Sustainability: Understanding the alarming decline of the Blue Crane

17 minutes before 8 o'clock, welcome back to 7 or 2 weekend breakfast with me, Gorg

Zantlow.

Time for us to talk sustainability and a recent study suggests that intensive agricultural

landscapes in the Western Cape could be reducing the breeding success of the iconic blue

crane.

Now the blue crane isn't just any bird, it is our national bird and so there's a bit

of concern that the ability of the national bird to breed is being impacted.

The study was done by researchers from UCT, that's University of Cape Town, through their

Fitzpatrick Institute of African Ornithology, what a delicious word, ornithology is, as well

as the International Crane Foundation and the Endangered Wildlife Test.

And joining us now is the study's lead researcher, they are also a conservation scientist at

the International Crane Foundation.

Dr. Christy Craig joins us on the line, Dr. Craig, a very good morning to you, welcome

to Weekend Breakfast.

Good morning, thanks for having me.

Thank you for your time.

So Dr. Tell us about the study, what did you set to look at or to try and find through

the study?

So yeah, this was my PhD study and the purpose was to look at the viability of blue cranes

in the Western Cape because because they are an unnatural population, they didn't occur

here when the whole of the Western Cape was famous, they have moved in because of agriculture

and they have up until 2010 done very well in this agricultural landscape.

But unfortunately, the research showed that over the last 15 years things aren't looking

as good, the population isn't decline and the breeding success in the Western Cape is

lower than it was 30 years ago and it's lower than in the career in the grassland which

is more of the natural range.

And so when you say that the crane, the blue crane is certainly where it is in the Western

Cape, it's an unnatural population, is that also part of why we're seeing this impact

on their breeding numbers or had they, and you can correct me if this isn't the right word,

that they adapted to their habitats in the Western Cape and then something happened

after 2010.

Yeah, so that's what that's a question that we're interested in and it's continuing research

is what has changed because they obviously did adapt and they did a great abuel and this

became sort of a stronghold for blue cranes but something has shifted either in agricultural

landscape or perhaps in terms of climate and so we thought from the teaser part exactly

what what it is that has led to the decline, but certainly there are some warning signs

that what was a stronghold population no longer is and we're not entirely sure why.

Speak to our instructor about the findings that indicate that these agricultural areas

in the Western Cape have or could have become an ecological trap.

What does that mean and how is that impacted potentially the blue cranes numbers?

So an ecological trap is something essentially that it's a ecosystem that animals are drawn

to.

I like to think of it a bit like human eating junk food because it tastes good but it's

not good for us.

So basically if animals coming into an area that is attracted to them but it isn't necessarily

good for their survival or their reproduction and so yeah it's basically an attractive habitat

that isn't good for the animal.

And so what is the current I guess status of the blue crane is it threatened is it endangered

what do we know about the current numbers of the blue crane?

So they are most vulnerable on the IEC and Red List so that's the category between endangered

and near threatened which means they are threatened on the IEC and Red List.

And also speak to us about the numbers of young chicks that are joining the flocks.

It sounds as though the study also found that that number isn't quite where it should be

that's also concerning.

Yes so what we looked at we monitored breeding in another way so one of which is monitoring

the pairs when they're breeding to look at how many chicks they pledge but then during the winter

we also go and look at blue crane flocks and look at how many juveniles they are and that

measures concerningly low we found that about 4% there's about 4% juveniles in the population

and we know that they're survival in terms of at a population they're born a wasting cape

about 9% of cranes die in a given year so that means that their mortality rate is lower than

their breeding rate which is how they're in the population declines because they're not replacing

themselves.

Do we have any indication on what could be a underpinning or contributing to that chick mortality

We do know that there are a couple of things that affect good breeding cranes so there was a

master study by Michelle Bauer who looked at crane nets and actually didn't pull the nest

but they were breeding fights and what she found was that the sterbens at the nest

left laid to higher predations and higher numbers of eggs failing and she also found that higher

temperatures led to nest failures and then when it comes to the chicks we do know that they get

entangled in the senses so they try to walk through senses and get stuck

as well as when they're quite small if they try to drink out of a water trough they can fall

in and drown and yeah so there's a couple of couple of things that can impact chicks and

and the eggs and I think a big one an agricultural landscape will be disturbance because they are

quite a lot of people and wasting cape farms with a lot of machinery and so I think disturbance

is quite an important one and wasting cape.

Speak to us finally doctor about the role that farmers can play potentially in conserving

these blue crane numbers. Yeah so I think farmers I think the

almost responsibility or ability to turn the trend around for big cranes isn't the

farm at hand and many farmers already are very protective of their big cranes and large

they have them there and do everything that they can to help their survival. So I think some

of the things the farmers can do is during the breeding season try and limit disturbance with the nest

if need be make sure to mark the nest so that people know if they can put like a couple of rocks

or something because they don't pull the nest bake but just on the ground it can be just good to

see them and then if you have a camp that's possible to leave the gate open so that birds can

access water without going through a fence that can help as well as making water trops

blue crane safe so packing some rocks or something in the truss so that the chicks can get out

of the study fallen and I think just generally looking at blue cranes and if they see something

like a parlor and collision or a blue crane state but could a little trick so that we can

investigate. Yeah doctor I must thank you very much for giving us your time this morning a great

pleasure having you on the show. That is Dr. Christy Craig she is a conservation scientist at the

International Crane Foundation in the endangered world of truss. She's also the lead researcher on

a recent study looking at the alarming decline of our national bird.