Most people assume that this is a predation problem, but this is not usually the case. Predators rarely wipe out whole broods. The more likely cause is starvation through lack of insects. Fish can often be present at such high numbers that very few insects survive to hatch at the surface where mallard ducklings can get at them. Another cause of low insect availability is nutrient enrichment causing algal blooms and ‘green’ water in farmyard ponds.
Where insects are in short supply it may be possible to supplement the food supply for ducklings by providing chick crumbs through a creep feeder.
It may be that your pond is too small for ducks to nest and rear successfully. In this case nesting sites may not be limiting. Ducks are often very slow to take to artificial nest sites. On balance it is usually best to try to improve the available cover by allowing natural vegetation to grow up. A wide margin of rough grass and rushes is far more likely to attract ducks to stay and nest. It also offers cover to other wildlife including ground nesting birds.
For a duck flighting pool, we recommend that you have some deep areas. While it is true that mallard only normally feed in 40cm of water or less, it pays to have some areas at least 120cm deep to prevent the whole pool being choked with reeds and rushes. So, extensive shallows are important, but some deeper water is valuable too. It may also mean that diving ducks like tufted and pochard find your pool attractive too.
As far as fish are concerned, water up to 120cm is probably ideal for species like carp and tench. Trout need water that does not get too hot in summer, and some areas up to 2.5 to 3 metres deep will be needed.
A note of caution should be added about combining fish and ducks; namely that fish usually compete quite strongly with ducklings for insects and other invertibrate foods. This can lead to poor duckling survival, although a creep feeder can help.
There are several possible reasons for this, the most likely of which is shooting too often. A pool can rarely be shot more than once every three weeks without driving the ducks away. It also pays to try to leave the pond before the flight is fully over. In this way, a small lead of birds is able to come in undisturbed at the end of the flight, and maintain continuity till next time.
Unfortunately, grants for ponds are not so easy to find as they used to be. The only nationally available source is through the Countryside Stewardship scheme. This means that the pond would need to be part of a bigger conservation plan for the whole farm. Also the grant for ponds is really targeted for small ‘conservation’ ponds up to about 10m across. If you want to make a bigger pool, the proportion of costs which the grant would cover is relatively low.
Teal are not so inclined to fly long distances as mallard, so remote isolated pools are never likely to be visited by teal in numbers. Two things that teal particularly like are very shallow water (not more than 15cm), and small seeds. Broken corn, thin tailings and weed seeds are all particularly attractive.
The most likely reason is that your pool has become less attractive. It may be that surrounding trees or overhanging branches have grown in, making it harder for the ducks to flight in and out safely. Another possible problem is that there is less shallow water for them to feed in. This may be because reeds and rushes have grown into the shallows, forcing the birds into deeper water. It may also be that the ducks themselves have eroded the shallows away by feeding activity, in which case a bit of regrading with a digger is called for.
By common consensus, barley seems to be particularly attractive. Ducks are pretty happy with wheat too, but it seems less interesting to them once it begins to germinate and ferment. Rotten potatoes are also very useful for mallard, especially when the weather goes frosty, but they often draw rats and when used in large quantities can pollute water, so take care.
You can, but lots of things can go wrong. For example, piles of food can easily attract rats and even a gang of scavenging moorhens can be a nuisance. Flighting patterns can become very irregular, especially at around the time of the full moon. Ducks that have the opportunity to stay late in the morning, and keep feeding, may well be late coming in next evening. Also, if corn starts to ferment, there is a risk of water pollution.
If you cannot feed daily, it pays to consider buying an automatic feeder. This can be set up to scatter a little barley into your pond late each afternoon, just in time for the ducks, and after the moorhens have gone to roost.
Size is not as critical as many people think, and very small pools can attract a lot of wildfowl. However, shape and depth profiles can be critical. Also, requirements vary from species to species. Diving ducks, for example, will feed in water several metres deep, while mallard can only upend to depths of about 45 cm. Getting the whole design right, and fitting it into the local landscape is critical to success, and a visit from your Game & Wildlife Conservation Trust's local advisor is the way to be sure that you will get the most out of your new pond.
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