Bird week special Episode 4 : WETLANDS BIRDS : Mr. Prathamesh Desai

So hi everyone and good evening. Welcome to our webinar session. So for today's webinar session, we're going to talk about what are wetland birds and how important they are. We are also going to look after some of the most common known wetland birds of Mumbai region. So without wasting any more further time, let's start with our today's session. What exactly are wetlands? What does wetlands mean? As per the Ramsar Convention, wetlands are defined as wetlands are areas where water is the primary factor controlling the environment and the associated plant and the animal life. Wetlands are areas where water is the primary factor controlling the environment and the associated plant and the animal life. That's why wetlands are extremely important. Wetlands as an habitat, the Indian region extends from tropics to Himalayas to the highest mountain ranges in the world. The great diversity of the climate and the habitat is reflected in the large diversity of the birds and other animals and life. I'm sure everyone knows that we have an amazing biodiversity. Habitat in its natural home are an environment to a living organism like birds, insects and animals. For those who don't know, what does habitat mean? It's basically a home. Like our homes, societies and all these are our habitat for us. Over 20% of the global threatened species are found in the wetland habitat. So it's quite important to understand why wetlands are the most important as compared to the other habitats that we have. Wetland habitat ranges from a large ocean to a human-made backyard pond also. It will include seawater, freshwater lakes, rivers, estuaries and marshlands are some of those examples that you can see. Now this is a map of Mumbai. If you look at how the wetlands are spread across the entire Mumbai region, you can actually see. If you look at it here, this is the Thane Creek that we have, which eventually connects up to the Arabian Sea further up in the north. Then we have the entire Bagpi area over here. We have the Shivru mangroves in this area. This is all. We have the Gharapuri caves over here, the Elephantar caves and the Gharapuri caves over here. So you can see how wetlands are there. Then we have some freshwater lakes over here, which is over here, which is the Pawai Lake, Tulsi and the Vihar Lake over here. Then we have the Manuri Creek over here as well. So it's quite interesting to see how Mumbai is completely surrounded by wetland habitat. And hence it's very, very important that Mumbai is actually home to a lot of wetland species. Moving on. So Mumbai is actually home to some of these wetland habitats. As you can see, we have the entire ocean, the Arabian Sea. We also have the freshwater lakes. So this is a picture from Pawai Lake. We have the mangroves, the heart of the warriors of the Mumbai region. Then the small wetlands that you can come across anywhere or in your Bhakya Pond. These are all the types of the wetlands. Now let's try to understand wetland birds. What are wetland birds? So the term wetland birds is often used for these various groups. Commonly identified by habitats or resource-related descriptions. So it could be waterfowl. You can call them as waterfowl species or white owls. They can also be called as shorebirds. That term is commonly used in Europe. We call them waders. Littorial or water-edge birds. Aquatic birds, coastal birds and estuarine birds. All these basically are called the wetland birds. Some of these groups of birds avoid saline waters but may use coastal or inland water bodies as long as they are freshwater. Now this is a very important and interesting slide. Some of the even adaptations to the wetland habitats. When we compare wetland birds with other types of birds like forest birds, scrubland birds or grassland birds, how do these birds differentiate? How do these birds understand that these birds are only found in water? There is a description for this. Short-term adaptability. With years and years of evolution, the birds have evolved to be like this. Short-term adaptation basically means that they adapt in a short period of time. For example, in terms of the long-term adaptability, we have seen such examples in pictures. Rear legs placement for swimming and diving. For example, ducks are a really good example for this. Bones and lungs are modified for diving. So the lungs have been modified for the diving purpose. Their eyes have been modified for nocturnal and as well as for underwater vision. So it's quite amazing to see how birds have adapted themselves. Long legs for wading, webbed and lope feet. So for wading, basically if there is a water well, how to go and feed there? We see this in examples, so there is a lot of understanding. Bill specification for grabbing, straining and digging. Water-resistant plumage, pruning and drying. Because they are in water, it is very important to