0:00

Disney. Land is a weird

0:02

place. I. Grew up

0:04

near their in Southern California so

0:07

as a kid I get really

0:09

familiar with rides like The Jungle

0:11

Cruise, Pirates of the Caribbean, and

0:13

the Haunted Mansion. I'll admit,

0:15

I used to love going to

0:17

Disneyland. But. Yeah, it's

0:20

weird. It's. Teeming with

0:22

all these animals and fantastical

0:24

creatures that are one hundred

0:27

percent fake. Their. Puppet

0:29

saw robots made of plastic or

0:31

metal or concrete. When.

0:34

You visit Disneyland, you're supposed

0:36

to suspend your disbelief so

0:38

that all those fake things

0:40

seem kind of real. But.

0:42

Unless you're four year old, it's hard not

0:45

to see the facade for what it is.

0:48

So. I guess that's why I have this

0:50

memory from one I was a kid. I

0:52

remember being amazed to see

0:55

real live songbirds hopping around

0:57

on the ground at Disneyland.

1:00

These. Small living animals

1:02

were a striking contradiction

1:04

to they're mostly artificial

1:06

surroundings. Now. No

1:08

doubt you've seen the title for this podcast

1:10

episode, so you know where I'm going with

1:12

this. Those. Disneyland. Birds

1:14

were house sparrows, I

1:17

remember them chirping and begging me for

1:20

french fries. As is the custom

1:22

of their kind, As

1:28

a naive kid, I thought those

1:30

house sparrows at the Magic Kingdom

1:32

were quote unquote wild birds. I.

1:35

Had no idea what species they

1:37

were and I didn't know there back

1:39

story. Band. Oh boy

1:41

does that house Sparrow have quite

1:44

the backstory. Hello

1:52

and welcome. This is

1:54

the science of birds.

2:01

I am your host. I've been

2:03

filled with the Size of Birds

2:05

Podcast is a light hearted exploration

2:08

of bird biology for lifelong learners.

2:11

This episode which is number

2:13

ninety three is all about

2:15

the House Sparrow passer domestic.

2:17

This will get into what

2:19

this species looks and sounds

2:21

like where it lives. It's

2:23

behavior is breeding, biology, and

2:25

it's opinions on several hot

2:27

button political issues. The

2:30

choice of species for this episode

2:32

was made by my awesome supporters

2:34

on Patriotic. A few weeks

2:36

ago, I sent them a poll asking them

2:38

to cast their votes. The. Choice

2:40

was between the house sparrow and

2:43

the Canada Goose. I

2:45

was kind of surprised that the Sparrow

2:47

had a landslide victory. It. Blew

2:49

the goose out of the water with

2:51

sixty one percent of the vote vs

2:53

thirty nine percent. Does

2:55

this result tell us how excited

2:58

people are to hear about how

3:00

sparrows. Or. Does it

3:02

tell us more about how much some

3:04

people dislike Canada? Geese? Like. Maybe

3:06

those people think the House Sparrow is

3:09

the lesser of two evils. Who.

3:11

Knows. Well. I'm sorry

3:13

to tell all you goose haters

3:16

that the Canada Goose will indeed

3:18

get it's own podcast episode. Someday.

3:21

Voting. In polls like this is

3:24

one per to that my supporters

3:26

get. So if you would like

3:28

to wield the god like power

3:30

of condemning one bird species while

3:32

celebrating another or by choosing the

3:34

lesser of two evil birds, please

3:37

consider becoming a member of my

3:39

patriot community. You can

3:41

do that by going to

3:43

patriarch.com/science of Birds. There's.

3:46

Also a link in the show notes on

3:48

your podcast app a link that says support

3:50

the Show way down at the bottom. All.

3:54

Right passer domestic Us:

3:56

the house sparrow. this

3:58

is one of the most you big one and

4:00

familiar bird species in the

4:02

galaxy. There's an enormous

4:05

number of these birds flying and hopping

4:07

around. BirdLife International gives

4:09

a rough estimate of the species'

4:11

global population as between 900 million

4:14

and 1.3 billion mature individuals. For

4:19

comparison, consider that another widespread

4:22

bird, the Rock Dove, aka

4:24

the feral pigeon, has an

4:26

estimated global population of only

4:28

260 million. Like

4:32

pigeons, many people seem to

4:34

take house sparrows for granted.

4:37

They're just ubiquitous urban birds,

4:40

something to be ignored as part of the

4:42

background noise of city life. Or

4:44

some people actively despise these birds.

4:48

For example, one biologist in 1912 wrote

4:50

that the house sparrow among birds,

4:53

like the rat among mammals,

4:55

is cunning, destructive, and filthy.

4:58

We'll touch upon the reasons many people

5:01

dislike this species along the way today.

5:04

One group of people that hasn't taken

5:07

house sparrows for granted is scientists. Passer

5:10

domesticus is one of the

5:13

most well-studied birds of all

5:15

time. There have been

5:17

over 7,000 published scientific studies

5:19

on this species. The

5:22

house sparrow has become a model

5:24

organism, a model for studying the

5:26

basic biology of birds. One

5:29

reason this species makes a great

5:31

model is because of its geographic

5:34

variation in things like body size,

5:36

plumage color, metabolic rate, immune defense,

5:38

and clutch size. Traits

5:41

like these vary among sparrows

5:44

in different habitats and at

5:46

different latitudes, and between introduced

5:49

populations and their native source

5:51

populations. The house

5:53

sparrow is also a good model

5:55

organism for practical reasons. These

5:58

birds live close to humans, pretty much. much

6:00

everywhere. They're relatively fearless around

6:02

people and they're super abundant.

