Monitoring of breeding Kingfisher (Alcedo atthis) in  infrared lighting

(videofoto: author)


    The paper decribes monitoring of breeding Kingfisher (Alcedo atthis) with use of an infrared camera system. Some of newly discovered behaviour was described as well as comments and questions were presented.  


    Autor has been filming and photographing kingfishers both in nature and on a nest for many years. In 50-ties of the previuos century, same as some other film makers, attempts of filming in a daylight were undertaken. In spite of many colourful records, it’s obvious that behaviour of birds was affected by artificial filming conditions. Thus the author took an effort to discover the way how to investigate life habits of kingfishers with no impact on their behaviour. This could allow to follow the whole breeding cycle naturally, including lying eggs, with no risk of interruption. Yet the first attempts of IR filming put the limits as the birds registered the IR source. However in August 2007 the method was improved and allowed filming broods with no influence on their natural behaviour.
    The observations were carried out along the Chotýšanka stream in the Czech Republic, based on the permission from  the authorities CHKO Blaník. The filming took place in an artificial nest chamber located on the bank. Except filming and voice recording, also plenty of statisctic data were collected. The time was described according to CET (Central European Time) and the day of hatching was described as „D“.
    Monitoring of several breeding pairs does not allow to present extend summaries, however plenty of notes during filming helped to understand many of habits of breeding kingfishers. In the following chapters decription of the breeding season together with questions and comments are presented. 


    Year 2007
    In the year 2007 observations were carried out during 200 hours with about 20 hrs of filming.
The pair laid the first egg (of a total 7) one week after instalation of the filming equipment in the chamber. The pair built up the isolating surface at the bottom of the  chamber by pecking and grinding pellets with a bill. Incubation (both birds) started soon after laying of the fifth egg. The both birds shared incubation during the day. As there were no significant differences in behaviour, filming took place only five times during the incubation period. Four times it was a male sitting in the nest, up to 5 hours in one turn. Dute to time limits, filming during the night was skipped. Both birds were very carefull in the chamber. They extracted pellets after every switch (Pic. 1), and fragmented them immediatelly afterwards. Regurgitation of a pellet started with several slow, waving moves of a head on the contrary to the behaviour observed out of the nest hole where it followed rapid horizontal moves of a head. A shape of a pellet inside the chamber seemed to be a little bit narrower than those the author found outside a nest hole. Grinding of pellets took about 2 minutes approximately. Several times voice contacts between a bird inside a hole and its patner staying outside were recorded. Both birds never stayed together in a chamber at that stage.

    „D“ day. In the 20th day of incubation the chicks hatched. It took place under the body of a female, so the details were not recorded. The chicks were hatching during the day with no help of the female. She left the chamber only for a very short time (2-5min.) and came back with a fish for the chicks. Only once she stayed 10min. out of the chamber. Feeding started by touching a chick with a bill and putting a fish carefully into a gorge afterwards. Then the female seated on the chicks again. It was observed that the female brought a fish too big for the chicks. It felt on the ground (Pic.2) and most probably the female ate it afterwards during the night (Pic. 3).
Excrements are liquid drops. The last feeding took place at 18:58 CET. It was not observed on the day „D“ the female regurgitating pellets or excrements inside the chamber. The question is if she was fed by the male that day at all. The chicks were growing up quicky. They called with quiet squeals and in the afternoon they started turning heads while the female returned to the chamber.
    Day „D+1“. The 6th chick hatched. The female was continuing heating of the chicks and grinding pellets, but it wasn‘t observed she produced excrements. The female stayed out of the hole up to 3-6 minutes and fed during one interval 1 or 2 chicks. At 18:58 CET a big fish was brought so a chick swallowed it in 10 minutes. In the meantime the female fed another chick. The male was not observed in the chamber, but was heard nearby.  
    Day „D+2“. There were 6 eggs and 1 egg in the chamber. The female usually fed 2 chicks during feeding intervals. Feeding frequency was similiar to the previous day. Again the female was grinding pellets. The male was heard outside the hole but did not enter the chamber (it was like that till end of the season).
    Day „D+3“. There were 6 eggs and 1 egg in the chamber and the female was grinding pellets. Feeding intervals were slightly longer with 2-3 chicks fed in one run.
    Day „D+4“ and several following days monitoring was not carried out due to time limits.
    Day „D+5“. The last egg dissapeared as well as all egg shells (the female seemed to ignore them before). Again a question araises, when and how they were removed. The female stayed most of the day outside the hole and warmed the chicks several times (intervals approx. 30 min). Regurgitation of pellets was not observed. The chicks spread excrements in all directions (not only into a tunnel). As feeding was done between the chamber and the tunnel, it was not possible to define a gender of the adults. After picking up a fish, the young were moving accidentally, sometimes with some delay. They started calling louder and sounds become deeper and lower.

Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 1                                                                                                              Pic. 2
Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 3                                                                                                              Pic. 4
    Day „D+6“. Wings, heads and back with visible dark spots of growing feathers. The female didn’t warm the chicks during the day. At 19:34 CET she returned to the chamber and stayed inside during the whole night. After 3 hrs from the dusk, the chicks stoped moving and slept, same as the female (Pic. 4)
    Day „D+7“. Feeding of the nestlings started before the dawn, at 5:05 CET. The narrow chinks appear on the eyelids (Pic. 5). The chicks spead excrements in all directions, but more and more frequently into a tunnel. The female brought headless fish four times (Pic. 6). The chicks refused having those fish, so the female leaved the chamber with the prey. The question is where headless fish were found or how their heads were taken away.
    Day „D+9“. Again a fish laid at the substrate. It proves that sometimes too big fish are brought for the nestings. When a big fish is given to the chicks, they try to ballance with the wings spread aside. It is not a competitive behaviour anyway. It was observed a white grit substance draining out of the bill for several times. The chicks spead excrements more and more frequently into a tunnel. Again headless fish was brought to the chick and again after several unsuccesfull attempts to swallow,  it was rejected. A headless fish has no quoin shape and it is difficult to swallow it smoothly, especially whereas a chick has limited manover space. The chicks called louder but not so frequent (Pic. 7).
    Day „D+11“. The chicks started stretch their wings to get more space and compete for food. Feeding took place in the nest tunnel. White grit substance was draining out of the bill while a fish was swallowed. Excrements were squirt into the tunnel light. The first pellets were observed. The chicks stayed calm, exept feeding.
    Day „D+12“. The nestlings stayed calm, frequently extracting grid pellets (draining out of the bill or spread away with some wavy moves). Between feeding intervals, the chicks were burling their wing feathers. The female did not stay at the hole during the night.
    Day „D+13“. The chicks frequently spread away a grid substance, rarely also pellets (Pic. 8). Feeding took place at the entrace to the chamber.
    Day „D+15“. Except feeding, the chicks stayed calm. Again a headless fish was brought and again after 10 min. attempt to swallow it, was finally dropped down.  

Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 5                                                                                                              Pic. 6
Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 7                                                                                                              Pic. 8
    Day „D+18“. The chicks stretched their wings. Remigies had started to be visible (Pic. 9). The chicks pushed on the entrance hole with the stretched wings. This explains a „pear“  shape of the entrance in old nests.  Pellets were dropped rarely, their size was 1/3 of those from adults.
    Day „D+21“. Remigies and rectrices were well grown, but when wings stretched, it was still visible that some of them were not equally grown.  The chicks  were often burling their feathers (Pic. 10) and waving with wings rapidly. Pellets were dropped quite seldom.
    Day „D+23“. The nestlings were often burling their feathers and stretching the wings (Pic. 11). Fledging is advanced and the chicks entered the tunnel while feeding and defecate. Pellets were dropped seldom,  their lenght was 1 cm approximately.
    Day „D+24“. The young birds left the nest. The day after they were seen nearby, but did not enter the hole.
    Monitoring was finished.