have water-resistant plumage. Their specific feeding on short-term adaptations. How do they feed? So snails, small crustaceans, crabs, fishes, etc. The way they feed, the techniques they use for hunting. Some birds feed in flight, which is a unique adaptation. Some birds prefer to feed in water. Some birds feed in knee-deep water. Some birds feed in ankle-length water. Some birds do not feed in water. So it is their preference. And lastly, nesting sites and vegetation type. How do they prefer to build their nests? Where should they build their nests? This is also their preference. Let us look at some examples. So for example, different types of shorebirds. This is a simple slide. You can see how different types of birds have different habits. There are stilts, which like to feed in knee-deep water. Similar to them, there are avocets. There are sandpipers, which like to feed on the shore. They just touch the ground. There are oyster catchers and plowers, which feed on the shore. That is why you get to see them on the shore. There are jassanas. Normally, jassanas do not live on the beach. But they are just a representation of their long legs. This is just another good example to see how feeding actually allows them to understand. You can see different types of birds and how their beaks have been modified for feeding. Here is a Eurasian Curlew. The beak of the Eurasian Curlew goes all the way down. Similarly, we have a Godwit, oyster catcher, vimbrel, and plowers. You can see how they feed. Based on their feeding techniques, For example, plowers and all feed on crabs. That is why this crab is on top. Vimbrels and Curlews feed on marine worms. Crab and shrimp feed on the bottom of the water. That is how they have been designed. Oysters, for example. Moving on. As I explained earlier, let us see the adaptations. This is a common sandpiper. It is one of the most common winter migrant birds in Mumbai and throughout India. You can see how it has been modified. Overall, the body appears to be much smaller. With smaller legs and a very fine bill. There is a unique modification to the bill. The tip of the bill has a special sensory nerve. For example, during their feeding. Now, feeding is all underground. They do not know if there is a snail or shrimp underneath. There is a particular sensory nerve at the tip of the bill. The moment they touch the feed, Automatically, signals are sent to their brain. That is how they grab it. That is how it works in the wetland species. It is quite interesting to see how it has evolved as an adaptation. Their sensory nerve is at the tip of the nose. They understand it immediately. For them, it is beak. This is a common sandpiper. Similarly, ducks have a bill to cut vegetation. Similarly, they adapt their legs for diving. That is the reason we call it the webbed feet. It allows them to do diving. This is a very good example. This is a bird which is quite common in any freshwater. It is called a common pool. You can see that it has both adaptability. It has a paddle. At the same time, it has proper nails. It has long legs. It is someone who can be seen swimming in the water. At the same time, it is known to feed on the ground also. That is the reason it has both adaptability. Jassana and jacana, as you can call it. Or the lily trotters, the simplest way to call it. A species which has got the longest toes in any wetland bird. You can observe that its habitat is like a dying bird. That is why you can find it in places where lotus grows. The feet of a lotus are so big that they get a lot of surface tension. That is why they can walk on water. Not on water, but on leaves. Lotus leaves. They can walk on them. That is the reason they can walk from one lotus leaf to another lotus leaf. That is why they can be seen in the same habitat. It is one of the most interesting species, a resident species. Then, this is a Temex Tent. You can observe the feeding behaviour. A species like Temex Tent, by its eye, it can observe where the prey is. It will chase it and eat it. At the same time, it will also do preening. It will always preen in the mud, find it and eat it. A plover, which is completely dependable. You can observe its beak. As compared to the Temex Tent over here. The plover's beak is much smaller. And it is not really long enough. Because the plover's feeding behaviour is basically run, observe, observe, watch, observe and then run. It will stop for a while. It will observe if the crab is running, if there is a shrimp in the water and then chase it. This is a small photo of a greater sand plover. Then, black-winged stilt. Again, a very long legs. In fact, in Vedas, it is called the biggest leg. One of the most elegant species is in fact a black-winged stilt. We have this resident and migratory species as well. In some parts of Mumbai, we have this breed as well. Its identification is quite unique. Its legs are pinkish-reddish. It is quite standard. It is called