6:06

Today may not be the day

6:08

I distill and explain to you

6:10

everything there is to know about

6:12

the House Sparrow based on those

6:14

7,000 scientific papers. Nevertheless,

6:16

I'll do my best to tell you

6:18

more than you probably ever wanted to

6:20

know about this plucky little bird. As

6:34

always, when talking about a single

6:36

bird species, we begin by describing

6:38

its appearance, as well as a

6:40

few behavioral traits and the sounds

6:43

it makes. Now

6:45

I'm just guessing, but you can probably

6:47

already picture what a House Sparrow looks

6:49

like. But for the sake

6:51

of being thorough, let me do a quick review.

6:55

These are stout little birds

6:57

with thick cone-shaped bills. Beaked

7:00

to tail, they're about 6 to 7 inches or

7:02

15 to 17 centimeters long. In

7:07

terms of plumage, the male is

7:09

more boldly patterned and more colorful

7:11

than the female. During

7:13

the breeding season, the male has a

7:15

black beak and lures, a

7:17

chestnut colored neck, white or

7:20

pale gray cheeks, a gray crown,

7:22

and a black bib running from

7:24

his throat down to his breast.

7:27

There's also a little white dot just

7:29

behind each eye, or more

7:31

technically we'd call it a post-ocular

7:33

spot. The male's

7:36

back is a rusty brown color

7:38

with black streaks. The underparts are

7:40

gray. In the

7:42

nonbreeding season, the male's bill isn't

7:44

black. Instead, it's light gray with

7:46

a yellowish base. The

7:49

black bib is also much less

7:51

conspicuous in the nonbreeding season. I

7:55

say less conspicuous because the bib

7:57

is actually there in the nonbreeding

7:59

plume. plumage, it just hasn't

8:01

been revealed yet. Adult

8:04

house sparrows molt once a year, in

8:06

late summer or early fall. At

8:09

first the fresh feathers of a

8:11

non-breeding male give him a relatively

8:13

dull appearance. He lacks

8:15

the bold black bib. But

8:18

as the months go by and

8:21

spring approaches, the male's plumage becomes

8:23

more and more richly colored and

8:25

more boldly patterned. Without

8:28

any further molting, the bib

8:30

appears. What's

8:32

going on here? Well, these changes

8:34

result from the way the feathers wear

8:36

down over time. The tips

8:38

of the bib feathers, for example, are

8:40

gray or white when they first grow

8:43

in. The black parts

8:45

are concealed underneath. But

8:47

as the little sparrow lives its rough

8:49

and tumble life between fall and spring,

8:51

those pale feather

8:53

tips get worn off through

8:55

abrasion. And behold,

8:58

there is the glorious black

9:00

bib. It was there all along.

9:03

The female house sparrow does not have a

9:05

bib. Her upper parts

9:08

are a brownish buff with some

9:10

black, brown, and buff striping. Her

9:13

under parts are gray. There are

9:15

no black markings on the female's head,

9:17

but she has a buff-colored stripe running

9:19

behind her eye. One

9:21

reference I came across pointed out

9:24

that, compared to house sparrows living

9:26

in pastoral, agricultural environments, like on

9:28

farms, the ones living

9:30

in cities tend to have feathers

9:32

with a, quote, dull, unkempt appearance.

9:35

Unkempt, as in disheveled,

9:38

scruffy, bedraggled. I

9:40

guess because life for a sparrow on the streets

9:42

is hard? Because

9:44

in the concrete jungle, survival is

9:46

a daily battle against rats, feral

9:49

cats, cars, disease, and pollution? There

9:52

have been some scientific studies highlighting

9:54

the connection between feather quality and

9:56

the degree of urbanization in house

9:58

sparrows. For example,

10:00

researchers studying sparrows in France

10:03

found significantly higher levels of

10:05

the stress hormone corticosterone in

10:07

the feathers of juveniles born

10:09

in cities. This

10:12

suggests that chicks raised

10:14

in urban environments may

10:16

suffer from lousy growth

10:18

conditions. Maybe they have lower quality food

10:20

than their cousins living out in the countryside.

10:23

Or they might experience more frequent

10:25

threats from predators. Regardless

10:28

of whether house sparrows are living

10:30

on a farm out in the

10:32

country or in the shadows of

10:35

skyscrapers, these birds tend to be

10:37

gregarious. They breed in little

10:39

colonies and move around in

10:41

small flocks during the nonbreeding season. And

10:44

this brings us to look at a

10:46

few aspects of house sparrow social behavior.

10:50

Within a flock of house sparrows, there's a pecking order,

10:52

a dominance hierarchy. If

10:55

you want to learn more about

10:57

this topic, I did an entire

10:59

podcast episode on pecking orders or

11:01

dominance hierarchies. That was episode 48.

11:05

So some individuals in the

11:07

house sparrow flock show dominance

11:09

by intimidating or beating up

11:11

their subordinates. A

11:13

significant number of those 7,000 research

11:16

papers on house sparrows have

11:18

tackled questions related to dominance

11:21

and competition within flocks of

11:23

this species. In

11:25

general, it seems that the most

11:27

dominant males, the top dogs, are

11:30

the ones with the largest black

11:32

bibs. And these tend to

11:34

be the older males in the flock. Subordinate

11:37

males with smaller bibs often avoid

11:40

challenging the dominant males. When

11:43

a subordinate male sees another male across

11:45

the room wearing an impressively large bib,

11:47

he avoids eye contact and keeps his

11:49

distance. And that's going

11:52

to be my survival strategy if I go to

11:54

prison. When I go to

11:56

prison, instead of keeping an

11:58

eye out for scary prison dudes with

12:00

the largest black bibs, I'm

12:02

going to avoid the ones who have

12:04

the most face tattoos and the ones

12:06

with the creepiest staring eyes. You

12:09

know, the sociopathic ones? Anyway,

12:12

with house sparrows, a dominant individual

12:15

will make threats when it feels

12:17

the need. It

12:19

faces its opponent and holds its body

12:22

in a horizontal posture. The

12:24

head is pushed forward and the beak is wide

12:26

open. If that doesn't

12:28

cause the other bird to back off, the

12:30

threatening male may kick it up a notch

12:32

by showing off the black and white markings

12:34

on his wings and by generally

12:37

fluffing up his feathers. If

12:40

the other bird still isn't getting

12:42

the message, because of stupidity perhaps

12:44

or a brazen attempt to improve

12:47

its own social status, then

12:49

it might be time to throw down.