    Year 2008
    The breeding attempts in the year 2008 were observed and described.
    On the 24th and  26th of February 2008 a male staying close to the nest site was noticed. The entrance to the tunnel was partly damaged by erosion, so the author cleaned it on the 11th March 2008. During the following visit (15.3.2008) the male occured at the site, but also a dead Great Tit (Parus major) was found at the entrance to the nest tunnel. It proved that Kingfisher nest holes can be sometimes used as a hiding place by other birds (f.e. Tits). It was indundating of the tunnel that most probably caused the death of the Tit. After clearing the entrance on 11. Mar. the male of Kingfisher  removed the Tit. Instalation of the camera system took place.
    Till the 15th April 2009 only a male appeared in the area, and it was the first time when also a female was observed. On the 17th of April the male with a small fish in the bill attracted the female but in vain. Following observation showed some ubnormal circumstances. It was mainly male who entered the chamber (Pic. 12). He grinded pellets, prepared substrate while staying at the nest. On the contrary, the female stayed at the nest rarely. Several male attempts to give a fish to the female were in vain.  The situation did not changed till 22.5.2008, and afterwards the female was no longer observed at the site. Soon after the male disappeared too. In June the nest was controlled several times, but except some evidences of the kingfisher presence, the birds were not seen.  
    Except preparing the chamber for a brood, no eggs were laid. The question why it failed arises.
    As the nest was ready for a brood, it looks like the reason was not concerned with the nest itself.
Also the male behaved normally. The female stayed at the site for 5 days, but she behaved somehow strange. It seemed like she was the reason of the brood unsuccess. As the observations were not so detailed, there could be also some other reasons which were not spotted.

Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 9                                                                                                              Pic. 10
Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 11                                                                                                              Pic. 12
    Year 2011
    In the year 2011 Kingfishers reared two broods at the site. On the 28.3.2011 the female was observed and soon after (6.4.2011) eggs were laid. The male came with a fish. On the 10.4.2011 the camera system was installed and there were 7 eggs yet in the chamber. Both birds shared incubation intervals, grinded pellets, picked their wing feathers and extracting from time to time. On the 20.4.2011 a strange way of replacement of the birds in the chamber was noticed. A minute after entering the male was thrown away by the female. Shortly before the expected date of hatching, the eggs were damaged (most probably by a human). The day after the pair of Kingfishers still stayed nearby flying nervously up and down.
    The next brood took place in June/July. The observations took 280 hrs of which about 30 hrs were recorded. The exact date of the start of the brood was not found as the controls were not carried out every day. It was noticed however that on the 14.6.2011 the last egg (of total 7) was laid. Incubation started soon after the fifth egg was laid and run properly. Both birds shared incubation. The longest interval lasted 6.5 hrs (could be even more if recording would continue).
    Most frequently incubation lasted 3-4 hrs. In the night it was only the female who stayed in the nest (it was proven by recording as well as early morning controls of the nest). The female stayed in the nest for the whole time during the night. Prior to leaving the nest the birds were rapidly waving with wings close to the entrance. It took up to tens of seconds.
    The birds were picking their wing feathers, regurgitating pellets, extracting while staying during the day in the nest chamber. Grinding pellets took up to 28 min. with several very short breaks. In the night the female slept with her head partly hidden into a wing (Pic. 13). During the last night before hatching she was mainly grinding pellets and sleeping.
    Even after heavy rains when the water level raised, behaviour of the Kingfishers remained unchained. The nestlings hatched after 18 days.  
    Day „D“. The day started as usuall and the birds shared incubation. In the afternoon hours calls of newly hatched chicks were noticed. The female was replaced by the male, with quick feeding of a chick in the meantime. During the feeding the male attracted the chicks with the noisy caws. There were 3 nestlings and 4 eggs in the nest. The chicks moved blindly while feeding. Both the male and the female were pecking the egg shells, and they removed them from the nest afterwards. The switch of the parents as well as most of feeding took place inside the chamber.  (Pic. 14).  The birds had limited ability to see in the chamber, especially when the partner stayed in the tunnel. The voice contact helped to communicate and feed, that could last even sevral minutes. Both parents touched themselves with their bills and tried to find the right way to feed. The longest absence of the adults in the nest was 1 minute only,  at that stage (only once it was 5 minutes). On the day „D“ intervals of warming by the parents were shortened.  All other habits like grinding pellets, picking their wing feathers and extracting were continued during the following days while adults stayed at nest. Observations of the nestlings were limited as they stayed under the body of the parents. At 20:24 CET the female behaved strange, with some bites to the substrate and rapid waves of the head. It lasted 2 minutes. Similiar behaviour was observed only twice during monitoring.
    Day „D+1“. During the night the female mainly slept, from time to time pecked the substrate. At 4:25 CET the male arrived and fed the nestling. After an hour, four nestlings were visible and the fifth was actually being hatched (Pic. 15). When the male arrived, he sat on the chicks and didn’t care about the hatching chick. It proves that hatching runs with no help of the parents. All the nestlings in that brood  hatched within 30 hours. Switch of the parents in the chamber took roughly one minute. It was however noticed exceptionally absence of parents for 8 or even 23 minutes. As the nestlings stayed hidden under the body of the adult birds, their observation was limited. Also several feedings took place like that. The young birds had no perception of the space. On the 11 pm. the female rapidly shaked her head again.
    Day „D+2“. At night the female usually slept. At 3:52 CET the male entered the nest with a fish. The chicks were still sleeping, so he left the nest after a while. During the day the nestlings sprayed excrements and excrete secretion from their bills. No perception of the dirrection was visible. The adults stayed at the nest and left it for only for approximately one minute, exceptionally 3 and 7 minutes.

Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 13                                                                                                              Pic. 14
Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 15                                                                                                              Pic. 16
    Day „D+3“. The chicks moved actively and started being aware of a dirrection. Size difference (cca 2/3) was visible between the smallest (7th) and the biggest chick. The smallest nestlings was vital and active. In spite of trying to be close to the entrance, it failed to get food. The parents fed the young above his head and it started starving and loosing its weight. The female returned to the nest and touched the 3 nestlings with her bill, whereas the third chick reacted with exctraction. The female sat down shortly afterwards. Feeding took place when both parents stayed in the chamber. The nestlings stayed without the parents maximum to 2 minutes usually, only scarcely up to 4 and 10 minutes.
    Day „D+4“. At 5:15  CET the female brought a fish and tried to feed the chick for nearly 2 minutes. Athe nestling didn’t take it, she swallowed the prey. Both parents were present while most of feedings. Excrements were spread with no preferred direction. Size difference between the smallest and the biggest nestling was nearly double. On that day the smallest chick was fed only once. It tried to warm up staying between the other nestlings, but it was visible it got weak.  At 20:14 CET the female started picking the substrate and continued that behaviour for the consecutive 24 minutes. The parents were absent in the hole usually from 1 to 5 minutes, but sometimes also 11, 19 and 40 minutes. Some dark feathers were visible at the wing edges.
    Day „D+5“. The Kingfishers brought fish bigger than the chicks were able to swallow. Some of feedings took place with presence of both of the parents. Again the female touched with her bill the chicks before sitting on them. Intervals with absence of the parents in the nest reached up to 10 minutes, occasionally even more than 20 minutes.
    Day „D+6“. Big changes were spotted in the nest on that day. The parents spent the night outside  and discountinued warming the chicks. Several times the female without food appeared at the entrance to the chamber. It was also the place where the chicks were fed. Fish were nearly the equal size to the biggest nestling, so obviously were too big for the smallest chick. Thus it was fed very scarce, mainly by the male, even if in most of the cases it stood in the first row. Black pterilia were visible on head, arms and spine. The voices were deeper and lower.
    Day „D+7“. Feeding of the chicks moved deeper inside the tunnel so it was impossible to recognize the gender of a parrent. The nestligs stood in a row before feeding. Again the smallest chick failed to get food which was given above its head. While feeding the chicks stabilized their bodies with their wings. After being fed, they stepped back with no regular direction. The nestlings were often picking their tiny feathers and stretched the wings
    Day „D+8“. Big chicks had most of their bodies covered with dark feathers, and quills became visible on the wings. A dropped fish laid at the bottom of the chamber. Uneaten fish remained trodden to a lining. Larger chicks could already eject droppings into the tunel. Partially open eyes weres registered at the biggest nestling.  
    Day „D+9“. Monitoring was quitted due to time limits.
    Day D+10. At 8:35  CET the male brought a fish and the smallest chick tried to grab it. After more than half a minute exertions, the male gave the fish to a bigger nestling, that  swallowed it easilly. At 9:23 pm CET another fish was given to the smallest chick but again with no success. The nestling however  had visible dark hints of a budding feather wings as well as on the head, shoulders and along the spine. His body was only slightly bigger than the head of the biggest chick (Pic. 16). A voice became louder.
    Day „D+12“. Big nestlings had most of their body covered with quills. They often were picking growing feathers. The smallest chick got stronger too, but delay in its growth (about 5 days) was visible. It took it about 30 minutes to swallow a big fish. The parents fed the young birds at the entrance to the chamber. When fish was swallowed, the chick turned back and splashed droppings into the tunnel. Then moved bakward, sometimes throughout the other nestlings. If a fish was bigger, it forced remaining substance out of a digestive tract. Voice was louder and quite squeaky.

Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 17                                                                                                              Pic. 18
Ledňáček říční (Alcedo atthis), Kingfisher          Ledňáček říční (Alcedo atthis), Kingfisher
                                            Pic. 19                                                                                                              Pic. 20
    Day „D+14“. Shape and size of pellets in the chamber were normal. The chicks were begging for food at the entry of the chamber with outspread wings to fill in all the room. Thus their wings rubbed the mouth of the chamber. Competition for food caused some skirmishes and the chicks became generally noisier. Again the smallest nestling got a fish that was swallowed more than half an hour.
    Day „D+16“. The young after ringing behaved quietly and timidly. They stayed away from the entry hole and did not attempt to seek for food. Adult birds after ten days of a break inspected the chamber again. The chick regurgitated a pellet. Contour feathers started to be visible.
    Day „D+18“. Young kingfishers againg seek for food into a entry hole. Again regurgitation of a pellet was recorded. Whereas the smallest chick was covered with feathers scarcely, the others were already well feathered. Contour feathers had 1/3 of their final lenght.
    Day „D+20“. Feathers of young kingfishers were developed by more than half. Very common was picking their feathers and strengthening the wings. Due to lack of regular feeding some fierce fighting was observed at the entrance  (Pic. 17).
    Day „D+22“. Behavior of adult birds changed. Very obviously they tried to attract the chick to leave the nest. Chicks were offered fish, but got it only during the third or fourth attempt. Those happened many times during the observation. At the mouth of the chamber again furious fights were noticed. Although feathers of larger chicks looked developed, while stretching the wings it was seen they still needed to grow. The remigies and rectrices of the smallest kingfisher were also pretty well grown up. The nestlings were often picking their feathers and strengthening the wings. One of the chicks regurgitated a pellet and immediately grinded it.
    Day „D+23“. The behavior of kingfishers calmed down and feeding came back to the previous, normal rhythm.
    Day „D+24“. Feeding in the morning hours went as normal. Three birds left the burrow in the afternoon.  
    Day „D+25“. Young kingfishers picked their feathers , slept or strengthened the wings and sometimes fought. At 10:28 CET two chicks entered the tunnel  and one of them returned to the chamber. In the afternoon two chicks sat on a branch about 10 metres from the nest site and  picked their feathers. Over the entire period of observation there was no feeding of young kingfishers recorded.
    Day „D+26“. Two young kingfishers left the nest in the morning. Only the smallest chick stayed in the nest. A young bird picking its feathers was seen nearby the nest in the evening hours.
    Day „D+28“. The last chick left the nest in afternoon. Monitoring was finished. Kingfishers did not enter the nest no more.

