In our childhood times we used to see different species of birds, which may have disappeared from our urban areas. But still some birds like pigeons etc live in flocks in our urban areas. Since childhood I wondered where all the crows and sparrows die because I rarely saw them dead (which were accidental deaths) on the streets/paths/gardens of any city.
Still, I notice flocks of pigeons every day. Living and breeding in the shop shed/floor in front of my house, playing in the window of my house. Strangely, although I see eggs being laid, chicks hatching, growing, etc., I rarely see them dead (again accidental deaths which are rarely caused by cats). This type of pigeon is not migratory in nature, there are not many water bodies left in my urban area, no bushes/forests nearby. So I still have a mystery where they die?
Their bodies probably get eaten by rats before you see them.
In my nearest city there are peregrine falcons that live on feral pigeons - there may be other similar birds of prey in your city catching the weaker birds before they die.
Just here to say what a great question!
It’s one of those child-like questions that seems too simple or obvious to ask, but when asked none of the adults know the answer. One of those things we take for granted or otherwise aren’t questioning.
Good question. Equally valid I think is where all the wild birds die? I have spent a lot of time walking around in the bush, but it is not often one sees a dead bird. Sometimes a few feathers which could be from either a living or dead specimen. Maybe it is because flying birds have less density than non-flying vertebrates. The bodies of pelicans or large cranes probably occupy the same volume as a pig or a calf but weigh much less, and therefore disintegrate more quickly.
I think Most of the Urban birds die before they reach to their Old age by the raptor’s or some other natural accident, and then the leftovers of their body’s get decay by fungus or other rodents
No, that is very unlikely. This place has now become very urban. No bird of prey can be seen here anymore. Not even a kite. Species like Civet Cats etc have completely disappeared from our locality. There may be a few rats but they went up to the shed, found the dead ones out of all and ate them whole while I never ever saw the event or heard any noises- nah
Decomposition takes some time. So many Pigeons are here. Never seen their dead body being decomposed.
These pigeons do not move much. No Raptors come here. Accidents- Very rare events.
Yes, that’s why I didn’t talk about wild birds. Raptor Birds, foxes, invisible areas, Night events etc. may be valid logics in the case of wild birds but not for the urban birds.
Still I say I have visited many water bodies in our country and seen numerous birds there including the raptors, seen the raptors eating smaller birds-
but still, compared to all the birds I saw there( may be over lakhs in some wetlands), I have seen dead birds in very negligible numbers. I don’t want to see that though. But, OK I can accept that something is happening there which I can not see all the time. So not talking about them.
Just adding to what people said before:
If a bird should die in a “public place” often they get removed by the city. Sick/old birds often hide somewhere, before they die, hence are not too visible to start with. And city or not - birds become part of the food chain very quickly- may it be that they become easier prey for other animals when they are weak or just by getting decomposed quickly after they die. But a more in detail answer, see the comments in from experts in the second article I linked below.
“Birds are light in weight, thin skinned, have little fat, are covered with feathers, and have some hollow bones, so they are less dense and weigh a lot less than comparable sized mammals. When a dead bird hits the ground, it is almost immediately invaded by small decomposers in the form of bacteria and insects” (Ornithology.org)
And here answers to the question by 5 experts in the NewScientist
P.S.: The question is very good - it reminds me of Holdens questions about the ducks in winter in the Catcher in the Rye :)
Birds tend to decompose very quickly, with the entire body decomposing in only a couple of days in the case of small birds. They’re also small and easily overlooked when dead.
On top of that, in urban environments there are a number of scavengers ranging including ants and cockroaches,maggots, feral cats and dogs, gulls and crows, racoons, foxes (for the UK), monitor lizards and monkeys (for some SE Asian cities), etc. plus relatively regular street cleaning. These things can speed up the disappearance of a dead bird body quite a bit over the few days one would otherwise take to decompose.
Once dead, a bird decomposes fairly quickly. Because they need to be as light as possible to fly, their bones are hollow, they carry very little fat, and they have air sacs distributed throughout their skeleton which aid respiration. All of this makes a bird very fragile. It won’t take long for natural decomposition to occur through flies, insects, and bacteria, and a dead bird can decay in just 2 or 3 days.
In London (where I lived until recently), I have seen dead birds, Pigeons, Blackbirds etc. (even a wren) But you need to be out early, as they are cleaned away quickly by the council street cleaners.
I second this. Insects, especially ants, can break down a vertebrate carcass quite quickly, leaving just the bones (which for birds, are very small/fragile). Ants are also active nocturnally, so a body may be skeletonized in just a few hours at any time of day if it is close enough to some ant colonies.
More broadly, many species will eat carrion - pretty much any mammal and many birds. Even things you wouldn’t think of like tortoises may take carrion (not that they are common in most highly urban areas). Carrion is a great source of nutrients and calorie-rich, so it doesn’t stick around long.
Either that or the bird drones are just being recalled to their home bases.
I bet it is more then you imagine… but I guess feral cats and dogs are plentyful and always happy for a snack
playing around with the iNat maps in India showed plenty of observations for dogs, cats, rats and even birds of prey also in the larger city… so they are quite probably there
Let me offer a slightly different perspective - I am a collector of bones, what’s sometimes called a part of the “vulture culture”.