12:52

The dominant male making the threat

12:54

display switches into attack mode. He

12:57

pecks at his rifle and bites the other

12:59

bird on the nape or wherever he can

13:01

reach. The birds may

13:03

leap into the air and engage

13:05

in fluttery aerial combat with claws

13:07

and beaks. Or they

13:09

may scuffle on the ground. In rare

13:11

cases, a fight like this can end

13:13

up with one bird severely injured or

13:15

even dead. But

13:17

more often, conflicts are avoided, because

13:20

subordinate birds simply respect

13:22

the bib, or

13:25

they back down after the first threat display.

13:28

Female house sparrows too are pretty tough little

13:30

birds. They can also take

13:32

on a dominant position in the flock. Multiple

13:36

scientific studies on the roles of

13:38

female sparrows in the dominance hierarchy

13:40

have produced some conflicting results. So

13:44

it's a little unclear how this all works

13:46

with females. In

13:48

some populations, females show

13:50

dominance year-round. In

13:52

other populations, they are dominant only in

13:55

the breeding season or only under certain

13:57

conditions. In any case,

13:59

they can sometimes hold their own

14:01

against the larger dominant males. One

14:05

social activity that house sparrows

14:07

seem to enjoy is bathing

14:09

together, in water or

14:12

in dust. These little

14:14

buggers take dust baths all the time. They

14:17

squat or lay on the ground and

14:19

wiggle their heads and their bodies around

14:21

rapidly, rubbing themselves with dust.

14:24

They flutter their wings to throw dust onto

14:26

their backs and tails. It's

14:28

pretty cute to watch. Just

14:31

search YouTube for house sparrow dust bathing

14:33

and you'll see what I mean. Dust

14:36

bathing is a form of self-care

14:38

for birds. It allows a bird

14:40

to get rid of parasites and

14:42

flakes of dry skin and it

14:44

helps to keep the feathers from

14:46

getting too greasy from preen gland

14:48

oil. After

14:51

some vigorous dust bathing, a

14:53

house sparrow ends up excavating

14:55

a shallow crater or wallow

14:57

for itself. This

14:59

little depression in the dirt is

15:01

something worth defending apparently because

15:04

the crater maker will often make

15:06

a threat display to any other

15:08

nosy sparrow that hops too close.

15:11

Okay, let's move on to listen to the

15:13

sounds of the house sparrow. The

15:16

song of Passer domesticus is

15:19

a rather simple vocalization, at

15:22

least to our human ears. It's

15:24

called the cheap song. Not

15:27

cheap as in a cheap date or

15:29

a cheap trick. Cheap

15:31

in the case of the

15:33

sparrow song is spelled C-H-E-E-P,

15:36

not C-H-E-A-P. Some

15:39

field guides or other publications describe

15:41

this song as chirp, chirp, chirp,

15:44

or cheer up.

15:47

All of those could work. I

15:49

mean, have a listen to these sparrows

15:51

and decide how you would spell their

15:53

songs as written words. I

16:11

heard several different sounds in that

16:13

recording. There was chirp,

16:16

chirp, and cheer up for

16:18

sure. And isn't that

16:20

nice? The birds are saying, cheer up.

16:23

They're like, hey there human friend, cheer

16:25

up. Life ain't so bad. Turn

16:28

that frown upside down. But

16:30

don't you step one inch closer to

16:32

my best crater or I swear I

16:35

will murder you. The

16:49

house sparrow belongs to the

16:51

avian family, Pasuridi. This

16:54

group is known as the Old

16:56

World Sparrows. Pacer domesticus

16:58

is one of about 43 species

17:01

in the family, Pasuridi. And

17:04

there are 27 other species in

17:06

the genus, Pasur. This

17:08

word, Pasur, comes from Latin.

17:11

And it means, you're not going to

17:13

believe this, it means sparrow.

17:17

Now again, this is an Old

17:19

World Sparrow. It's not all that

17:21

closely related to New World Sparrows.

17:24

The latter are in the family,

17:26

Pasur-re-l-i-dee. You got that? It

17:29

can be a little confusing. Old

17:31

World Sparrows are in the family,

17:33

Pasuridi. New World Sparrows

17:35

are in the family, Pasur-re-l-i-dee. Even

17:38

though the house sparrow is technically an

17:41

Old World Sparrow, we find them swarming

17:43

all over the New World, including

17:45

at Disneyland in Orange County, California.

17:48

You probably already know the reason for

17:50

this, but if not, don't worry, we're

17:52

getting to it. For

17:55

the moment, let's consider which birds are

17:57

the closest relatives of the house sparrow.

18:00

An updated evolutionary tree, aka

18:02

phylogeny, for the Old World

18:04

Sparrow family was published in

18:07

2021. It's

18:09

based on genetic data from DNA. This

18:13

tree revealed that Passer domesticus, the

18:15

house sparrow, is most closely related

18:17

to three other species, the

18:20

Spanish sparrow, the Italian sparrow,

18:23

and the Socotra sparrow. The

18:26

house sparrow shows some geographic

18:28

variation in plumage and body

18:30

size across its natural range.

18:34

Passer domesticus, the species, is divided

18:36

into 11 subspecies. The

18:40

particular subspecies we have here

18:42

in North America is Passer

18:44

domesticus domesticus. These

18:47

birds originated in England and Germany.

