An introduction to cooperative breeding and why helpers help: Part 1: What is a cooperative breeder, and what does a helping bird do?

Disclaimer: This series on "An introduction to cooperative breeding and why helpers help" is in no way a review on all the hypotheses that exist or in no way attempts to review all literature and books on this topic.If you are interested in this area of research there are plenty of resources available. Further interest in apostlebird research can be found on my website at www.animal-acoustics.com.

An introduction to cooperative breeding and why helpers help:

Part 1: What is a cooperative breeder, and what does a helping bird do?

Apostlebirds have many common names, Lousy Jacks, Grey Jumpers, and Happy Families. They indeed look like happy families with all their preening, chatting and cuddling up together on a branch. But, why all this cooperation?

In an earlier post, I told you about the drama I witnessed during the winter/ off breeding season and all the fighting, screeching and foot biting. Also, all the chasing of other groups, the scramble for bread and monopolization of access to the food lady- all this conflict! But despite all the fighting, year after year, since at least 2004 when this study was started (not by me, but by my adviser) these hardy birds breed cooperatively.

What is cooperative breeding, you ask? Well, it is when adult birds help to raise offspring that are not their own. And help they do, with everything from the diligent building of cup shaped mud nests, to the hours and upon hours of protecting the eggs from the cold of the outback nights and the arid heat of the Australian sun, to the feeding of the every begging and hungry young. And then they help some more, as the growing birds in the nest need care beyond filling their gaping mouths. They need preening to clean the chalky sheaths of their newly emerging feathers, and parasites need to be picked away from their delicate baby skin and they even need their poo to be carried away ( and some cases eaten away!) so that they do not sit in an ever growing mound of partially digested food.

All these baby care task, and more, the helpers do. Helpers will even remain vigilant for predators that they will mob and chase away, if necessary. But why? Why all this effort in a land that can be so unforgiving, that can go from tolerable to hot and dry with nary food (insects and seeds) in a blink of the eye? And to raise offspring that are not your own? Why not settle down and wait until you can have your own children?

Well, first thing that comes to most people’s mind is that, well maybe you can’t have children on your own. Maybe waiting for a good season is too long, longer than your breeding life. Alright, so you need help? Who will help you? Maybe they themselves want to breed? That sounds like one big bird fight waiting to happen- and maybe it does, and maybe that is what all this conflict during the winter is about. Fight it out, beak to beak, who gets to bred. Well, somebirdy comes out a winner and somebirdy has to help. But what keeps a bird from being a sore loser and birdy-ing off. That would be system collapse wouldn’t it? Maybe the helpers get something then for helping.

Think of it this way. Maybe you are an older child, or maybe you have younger cousins. Remember being made to babysit when you were a teen? Your parents may have paid you for it, but chances are it was “your responsibility” to help. Society expectation, maybe, but also as a “rent payment” . This is especially the case, if you are an adult and later visit with parents, aunts, friends with children, etc....

Some other adult keeps a roof over your heads the fridge stocked, shampoo in the bathroom, etc… and those are all resources in their territory and their house. So, maybe cooperative breeders, like the Apostlebirds, pay rent (Pay to stay- see the papers below for more info). Apostlebird juveniles (younger than 1 year) stay at their parents place and continue to beg at adults for food, although they also look for food and feed themselves. When they get older, they will feed younger siblings and by the time they are an adult (~2 years) they start to help at the nest. Younger adult birds will tend to stay at home and help mom and dad raise their younger siblings, until at some point, mainly the daughters leave home, while their brother stick around the territory where they were born, sometimes even after mom and dad are long gone. Maybe a male will inherit breeding status and take over the home stead himself, in a few seemingly rare cases, he may leave himself, or maybe he just continues to help as an adult. We don’t conclusively know what apostlebird males do yet, as the current study is only 6 years old, not long enough to follow enough birds from egg to breeding (yet another story waiting to be told).

Next time, Part 2: When are you going to have kids? Why an adult bird may still be helping rather than having their own children.

1-A few interesting papers on "Pay to Stay" here:

http://www.anu.edu.au/BoZo/kokko/Publ/Rent.pdf

http://www.ericlwalters.org/koenig_walters2011.pdf

http://people.bu.edu/msoren/McDonald.pdf

http://www.life.umd.edu/faculty/wilkinson/BIOL608W/Sachs&Rubenstein07_BP.pdf

Magpie Maniac (written last field season, aug 2010)

Sometimes, in the cold and monotony of waiting for an animal to do something, my mind enters strange realms, strange anthropomorphic realms where animals engage in weirder thoughts than I. Like watching their surroundings like cable network. I contemplate this while staring up at the bird sitting on her nest. She gives me a quick glance and decides that I am not worth watching and I don’t blame her. She continues to ignore me as I stare up at her through binoculars, pointing a microphone at her in the hopes of a nest vocalization. The cold wind stings my face and I try to hide behind the fuzzy wind guard of my microphone. The bird, on the other hand, has tucked her face into the fuzziness of her chest feathers. Lucky bird. There is really not much to watch as bird sits and I stand in the cold early spring wind.

