Somerset Wildlife Trust

Work For Us|

Dippers on the River Axe by Victoria Hillman


I have been following a pair of dippers now for a few months and photographing their daily life on the river with the highs and lows of living in a changeable habitat, and seeing how they have become so well adapted to the fast flowing river.

 

About Victoria Hillman

Victoria is from Frome, and is a UK based wildlife biologist, photographer and guide working not only in the UK but also around the world.

You can see more photographs by Victoria at her website:
Victoria Hillman Wildlife Photography

Dippers are small birds with a short tail and short stumpy wings but very strong legs and unique amongst passerine birds as they are aquatic. They are approximately 18cm in height and 60 - 70g in weight with males being slightly larger than females. They are reddish brown in colour with a striking white throat patch and get their name from the characteristic bobbing motion when perched on rocks. These birds depend on fast-flowing fresh rivers and streams with plenty of perches where they forage for aquatic invertebrates (mayfly and caddisfly larvae in particular) and fish and have evolved several wonderful ways of hunting: they can swim underwater using their wings, swim on the surface making dives and also walk along the bottom.

As such they have developed morphological and physiological adaptations including dense plumage with a large preen gland which allows them to waterproof their feathers, they have a nictitating membrane or third white eye-lid which protects their eyes when submerged, nasal flaps to prevent water from entering their nostrils and a high haemoglobin concentration allowing for a greater storage capacity for oxygen increasing the time they can spend underwater. Generally dippers are considered of least concern but as they are completely dependent on fresh fast-flowing water, accessible food and suitable nest sites they are susceptible to problems such as water pollution, acidification and changes to the overall habitat.

Here is the diary of my endeavours to photograph the dippers over four months...

April

I first noticed the dipper on the river when opening and closing up at work when it would sit on top of the waterfalls or on the rocks in the river. After watching this charismatic little bird for a couple of weeks I became increasingly mesmerised by its daily life of preening on the rocks and hunting for invertebrate larvae on the river bed. It was only after a few weeks of observing the dipper I decided that it would make a wonderful subject for a mini project and one that would prove to be a challenge not least due to the location and weather.

The territory of the dipper is located at a busy tourist attraction and as a result would be absent from the main part of the river during the day, being present only early morning and late afternoon onwards. Taking this into account, I found the best times to try to photograph the dipper were before I started work and after closing. By staying on the bridge just above the river the bird seemed at ease with my presence but it wasn’t until May that I took my first images.

Photo © Victoria Hillman: Calling

Only on a couple of occasions have I heard the dippers calling and this image shows the male on his favourite rock in the river calling to his mate who was just by the bridge. He had been taking a break from foraging in the river bed and this photograph shows the third white eyelid closed mid-call.

 

Click the X top-right to enlarge - © Victoria Hillman



Click the X top-right to enlarge - © Victoria Hillman

Photo © Victoria Hillman: Foraging for insect larvae

As well as swimming in the river and diving to the river bed in search of insect larva, this dipper would often grip the rocks tightly with its feet and submerged its head into the flowing water. This image was tricky to capture in focus as they move their heads rapidly in and around the flora. I had a good idea of an image with the water coming around the dipper’s head as it looked for insects and after many, many attempts I finally captured the moment I was looking for and if you look closely you can see the beak of the dipper through the water.

 

May

Initially I watched and photographed just one bird around the river and I had noticed that it kept flying off under the bridge often with food only to return a few minutes later. Perhaps there was a nest under the bridge but it wasn’t until the river flooded and a second bird appeared that I knew for sure. Unfortunately, the continuous heavy rain caused the river to swell and rise to a level that wiped out the nest under the bridge. Once the river levels receded it was reassuring to see both birds collecting nesting material from the banks of the river to repair the nest.

Within a few days the female had disappeared back to the nest leaving just the male on the river and the more time I spent with these birds, the more intrigued I became about the relationship of the dippers with their fast flowing watery environment. As the days went by, I began to notice some of the adaptations they have evolved. The  most visible being a third white eyelid or nictitating membrane which enables them to see underwater when foraging for insects and short, almost stubby wings that they use to swim underwater.

I made the most of the light when it was there before it started to turn grey and the rain started to fall again, the worsening weather played a huge part in being able to capture the daily life of the dippers with poor lighting resulting in rare photographic opportunities. Despite the bad weather, I continued to observe the dippers and had some concerns that something had again happened when there was no sign of either bird for over a week.



June

The beginning of the month brought good news as both of the dippers were back on the river, preening and feeding through the day. Following the half term week they changed their routine were only foraging on the river through the valley late afternoon so I changed my plans to stay after closing to be able to photograph them.This worked in my favour as by late afternoon most of the rain had cleared. Despite the continuing rain the river levels were kept lower than usual to cope with the large volumes to avoid any further flooding. This provided some spectacular chances to photograph the foraging behaviour in shallow water as the dippers foraged for insect larva underwater.