18:51

There's another subspecies that I

18:53

find especially interesting. Passer

18:55

domesticus bactrianus. These

18:58

birds have a very different way of life

19:00

compared to those belonging to the 10 other

19:03

subspecies. The bactrianus subspecies

19:06

is found in parts of the

19:08

Middle East, Central Asia, Pakistan, and

19:10

China. The root

19:13

word bactrian here, also applied to

19:15

the two-hummed camel, refers to an

19:17

ancient country in Central Asia, a

19:20

country named Bactria. Unlike

19:23

all other house sparrows, the

19:25

bactrianus subspecies is migratory. These

19:28

birds spend their winters in India, for

19:31

the most part. Perhaps even

19:33

more interesting, this subspecies doesn't really

19:35

hang out with humans. Bactrianus

19:39

sparrows breed in natural habitats like

19:41

the banks of rivers flowing through

19:43

grasslands. These house

19:45

sparrows are more fearful around humans, and

19:48

they don't want anything to do with

19:50

houses. Now, the

19:52

next time you find yourself at a fancy

19:54

cocktail party, and you're trying to meet new

19:56

people and make some friends, you will know

19:58

that you're a bactrian. doubt be eager

20:01

to tell them about this fascinating

20:03

subspecies of the house sparrow. But

20:06

there's a problem, isn't there? Saying

20:08

Bactreanus out loud might make

20:11

you feel silly or nervous.

20:14

Maybe you're worried about everyone at the party

20:16

pointing and laughing at you in mockery. To

20:19

my knowledge, Bactreanus is

20:21

the quote-unquote correct pronunciation.

20:24

However, to save yourself from

20:26

a social disaster, you could

20:29

just pronounce it Bactreanus. Bactreanus,

20:32

Bactreanus, whatever you're

20:35

comfortable with. At

20:43

the beginning of this episode, I

20:45

implied that the house sparrow has

20:48

an interesting backstory, an interesting origin

20:50

story. So let's get into it. Once

20:53

upon a time, there was a sparrow

20:55

species hopping around in the Middle East.

20:58

This was the ancestor of the modern

21:00

house sparrow. The earliest

21:03

fossils paleontologists have unearthed for this

21:05

bird are tens of thousands of

21:07

years old, and they were found

21:09

in Israel. Paleontologists

21:12

found an even older fossil dating

21:14

to several hundred thousand years ago

21:17

in Palestine. The guy

21:19

who discovered this fossil named

21:21

the ancient bird Passer pre-domesticus.

21:24

Passer pre-domesticus. Making

21:26

the case that this was the

21:29

wild ancestor of today's Passer domesticus.

21:32

Alongside those ancient sparrows in

21:35

the Middle East, there lived

21:37

a species of bipedal naked

21:39

ape. Around eleven

21:41

or ten thousand years ago,

21:44

this clever ape, Homo sapiens,

21:46

figured out how to domesticate

21:48

some food plants. It

21:50

had invented agriculture. And

21:53

that changed everything for our little

21:55

sparrow. With the rise

21:57

of agriculture, there was a nutritious, and

22:00

plentiful new food source in the

22:02

form of domesticated grass seeds. In

22:05

other words, grain. Some

22:08

of those ancestral house sparrows learned to

22:10

gorge themselves on the grain that humans

22:12

left lying around on the ground. The

22:16

birds also learned to build their nests

22:18

close to humans, in little nooks and

22:20

crannies in man-made structures. Over

22:23

time they lost their fear of humans. As

22:27

agriculture spread outward from the Middle

22:29

East, the sparrows too spread across

22:31

Europe and Asia. But

22:34

not all of those original sparrows in

22:36

the Middle East cozied up to humans

22:38

and adapted to a life that depends

22:41

on agriculture. Some of

22:43

them remained wild and free. Ornithologists

22:46

think that the subspecies

22:48

Pacer domesticus bactrianus that

22:50

exists today is closest

22:53

to the ancestral form of the

22:55

house sparrow. And

22:57

yes, I'm sticking with the anus

22:59

pronunciation. I hope you can handle it.

23:03

Sparrows of the bactrianus subspecies still

23:05

live in their ancestral homeland in

23:07

parts of the Middle East and

23:09

Central Asia, and they

23:11

still migrate long distances every year. I

23:18

imagine them as stoic birds who

23:20

hold fast to their traditional values

23:22

and their customs. Choosing

23:25

hard work and clean living over

23:27

the easy life, they look down

23:29

on their lazy human-loving cousins who

23:31

were too soft and weak to

23:34

resist the seductions of free grain

23:36

and cheap housing. Those

23:40

human-loving sparrows, all the other house

23:42

sparrow subspecies out there, have co-evolved

23:44

with us over the last 10,000

23:47

years or so. They've

23:50

become what biologists call

23:52

commensal animals. In

23:59

a commensal relationship between two

24:01

species, one of them benefits

24:03

without harming or helping the other. House

24:07

sparrows get the benefits of food and

24:09

shelter from us, and they don't really

24:11

bother us all that much, as

24:14

long as you don't mind monotonous

24:16

incessant chirping. The

24:22

house sparrow depends on humans so

24:24

much that some scientists call this

24:26

species an obligate commensal.