a black-winged stilt. The preference of this bird is that it feeds in deep waters. Naturally, because of its long legs. It gets an advantage and it feeds there. Again, a species quite common. If you go near a freshwater pond, you will see it. It is called a purple-swamp hen or a grey-headed swamp hen. The main reason behind calling it a hen is that the overall body appears to be more of a fowl species. Like a peacock or a quail or a pheasant like that. That is why it comes in the waterfowl. If you observe the beak, it is quite interesting. It has a very sharp beak. The reason why it has got a very sharp beak is because it feeds on small-small vegetation. It feeds on lotus seeds. At the same time, it feeds on crabs, frogs and small worms. Again, its surface area is quite large. Its toes are quite large. It is one of the most colourful birds across any freshwater habitat that you will come across. Purple-swamp hen. Adaptability again in the water. It is a duck species. There are surface feeders. There are two types of ducks. There are surface feeders and divers. Surface feeders feed on the vegetation or small crustaceans on the surface of the water. Deep divers are called poachers. They dive under the water and feed there. There are such types of ducks. This is a gargoyle male over here. Feeding by flying as we saw earlier. This is a whisker turn. It feeds on small insects and flies on the top of the water level. It is quite interesting to see how it feeds. In flight, it catches small insects and flies. Quite an interesting adaptation. This adaptation has been observed in most turns. Habitat preference. This bird is called yellow bittern. It is related to the family of pond herons. We can see how the bird has adapted itself in such a way that it is camouflaging itself. It is very difficult to differentiate that the bird is in the tree. There is a behaviour hunting technique where it hides in the tree. It acts as if it is one of the part of the tree only. If a fish, crab or frog comes, it has to be immediately pounced. Grab it and eat it. That is the feeding technique which is followed by most of the herons and bitterns also. This is another example of a little bittern. As I said earlier, especially wetland birds, they have a special sensory nerve at the tip of their beak. This is a very good example of the feeding. This is a painted stalk. It is named painted because of the beautiful colours that the bird actually has. A very common bird across any wetland water body This is again called the feeding method. The painted stalk does not know what to do under the water. The water is completely wet and there is no clarity at the bottom. But then it just relies on its beak. Its technique is to continuously move its beak left and right. The moment something touches its beak immediately, it actually realises and immediately grabs it. That is the feeding technique which is followed by painted stalk and by spoonbills also. It is quite interesting. Similarly, my favourite species, the flamingo, which are called the filter feeders also. They are easily found in Thane Khadi. Flamingos are filter feeders. If you get a chance, observe their beak. There is a unique adaptability in their beak. Instead of teeth, they have something called the sieves or serrations. They have small bristles. Just like the bristles on a toothbrush, similarly, there is a bristle lining under their beak. When they sieve the salt, basically, as you can see here, they tap the salt into the water. Tap, tap, tap. When they tap, the vertebrates come out from the bottom to figure out what exactly is causing the vibration. After that, they sieve the salt by moving it left and right and it goes inside the beak. Only what is needed goes inside the beak. The excess of water or unnecessary matter gets separated from the beak. Flamingos are an excellent example for that. Some birds are so well adapted. For example, this is a northern gannet over here which is from South Africa. They do deep dives under the water and feed. I am sure, more often, you must have seen this particular scene on National Geographic or Discovery Channel. This is a northern gannet over here. As you can see, it has a special membrane around its eye and it feeds under the water. This is a northern gannet over here. For the next few slides, we are going to look at some of the most common wetland birds of the Mumbai region and try to understand something more about them. Naturally, to start with, some of the most common wetland birds of Mumbai region are the flamingos. I have shown two species of flamingos here. Greater and lesser flamingo. Greater flamingo is a species which breeds and migrates from Sambar Lake, Rajasthan and Greater Runoff Cuts. Similarly, lesser flamingo which is from Greater Runoff Cuts towards Pakistan border and they come in massive, huge numbers. For a greater flamingo, in order to acquire this pink coloration, it takes around 4 plus