Unwelcome Visitors to your Garden Pond

Beware the Heron        Kingfishers        Wasps        Rats       

Beware the heron.

In recent years, herons have been forced out of their normal hunting ground on rivers and lakes by cormorants. Cormorants should be sea birds and are a protected species but they have been moving further and further inland and have decimated the fish stocks in many areas. One of the results of that has been to push the heron away from the rivers in search of food. Herons seem to be extremely patient birds and once they have decided to use your pond as a hunting ground, they will come back every day until they have either eaten all your fish, or decided that they couldn't get at them. Herons like to stand in shallow water to feed so I have always ensured that where I have a shelf in my pond, it is full of plants and that the remaining edges of the pond have sides that don't have any shelves at all. As a result, I had never had a heron take any fish until last year. During the summer, I got a lovely big plant and put its pot on the central ridge in my bottom pond. It looked great all through the summer but as with most pond plants, it died back in the winter. Unfortunately, I forgot to move the pot and with the dead foliage removed, I had inadvertently provided a perfect resting perch for the heron that was about 20cm below the water level. It was over 3 weeks before I worked out how he was taking my fish and in that time I lost about a dozen, including Shamoo who was now over 35 cm long and was the pride of my pond. Since the plant pot was moved, the heron has not come back. Top


Just because I hadn't seen him, I had assumed that he had gone away. Talking with my neighbours it appears that he visits most days when I'm in work and now I've lost another couple of fish. Luckily only small ones but a shame none the less. So now I have had to put up some wires. I fould some cheap plastic pegs in the garden centre and used the sort of green plastic covered wire that is used to train plants up fences. Just the thin stuff as I don't want the wires to detract from my view of my ponds. So now I have a criss cross of wires about 15cm above the surface of the water and haven't lost any more fish. Top


In August this year, we were awoken by a strange scratching sound in the garden at about 04:45. I looked out of the bedroom window to see a heron sat on top of the garden fence. Unusually, he didn't fly away at the first twitch of the curtains so I was able to watch him. As I got used to the limited light, I noticed another heron in the garden by the pond. By this time, management was awake and also looked out. Her better eyesight (I didn't have my lenses in) spotted a third bird on the bridge. We soon realised that we had a family of herons and whilst Dad was keeping watch on the fence, Mum was at the pond trying to teach the baby how to fish. She was showing him how to duck his head sideways under my wires to stab for the fish. Luckily she wasn't successful on the first couple of attacks and by that time, I had gone downstairs to get a better view so I put on the garden lights and they all flew away. Now I have high level wires from the eves of my house to my shed roof and those at last seem to be working. The idea is not to prevent the herons from flying in but to ensure that they can't make a quick escape if they get startled. We have seen the horons going into other gardens in our street but they haven't come back to our pond since the wires went up. Top


Sometimes, leave from work can be quite depressing. I've just watched a lovely young heron fly into my garden via my neighbour's shed roof and have a casual wander around the pond before flying back up through my wires as if they were not there. Determined not to have to put a net over my pond, I scoured the internet for solutions and found a product that looked as if it was worth a try so, as usual, I worked out how to make it myself. I obtained a number of 5cm diameter galvanised metal rods and, using a piece of 15mm copper pipe, I bent a series of 4 loops into each one with the loops about 15cm apartand with about 20 cm from the bottom of the rod to the first loop. Then I drilled holes the same size as the rods into the slabs around my pond at all the corners and no more than 500cm apart and slotted the rods into each using "No More Nails" to seal them in place. I bent the rods towards the pond at about a 45 degree ange from the first loop and then threaded wires through the holes until I had a complete ring of wires around the pond. (Where I didn't have a slab to drill into, I made the distance to the first loop a lot longer and simply pushed the rod into the ground. Once I had threaded all four wires, I pulled them tight and tied them off. Don't do too good a job of tidying up the ends because you'll still need to gain access to your pond every now and a again.