24:30

Obligate meaning that it has no other way

24:32

to live. It can

24:34

only survive as a commensal species

24:36

in environments created by humans. When

24:39

people abandon a town or village,

24:42

the local house sparrow population will

24:44

often go extinct. There

24:47

are other birds out there with the

24:49

word house in the common name. House

24:52

wren, house finch, house swift,

24:54

house atrades, house Lannister, and

24:56

so on. But the

24:58

house sparrow is the only bird

25:00

species in the world that has

25:02

the word domesticus in its scientific

25:05

name. Just an interesting

25:07

fact that I thought I'd add here. Research

25:10

using genomic data from house

25:12

sparrow DNA revealed evidence of

25:14

recent natural selection in this

25:16

species. A study published

25:18

in 2018

25:20

in the journal Proceedings of the

25:22

Royal Society B highlighted a couple

25:24

of interesting genes in the house

25:26

sparrow genome. In

25:28

the human-dependent subspecies, one of

25:30

these genes appears to have

25:33

produced a thicker skull and

25:35

beak. Better for

25:37

cracking open agricultural grains, perhaps.

25:40

The other gene is for an

25:42

enzyme that helps with digestion in

25:44

high starch diets. Again,

25:47

because of the grain. In

25:49

contrast, the genomes of the

25:51

ancestral bactereanus sparrows don't appear

25:53

to show such evidence of

25:56

adaptation to life among humans.

26:07

I'm going to move on now to

26:10

talk about the distribution and habitat of

26:12

the house sparrow. There

26:14

are two versions of the distribution map

26:17

we can picture for this species. First

26:20

there's what we might call the

26:22

natural or native distribution. If

26:25

we were to travel back in time

26:27

several hundred years, we'd find house sparrows

26:29

across most of Eurasia, from the British

26:31

Isles all the way to eastern Siberia.

26:35

Their natural distribution also included

26:37

northern Africa, the Middle East,

26:39

India, and Southeast Asia. Then

26:43

there's the map of everywhere this bird

26:45

is found today, including all

26:47

the places it's been introduced by humans.

26:51

This map includes the bird's native

26:53

distribution I just talked about, plus

26:56

everywhere else. House

26:59

sparrows have been introduced to

27:01

North and South America, Southern

27:03

Africa, Australia, New Zealand, and

27:05

other islands like those of

27:07

Hawaii. These little

27:09

buggers are all over the place. Okay,

27:12

so they don't live everywhere. For

27:14

example, they seem to know better than to

27:17

live in Antarctica. And

27:19

again, there are house sparrows way up

27:21

in the frigid Arctic of Scandinavia. So

27:25

maybe if there were some larger permanent

27:27

human settlements in Antarctica, some hearty little

27:29

house sparrows would set up shop there

27:32

too. Who knows? So

27:35

the epic saga of the house

27:37

sparrow didn't end thousands of years

27:40

ago when these birds finished spreading

27:42

across Eurasia with the rise of

27:44

agriculture. Their domination of

27:46

the rest of the planet happened much

27:48

more recently. In North

27:50

America, for example, there have apparently been well

27:52

over 100 intentional or

27:55

accidental introductions of house sparrows. People

27:58

brought them here from Europe. The

28:01

first introduction to North America was

28:03

in Brooklyn in about 1851. That

28:07

was followed by more introductions and the birds

28:09

began to spread on their own. By

28:12

1900, they were chirping

28:14

triumphantly across the entire continent.

28:18

But they still haven't gotten very far

28:20

into Alaska or the far north of

28:22

Canada. So backing

28:24

up, why did someone dump

28:26

a bucket full of sparrows onto the

28:29

streets of Brooklyn, New York? And what

28:31

about all those other introductions in North

28:33

America? What were these people thinking? One

28:37

reason was that some people who

28:39

had emigrated from Europe missed seeing

28:41

familiar European songbirds like the house

28:44

sparrow. They wanted to have some

28:46

around. And a

28:48

seemingly more practical reason was to

28:51

control pests. With those

28:53

sparrows released in Brooklyn, for example, the

28:55

hope was that they would eat linden

28:57

moth caterpillars that were munching on trees

29:00

in the city. In

29:02

the mid-1800s, many people in North

29:04

America were all jazzed about having

29:06

more and more house sparrows around.

29:09

But as the birds spread aggressively

29:12

and their population exploded, the public

29:14

attitude toward them eventually did a

29:16

180. They

29:18

came to be seen as pests, nuisances.

29:22

Some cities offered bounties for dead house

29:24

sparrows. But accidental

29:26

introductions continue around the world.

29:29

House sparrows have apparently arrived on

29:32

distant shores as stowaways on ships.

29:35

I haven't seen any house sparrows on

29:37

ships, but I have seen them flitting

29:40

around inside airports. You probably

29:42

have too. With a

29:44

climate-controlled environment, plenty of crumbs

29:46

and food scraps around, and

29:48

nooks for nesting, sparrows can potentially

29:51

live in an airport for a

29:53

long time. But

29:55

I think I know what they're really up to. These

29:58

cheeky birds have decided... like

30:00

most humans, that intercontinental travel by

30:02

ship is just too slow. Those

30:06

airport sparrows are just waiting for an

30:08

opportunity to sneak onto a plane. They

30:11

don't care where it's going, they just

30:13

want to go somewhere, anywhere, as

30:16

long as there's some dust to bathe

30:18

in and some humans to irritate. It'll

30:21

be like a sequel to the 2006

30:23

movie Snakes on a Plane starring Samuel

30:25

L. Jackson. This time

30:27

it'll be Sparrows on a Plane, an

30:30

action-packed thrill ride critics are calling

30:32

the best movie ever made about

30:34

small birds mildly annoying people on

30:36

a commercial aircraft. Rated

30:38

PG-13 for intense sequences of

30:41

avian action, disturbing content, some

30:43

strong language, and pervasive chirping.

30:47

Okay, so far we've looked

30:49

at the distribution of the

30:51

house sparrow. How about its

30:53

habitats? As obligate commensals, most

30:56

house sparrows breed in or

30:58

near human structures. They

31:01

live on farms or in other

31:03

agricultural settings where there are plenty

31:05

of loose cereal grains lying around.

