Darren O'Connell, Author at EcoEvo@TCD

10/07/202010/07/2020

The remarkable bird life of the Wakatobi Islands, SE Sulawesi: hidden endemism and threatened populations

Working on the avifauna of the Wakatobi Islands was an opportunity to follow in the footsteps of some great ornithologists and biogeographers, out to a remote string of islands off South-east Sulawesi, Indonesia. The Wakatobis have always sat in glorious isolation, they’re a coral uplift which formed upon a platform of Australasian origin and have never been connected to mainland Sulawesi. This isolation has meant these islands are home to a unique mix of species, and have been largely understudied.

Until recently, knowledge of the islands’ biodiversity came solely from a brief visit at the beginning of the 20^th century by specimen collector Heinrich Kühn. This trip provided some important museum specimens and hinted at a potential hotspot of new species on theses islands, but no subsequent visits were made, and the Wakatobi Islands largely remained a mystery to science. Then in 1999, teams of researchers from Trinity College Dublin, Halu Oleo University and Operation Wallacea, led by my PhD supervisors Prof Nicola Marples and Dr David Kelly, began a series of eight research expeditions which aimed to investigate this potential trove of unique biodiversity. In our recent paper in the Raffles Bulletin of Zoology we summarise 20 years of remarkable work by Prof Marples, Dr Kelly and others, recording 100 bird species for the islands, highlight recently described species, and discuss the threats facing the resident Critically Endangered species.

30/06/202006/07/2020

The Bird Life of Wawonii and Muna Islands Part I: biodiversity recording in understudied corners of the Wallacea region

With Indonesia I’ve always felt like I’m just scraping the surface. Even after five field seasons in that incredible country I feel I’m always just finding further questions. One of my favourite bits was just driving around to new sites and travelling to different islands. There are always feats of incredible daring to observe (just piloting a car on a rural road takes nerves of steel), and engineering marvels and follies cut out of rainforest or carved from the hills. Any local leader could seemingly achieve anything with sufficient ambition, the consequences of which could really go either way! Easy explanations are usually not forthcoming. It is a culture where much is left unsaid, where one must ask the correct question the correct way to receive an answer. Perhaps it is this sense of mystery that keeps me coming back year after year, with each new island a world in itself.

09/12/201910/12/2019

Comparing the biodiversity and network ecology of restored and natural mangrove forests in the Wallacea Region.

Habitat loss is the primary threat to most species, as humans convert ever more areas of the globe to intensive land uses for our purposes. While some of this is unavoidable, the unsustainable level of global habitat loss has caused great damage to biodiversity, the fight against climate change, and the local economy and culture of vulnerable communities in the poorest parts of the world. It is increasingly clear that slowing habitat loss will be not be enough to repair this damage, we must restore/rehabilitate lost and damaged habitat. This process is already happening in many areas where human use is no longer economical, such as abandoned mines, upland farms and elsewhere. However restoring an ecosystem is not a simple process, many of these projects fail, and the reasons for this are not always clear. There are no agreed standards for measuring the success of habitat restoration. However in the Newcastle University Network Ecology Group we believe that ecological networks may hold the key to monitoring and directing restoration efforts. As part of the CoReNat consortium we are seeking to use ecological networks to assess the success of mangrove forest restoration projects in remote Northern Sulawesi, Indonesia.

12/09/201919/09/2019

Surveying birds on an unexplored tropical island – the TCD/Opwall expedition to Menui, South-east Sulawesi, Indonesia.

A big draw for those who study the natural world is the search for adventure – the chance to make a novel discovery, and to explore regions unknown to science. Despite that, in today’s world, such an opportunity rarely presents itself, and it is exceedingly rare to truly break new ground. However, in the summer of 2017 circumstances allowed a team of scientists from Trinity College Dublin (TCD), Halu Oleo University (UHO) and Operation Wallacea (Opwall) to venture to the remote, and scientifically unknown, Menui Island, in South-east Sulawesi, Indonesia. The expedition’s motive was to provide an account of the bird species present and their associating habitats. Our survey work, published in the latest issue of Forktail, found the island to be home to a unique avifauna and several important habitats, though these face serious threats from over-exploitation.