I'm pretty sure that this has worked because when we hate some snow ealier in the year, we found heron footprints all around the pond where he had obviously been looking for an opening in my defences and having not found any, we don't think he's been back. And we haven't lost a fish since.   Top


I once also lost a number of small fish to a kingfisher. Over a period of about 2 weeks, presumably when he had chicks to feed, my pond was visited by a kingfisher who used to sit on my fence watching the small goldfish that I had put into my middle pond. Then he would swoop down to take his prey before coming back to the fence to check that he had a good grip on the fish before flying back to his nest near the local pond. The kingfisher is such a beautiful bird that I put new fish into the pond each year in the hope that he will come back but I haven't seen him for a few years now. Top


With all flowers in and around the pond and, of course, the ready supply of water, we expect to see a large number of insects in the area around the pond. However, one summer a few years ago, we noticed an unusually large number of wasps flying around the bottom of the garden. Normally, welcome visitors because they eat so many aphids, the gradual increase in their numbers caused some concern and soon we realised that we had a large nest in the bank of the pond. We contacted the pest control people who came to check out the problem and they gave us a bigger one. The chemicals they use to kill the wasps also do a very good job of killing everything else they come into contact with. Before they would treat the wasps, they insisted that I empty my pond and ensure that my fish were moved to a safe location away from where they would be spraying. Then once the job had been completed, I would have to thoroughly clean and decontaminate my pond before I could replace my fish.

As you can imagine, it wasn't going to be easy with a swarm of wasps around. I decided to tackle the job at the end of the afternoon since the wasp activity seemed to be less enthusiastic that at other times during the day. I cannoy say that I was happy though because I really don't like getting stung. It took two days to get everything out of the pond and into a make-shift temporaray pond, and another day to mask up and protect the pond as well as I could before the treatment. Two days later, when all wasp activity had ceased, I was able to dig out the nest. There were thousands of wasps and they had dug out a small cavern over 50 cm in diameter behind one of the larger rocks in the bank. I was extremely glad that I hadn't provoked them too much. Once they were all out of the way, I cleaned and scrubbed the pond liner and carfully poured all of the water down the drain. I refilled the pond and put the two smallest fish back in to test the water. After 2 days of freedom, I put the rest of the fish back in and all was well once more.Top


This one caused me a lot of concern because it took drastic action to discover the cause. A couple of years ago, my pond went from its usual crystal clear appearance to extremely cloudy overnight. My immediate thought was that despite my wires, the herons had come back and that they had scared the fish enough that they had stirred up all the sediment at the bottom of the pond as they darted around seeking protection. Although I was annoyed, I wasn't too concerned. I put my net over the pond and fully ecpected that it would clear within about 48 hours as usual. When that didn't happen; indeed, it appeared as if the condition of the pond was getting worse rather than better, I began to worry about the health of my fish. I carried out a water test to check the Ph reading and the levels of Nitrates and solid waste but the tests showed that there was nothing wrong with the pond. I was still concerned that something might have got into the pond some how but as I couldn't see into the water, I decided that I would have to empty the pond at the weekend. Luckily, Autumn was approaching and the water temperature was close to that of the water in our taps so I could risk a substantial water change without too much harm coming to my fish.

It took most of the morning before the level had gone down far enough to see what the problem was. As the water level dropped, we discovered a huge mound of earth resting against the back wall of the pond. It was about 60cm tall and about 40cm wide at the base. With all that earth in the water, it was no wonder that my filter hadn't been able to clean the water. That at least was a relief; the filter was still working. Even then, it wasn't until I pulled back some of the overhanging vegitation that I found the cause. As I have mentioned in other pages on this site, I have put hollow areas behind all the rocks in my pond so that the frogs have somewhere to live. The frogs have extended what I prepared for them and have tunnelled up to the surface of the bank for easy access to the pond. It would appear that those tunnels had been taken over by at least one rat. In the process of enlarging the bores of the tunnels, the rat had pushed all of his unwanted spoil into my pond. As he had done it at just above the water level, we hadn't noticed the hole as it was covered by the plants on the bank. Having found the problem, it took the rest of the morning to try to get all of the earth out of the pond and to dig out the rat tunnels.

Despite the amount of work that it had taken, I was at least happy to note that the problem had not been caused by herons so I wouldn't have to put the net back on. Having removed as much of the earth as I could, and having made what little water was left in the pond extremely cloudy, I started to refil. Whilst that was in progress, I took the opportunity to thoroughly clean my filters and pump. For the next couple of days, I insed out the filter sponges twice a day and by the third day, my pond was reasonably clear and by the end of the week all was back to normal. The fish have all survived but there was one unexpected occurence during the refil. My biggest ghost koi changed colour from his usual dark gold with brighter markings to almost flourecent gold. He stayed like that for about two whole days befre going dark again. He seems to be OK now though. That all happened a few years ago and I am still here so I don't think I have got weils disease.   Top