31:08

But they also thrive in suburban

31:10

and urban areas. Even

31:12

zoos and amusement parks make for

31:14

some great house sparrow habitat. Besides

31:18

airports, these birds will also

31:20

live and breed inside malls,

31:22

grocery stores, factories, churches, Walmarts,

31:25

and the Home Depot. So

31:28

maybe we should ask, where don't we

31:30

find these birds? House

31:32

sparrows have a hard time surviving

31:35

in remote, wild places far from

31:37

humans. That means

31:39

we don't find them in forests,

31:42

grasslands, deserts, or alpine wilderness. But

31:45

if there's even one lonely gas

31:47

station or a farmhouse in an

31:50

otherwise barren landscape, there's probably a

31:52

little flock of house sparrows living

31:54

there. These birds

31:56

are so good at colonizing

31:58

isolated human settlements I

32:00

wouldn't be surprised if some of them

32:02

have already infiltrated the International Space Station.

32:05

And if these sparrows follow humans

32:07

as we build spaceships and expand

32:10

outward to the stars, maybe

32:12

they'll evolve into a new species.

32:15

We can name it Passer

32:17

Galacticus. The

32:26

conservation situation with the house

32:28

sparrow is... complicated. For

32:32

people living in places like the

32:34

United States, Argentina, or New Zealand,

32:37

the bird is a non-native

32:40

pest. They're a problem. On

32:43

the other hand, the sparrow is a

32:45

cherished native species in places like the

32:47

UK, mainland Europe, the

32:49

Middle East, and India. The

32:52

International Union for the Conservation of

32:54

Nature places the house sparrow in

32:56

the Least Concern category at the

32:59

global scale. That's no

33:01

surprise since this is one of the

33:03

most abundant bird species on the planet.

33:06

Remember that there are somewhere between 900 million and 1.3

33:08

billion of them. Despite

33:11

the house sparrow's enormous population

33:14

and enormous distribution, it's been

33:16

having some problems. Data

33:19

from the North American Breeding Bird Survey

33:21

showed that the population on this continent

33:23

plummeted by 80% between 1966 and 2019.

33:30

In the UK, the house sparrow

33:32

is still the most commonly observed

33:34

garden bird. But there,

33:37

too, the population has declined

33:39

dramatically. It's dropped by at least 70%

33:41

since 1977. The

33:45

Royal Society for the Protection of Birds gives

33:47

the house sparrow a conservation status of red

33:49

in the UK. And

33:52

in case you're wondering, red is bad. Scientists

33:57

still aren't sure what's causing it.

33:59

decline of house sparrows in some

34:01

parts of the world. Hypotheses

34:04

include a reduction in grain

34:06

or insects that the birds

34:08

eat, increasing pollution,

34:11

loss of nest sites, increasing

34:13

disease, and increasing pressure

34:15

from predators like hawk. Now,

34:19

maybe you can't be bothered to

34:21

shed a tear for a species

34:23

declining in places where it isn't

34:25

native, places where it's considered a

34:27

pest. I can understand that.

34:30

All the same, we should probably pay

34:32

attention to what's happening to the house

34:34

sparrow and try to understand

34:36

the causes of its decline, because

34:39

the same things might be affecting the

34:41

birds that we do appreciate, the native

34:44

species we definitely don't want to lose.

34:47

But if you're worried about the

34:49

plight of the house sparrow in

34:52

particular, one thing you can do

34:54

is celebrate World Sparrow Day. It's

34:57

on March 20th every year. And

34:59

get this, it is 100% a

35:02

total coincidence that the day I'm

35:04

publishing this podcast episode is March

35:07

20th. Until I was researching

35:09

this episode, I had no idea there was

35:11

such a thing as World Sparrow Day. Quoting

35:15

Wikipedia, World Sparrow Day is a

35:17

day designated to raise awareness of

35:19

the house sparrow and the other

35:21

common birds in urban environments and

35:24

of threats to their populations. So

35:28

happy World Sparrow Day, everybody!

35:38

You know, I looked at a lot of

35:40

photos of house sparrows as I was writing

35:42

this episode. In a bunch

35:44

of those photos, the sparrow had little

35:46

bits of food crud stuck to its

35:48

beak. It cracked me

35:50

up. It was like the photographer had just

35:52

caught the sparrow with its face in a

35:55

pile of garbage or something. Of

35:57

course, the bird looks like it has no shame.

35:59

It could- care less. It's

36:01

like, what are you looking at,

36:03

human? I eat whatever I want. You're

36:05

the dummy that threw away all these

36:07

delicious scraps. It's like they

36:10

say, one man's trash is another

36:12

sparrow's treasure. Garbage

36:14

is on the menu because

36:16

the house sparrow is an

36:18

opportunistic omnivore. Now

36:20

that said, its primary diet is

36:22

seeds. More specifically,

36:24

grains, including domesticated cereal grains

36:27

like corn, wheat, and oats,

36:30

but also grains from wild grasses,

36:33

and they'll eat weed seeds too. House

36:36

sparrows are persecuted as agricultural

36:38

pests in many places because

36:41

of their love for domesticated

36:43

grains. Other

36:45

kinds of plant material in the

36:47

house sparrow diet include berries and

36:49

other fruit and buds. In

36:52

the spring and summer breeding season, insects

36:54

make up about 10% of the diet.

36:58

Other small animals sometimes end up in

37:00

the bellies of house sparrows too. Worms,

37:03

slugs and snails, small frogs

37:05

and lizards, and even crustaceans.

37:09

And since this species is

37:11

an obligate commensal, or as

37:14

some scientists put it, an

37:16

anthrodependent species, it eats

37:18

plenty of food that it gets from humans.

