19-APR-2011
Dead chicks!
Regular readers of my blog will know that I hae been monitoring, photographing and recording the events at a White Throated Dipper - (cinclus cinclus) nest site since the end of February. My almost daily visits and a total of well over 100 hours have recorded many interesting facts and I have gained a real understanding of the behaviour of this most iconic and interesting species. I am attempting to put together a book, a "Devon Dipper Diary" which will be published either in the traditional way or/and online as an iPad app or online book. Things were going so well until yesterday when 20.8mm of rain fell near to the river's source miles up stream which led to an almost, flash flood. The water level rose at an unbelievable rate, flooded in to the nest and prevented the parents from gaining access. The water level quickly receeded but by then the damage was done and the chicks were cold and lifeless in the nest. However, at that point they were not dead. I warmed them with my own body heat until they became active and then, having made a new access hole to the nest, above the water line, replaced them. The parents quickly returned, and now able to get in to her chicks, the female tried to brood them and the male continued to bring food. Sadly all to no avail as this morning, with the river level down 2 feet again, the chicks at 7 days old were dead in the nest. Their eyes were just about to open and pin feathers were about to emerge from their wings.
18th April 2012
The nest gets flooded out!
Getting straight to the point...... the Dipper chicks are with 99% certainty, dead!
It had rained a little bit off and on all day but by 4 pm it had brightened up. I had always planned to visit late afternoon and early evening. As I walked across the field and reached the river, immediately my heart sank, the water was so high it was lapping at the bottom of the nest. I saw a Dipper nearby so I didn't immediately think that it was a full blown disaster. I quickly concealed myself and then looked properly, there was no entrance hole visible, this was under the water. The majority of the nest was not submerged though. I sat and waited to see if the parents came and it wasn't long before the male arrived with a beak full of food. As you can see, he perched on the nest and tried to find a way in to feed his youngsters. It was a pathetic spectacle as he searched around the nest, all he time with a beak full of food, trying to get in to the nest. I quickly made a decision, I decided to cross the river and planned to open up the top of the nest so that the birds could get in to their chicks. It was either give them that chance or let the chicks perish for certain, if they were not dead already that is. I ran back across the field and down the road to cross by some stepping stones but when I got there the stones were totally submerged as well, I had no way of getting across the river! There was another way, via a bridge quite a way upstream which is what I did. I made my way down the side of the swollen river being careful not to fall in and eventually some 30 minutes later I was at the nest which was just below me. I lowered myself down head first towards the nest, holding on with my left hand and praying not to fall in to the torrent. I poked through the top of the nest and sadly I could feel the stone cold chicks, lifeless and seemingly dead. I removed them one by one, cupped them in my hand and blew on them with my warm breath. Miraculously, after 5 minutes or so there was some tiny movement and they started to come back to life again. I was really heartened by this, with them in my hand I put them in to my arm pit and held them next to my skin, the warmest part of my body. I had them there for 20 minutes trying to bring up their body temperature. However, I needed to get them back in to the nest as soon as I could so I took the decision to put them back in and hope for the best. I tidied up the new entrance hole and retreated back the way I had come. Back at the hide opposite I watched and waited, and prayed. Suddenly the female arrived at the nest, after some investigation she entered through the new entrance and to my utter amazement and joy she seemed to start to brood the chicks. At one point she did some tidying up of the new entrance and later even emerged to catch some food which she took in to the nest. Whether she fed that to the chicks I will never know, were they alive or had they continued to lose body heat again. After quite a while the male returned to the scene with a beak full of food, he tried on several occasions to feed his youngsters, perching on the edge of the nest calling to them loudly but sadly he didn't feed them. I am guessing because they didn't gape for food which was a really bad sign. I am praying that the female was able to brood them enough to get them active again but I will not know the answer to that until the morning. I appreciate that it is almost certainly against the law to take chicks from a nest but my conscience is clear on this. I have been with this family of Dippers for 7 weeks, almost daily and watched them build a nest, watched them incubate and watched them feeding their chicks for the last 7 days. It would have been impossible to sit and watch them perish without trying to help. Perhaps I should have let nature take its course? But I didn't, I did what I think is right. However, the chicks have almost certainly died in the nest. The parents were unable to brood the chicks or feed them for several hours. There is a very small chance that my intervention may have saved them but I am not hopeful. If they have survived it will be an absolute miracle.
17th April
A worrying rise in River level.
I was horrified when I went to the nest site late this afternoon. Last night it rained, not hard, but enough to leave puddles in the road. I guessed that the river would have risen but I wasn't prepared for 2 feet higher though. Every boulder was completely submerged and the river was a torrent. The Dipper nest was now 1 foot above the waterline but still reasonably safe. The parent birds were a litle subdued, they flew in with food, aiming for their favourite boulder perches and then at the last minute they would suddenly realise that it wasn't there anymore and veer away to land opposite. Yesterday they carried food to the nest every few minutes but today they were feeding much less. At one point the male was away from the nest for quite an extended period, at least 40 minutes. The female brooded the chicks for longer periods than yesterday but did emerge from time to time and carried food to them as well. I left the site reasonably content that everything was fine and with the knowledge that the oldest 3 chicks are 7 days old tomorrow. However, the weather forcast is not good, more heavy rain is on the way, yesterday's rain had added two foot to the river level, if that happens tonight then I fear that the nest will be flooded out and that will be the end of it. I am keeping everything crossed that they remain safe. Nature is extreme and always takes it's course.
