Protecting your Pond from Predators

Types of Predator
There are a range of native animals that could potentially pose a threat to your fish, including herons, cats, foxes, crows, cormorants and mink.

However, by far the most common predators are herons, and to a lesser extent, cats.All ponds are at risk from predators so it is wise to take some preventative measures to avoid losing any of your fish. Even if they are unsuccessful at catching your fish, these attacks will unnerve the fish and deter them from coming to the surface where they can be seen.

Herons
The Grey Heron (Ardea cinera) poses the greatest threat to pond fish, and also frogs.An adult can consume 350g of fish a day (700g if it has young to feed), and is quite capable of rapidly emptying a pond. Even if they fail to catch a fish, their beaks are capable of inflicting nasty puncture wounds, which can quickly become infected.

Herons are protected by law (Wildlife and Countryside Act 1981), and it is illegal to kill or injure them. Even if it were legal, it would be pointless killing one, as a new heron would soon replace it.Therefore, it is necessary to prevent them from getting close enough to the fish to catch them.

Herons tend to feed predominantly during the first few hours of the day, before we are up and about. If all is quiet they may also return later on in the evening.They often, therefore, go unnoticed, the only sign of their presence being a pond full of spooked fish that are reluctant to rise to the surface. During the summer, numbers of herons, and consequently the demand for food, may increase, due to the presence of newly fledged juveniles.The nesting period (which may last into March and April), also creates an extra demand for food, as parents have young to feed.

Protecting your Pond from Herons
A number of methods have been employed to reduce the risk of predation, the most controversial of which is the use of a plastic heron.Although many claim that it works, it is perhaps the least effective method of protection.

Over time, herons may get used to the plastic replica, and quite happily set down beside it to feed. In the breeding season, when they are actively searching for a mate, they may even be attracted to it.

Putting a net over the pond, or a fence around it, is a far more effective means of protection.The more comprehensively you cover the pond, the less likely it is that a heron will get to it. However, too much netting can detract from the pond’s appearance. If you don’t want to put a net over the pond, then constructing a fence around it is also effective.This is because, in most cases, herons will land on the ground, before walking to the pond to feed.A fence made from netting, about 90cm (3ft) high, and placed about 60cm (2ft) from the edge of the pond, will serve to deter most attacks. If this is still too obtrusive, you can make the fence out of pieces of twine, placed at 15cm (6in) intervals to a height of 60 – 90cm (2 – 3ft).

Preventing Other Predators
Cats and foxes can also be kept out of the pond with nets and fences, although they will generally have to be sturdier and more carefully constructed, to ensure that there are no holes, or areas where they can be got under. Fences made of twine are far less appropriate where such predators are active, and it may be that some form of netting is the only option. Having a good growth of marginal plants around the pond will make life harder for cats and foxes, as will the use of rocks around the edge.These rocks should be uneven and “wobbly”, as this is said to help deter cats.

General measures of protection, which also apply to herons, involve creating plenty of hiding places for your fish.This is particularly important in the winter, when the fish are inactive and less able to escape a predator.

If you do not have suitable hiding places, then it is a good idea to lay a bucket on its side, at the base of the pond, for the winter period.This will provide a refuge for the fish.

Taking these measures will reduce the likelihood of your pond falling victim to a predator, and keep your fish confident and at ease in their surroundings.