The Chobe river flows east along the Botswana border past the town of Kasane until it meets the Zambesi river just above the Victoria Falls. The Chobe is a perennial river though its water level varies many metres with the flood waters flowing through around May and June each year. The flood waters come from the rains in Angola many months before.
“Stars do not struggle to shine, rivers do not struggle to flow, and you will never struggle to excel in life because of the power of your passion.” ~ Donald Driver
In the winter month of June in southern Africa, we did not get to see all the herons and egrets that one could see along the Chobe. We did not see the night-herons, the Black-crowned night-heron nor the White-backed night-heron. I was rather hoping that they might come out in the late afternoon in winter but it was not to be! I was also hoping that the rising high flood waters might attract them. I have never seen a White-backed night-heron along the Chobe but have seen many Black-crowned night-herons getting ready to start fishing in the late afternoon in the summer months.
“At the start of the day, I clear my expectations and open my awareness. I need all my senses to see. It is about hearing that alarm call before seeing the predator. It is about watching the bird’s behaviour before it is about to hunt. It is about feeling something will happen which will need stillness and patience.” ~ Mike Haworth
The Goliath heron is an uncommon visitor. Goliath because it is the largest heron by far. This is a large heron standing around 140cm. Its back and wing feathers are a slaty grey and its belly, neck and head are a rufous ochre or chestnut colour.
The Goliath heron is an excellent fisherman. I have seen a Goliath heron beat a large barbel into submission and swallow it. The Goliath does not have a David in the egret world but it does have major competition from Fish eagles which try frequently to steal its prey. The Goliath has a major defensive weapon, it has a long sharp beak and a neck with surprising reach. The Goliath heron is not a fussy eater, it will prey on everything from barbel to bream, and from frogs to rats, snakes and even prawns.
“Don’t just look. There is a reason for everything in nature. Delve deeper into the why. It will reveal unseen intelligence and design. These insights will provide endless fascination and realisation that everything is more dynamic and interconnected than can be seen at a glance.” ~ Mike Haworth
The Goliath heron is a solitary hunter wading in the shallow waters along the edge of the Chobe river. It seems to enjoy this aquatic environment but is not a fast mover, until it is time to strike its prey. The Goliath heron is a good flier moving with slow heavy wing beats. Interestingly, this heron flies with its legs slightly lowered and not horizontal like other smaller herons. This could be due to its size but it flies with its neck retracted so it could be for longitudinal balance. This heron, similar to most herons, has long, wide wings which are markedly bowed in flight. The low aspect ratio (square of the wingspan/wing area) of the wings is ideal for gliding and manoeuverability.
Grey heron hunting in the shallows along the Chobe river. The black streak from its eye back across its head is an identifying characteristic. By contrast, the Black-headed heron, which is a similar size, has a black head. These herons are waders and prefer an aquatic environment yielding a diet of small fish, frogs, insect and beetles. Unlike the Goliath, the Grey heron is gregarious and breeds in colonies called heronries. Herons have feet which are designed for standing on soft muddy wet soil while their beak is designed for spearing their prey.
“Patience is the calm acceptance that things can happen in a different order to the one you have in your mind.” ~ David G. Allen
Other visual differences between the Grey and Black-headed heron are firstly the Grey’s yellow beak while the Black-headed has a dark grey beak. Another differences is the colour of the legs. The Grey has yellowish-brown legs while the Black-headed has dark grey legs. The Grey heron is altogether a lighter colour grey with a predominately white neck with black streak in the front of the neck. The bBack-headed heron tends to hunt in the wet lands adjacent to the water rather than in the water itself like a Grey heron.
Herons can swallow surprisingly large fish. Herons do not have the ability to tear their prey apart and eat it in smaller prices so they need to be able to swallow it whole. First they keep the fish out of water long enough for it to suffocate then they drop it in the water to lubricate it while actively repositioning the fish so that it is head first in the beak.
