ diet;
• provide ample nesting and roosting sites;
• provide protection from possible predators – of eggs, chicks and adult birds – due to their being less predators around, especially on courses situated far from natural areas and reserves.

 Culling has proved unsuccssful in the long-term in reducing Egyptian Goose populations on golf courses and also on croplands where these birds are a problem.

 There is only one mid– to long-term solution to problems of high Egyptian Goose populations on golf courses: environmental management.  There is an industry drive towards implementing environmental management systems on golf courses.  Part of this involves the creation of mini-ecosystems and a replica of natural environments which will, among other things, reduce the incidence of Egyptian Geese on golf courses and also have the function of increasing the biodiversity of plants, birds and animals on course, which will in turn also serve to control Egyptian Goose populations.

 Access to Water

 Access to water is of utmost importance to these geese, as they use water as a refuge and will escape to water whenever perceived or real danger threatens.  Adult birds will fly onto the water briefly but not remain there.  However, when breeding, they need easy access to water, particularly when needing to move their young from danger.  Planting up the edges of all larger water bodies with indigenous plants including reeds, sedges and wetland grasses will create a vegetation barrier making it more difficult for Egyptian Geese with young to access the water.  The birds will also think twice about breeding in that area.  This will have the added benefit of creating additional habitat for birds such as Reed and White-breasted Cormorants (which occur inland), other species of ducks and geese (e.g. Yellow-billed and African Black Duck and Spurwing Goose) and herons.  Herons are particularly useful in that many herons eat the eggs of birds such as ducks as part of their diets, as well as aquatic insects, fish and frogs.  Some herons are also known to eat chicks of other bird species nesting in the area.

 Egyptian Geese may be highly aggressive to other water birds during the breeding season when protecting young.  However, they generally prefer to remain aloof from other species.  Encouraging other wetland birds to populate dams and wetland areas on course will also serve to deter Egyptian Geese from populating the same areas.

Food

Not much can be done about the large swathes of short-grass areas found on golf courses as this will always attract Egyptian Geese, particularly when combined with several large open water bodies in the same area. 

  However, by planting up out-of-play areas with indigenous grasses rather than having extensive stands of kikuyu, this can reduce the base of available food for these birds to some extent.  Doing this will also increase the diversity of terrestrial bird species on your course.  Bringing in more wild birds – naturally – may also increase competition for the Egyptian Geese encouraging them to move on.

 Predation

 Creating suitable habitat for other birds including small birds of prey such as African Harrier Hawks (Gymnogenes), which are often found in suburbia, Black-shouldered Kites, kestrels and owls as well as small aggressive animal hunters such as mongoose, will increase the predation on Egyptian Goose eggs and chicks, which will naturally help to keep populations in check.  Some means of creating this environment include putting bare dead trees in dams and waterways (birds of prey use these as perches when hunting) and owl nesting boxes in suitable sites.  One of the primary sources of food for many owls and small birds of prey are rodents such as rats and mice, as well as small snakes.  Planting indigenous vegetation may in some cases encourage rodents; the birds of prey should arrive to find them and feed on them, in addition to young birds such as Egyptian Geese. 

 Various species of mongoose generally favour a variety of habitats as long as there is adequate cover.  Once natural grasses grow they will create dense stands, which will provide cover for mongoose.  Mongoose are generally vicious and aggressive hunters; food includes bird eggs (particularly of birds nesting on or close to the ground) as well as young chicks.  Encouraging mongoose on your course will also help to create natural attrition of young Egyptian Geese. 

With proper environmental management, Egyptian Goose populations CAN be controlled - naturally

 Nesting Sites

 Approximately 67% of Egyptian Goose nests are on the ground, most often close to water.  They also use islands in the middle of water bodies for nesting sites.  This makes them vulnerable to predators such as mongoose, otters, herons, etc.  Stocking water bodies with appropriate indigenous fish will also encourage fish-eating birds (darters, cormorants, herons, kingfishers), water mongoose and otters.

 To arrange a consultation and a full environmental assessment of your course, as well as more advice on how to deal with the Egyptian Goose problem in your area, please contact:  JT Consultancy (Jock Tame) – 011 425 2057 / 084 418 9283.