09/05/201909/05/2019

PhD Retrospective: Finding new bird species in Sulawesi

Almost as long as I can remember, I’ve wanted to be a Zoologist. Growing up on a steady diet of Attenborough documentaries, I dreamed of exploring new lands, discovering weird and wonderful species. I wanted to be the next Darwin. The next Wallace. In a lot of ways, my PhD research has been the fulfilment of that dream. It all started with my undergraduate thesis project in the Trinity College Dublin (TCD) Zoology Department. When Prof Nicola Marples and Dr David Kelly offered a project studying speciation on islands, I jumped at it. I spent the summer before the final year of my undergraduate island hopping in south-east Sulawesi, Indonesia, collecting data on how the physical traits of sunbird species had changed on isolated islands. Nicola and Dave’s project fieldwork was organised by Operation Wallacea, so we worked with Operation Wallacea staff as we moved around the islands and got to interact with scientists focusing on some of the other unique wildlife of Sulawesi.

Sulawesi is a region of massive interest to evolutionary biology. It is the intersection where Asian and Australian flora and fauna meet, and is separated by deep ocean trenches ensuring it has never been connected to a continent, allowing many unique species to develop there. As well as providing a fascinating study system, South-east Sulawesi has some incredible wildlife. Knobbed Hornbills, Tarsiers and Sulawesi Bear Cuscus are weird and wonderful treats. In particular, working with the birds of this region was incredible, and I was adamant it wouldn’t end up being a once in a lifetime experience! As well as allowing me to follow my island-hopping ambitions, this project kicked off what I predict will be a lifelong obsession. Having previously been a typical fan of large charismatic mammals, I became a full convert to the world of birds (it’s fundamentally all about the birds!).

Read the full post on the Operation Wallacea blog!

23/04/201922/06/2019

Two new bird species from the unique and understudied Sulawesi region

This blog was first published on #theBOUblog. Check it out at https://www.bou.org.uk/blog-oconnell-two-new-white-eye-species-sulawesi/

The Wallacea region has always been known to be home to many unique species, with birds of paradise, giant reptiles and marsupial versions of sloths found among its many islands! The region takes its name from Alfred Russel Wallace, who along with Darwin, developed the theory of evolution from his studies of the species of Wallacea. When I first set my heart on a career as a Zoologist (a decision made with absolute certainty at age 12!) I dreamed of following in the footsteps of these great naturalists. So it is of no surprise that when I finally got around to starting my PhD many years later, I chose to study speciation (the formation of new species during the course of evolution) in the birds of Wallacea, with the hope the region still held mysteries to uncover. Our research focused on South-east Sulawesi, Indonesia. Sulawesi is a weird and wonderful part of the world, and island hopping through that region has provided me with a lifetime of unforgettable memories. It also allowed me to fulfill my dream, as in our recent paper in the Zoological Journal of the Linnean Society, we describe two new bird species from the Wakatobi Islands, an island chain off South-east Sulawesi (Figure 1).

25/03/201909/05/2019

Battle of the sexes – Niche contraction in females but not males in high density island populations

olive-backed sunbird sexual dimorphism and competition in Sulawesi, Indonesia

This blog was first published on #theBOUblog. Check it out at https://www.bou.org.uk/blog-oconnell-olive-backed-sunbird-sexual-dimorphism/