37:21

This could be birdseed from feeders,

37:23

or breadcrumbs, pizza crust, or those

37:25

pieces of ravioli that you left

37:27

on your plate after you had

37:30

lunch on the patio at the

37:32

Italian restaurant. House

37:34

sparrows forage by hopping around on

37:36

the ground, looking for seeds or

37:38

whatever. In some

37:41

places, flocks of house sparrows descend

37:43

upon backyard bird feeders and end

37:45

up dominating the scene. They

37:48

stuff their little beaks with seeds and

37:50

can prevent native birds from getting their

37:52

fair share. Many

37:55

predators eat house sparrows. In

37:58

North America, the list of avian predators includes

38:00

species like Cooper's hawk,

38:03

sharp-shined hawk, northern Harrier,

38:05

Merlin, American kestrel, and

38:08

loggerhead shrike. Other

38:10

animals known to kill house sparrows

38:13

include cats, dogs, and snakes. And

38:16

humans. People have been eating

38:18

house sparrows for hundreds, if not thousands,

38:21

of years. People in

38:23

Europe used to hang so-called sparrow pots

38:25

from the eaves of their houses. The

38:28

birds would come along and build nests in

38:30

the pots, then people would scoop out the

38:33

nestlings and eat them. Yikes.

38:35

That's kind of rude. But

38:38

yeah, sparrow dumplings and sparrow pie

38:40

used to be a thing. And

38:43

I guess some people in the Mediterranean

38:45

region still eat house sparrows today. Our

38:59

last major topic today is

39:01

the breeding biology of Paster

39:03

domesticus. This species is socially

39:06

monogamous. They tend to pair up

39:08

for life. However,

39:10

there's often some mating on the

39:12

side with birds outside of the

39:15

pair bond. Courtship behavior

39:17

is important for the formation

39:19

and maintenance of breeding pairs.

39:22

Females appear to choose males with

39:25

the largest, darkest black bib. This

39:29

role of the bib as

39:31

a signal in sexual selection

39:33

is the most recent explanation

39:35

for the bib's existence and

39:37

for its variation. Now,

39:39

I know I was joking around earlier

39:41

about the male sparrows being sort of

39:43

like human males in prison. The idea

39:46

that subordinate males avoid challenging

39:48

dominant males with larger bibs

39:51

is sort of the old way

39:53

of looking at this biological situation.

39:56

We used to think the bib was

39:58

a signal of social selection. status. More

40:01

recent research has revealed that

40:03

bib size may not be

40:05

as important for avoiding conflict

40:08

among sparrows as ornithologists once

40:10

thought. In any

40:12

case, when a male house sparrow wants to

40:14

win the heart of a lady, he puts

40:16

on a little show for her. He

40:19

fluffs up his bib and chest

40:21

feathers, opens his wings a bit,

40:23

spreads his tail feathers, and hops

40:25

all around the female. Established

40:28

pairs maintain a small territory

40:30

centered on their nest site.

40:33

They defend the territory fiercely in the

40:35

breeding season, but they're more

40:37

chill about the whole thing at other times of

40:39

the year. If an

40:41

outsider gets too close during the

40:43

breeding season, the territory-holding pair will

40:46

chirp loudly and chase the intruder

40:48

away. House sparrows

40:50

don't just show aggression and attack

40:52

members of their own species. They've

40:54

been recorded attacking at least 70

40:57

other bird species. They

40:59

do this to defend their own

41:01

territories, or they will also forcibly

41:03

evict other bird species from their

41:06

nests. For example, house

41:08

sparrows will sometimes enter the nest of

41:10

a bluebird, swallow, or marten and throw

41:12

that bird out of its nest. The

41:15

house sparrows just take over. The

41:18

fact that non-native house sparrows steal

41:20

the nests of native birds like

41:22

this is another reason many people

41:25

dislike them. As

41:27

a commensal species, house sparrows prefer

41:29

to build their nests in man-made

41:32

structures. They set

41:34

up shop in little nooks

41:36

and crannies in buildings, walls,

41:38

neon signs hanging outside of

41:40

fast food restaurants, and so

41:42

on. Apparently, there

41:45

was even a sparrow colony breeding in

41:47

a coal mine, 2,000 feet or about

41:49

670 meters underground. Crazy. In

41:55

general, this is a cavity

41:57

nesting species. They'll also use

41:59

natural cavities in trees or

42:01

on cliffs. The nest

42:03

itself is a messy jumble of

42:05

sticks, grass, and leaves on the

42:07

outside, and it's lined with

42:09

feathers and other soft items on the

42:12

inside. A

42:14

clutch of four to five eggs

42:16

is typical. It's also typical

42:18

for house sparrows to lay two

42:20

to seven clutches every breeding season.

42:23

So these guys really crank them out. Both

42:26

parents sit on the eggs and both

42:28

help to feed the growing chicks. Baby

42:32

house sparrows are altricial. They have no

42:34

feathers when they're first born and their

42:36

eyes are closed. They're basically

42:39

helpless. But

42:41

in about two weeks, the little guys are

42:43

ready to leave the nest. By

42:45

that time, they can already fly. And

42:48

off they go, chirping their hearts

42:50

out and scouring the land for

42:52

grain and table scraps. Only

42:55

about 20 to 25 percent

42:57

of young house sparrows will survive

42:59

their first winter. Lifespan

43:01

in this species is probably just a

43:03

few years, but some have

43:06

lived almost two decades in the wild

43:08

and about 23 years in captivity. The

43:12

sparrows that do survive their first year

43:14

or so will look for a mate,

43:16

then settle down to breed. Most

43:18

house sparrows are residents. They live in

43:21

more or less the same small area

43:23

all year long. An

43:25

individual might stay within a range

43:27

of only about a mile in

43:29

radius, somewhere between one and two

43:31

kilometers. I

43:38

have mixed feelings about house sparrows.