Birds do not have teeth and therefore do not chew so have to swallow their prey whole. It is vital that the prey is lubricated with water and that it is positioned head first, especially with fish so that they will slide down the throat without the fish’s dorsal fin spines catching in the heron’s throat. The fish scales also need to be laid pointing backwards on its body. I have often wondered how a heron does not choke when swallowing a large fish. Birds, unlike humans, do not typically choke in the same way as humans. Birds do not have an epiglottis which covers its trachea. The bird’s tongue shape and grooved mouth aid the movement of food past the tracheal opening.
All fish eating birds have a specialised two chamber digestive system. The first chamber secretes the acid which helps break down the bones and scales and the second chamber, the gizzard, grinds up the food into smaller bits.
“The two most powerful warriors are patience and time.” ~ Leo Tolstoy
Herons do not seem to be harassed by crocodiles. There is a lower drag on the wing when the bird is flying within a wing length of the water, it is called the “ground effect”. This means it is easier for a bird to fly closer to the water. Usually the inland water surface is relatively flat so flight is easy and does not require the same manoeurveability that a seabird needs on the surface of the sea.
Great heron in flight along the Chobe river regaled in its non breeding plumage. From a distance the egret species could be mistaken so you need to rely on the key colour differences in the beak and legs for identification. The Great heron has a yellow bill in non breeding season and a black bill, often with a greenish lores, in breeding season. The Great heron’s legs are black throughout and it feet are black.
During breeding season the lores of the Great heron turn green and it develops plumes on its back. It legs are always black.
A pair of Little egrets fighting in the shallows. These Little egrets are usually solitary. When breeding, the bird acquires distinctive head, chest and back plumes and red lores. The Little egret has all white plumages, black legs with yellow feet.
Normally these Little egrets fight over food but for some reason this appeared to be a turf fight. They did not seem to have breeding plumage but the yellow feet are clear on the attacker and the egret in the water did have the two long white feathers on the rear of its crown.
“Life is like the river, sometimes it sweeps you gently along and sometimes the rapids come out of nowhere.” ~ Emma Smith
I was surprised how savage and prolonged the fight lasted. Although in the shallows, the airborne egret tried hard to “dunk” its opposition.
Little egret in flight on its way to the next feeding spot along the Chobe river. The adult in breeding plumage has greyish-blue face and reddish lores. It also develops two white long and fine feathers on the rear crown, extending from the nape to mid-neck. It also has “aigrettes”, long feathers on the upper breast and recurved scapular feathers. In winter , the Little Egret’s plumage remains white but its lores are grey and its feet turn a pale yellow or greenish-yellow colour. It also loses the long nape feathers, and the “aigrettes” on its body.
Purple heron standing in the reeds along Jacana alley just off the north channel of the Chobe river. We don’t usually see many Purple herons but on this occasion we saw them surprisingly frequently in the reeds around this part. Perhaps there is a seasonality factor but it was wonderful surprise.
The Purple heron appears to have a more slender build than a Grey or Back-headed heron but its the colour of its plumage is distinctive. It is not purple but from a distance is back and wing feathers are grey mixed with chestnut brown which gives its slightly purplish appearance. It has a black crown that extends down the back of its neck. The sides of the head and the neck are buffish chestnut, with dark streaks and lines down either side of the whole the neck. The front of the neck is a buff colour with dark brown streaks.
The Purple heron has the most snake-like neck of all the herons. It was perfectly blended into the wintery brown and yellow coloured reeds along the river.
A sub-adult purple heron in flight which has not get grown its distinctive adult plumage.
The Purple heron is surprisingly well camouflaged in the winter reeds. This Purple heron, like all large herons, has the prominent characteristic of its very long neck, crooked in the middle to resemble an S shape, which helps to support the heavy bill and head. The neck has a modified sixth cervical vertebra which allows them to draw their neck into an “S” shape and then shoot their head and bill forward with lightning speed when striking at prey. This adaptation also allows these birds to fold their neck while flying, which helps longitudinal balance and improves the aerodynamics of their flight.