As the month progressed and given this unique opportunity I spent hours watching and photographing the male in and out of the water trying to capture as many different aspects of their lives as I could.  There were many failed attempts and blurred images, but learning from the images that didn’t work, combined with patience and persistence, it paid off as the dipper became more and more accustomed to my presence and would sit on rocks closer to me rather than those further away. This allowed me to capture some wonderful behavioural images including looking into the water whilst gripping tightly to the rock, coming up through the water with food and shaking the insect larva before eating it.

As well as the close-up images I wanted to show the relationship between the dipper and its habitat which did prove to be a bit tricky due to the fencing around the river. By changing to a small lens that would allow me to shot through the holes in the fence I was able to capture photographs such images. Unfortunately towards the end of the month the weather took a turn for the worse with heavy rain returning with a vengeance causing the river level to once again rise. Up to now the majority of my images have been of the male bird as he has been the most visible and active. Although I had seen the female occasionally appear briefly to clean and feed before heading back to the nest I was unable to photograph her successfully.

Photo © Victoria Hillman: In the waterfall

As the river level dropped, the amount of water pouring over the top of the waterfall was reduced providing an ideal backdrop for a dipper but I wasn’t sure whether it would forage in the waterfall or just sit on the top. I was very excited to see the dipper making the most of the lower water levels looking for insects in amongst the foliage of the waterfall now I just needed to capture the moment. This image was one of the most challenging in terms of exposure, despite the overcast weather the brightness of the water and the dipper’s white throat against a very dark background certainly gave me a few problems added to by the lack of time the dipper spent in the waterfall. There were several blurred attempts before finally capturing this image.

Photo © Victoria Hillman: Stretching the Wings

The dipper would spend plenty of time on rocks preening their feathers, in particular the short wings, between their foraging outings into the river. The wing stretch before flying off or diving into the water would occur in the blink of an eye and after a few days of watching I soon realised my best chance of an image of this was going to be in the morning as the bird first emerged from under the bridge and would spend five minutes or so preparing their feathers before heading off for the day. At almost full stretch you can see just how short the wings are but very powerful allowing them to swim against the current of the river.

 

 

Click the X top-right to enlarge - © Victoria Hillman

 

Click the X top-right to enlarge - © Victoria Hillman



Click the X top-right to enlarge - © Victoria Hillman

Photo © Victoria Hillman: Reflection

Dippers lead quite a frantic life and capturing a moment of calm was definitely a challenge. Late afternoon saw the male busy in the top area of the river where the level was lower than it had been for a while, as I watched him making his way around he would take moments out to stand on the or by the rocks. As it stood just behind a moss covered rock you could just see the reflection of its head on the water producing this wonderful serene moment in between the frantic foraging.

 

July

The start of the month saw the rain continuing to fall resulting in another flood of the river. Since this flood I have only seen the male with no sign at all of the female raising fears that the second nesting attempt had been wiped out possibly with the female. For weeks now there has only been one bird, the male, who has spent time on the river but has not returned to the nest once.

As the weeks passed, sightings of the male have been few and photographic opportunities have been restricted to short periods late in the day due to bad weather and the accompanying poor light has meant very few images.

From mid-month I haven’t seen any sign of the dipper and with school holidays around the corner I feel that the male, and who knows maybe the female, have found a quieter location for the duration of the holidays.

I will continue to keep an eye on the dipper(s) and hope that once the school holidays have finished they will reappear on this stretch of the river.



Click the X top-right to enlarge - © Victoria Hillman

 

Photo © Victoria Hillman: Shaking an insect larvae

After finding an insect larva the dipper would shake it several times before eating it and this was a behaviour I wanted to capture. But that wasn’t easy, as it would happen very extremely quickly and would require a high ISO and this coupled with the poor lighting resulted in numerous failed attempts. Finally perseverance paid off and using an ISO value of 1000 I managed to freeze the moment the dipper shakes the larva complete with the spray of water droplets.


Click the X top-right to enlarge - © Victoria Hillman
 

Photo © Victoria Hillman: A serene moment

A serene moment on the riverMornings are a quiet time on the river with most foraging taking place in the afternoon. The first half and hour of so when the dipper emerged from under the bridge was spent preening and sitting on rocks in the river.

I had already captured many images of the dipper close up showing off the wonderful colours and behaviours, however none of these really showed the bird in its habitat so by taking a step back and finding a low position from which to take this image I was able to capture the peacefulness of the morning in this shot with the dipper preening on a rock with the river flowing by in the background.

Video © Victoria Hillman: Dipper foraging on the Axe river