    Year 2012
    Also in 2012, kingfishers nested twice in the monitored nest.
    The first brood took place from April to June. During the incubation period everything went normal with no strange behaviour. On the nineteenth day from laying the last (7.) egg, the two chicks hatched.
    Day „D“. Both adults shared incubation but during 4 hrs of filming it was only the female feeding the nestlings. It looked like the male did not participate or brought a fish to the nest.
    Day „D+1“. There were 7 chicks already present in the nest chamber in the morning. For more than five hours watching the male didin‘t feed the young and stayed in the nest only once for  21 minutes. Again, it could be concluded that the male did not bring food.
    Day „D+2“. Feeding attempt by the male was recorded. The fish brought to the nest was too big for the young, so the male dropped it after a while and sat down on the young (Pic. 18). After more than an hour the male took another attempt to feed and was succesfull. Furthermore, both adult birds shared feeding and care of the young in the normal way.
    Day „D+4“. Adult birds shared their care of young and communicated with squauk.
    Day „D+7“. Young had the head, back, shoulders and wingtips with visible stains in places of  sprouting plumage. Only the smallest chick had yet only a few dark spots. Bigger chicks were picking their wingtips. The biggest chick already used the wings to take over the space.
    Day „D+10“. Adult birds did not warm during the day but only in the night. Between feeding intervals,  chicks sat quietly and without conflict. At 19:20 CET the chick got a medium-sized fish and after 20 seconds was again fed with a little smaller fish. The chicks moved sometimes clockwise or in reverse direction but often also random.
    Day „D+13“. Upon arrival at the nesting site it was found the birds were ringed and somehow anxiet. Juveniles were pecking with beaks due to starving. Adult birds began to announce their arrival to the hole with whistles.
    Day „D+16“. Juveniles sat quietly throughout the heavy rain. Feeding was carried out in the tunnel. During the haviest rain feeding was stopped. The chicks were picking their feathers and streached the wings.
    Day „D+19“. Harvest took place on a meadow nearby. The noise of tractors did not affect feeding.
    Day „D+23“. The young were about to leave the burrow. In the afternoon one chick entered the tunnel but after a while came back. A moment later entered the tunnel again and stayed there for 1.5 minutes. Then ran over to the chamber, turned and ran out. After 20 seconds of standing at the end of the tunnel it flew away. After seven minutes an adult bird appeared with a fish in its beak. It partly entered the chamber, spreaded  the wings of the walls in the tunnel and in particular a very broad attitude tapping, shaking fish and lifted it up. Then backed out with the fish kept in the bill. The young did not catch a fish. In less than a minute the chick was apparently fed in the tunnel in the normal way. Nine minutes later an adult bird without a fish came, tapped, opened its beak and shook his. It happened again in a minute (Pic. 19). The young did not react, and the adult went away. It repeated 4 times, then normal feeding took place. At 18:44  CET the old bird brought a fish and provoked the young, finally entered the chamber. Then left the nest with a fish and after a minute returned and fed the young.
    Day „D+24“. Six chicks stayed in the nest till evening. Feeding was less intensive compraed to previous days. In the evening feeding frequency increased again.
    Day „D+25“. Five birds leaved the nest in morning hours. The last chick a fish was offered several times in vain. Some offers were accompanied with squauk. The young was picking its feathers and run in the chamber. If sat quietly, still snapped with the beak.
    Day „D+26“. The last bird left the nest

    The second brood in 2012 took place in July and August, with 7 eggs laid. Monitoring was scarce.
    Day „D“. The parents shared incubation. At 16:00 CET while the male was sitting in the nest a slight snapping was recorded. At 16:59 the male started pecking around nervously. At 17:43 the first beep of a baby was heard and at 17:46 the egg shells were seen below the wings. At 18:08 the male took a shell away of the nest. Among the eggs one nestling was recorded. Then the female continued incubation. At 19:30 the male entered the chamber with a fish and fed the young. Some squauk voices were recorded. The male leaved the nest and the female stayed in during the night.
    Day „D+1“. The next 6 chicks hatched during the night and morning hours ofthe coming day (alltogether within 22 hrs). Both parents shared the care.
    Day „D+8“. Feeding took place at the entrance to the nest chamber. Chicks were waiting for food  predominantly in the position of wreaths, but already beginning to build into the raws. They started pecking their feathers. Size differences reflected time of hatching. Till end of th recording the female did not enter the nest.
    Day „D+18“. There were 7 nestings, more or less same size,  in the nest. During the recording, the voice manifested only minimally. The young were picking growing feathers intensively and occasionally stretched wings. Feeding took place deep in the tunnel. After feeding chicks moved irregularly on the left and right of the entry  hole.
    Day „D+25“. There were 5 chicks still staying in the nest. They stretched their wings and picked feathers. Moments of feeding could not be clearly determined because alternated with attempts to get out young from burrows. The behavior of juveniles indicated thay soon would leave the nest. Regurgitation of a pellet was recorded as well as 2 pellets laying on the substrate in the nest.
    Day „D+26“. In the afternoon, none of young stayed in the nest. Nearby the breeding grounds the adults stayed and whistled. 