Monday 16th April
But more about yesterdays watching which was incredibly interesting. The chicks are doing really well, I peered in to the nest which wasn't too hard because the opening has become larger due to constant use and the male's habit of hanging on as he feeds his chicks. I could see them really well and also noted that, at 5 days old they have trebled in size already. Feeding by the parents is none stop and at times both birds were back and forth in less than a minute, constantly feeding the obviously voracious youngsters. The female left-off from brooding and hunted for prey right in front of the nest, taking just seconds to find prey which she delivered, flopped back caught more and then delivered that morsel about three times in a minute. The male however seems to spend comparatively longer catching food and when he comes back to the nest he is usually carrying larger insects such as mayfly. Yesterday I saw him catch a small fish which he dealt with, Kingfisher-like, beating it to death, he didn't bring that to the nest but flew opposite to eat it himself, incredible that he could make the judgement that it was too large and not suitable for the nestlings. There seemed to be an uneasy relationship between the parent birds, at one point they displayed to each other and then tumbled in to the water rolling around as though fighting but is more likely to be a precursor to mating?
15 April, Dipper chicks day for
I had my first opportunity to photograph the baby Dippers today and I am very glad to say that everything is progressing splendidly. I watched from under cover nearby and with a clear view of the nest then as soon as the female left the nest and flew up river to feed I took the opportunity to check the nest. It is not necessary for me to do this daily but I am keen to know if the chicks are thriving. By using a small LED light I can see the chicks in the nest quickly without too much disturbance. The chicks, all 4, are now covered in very long charcoal-grey down, they are darker than they were on the day of hatching. I have been able to record some interesting behaviour today. The female left the nest several times in the 2 hours that I was watching this afternoon, not only to feed herself but also returned with food to carry back to the nest. This is a contradiction to other descriptions of breeding Dippers that I have read that suggest that the female does not help to feed the chicks until they are at least 10 days old. In this pair the female is already deffinitely helping to feed the chicks in the nest today and the chicks are 3 and 4 days old now. The male in particular is very industrious and constantly, either food or delivering it to the nest. There is going to be a video clip posted in the next half an hour so please check back.
13-APR-2011
Four Dipper chicks doing well.
At the nest this evening it was good to see the male working like a demon collecting food for his 4 chicks. What struck me was not only how efficient and skilled he was at finding food, but how much available insect life there must be. I kept a really accurate record of the time between visits to the nest. In 41 minutes from 18.11 to18.51, the male visted a total of 10 times. I have to confess that this level of feeding far exceeded what I expected. The prey being fed is larger than I expected and seems to be mainly Mayfly as I expected it would be.
11-APR-2011
Thursday 12 April, the 4th egg hatches.
Yesterday I had discovered three chicks and one unhatched egg in the nest. When I checked again today there were 4 chicks. This confirmed a few important facts. Incubation had been 17 days. Finding just 3 chicks in the nest yesterday and a 4th today could mean only one thing. Incubation had begun after 3 eggs were laid and before the clutch was complete. One of the things that I wanted to acheive by watching and studyng this pair of Dippers in the intense way that I have , was to establish my own facts rather than rely on other peoples research and information which is often recycled, 3rd hand information rather than anything based on private study. All previous information that I have read, told me that incubation would not start until the clutch was complete, in other words, after the 4th egg. This is to ensure that all the chicks hatch on the same day and have an equal chance of survival, However, this clearly is not the case and 3 chicks will have a head start on their younger sibling. In times of food shortage, the younger chick in the nest would certainly perish but in a season when food is plentiful this is not an issue. The male bird is already proving to be a brilliant father. I watched him for an hour tonight, he was working almost tirelessly catching prey undrwater and then delivering it to the chicks. At one point I counted to 30 before he emerged again, but mostly he would spend just a second or two delivering his morsel. he seems quite happy to catch food from around the nest so this will give me some great opportunities to watch him feeding as well.
11-APR-2011
Chicks hatch on cue.
When I checked the nest yesterday there was still no chicks in the nest which wasn't a surprise as they were not really expected until 11th or 12th of April. So I was quite hopeful when I visited to check this evening.
Thankfully the water level hadn't risen any further, infact it had brobably gone down an inch or two. I waited for the female to leave the nest before moving down to check the nest. I am really glad to be able to report that 3 of the eggs have hatched and three healthy chicks are in the nest. One egg is either infertile, or "dead-in-shell" or more likely incubation started with the 3rd egg and not the 4th. If this is the case this will contradict everything that I have read previously which seemed to suggest that incubation always commenced when the clutch was complete. If the 4th egg should hatch tomorrow, then this will confirm that incubation started on Sunday, when there was only 3 eggs in the nest. I am looking forward to finding the answer tomorrow. The chicks were pink skinned which was a surprise, I expected them to be dark.