Going right back to the time of Darwin, competition has always been seen as a driver of evolution. When we think of natural selection we often think of hyaenas and lions fighting it out on the plains of Africa, or a pack of wolves hassling a bear over a carcass. Resource competition like this is a daily part of survival for most animals, with a delicate balance of power between competitors which can change in different environments. However competition for resources takes place not only between species (interspecific competition), but within them (intraspecific competition), and often this is where competition is at its most fierce. Sexually dimorphic species present a special case when studying competition in different environments. They are species where the males and females are physically different, often in body size, but also in colouration and other characteristics. Males and females in sexually dimorphic species often occupy different but interlinked ecological niches. If intraspecific competition becomes more intense within a population of a sexually dimorphic species then one sex may suffer more than the other due to being smaller. In our recent paper in Emu – Austral Ornithology we report on one such case with a niche contraction in female Olive-backed Sunbirds (Cinnyris jugularis), but not males, in a highly competitive environment on small islands. This work was carried out on the remote and understudied islands of South-east Sulawesi, Indonesia (Figure 1), where a joint team of scientists from Trinity College Dublin (TCD) and Halu Oleo University (UHO) have been carrying out research into bird evolution since 1999.

07/11/201818/02/2019

Kingfisher Evolution in the Wallacea Region

Studying diversification in the Todiramphus kingfishers of Sulawesi often brought to mind the adage, ‘what is rare is beautiful’. Though I certainly also learned that rare beauties can be incredibly frustrating! While I could be guaranteed to catch my other main study taxa, Zosterops white-eyes, by the dozen in the right habitat, Collared Kingfishers (Todiramphus chloris) and Sacred Kingfishers (Todiramphus sanctus) were much more elusive. This made them maddening study species, but ensured that every time I got to grips with one was a special moment. Each bird caught was measured and had a few flank feathers taken before release. Even the most disappointing site could be made worthwhile by catching a kingfisher. In particular, I’ll never forget a particularly fetid swamp in the backwoods of Sulawesi, as I’m pretty sure all the mosquitos in the world lived there. It yielded our worst ever bird catches, but two crucial Collared Kingfishers! These moments of elation have stuck with me, and have ensured that the Todiramphus kingfishers are the study species I’m most fond of.

Darren O’Connell and Adi Karya examine birds, while being examined by passers-by. Photo by Suliman La Ode.

Continue reading “Kingfisher Evolution in the Wallacea Region”

17/08/201818/02/2019

Range extension for the Dwarf Sparrowhawk

Biodiversity monitoring work can often be disheartening. Typically, we end up documenting a decline in whatever species we are working with. So it’s always a pleasure to have the opportunity to deliver some positive news. A stroll with my collaborator Adi Karya around his university campus in Kendari city provided an unexpected opportunity to do just that. Halu Oleo University has quite a unique green space, a 65 ha patch of city forest, an island of jungle in a sea of urban development. While picking our way through a particularly muggy gully we saw the flash of a small raptor in the canopy, giving me just enough time to snap off a shot before it skulked away. Continue reading “Range extension for the Dwarf Sparrowhawk”

31/07/201818/02/2019

The avifauna of Kabaena Island

Most of us start off in ecological research for the fieldwork. I always dreamed of following in the footsteps of Darwin or Wallace, discovering species and exploring new lands. While I haven’t quite reached the level of my august peers (yet!), my PhD has allowed me to take a step on the road towards following that dream. My PhD field work involved travelling around beautiful tropical islands in remote parts of Indonesia. Tough work, but someone has to do it. We moved site every week as part of our sampling regime, working in mountains, swamps and everything in between. We stayed with local families, sometimes in hovels, sometimes in veritable palaces, often with one following the other. I find it hard to pick my favourite site, I loved them all in their own way, but if I have a favourite it’s Kabaena Island, off the south-east peninsular arm of Sulawesi. In 2016 I spent three weeks there surveying bird populations as part of joint research by Trinity College Dublin (TCD) and Halu Oleo University team. This work complemented previous research by previous TCD teams in 1999, 2001 and 2003 which led to the discovery of a new species of the Red-backed Thrush, the Kabaena Thrush (Geokichla erythronota kabaena). Continue reading “The avifauna of Kabaena Island”