    In the following section, the author presents conclusions from these observations in context with the filming of kingfishers in previous years with less suitable techniques. The findings of the monitoring  brought a different explanation of many claims arising out of incidental considerations of short-term observations.
    1. Pellets. The issue of pellets can be divided into two parts. Monitoring clearly showed that the pellets are not produced by young, but largely come from adult birds and are important insulating layer in the nest. It is produced throughout the whole period in which the adult birds stay in a nest. This clearly demonstrates that the assessment of food composition analysis of nestlings using the pellets from the nest is completely false assumption and is therefore wrong. Share of pellets from adults and young varies. Also depends on the number of juveniles and the size of fish brought to a nest. It also depelnds on the length of time since the occupation of burrows till laying eggs, because in this period pellets can come also from not paired bird. Moreover skeletons of small fish are in the digestive tract partially decomposed. This explains low number of big pellets in monitored nest. The second part of the ejected material is pulpy substance. During monitoring in 2007 it was detected after the eighth day of life of young. It is, however, that at an earlier age it could be difficult to observe this behaviour  with a camera. Regurgitating pulpy food debris continues till leaving the burrow.
    2. Shares during incubation period. During the incubation period shares during incubation as well as switching both genders in the nest were recorded. From the total time of recording in 2011 the male remained in the nest for 44 hours and 47 minutes and the female for 81 hours and 50 minutes.
    Both birds were engaged in incubation. However they behaved different. Incubation sessions lasted around four hours. In the day between dawn and dusk it was a male who stayed in a nest more often. In the night it was a female who stayed in the nest and a male presence was not recorded at all.
    In the year 2011 same model followed (Graf 2.; „0“ means „D“ day).  Birds changed more frequently in the nest however. Nesting in 2007 the author sees as somehow specific in many aspects. The male stayed in the area only till the young hatch and soon after dissapeared. The question arises, how often it happens and why a male did not enter the nest chamber at all. The author observed many times a male more intensively feeding young, especially bigger ones. Some explanation of the behaviour in 2007 could be a fact it was the last breeding in the season. Also additional observations of the behaviour outside the burrow could be some help.
    3. Shares during feeding. Kingfisher is a successful hunter. It can be assumed that the commonly stocking flow does not limit the frequency of feeding, but it is influenced by needs of chicks. It‘s prooved by a very short time, which was needed to bring food in the first few days of life of nestlings. In 2007 it was only the female who fed nestlings. The most intensive feeding took place in morning and evening hours. All individual feedings are marked on graphs (Graph 1. and 3.; 0=“D“ day). In 2007 the male didn’t participate in feeding. In 2011 in 53 cases it was a female, 74 - a male and in further 102 feedings a gender was not defined. The group without sex recognition includes birds feeding in a nest tunnel, however collected data give some idea of involvement of both parents.
    4. Irregularity feeding. Growth of the smallest chick was related with the way of feeding. Although all chicks hatched in a short time span of about thirty hours, soon appeared size differences. Their growth during the first days of life is very fast and logically directly dependent on the amount of food ingested. Consequently, chicks were not fed equally what affected size differences. In 2007, the last chick hatched apparently with great delay and it was only a female feeding it. But inspite of that there were no size differences visible. On the contrary to 2011, where size gap increased rapidly since young were fed in the entry of a nest chamber. Although a vital small chick was first in raw, feeding went over its head. It was only a male who fed the smallest nesting succesfully during several days. With growing age, chicks were brought larger fish.That time appeared tertiary reason for the slow growth of the smallest nestling. The difference in the size of the chicks was already such big that a small young was not able to take most of broght fish. Twelve days after hatching estimation of growth delay was at least five days. This corresponds well with four days delay in leaving the hole. In the third decade of its stay in the nest, the smallest chick compensated that gap through the vitality and aggressivity.