My mind wanders to the thought of warmth. “A cup of tea, some cookies, a warm blanket. Mmmm. Maybe a couch, oh and a tv. What would I watch out here?” Never mind that I have no tv or cable for that matter. “Well then, what would the bird watch?” Sheep Show. Kangaroo Kable. Biologist Bloopers. Emu Entertainment. Magpie Magee. Chicken Channel. Artist Antics (yes, there are artists that use the field station as creative inspiration.)

I am snapped back to reality as the wind tries to steal my microphone. It is already 7 am and the wind has picked up enough to register 40% noise on my Marantz recorder. I sigh and glance up at bird. She has gone to sleep with her beak lost in the softness of her chest. I pack up my gear and head inside. If I am lucky, in a few hours, I will be able to go out again.

Later that day, the wind has died down, and I gleefully run out the door and head off down the creek to visit the Hills Clan. I am laden down with gear but I skip across the rocky ground. It had been a fairly wet summer, and here and there, along the creek are pools of water, and in some places the creek bed is coated with a layer of slippery mud. And there along the sides of the creek, I was reacquainted with some of the fundamental rules of fieldwork. 1) Recording equipment + tripod + gel batteries = heavy knapsack, 2) Large gap + muddy sides = suboptimal jumping conditions, and finally putting the two together, 3) Heavy equipment + suboptimal jumping conditions = crap landing + twisted knee.

With my knee aching, I push forward towards the group. The weather is clear and I ache even more to see my group, and as I approach the pass that leads to their favorite hangout spot, I feel a sudden whoosh of air behind my head. It is Mr. Maniac, the resident rogue magpie. It is not actually him that is the maniac but I. That is, under the careful tutelage of my supervisor. The thing is, is that Magpies can actually be quite dangerous. No joke. In parts of Australia they have dive bombed cyclist causing head injuries and accidents. The large bird picks up a lot of speed and when they actually hit you, (and they aim for the head) it is like being hit with a lance. If you are lucky enough to remain standing (very very lucky) your head and neck will ache for days. Don’t even think about the eyes, it’s too much like Alfred Hitchcock’s “The birds”. So, to discourage the bird from dive bombing humans, I went maniac on him. I screamed nonsensical gibberish (no, I did not lecture him on my research), waved my arms and ran at the tree he had perched in. He hesitated for awhile, taking in the show and then flew off to the next tree. I followed, repeated the act and threw sticks at him, and with that he took off. The next time I encountered him, I repeated the act, and the time after that I simply yelled “Bird! Bird! Bird! (probably one of the most comment curses given by field biologists, especially when done with a shake of the fist) and he flew off. The whole act was rather cathartic, and when he moved away, I missed the chance to go off my rocker.

Begging Babies

Chatty birds such as apostlebirds don’t just become chatty at a particular age, here in this video (below) you can see three hungry nestlings begging for food. Of course, begging like this is nothing new for birds, but what is cool is that I can sit here and watch them go back and forth and feed their young. If I give them bread, they will go back and forth between me and the nest feeding the bread young. But, this is not something I normally something I do as I prefer them to go about their natural birdy business.

Once while I was sat reclining in the long grass, with my neck craned up to pear high into the branches of the tallest nest, I noticed that the usual fare being brought to the nestlings seemed to be changing. The adults at first had been bringing food gifts of grasshoppers, flies and other various black legs cramming out of their beaks, and suddenly it changed to …. White fluff? What? It looked soft going in, and then it occurred to me that it might me bread. Not my bread, mind you, but that of my supervisor, who had made his way down the creek towards where I was working. Kinda funny because I had heard no alarm calls earlier, but with these birds, we are not considered a threat. Even an over 6 foot tall man, or a smaller unassuming female with a long long nest pole and recording equipment.

Why do birds chatter?

I like to watch chatty birds, I like to watch how they move and dance about with each other, but mostly I love the constant chatter. I want to know what they are talking about, what they say to each other and why it matters. But as a scientist, I also wonder why? Why all the chatter? Do they exchange “gossip” on other birds. Do they say, Missus so and so had an argument with her sister, now they are not exchanging tips on where the best food is?

Why talk, why communicate? Well, communication allows for the exchange of information, where the best food is, where everyone else is heading, when everyone else is ready to fly away, as well as anything else that matters to a bird. You would expect this to be of great importance in birds that live together in a group- communication is paramount.

With the apostlebirds that I study, they chat and chat and chat. Constantly. Lots of calls. Calls while looking for food, calls while preening, calls before flying away, calls when they approach me, calls when they sit on nest, calls when they switch nest duties, calls when they leave the nest, calls when they are scared, calls when they are alone, calls when moving newly fledged birds, calls when they approach a rival group, calls looking at me. They never shut up. What are they saying? Does this smooth out their social interactions?

Here's a little video clip of the birds in a calmer setting (so no initial excitement of food).