Thread by @_erikaroper

THREAD: I research the adaptation of #BlackCockatoos to novel environs, w/a focus on diet and food resources.
This is becoming highly relevant in light of the ongoing bushfire crisis here in Aus, so I wanted to write some thoughts based on my experience and research. /1

The focus of this thread is parrots, but can be applied to other animal groups too.
I also work on adaptation to urban areas, but fire-affected habitat can be classified as a novel environment as well, as the resulting habitat and resource availability is drastically changed. /2

So, fire kills animals and destroys habitat, which can take a long time to recover. For survivors the most immediate concern is a lack of food resources. Longer term they will also be impacted by loss of breeding resources, like nest hollows, which are already in short supply. /3

For parrots, "food resources" usually means plant species, as most parrots are herbivores/nectarivores, eating seeds, fruits, nectar, sap, lichen etc. Some also eat grubs which are extracted from tree. Food resources are easily impacted by fire, drought, and land clearing.
/4

Many parrot species are dietary specialists, meaning they only feed on a handful of food resources. In the case of Black-cockatoos, this is often seeds, sometimes from just one or two plant species. E.g. Glossy Black-cockatoos feed almost exclusively on Casuarina seeds.
/5

For dietary specialists the loss of their main food resource can be devastating to populations.
Parrots learn what is food, where to find it, and how to process it from conspecifics (other individuals of the same species). Usually this is parents teaching their young.
/6

Fortunately, parrots are highly adaptable and intelligent. There are numerous examples of parrots discovering and exploiting novel food resources, especially in urban areas. Even species once thought to be dietary specialists.
/7

For example, my study species, the Karak (Forest Red-tailed Black-cockatoo) used to mostly eat the seeds of two native Eucalypt species (marri & jarrah). In the past 20 yrs pops have moved into urban areas and have discovered new foods to eat, mainly non-native plant species.
/8

Other examples include Gang-gang Cockatoos eating Cotoneaster and Hawthorn seeds, and Yellow-tailed and Carnaby's Black-cockatoos eating pine seeds.
I'm trying to document novel food use by parrots using the #HungryParrots hashtag and eventually a citizen science project.
/9

So, it is possible for parrots to find and exploit new food resources. However, it can take time. Karak started feeding on cape lilac (novel food) around 1999, but it wasn't until 2017-18 that a large proportion of the population knew about cape lilac as a food resource.
/10

Also, Karak do not eat cape lilac out of necessity. There's still enough traditional food for them in their historic range (the Jarrah forest). They prefer cape lilac because it's faster to process and more efficient for them to eat than traditional foods. They have a choice.
/11

The Glossy Black-cockatoos do not have a choice. Most of their food resources have been lost to the fires. Remember, they only really eat casuarina seeds. Their beak is even specially adapted to processing casuarina cones and seeds.
/12

Any surviving Glossies are going to be severely impacted by loss of food resources (casuarina trees with cones). I'm already seeing questions from people as to whether we can help the Glossies via supplemental feeding. My thoughts on this are as follows:
/13

In captivity Glossy Black-cockatoos have adapted to new diets. Without choice they may become more adventurous and willing to try new foods.
Captive diets for Glossies I have worked with included parrot pellets, sprouted seeds, fresh veggies (no fruit), and casuarina cones.
/14

Can this be applied to wild populations as supplemental feeding? Maybe.
The Glossies might be hungry and desperate enough to investigate new foods. But they could also be confused and stressed, and less likely to take risks.
/15

Remember that parrots learn about food resources from their parents or flockmates. They might be wary of supplemental foods if noone has told them it's food and is safe to eat. They might also be wary of strange presentation, like food in dishes or on the ground.
/16

There's also problems with feeding wet foods (like sprouted seeds and fresh veggies), as they can start to grow mould very quickly, especially in hot weather. Birds are very susceptible to fungal infections, much more so than mammals. So feeding wet foods might be harmful.
/17

If casuarina cones or branches with cones can be brought in from elsewhere (nurseries or from areas with no Glossies), then they might eat them from trays, as they will be able to recognise the cones as food. Again, it comes down to how desperate the Glossies are for food.
/18

It is also possible that the Glossies might find new food species on their own. We have seen this in other Black-cockatoo species and other parrot species. Black-cockatoo beaks are strong and the cockies are smart. They could get seeds from other plant species.
/19

It can be difficult to predict how species will respond and adapt to the loss fo resources, especially food resources.
Might be possible for Glossies to adapt to new foods, but possibly not in the short timeframe required.
/20

However, species can and do adapt! We have to stay hopeful that fire-affected species like Glossies will survive through the immediate loss of food resources. We also need to focus on restoration of lost food resources & habitat, as that will be needed for long term survival.
/21

I also want to add that in light of the bushfires, urban habitat is more important than ever. Urban areas can be safehavens for wildlife, as they are less likely to be affected by disasters like fires. Urban bushland, street trees, & backyards all provide valuable habitat.
/22

Hopefully this thread has been helpful to some. I haven't gone into as much detail as I could have on some things, especially my research, but I'm happy to answer questions and discuss further. Thanks for reading!
/23

Here’s the thread from ThreadReader. I’ll also chuck all this in a blog post soon.

https://twitter.com/threadreaderapp/status/1217696258942554114?s=21

https://twitter.com/threadreaderapp/status/1217696258942554114