Squacco heron in flight in the late afternoon light. This is one of the most attractively coloured of the small herons. As the next image shows the Squacco heron displays all white wings when in flight. We only saw solitary Squaccos along the river in June but there have been times when I have seen hundreds of Squaccos spaced about 30 metres apart in the low grass on a flooded island.
The small herons tend to stand the same way with their heads pulled down onto their shoulders. The Squacco heron has two distinct breeding plumages. In the non-breeding phase, the plumage is brown with streaks on the head and throat and the bill and legs are greenish to yellow in colour.
In the Squacco’s breeding phase, the feathers become longer. The plumage is whiter with the back a cinnamon colour. The bill also turns blue. The previous and next image shows a Squacco in breeding plumage. I found it interesting to see how Squaccos were in different stages of the breeding plumage development along the same river at the same time. This Squacco was successfully hunting on a floating raft of reeds in the middle of the Chobe river.
Slaty egrets are uncommon so this was a wonderful sighting. The Slaty egret can be mistaken for a Black egret in bright light but the Slaty has some distinctive features which are quite different to the Black egret and its fishing style is very different to the Black egret’s umbrella-wing hunting technique. This Slaty egret was alone foraging along the edge of the Chobe river. Slaty egrets breed in temporary wetlands which the seasonal rains have filled to their highest level which is probably why we saw this individual in June.
A Slaty egret could be mistaken for a Back egret in certain light but a closer look reveals its characteristic salmon pink coloured throat and grey legs. The Black egret is all black including its throat. Both egrets have yellow feet.
In the grass next to the river adjacent to the Chobe Safari lodge we found these two Yellow-billed egrets fighting over a fish. The airborne egret held a fish in its beak as it was coming in to land when the second egret saw an opportunity to steal the fish. Needless to say with some deft manoeuvering, the airborne egret managed to keep its meal.
A Yellow-billed egret is identified by its yellow bill but it legs are two tone. The leg colouring from the elbow up to the body is a pinkish yellow. Below the elbow, the legs are black as are the feet. The greenish lores were an indication of the egret’s breeding colouration.
So often we see the Green-backed heron sitting on a branch overhanging the water in deep shade. This heron favours fresh water that has dense vegetation overhanging the water. Most Green-backs are very skittish but every now and then you will find one character that is not so skittish and will pose for a few seconds. Beside the beautiful greenish grey wing feathers, this egret has a bright yellow loral stripe in front of a yellow eye.
The Green-backed heron has a greenish black back with distinctive grey underparts. The long bill is bicoloured, it is black on the upper mandible and yellow on the bottom mandible. Green-backed heron are normally found solitary, foraging in the dense vegetation at the water’s edge. It is often seen in a hunched posture. This heron, like a Squacco, it quite acrobatic. It can hang from a branch and stretch its neck much further than you might expect when striking at its prey. The Green-backed heron is very territorial when it comes to feeding areas.
Chobe is known for it prolific bird life in winter and summer. Many of the waders are resident as are the storks, kingfishers and ducks. Even though we went on the Chobe in winter there was abundant birdlife despite the absence of the of the migratory birds.
“I choose to listen to the river for a while, thinking river thoughts, before joining the night and the stars.” ~Edward Abbey
I have been on the Chobe river many times and not once has it ever been the same. The level of the water and temperature has prevailing effect on the activity of the bird life. That said, you will find different birds in numbers at different times of the year. Just to keep the waders on their guard the Fish eagles are always on the lookout especially if they are struggling to find fish near the surface of the river.
“I experience the river differently every time I am on it. The water level changes, the flow fluctuates and the water temperature changes with depth. The light changes and the colour changes depending on the time of the day and the weather. All of these influences dictate changes in the wildlife activity along the river bank. Being aware of these dynamics creates endless fascination.”~ Mike Haworth
Explore, seek to understand, marvel at its interconnectedness and let it be.
Have fun, Mike