I watched the male already working hard finding food and delivering it to the nest, even if I had not checked for myself, I would have known that there were chicks in the nest just by the male's change in behaviour.
9th April 2012
Before you start reading this entry please be aware that I am a registered member of the BTO's nest recording scheme.
It's now 17 days since the first Dipper egg was laid in the nest at the territory that I have been keeping a close watch on since the beginning of February. This week is a crucial one. It is said that incubation will not begin until the last egg of the clutch is laid and there are 4 eggs in this clutch. It is likely that incubation commenced on the 25th March which coincided with the 4th egg, however as part of my records and individual observations of this pair, I need to confirm that this is the case. There are several possibly variables. Apart from the above there is the possibility that incubation could take 16 days or even less. It is also possible that incubation could have comenced after the laying of 3 or even 2 eggs. Only discovering the date that chicks hatch can this be confirmed. The earliest date that hatching could have ocurred is today. It was important that I checked the nest contents today. I can confirm that there are still four eggs in the nest and as yet no chicks. My method of checking, in accordance with the laid down procedure and advice from the BTO, is to sit unobserved, watching the nest. When the female has departed the nest is the time to make your move. My observations for the last 17 days have shown me that the female, after leaving the nest, has the habit of flying away upstream and is away for 8 minutes. This is ample time to quietly and without fuss, check the contents of the nest, but after first confirming that male is away from the area with the female. To check this nest requires a wet foot as it is situated above water on a vertical moss covered bank.
April 8th 2012
The weather forcast for the next couple of days is for rain and it is possible that I won't get the chance to check on the nest tomorrow, I hope to be able to because it is the start of an important week for the Dippers. I decided to have a quick check of the nest site and the breeding pair late this evening. The male was in front of the nest when I got there, it's always good to see him at the nest, confirming that there isn't a problem. Nothing special to add from this evening except that the male stood in front of the nest for quite a while, he was making that sibillant churring sound here and there, and had he got a response from the female in the form of a churring answer, I'm sure he would have flown up to her but he didn't. Considering that it's now 16 days since the first egg was laid and they are due to hatch within the next day or so, it's a surprise that she didn't invite hime to feed her. It will probably be easy to know when the eggs have started hatching because I am expecting the male to deliver food to the nest, that will be a change in recent behaviour. Just before dusk, the male was still in front of the nest and still making his churring noise. I felt a bit sorry for him, because he hasn't taken part in the incubation. He is detached from what is going on and has kept quite a lonely vigil for the last 16 days. Incubation is said to last 16 or 17 days and also to start on the day of the laying of the final egg of the clutch. This is to ensure that all eggs hatch simultaneously, not all birds use this syncronised incubation. Some species will incubate after the second egg meaning that chicks hatch on different days. The benefit of this is that the older chicks are inclined to get the "lions" share of the food brought to the nest. Only when their is a plentiful supply do all the chicks survive. In Dippers, all the chicks will have an equal chance of survival.
7th April 2012
When I arrived at the nest this morning, I crept in to the hide quietly and I expected to see the male Dipper waiting in front of the nest as normal. I have to admit that it started to frighten me when 15 minutes later I was still Dipperless! Was everything OK, I was just a little bit concerned. I was relieved when I heard the male approaching, fast and low as normal. He landed opposite with his usual noisy fanfare with a beak full of Mayfly. He flew to the nearest boulders just under the nest and called, bobbing incessantly but didn't fly up with the insects. I suspected that the female wasn't in the nest but I was wrong because out she came. She did a bit of dipping and then left upstream followed by the male. There wasn't a lot different to see, she was away for the usual 8 minutes, he returned and sang as normal. Just a few more days to go now before the eggs hatch and the only thing to report of note is the massive increase in insect life. It's also worth mentioning that in the hour that I was watching, the fem ale left to feed twice, the same pattern that I observed the day before yesterday.
April 5th Adult Mayflies on the wing.
I watched the nest yesterday for a couple of hours in the afternoon. It's now 14 days since egg laying began and incubation has thrown up a few interesting facts. To start with, the female, who does all the incubation has now developed the habit of leaving the nest to feed every 30 minutes or so. As I have said before, she is away from the nest for just 8 minutes, literally to the second. The male is not always aware that she has departed and yesterday I watched him arrive with a healthy beak full of adult Mayflies. This is the first time that I have seen the male, or female for that matter, feeding on adult Mayfly and my guess would be that the entire breeding cycle has been timed perfectly so that when there are chicks in the nest there is going to be a proliferation of Mayfly. He called to the female from a boulder close to the nest but didn't get any response because she was away feeding. He continued calling her but didn't fly up to her with the flies. I made the assumption that had she been in the nest she would have responded and he would have delivered the insects. I am certain that this is the case but I haven't heard her calling from the nest. before and it was interesting to realise that he was waiting for a response from her. Eventually after flying from boulder to boulder in front of the nest, he decided to eat the food himself but not before he had spent at least 5 minutes calling her. To think that the arrival of chicks in the nest has been timed to coincide with the Mayfly hatch is a stunning fact. Quite how that has been judged is a mysterious wonder to me.