    5. Mooves of young after feeding. The author dissagrees with the  theory of displacement of young clockwise after feeding. Chicks move quite irregularly and obviously is important their phisical condition and aggressiveness in competition for food.
    6. Paretial care with one or both birds. Also noteworthy is the comparison of feeding one bird or both parents. While the breeding season of 2011 can be considered as typical in 2007 was quite unusual. A male did not participate in feeding. The values in 2007 had greater variance due to shorter time intervals and no regular feeding. Scarcer feeding by alone female was compensated with larger fish. In a consequence, some large fish laid not swallowed in the chamber. Number of young determined feeding frequency. Time span of feeding was related to a day lenght. In spite of those limits, alone female was able to breed 6 young succesfully.
    7. Warming up of nestlings. In 2007 a female did not stay with nestlings in the chambes as of their 12th day. In 2011 where both parents cared of young, it happened as of the 6th day, and even during the day parents did not stay in the nest. Temperature was quite similiar in both seasons (no regular check was done). In 2012 adult kingfishers stopped warming up chicks as of 8 or 10th day.
    8. External factors. Feeding can be influenced by variety of external factors. During monitoring weather changies  were also recorded. To assess the impact of weather on feeding chicks there were compared some weather parametres (Fig. 3. and 4.); (0 = „D“ Day). The comparison surprisingly shown that higher water level and its pollution due to heavy rains did not negatively affect the frequency of feeding. On the contrary, frequency of feeding decreased in warm and sunny days.
    Figures 3. and 4. show the data recorded on the sixteenth day after hatching. Consequtive anomaly during feeding followed ringing the nestlings. They were taken away from the hole and put back after ringing. Both young and adult birds changed behaviour after ringing. Adult birds flew without fish and looked into the nest chamber (they did not do it for 12 days before). The young stayed at the back of the chamber and gradually in coming days went to normal. Aggresivity increased due to starving and there was a chance of getting hurt in fights. In the 22nd day from hatching adult birds attracted young to leave the nest. They left them starving for a longer time, then came with a fish that was given only after 3-4 trials. As the juveniles were not ready to leave the nest, the parents continued feeding in a normal way. It looked like they quickly compensated the gap.
    9. Headless fish. A very exceptional observations were feeding young with headless fish that happened several times in 2007. That phenomenon has never been observed before by the author. The explanation how heads could be taken away from bodies remains unknown.
    10. Removing of egg shells. Another topic is the way how the egg shells were removed (or unfertile eggs) from a nest. In 2007 that activity was not recorded. In 2011 it was found that parents did not care much what happened with shells after hatching. They manipulated with them accidentally and pecked into a substrate of the chamber (Pic. 20). Both genders thrown them away accidentally.
    11. Voices of young. The question of reason for loud or quiet families stay unexplained. Even when food reasources were rich, chicks stayed very loud. On the other hand, in some nests with foodshortages, chicks behave loudly only when food was brought, otherwise stayed calm.
    12. Man made nests. The monitoring confirmed that Kingfisher could nest in artificial nests if they complied with several requirements. This issue, the author does not describe in this article.

    Finally, it should be noted that the vast majority of information presented in the article is supported by video recording. The chosen IR monitoring enables recording during breeding season without affecting the behavior of birds. In order to determine which conclusions are generally valid and which are accidential it would be necessary to expand monitoring on higher number of clutches.  Nests should be be monitored continuously to obtain a comprehensive overview of what is happening in the nesting chamber. Obtaining further information on the nesting will help to understand phenomena in the life of this beautiful but endangered jewel of our waters.

Ledňáček říční (Alcedo atthis) - krmení, Kingfisher
Fig. 1:   Feeding frequency during recording (2007).
              „X“ time according to CET; „Y“ day of recording.  

Ledňáček říční (Alcedo atthis) - podíl sezení, Kingfisher
Fig. 2:   Share of genders during incubation (2011)
              „X“ time according to CET; „Y“ day of recording.  

Ledňáček říční (Alcedo atthis) - krmení, Kingfisher
Fig. 3:   Feeding frequency during recording  (2011).
              „X“ time according to CET; „Y“ day of recording.  

Ledňáček říční (Alcedo atthis) - intervaly krmení, Kingfisher
Fig. 4:   Average feeding frequency during recording (2011).
             „X“ time according to CET; „Y“ day of recording.