Dead birds are there in the city. Everywhere really. But they become as my mum would say “Part of the landscape” very easily. You walk past them without seeing them all the time, and you need to have trained your eye to notice them.
They rarely die in one piece in a place where they will stay in one piece for long, such as the very corner of the street, the base of a tree or the grass on a park is where I find most of the entire carcassess. But they never last more than a day before the city’s cleaning crew takes them out. And THESE, the ones that last a day as a full body, are the outliers.
The rest wandered sickly into a street and got crushed by a car, got taken by a bird of prey or cat leaving behind only a stray, very difficult to notice leg, or died under a bush where the ants made quick work of them.
Most of my collection are dead birds found in the city streets, but it took many years of “training my eye” to get to find them, and I still sometimes walk right next to them and my husband needs to point them out for me.
I moved this discussion to Nature Talk as it’s not related to iNaturalist.
I see them every so often. For pigeons, they’ll get too weak or sick to move out of the way, and will get run over by cars or eaten by coyotes/raccoons/raptors. I’ve even seen a dead Canada goose recently that was hit by a car. I also see dead grackles on occasion - usually in parking lots where they didn’t move out of the way when the car they were sitting under moved.
One thing to note is that insects (mainly fire ants) that will make quick work of a dead bird - the feathers are then taken by other birds for nests or scattered by the wind. As for bones, I do see them scattered about - I’ve seen crow and blue jay skulls out in the wild, for example.
We also have street services that clean up roadkill, so dead birds on or adjacent to the roadways (the most visible areas) are removed by humans.
Feral Cats and Dogs- Yes there are plentyful such friends in our locality whom some people fed regularly including my partner. Hahaha. They may eat dead birds. Although I have seen them chasing birds occasionally but never seen them successfully caught a bird ever.
I tell them “U all are lazy fellows, You will never learn to catch any prey.”
Raptors- U will find almost all types of Raptors and Scavengers scattered in India (yes in larger cities but not everywhere). It depends on the location. What U’ll get in a large numbers in Guwahati (Assam), u’ll not find a single one in rest of India, Same for Odisha, Rajasthan, Gujarat, NE States of India etc. Sundarbans is very near to Kolkata but u’ll not find the raptors which are seen abundantly there in kolkata. U’ll see lakhs of flamingoes in Navi Mumbai but not a single one in Mumbai, A large number of Crocodiles, millions of migratory birds etc very near to Bhubaneswar (a few Km away) but none in the proper City of Bhubaneswar etc. It can not be generalised in that way.
Well, I own a dog from the street and one would not see it in her, but she already killed a rat and a dove in our backyard this year alone… she has a lot of failed trials as well, but once in a while it will work out… otherwise those dogs/cats would not waste their energy on them.
Sure, but comparing urban areas to rural areas or specific national parks was not the aim here, or was it? You said you live very urban and I just want to point out that there are many birds of prey that specifically thrive in those environments, even if one may not see them all the time…
Here it seems to be mostly from house cats.
I’m glad someone said this, I was starting to seriously doubt myself because I have the same experience.
I have a LOT of dead bird observations from a single parking lot behind a shopping center, most of my bird observations from this area are dead. This doesn’t even include the Turkey Vulture skeleton I have that is still part of the parking lot, just a bit behind it in a maintenance area.
https://www.inaturalist.org/observations?nelat=26.04531230000002&nelng=-80.2480044&place_id=any&swlat=26.00924509999997&swlng=-80.25173579999999&taxon_id=3&user_id=lizardking&verifiable=any
Even the full body small perching birds you can find when you train your eyes an somewhat obsessively look for dead things, which being we are bone collectors, I’m sure we both do. Though most of my bone collecting of birds is just recording them on iNat due to American legal regulations.
https://www.inaturalist.org/observations/187005755
https://www.inaturalist.org/observations/185951076
I also have serious questions about the accuracy of these statements. I live in South Florida, and the amount of heat and moisture is great for decay. Even then, I have never seen bird bones decay in two to three days. When there is a non-native bird species I am able to collect, I deliberately put it in conditions to make it decay fast so I can get the bones. I let insects eat at it, and I macerate it in bacteria rich water. I processed this starling that way for at least over a week, the bones showed no sign of decay.
https://www.inaturalist.org/observations/40564649
For bones I can’t collect, I will often revisit them when I realize a new feature I need to study for identification purposes. I have revisited bird skeletons months after initially finding them, some as delicate as the gallinule in the parking lot. Some of the best resources for IDing bird bones are archeology based, implying the bones last much, much longer than 2 to 3 days, even on delicate passerines. From Olsen’s Osteology for the archeologist (which includes birds as delicate and small as swifts):
“Bird bones are characteristically light, delicate, pneumatic structures that on first appearance would hardly seem suited to survive the ravages of time. However, their occurrence is archaeological sites is quite commonplace”.
I do wonder if the people behind claims that bird bones can decompose that rapidly have worked with decomposing bird bones. Just because they are hollow doesn’t mean they are that frail, there is a lot of fascinating ways bird bones evolved to be very lightweight, but still strong. The high degree of fusion they display in things like their pelvic girdle or wishbone are examples of how they can be both lightweight but structured to be very strong despite that.