43:41

On the one hand, they're cute, interesting

43:43

birds with lots of personality. But

43:46

I'm not a fan of any

43:49

non-native or invasive species. I

43:51

know it's not their fault, but still,

43:55

I'd be happy to see a flock of

43:57

house sparrows in Eurasia, where the species is

43:59

native. But seeing them

44:01

in Disneyland or inside an airport or

44:04

at a bird feeder in North America?

44:07

Not so much. No magusta.

44:10

People in many parts of the

44:12

world hate house sparrows for being

44:14

non-native agricultural pests. And

44:17

because these birds compete aggressively with native

44:19

birds for food and nest sites. Because

44:22

they're destructive and filthy. Ned

44:25

Dearborn, the biologist who said that about them

44:27

way back in 1912, also wrote this. Quote,

44:32

the English Sparrow, that's another

44:35

name for the house sparrow,

44:37

the English sparrow defiles private

44:39

and public property, fights and

44:41

dispossesses useful native birds, replaces

44:44

their songs with discordant sounds,

44:46

and destroys fruit, grain, and

44:48

garden truck. End

44:51

quote. Wait. Truck?

44:54

Do you claim that house sparrows went

44:56

around destroying trucks? Like

44:58

did flocks of them attack vehicles on the

45:00

highway pecking at the eyes and hands of

45:02

their drivers causing the trucks to run off

45:05

the road and crash in fiery explosions? That

45:08

would have been kind of awesome. But

45:10

no. In this case, the

45:13

word truck is an old timey

45:15

way of saying vegetables or produce.

45:18

Anyway, love them or

45:20

hate them. House sparrows have become our

45:23

ever present companions on this planet. Despite

45:26

the population declines in recent decades,

45:28

this species will probably be with

45:30

us long into the future. We

45:33

can at least appreciate the house sparrow as

45:36

a model organism. With those

45:38

7000 scientific papers and more in

45:40

the works, I'm sure, this bird

45:43

has helped us learn a lot

45:45

about avian biology. And

45:47

even about some fundamental aspects of

45:49

just how life works. If

45:52

you normally ignore or even

45:55

passionately loathe your neighborhood house

45:57

sparrows, I have a

45:59

challenge for you. for you. The next

46:01

time you see a few of these

46:03

little birds, take a few minutes to

46:05

watch their behavior and listen to their

46:07

vocalizations. You might be

46:09

surprised at how interesting they can be.

46:17

Thanks for joining me today for episode 93 of

46:19

the podcast. Even

46:22

if it didn't change your opinion of

46:24

the house sparrow, I hope you learned

46:26

some new things and can understand these

46:28

birds a little more deeply. That's

46:31

certainly true for me after researching and

46:33

writing this episode. I've

46:35

got a few of them in my neighborhood, so

46:37

it was kind of fun to actually hear them

46:39

out there chirping and singing, cheer up to me

46:41

while I was writing. On

46:44

another topic, you know how I

46:46

was making jokes about pronunciation earlier,

46:49

bactrianus versus bactriannus and all that?

46:52

Well, you might know that I

46:54

care a lot about using proper

46:56

pronunciations. That can be

46:59

a challenge sometimes with scientific words, but

47:01

I do my best. But

47:03

I have to own up to some

47:05

pronunciation boo-boos that I made in my

47:07

last episode, episode 92, which was

47:10

on deserts. I mispronounced the

47:12

names of two deserts. It's

47:14

not the Namib Desert, it's the

47:17

Namib Desert. And

47:20

it's the Tar or Tarr Desert,

47:22

not Thar. Tar

47:24

is spelled T-H-A-R, but it's pronounced

47:27

with just a regular T sound.

47:31

So Namib Desert and Tar

47:33

Desert. And then

47:35

there's the name of those giant, iconic

47:37

cactuses in the Sonoran Desert of North

47:40

America. A friendly listener

47:42

from Arizona contacted me and told

47:44

me that people in Arizona say

47:47

Saguaro rather than how I

47:49

said it, which was saguaro. The

47:52

word is spelled S-A-G-U-A-R-O. I've

47:55

heard it said both ways, but yeah, Saguaro

47:58

is the best way to do it. to

48:00

say it. That's the correct way. So

48:02

my bad. If these

48:04

egregious errors haven't caused you to

48:07

lose all respect for me, hopefully

48:09

you'd like me to keep making

48:11

podcast episodes. Perhaps you'd

48:13

even like to offer me some

48:15

support to give me more opportunities

48:17

to mess up my pronunciations. If

48:20

so, you can become a supporter of the

48:22

science of birds through Patreon. To learn

48:25

more, just go to

48:27

patreon.com/science of birds. Or

48:30

like I mentioned earlier, there should be a link

48:32

at the bottom of the show notes in your

48:34

podcast app. I'm super

48:36

pleased to welcome my newest awesome

48:38

supporters, Tracy, Miss

48:41

Magic Munson, Deborah Cisco,

48:43

TJ Wells, Diane Seikman,

48:46

Julian Perez, and Helena

48:48

Seiber. Sorry, I'm

48:51

not sure which. In any case, thank

48:53

you all very, very much for becoming

48:55

members of my Patreon community. I

48:58

am kind of slow to respond to email sometimes.

49:00

But if you have something you'd like to share

49:02

with me, email is the best way to reach

49:05

me. Maybe you'd like to correct

49:07

the way I say a particular word, or

49:09

you're a Hollywood movie producer and you want

49:11

to give me a hundred million dollars to

49:14

put my sparrows on a plane idea on

49:16

the big screen. Whatever your

49:18

message is, you can send it to

49:20

ivan at science of birds dot com.

49:23

Again, this is episode 93. You can

49:25

check out the show notes for the

49:27

episode along with a few photos of

49:29

house sparrows on the science of birds

49:31

website, science of birds dot com. I'm

49:34

Ivan Phillips wishing you a great

49:37

day. Peace.