years. Similarly, lesser flamingo takes around 3 to 3.5 years for it to adopt the coloration. For them, in order to acquire more of the pink color, they need to feed on the particular pigment which is the blue-green algae. Again, lesser zooplankton that you can see throughout any freshwater as well as basically any marine area also. So, there is a feeding and through blue-green algae, they feed on a particular protein called as carotenoids. The same thing actually gives them the orange, pinkish, orangish color. Quite interesting is that greater flamingos prefer more often freshwater bodies. That's why you can see lesser flamingos all the way from Assam to all the way south of Kerala areas also. Whereas, lesser flamingos are a special species which is hardcore specific to estuaries. They prefer saline water. That's the reason, very rarely, you can find a lesser flamingo in a freshwater body. So, that's quite interesting thing about them. Moving on, there is another beautiful bird. It's called Eurasian Spoonbill. It's name is Spoonbill because you can see how the spoon appearance of the bill is. That's the reason it's called Eurasian Spoonbill. A species which is quite common across the entire Mumbai region as well as most parts of India also. Again, a species which has sensory nerves because of which it actually feeds on. Exactly, it feeds on painted stock. I have seen it feeding on painted stock We already talked about painted stock. Then, we have Asian Open-billed stock. It's name is Open-billed. It's quite interesting. This particular bird's adaptability has completely transformed. Open-billed stock has small snails in its feeding. They play an important role. Because of the bill that it has, if it's bill is not like open-billed stock, then what happens is it finds it difficult to grab the snails. As compared to your spoonbill or a painted stock, which normally feeds in the water by inserting their beak in the water and trying to grab something. Open-billed stock doesn't feed like that. Open-billed stock basically feeds on its own in deep waters. When it finds a snail, it picks it up and brings it out and then eats the meat inside it. That's the reason its bill is designed so that it immediately grabs the snail. That's the reason there is a gap between the bill of an open-billed stock. Hence, it's called the Asian open-billed stock. Again, a species which is a very good sign of the water body that you are around has got a very good population of snails also. So, it's a hardcore species which relies on snails for feeding. Snails and oysters, to be honest, for feeding. So, to grab these oysters and snails, the bill is modified for that particular purpose. Moving on, we have a species which is called the ibis. It has got a very unique pattern. This is a glossy ibis and a black-headed ibis. It has got the same name. Both species are found in fresh water as well as in estuarines. Its identification point is actually their beak pattern. They are quite huge birds. You can call them around, let's say, bigger than a kite. If you see a painted stock, their stature is slightly smaller. But, it's around a feet long bird. And, very attractive, very colourful. Glossy ibis, you can see them in bigger flocks. Could be around a flock size of 100 to 200 to sometimes 500 birds also. Whereas, black-headed ibis are usually found in smaller flocks. Could be a family of around 3-4 birds or maximum 5 birds. Oriental white ibis or black-headed ibis is a threatened bird by IUCN. My favourite duck species is called Northern Shoveler. The pattern on its beak is like a shovel. That's the reason it's called a shoveler. These are males. Females are more drab and brownish in colour. A very beautiful bird with a very emerald green head. Yellow is its standard colour. These species are the ones with surface feeders. Their beaks are designed so that even if you observe a duck's beak, you can see small bristles in the opening of the beak. Shovelers' habit is to continuously dig into the rocks, especially on the edges. They continuously shovel and use their filter feeders to separate them. What they need goes inside and excess of mud and salt water A Northern Shoveler species. It's a winter visitor. It's breeding range is in most parts of Europe, especially above Mongolia and Siberia towards France and Italy. It's a very unique species. It's an endangered species also. It's called an Indian Skimmer. It's named after its behaviour which is skimming in the water. It's a unique species related to the Tern family. Its lower beak is comparatively much bigger than the upper mandible. It's unique because of its feeding behaviour. While skimming, its lower mandible touches the surface of the water. The moment it grabs something, it will close the bill and that's how it catches its prey. It's quite interesting. If you want to see the Indian Skimmer, the best place is to go to Chambal. They are really in good numbers.