Obscure bird of the week: Palila

Get ready for the greatest, most mind blowing blog post you will ever read. It contains: science, evolution, rarity, conservation concern, a flow diagram and most important of all...a sexy bird!
Right lets start with the complicated part - adaptive radiation. Hawaii is one of the homes of the baffling phenomenon of adaptive radiation. What is adaptive radiation, I like to think I hear you ask?
Well, I shall try and explain it in a single paragraph, but apologise if it 1. Makes no sense 2. Bores the pants off you 3. Scares you half to death!
Adaptive radiation is a process of rapid diversification, usually taking place on small archipelagos. This normally occurs when a single species arrives onto the islands from the mainland, and then breeds with great success and the population threshold becomes full. As a result, there are lots of niches that need to be filled in order to accommodate the vastly increasing population. Therefore, the species expand and natural selection favours those with mutations that appear to benefit the individuals, leading to great change in the species and therefore speciation occurs through many generations. Now although in evolutionary terms, this is a very rapid process, don't expect it to occur in your lifetime as the evolutionary time-scale is a little broader than ours!
Adaptive radiation was first noted in Darwin's finches on the Galapagos archipelago, which was one of his findings that really made him famous in his Origin of Species. It is a process which also appears in Lake Malawi and Lake Victoria cichlid fish, Caribbean Anolis lizards and Heliconius butterflies.  

Flow diagram of Hawaiian Honeycreepers. From D. J. Futuyma. 1998. Evolutionary Biology. Sinauer, Sunderland, MA

Now, what has this got to do with 'sexy birds'? Now I know Darwin's finches are pretty awesome. I don't know anyone who has never heard of them, but lets be honest, they're all brown. Now don't get me wrong, I like brown birds as much as the next guy, but they're not the headline group for whom accounts for the greatest blog post of all time, are they?

Why of course not! The greatest parties you can possibly be invited to are fancy dress parties. This certainly isn't scientific fact, like the start of this post, but certainly is a valid point in my opinion! Have you ever been invited to a Galapagos party? No? Didn't think so. I bet you have/know someone who has been invited to a Hawaiian themed party though. There's a reason for this.

Hawaii is colourful, has a national dress and you get to drink out of empty coconuts! How very exciting! 

Hawaiian birds are no exception. 

(Disclaimer: this next bit may have been altered for entertainment value) The first
honeycreeper to arrive onto Hawaii must have been laying on the beach with Piña Colada in hand, flicking through the newly printed Origin of Species, when all of a sudden, looks
around and thinks, 'I like that adaptive radiation idea...I might give it a go...Hawaii style!'

One of the many beautiful honeycreepers - the I'iwi (Vestiaria coccinea), pronounced ee-EE-vee ©Chuck Babbitt

So this is what happened: That first honeycreeper arrived onto Hawaii, then bred, spread and diversified. Unlike the monotone Galapogos finches, the honeycreepers added a sense of hula party to themselves with a whole lot of colour! These Hawaiian honeycreepers are remarkably colourful, ranging from scarlet and black, scarlet and scarlet, yellow and slate, black and yellow, olive and even a splash of white in there too.

In addition, their morphological bill structures are somewhat out there with big finch-like bills, to overly droopy ibis-like bills to the small insectivorous bills as seen with 'our' Phylloscopus warblers.

There have been 56 described species that have radiated from that one 'base' species. It's not all hula parties and limbo challenges in the life of the Hawaiian honeycreepers though as in recent history, almost half of the species have become extinct due to us dastardly humans and our incessant need to hunt, destroy and introduce everything and anything that destroys the local fauna!

This time it's the Polynesians, who brought with them dogs, cats, chickens, rats and pigs. In addition, they hunted the honeycreepers who had no fear of humans, so were an easy target as well as converting the birds' natural habitat into agriculture.

Unsurprisingly, of the birds that have so far survived the introduction of humans, there are several species that are certainly close to joining their 'fallen comrades'. I therefore bring you to the denouement of this blog post. Let me introduce you to the beautiful Palila (Loxioides bailleui)...you wouldn't think it was in the same family as the i'iwi, would you!?

The beautiful Palila (Loxioides bailleui) ©Eric A. VanderWerf

The palila, as far as I'm concerned, is one of the prettiest birds in the world! They are in the finch-billed clade of Hawaiian honeycreepers and are present exclusively on the dormant volcanic island of Mauna Kea. You certainly wouldn't think this species was out of place on a bird table with greenfinch (Chloris chloris) or bullfinches (Pyrrhula pyrrhula). You wouldn't even think it's that far removed from evening grosbeak (Coccothraustes vespertinus) or female/immature pine grosbeak (Pinicola enucleator). Honeycreepers are classified within Fringillidae (Finches) though, so this does make a lot of sense...
Sadly, unlike the aforementioned four species, of which all are on the least concern list, the palila is one of the rarest birds in the world and is listed as Critically Endangered. Currently there is a population estimate ranging between 250-999 mature individuals covering a startlingly small area of 230 km².
Why have I chosen this species over the other 31? Well because population surveys in 2005 suggested there were 5,337 palila in Hawaii, which decreased enormously to <1000 in 2010. Why has this happened? Well palila breed in upland forest at 2000-3000m above sea level. The main threats to the population is habitat destruction from local settlements and predation from introduced rats, feral cats and even nest predation from short-eared owls (Asio flammeus)!
So what does the future hold for this enchanting species? Well, the population has been monitored since 1980 and there is an active captive breeding and reintroduction programme currently being undergone. In addition, prevention of habitat destruction from feral goats and sheep has been introduced into areas of the Māmane (Sophora chrysophylla) forest where the palila resides. In addition to this, there has been forest restoration in adjacent areas of the island to the Māmane forests to hopefully expand the range of the palila.
Conservation of the palila is a perfect of example of how conservation can sometimes require you to dig a lot deeper than the species you'd like to conserve. There are currently proposals for forest research in the Māmane forests of Mauna Kea to investigate possible ways to speed up reforestation.

So there we have it. A whirlwind adventure into the life and death or Hawaiian honeycreepers and the enigmatic palila....I hope you kept up!

-Zac Hinchcliffe

When Zac's not counting birds on patch (or making references to Star Wars), he's usually ringing birds on his regular Bangor site or is depressed that he does't have the money or time to twitch the latest big thing. Zac is 21 and currently studying a Research Masters at Bangor University and investigating Welsh Twite; adding a touch of science to his birding. 
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