Last month, the Zoology Department’s Dr. David Kelly launched his first book of Japanese short form poetry, Hammerscale from the Thrush’s Anvil. At the launch of the book, David invited us in the audience to try our hand at writing our own haikus.
Taking him up on his challenge, and taking inspiration from his book, a few of us in the School of Natural Sciences have penned our own poems based on our areas of study. We even have a contribution from David Kelly himself!
Trying not to sacrifice coherency at the alter of syllable number was a rather new struggle for most of us, but we managed and, I’d like to think, emerged with a greater appreciation for the poets in our midst. Read on for our science-y foray into the arts!
In the years to come, 140 ecologists working in Ireland will look back with fond memories of being part of the inaugural meeting of the Irish Ecological Association (24th-26th November). We will remember hard-hitting plenaries, compelling oral presentations, data-rich posters, influential workshops and the formation of the IEA’s first committee. The lively social events might be harder for some of us to remember…
There could not have been a more fitting way to open the conference than the plenary seminar from Professor Ian Montgomery (QUB) on Thursday night. Within the hour, he managed to given an incredibly detailed summary of the natural history of Ireland, showing how Ireland had been an island for 16,000 years and presenting evidence that human occupation dated back 13,000 years. Ian stepped us through successive mammal invasions, classifying them as true ‘natives’ and more recent ‘invasives’. His seminar was open to the public and the audience included local farmers with strong concerns about the impacts of invasive mammals on their stock.
We were welcomed the following morning with an energetic plenary from Professor Jane Memmott (U Bristol), covering her strikingly diverse career. She took us on a journey from life as a medical entomologist, to tropical ecologist living in a Costa Rican jungle tent, to invasion biologist in the land of invasives – New Zealand, to her more recent work on biodiversity in urban and farmland systems. Quantitative food webs were the central theme. Using both simple and complex food webs, based on enormous data sets, Jane clearly showed that we only see the full story about ecosystem dynamics by examining links between trophic levels. Continue reading “Ecology & Science in Ireland: the inaugural meeting of the Irish Ecological Association”
When attempting to conserve a rare animal population sometimes every individual counts. Conservationists regularly go the extra mile to protect their study species. The conservation efforts implemented for the Little Tern (Sternula albifrons) in Britain and Ireland demonstrate the success these efforts can have. This species nests on shingle beaches and had experienced catastrophic population declines due to increasing development and use of beaches by people. Little Tern adults are very vulnerable to disturbance and their eggs are particularly vulnerable to walker’s boots! Thankfully a network of wardened colonies, run by a mixture of conservation organisations and enthusiastic volunteer groups, succeeded in stabilising this species’ population.
However the Little Tern has lost much of its former range and is increasingly dependent on wardened colonies for their continued existence on these islands . Being concentrated in a densely populated protected areas has made them acutely vulnerable to predators. This has led wardens at the nationally important colony at Kilcoole in Co. Wicklow to adopt a practice of fostering Little Tern eggs abandoned after a depredation event in an attempt to maximise colony productivity, outlined in our recent paper in the latest issue of Irish Birds.
As Little Tern colonies are often squeezed into small protected areas this makes them a beacon to hungry predators. Corvids (members of the crow family), can be a danger to colonies. They are vigorously mobbed by the terns, but sometimes manage to slip through the defences. It was noticed that corvids often only managed to take one egg from a nest, perhaps because the parents were then more vigilant. However within a day of having an egg taken, the parents abandoned the remaining eggs in every case observed. This may have been due to anticipation of the predator’s return (Little Terns depend upon their egg’s camouflage to protect their nest), or in an attempt to re-lay a full clutch. However clutches laid later in the season often have poorer survival rates .
To maximise colony productivity, Kilcoole wardens fostered abandoned eggs abandoned after depredation events to other nests on the same incubation schedule when the colony experienced corvid depredation in 2011 and 2014. Nests were confirmed abandoned after the parent’s failed to return to incubate for several hours and the eggs went cold. The parents in recipient nests always accepted the foster eggs, apparently not questioning why they had gained an extra egg! Where possible eggs were fostered to other nests which had experienced partial depredation but had not yet been abandoned, replacing the eggs lost. Having a full clutch again seemed to stop the parents abandoning the nest. Fostering eggs resulted in the fledging of an additional 5 Little Tern chicks, a small but worthwhile number given the precarious status of the Irish populations.
The fact that the fostered eggs remained viable despite hours without incubation in cold conditions further demonstrate the extraordinary robustness of seabird eggs. In a previous paper we wrote about how Little Terns recollected eggs which have been washed out by tides and moved them into new nests. Many of these eggs hatched successfully even after hours without incubation, exposure to freezing seawater and potential mechanical damage from being moved.
This robustness can prove a boon for conservationists working with endangered species. In a recent case an egg abandoned by an inexperienced pair of Chatham Island Tāikos (Pterodroma magenta) was successfully fostered to another pair after being abandoned for 10 days. Even after all this time without incubation a healthy chick was hatched, an important victory as only 150 of these birds are left in the world, showing the potential value of egg fostering.
While the aspiration must always be for animal populations to be self-sustaining, in many cases hands on conservation measures are necessary to ensure a population’s survival. In order to ensure the continued survival of the Little Tern in Britain and Ireland wardened colonies are still necessary, at least until they experience a full tern around in fortunes.
Author: Darren O’Connell
Photo credits: Little Terns – Andrew Power and Peter Cutler. Chatham Island Taiko Chick – Dave Boyle.
A special thanks to all my co-workers on the Kilcoole Little Tern project, the volunteers who make the project tick and project manager Dr Stephen Newton of BirdWatch Ireland.
 Balmer, D., Gillings, S., Caffrey, B., Swann, B., Downie, I. and Fuller, R. (2013) Bird Atlas 2007-11: the breeding and wintering birds of Britain and Ireland. HarperCollins, UK.
 Nager, R.G., Monaghan, P. and Houston, D.C. 2000. Within-clutch trade-offs between the number and quality of eggs: experimental manipulations in gulls. Ecology 81: 1339-1350. DOI: 10.1890/0012-9658(2000)081[1339:WCTOBT]2.0.CO;2
For those of us with an interest in the natural world, Mute Swans (Cygnus olor) are a staple of urban wildlife in Dublin, present in many parks and along both canals. However, it has been 25 years since there has been any real assessment of the state of the Mute Swan population in the Dublin region (1). This has been a period of immense change in the urban landscape.
This summer, the Irish Midlands Ringing Group (IMRG) started a monitoring project to assess the state of the Mute Swan population in the Dublin region and to better understand their population dynamics, coordinated by Graham Prole of the IMRG https://irishmidlandsringing.wordpress.com/2015/10/05/mute-swan-colour-ringing/. The first stage of the project was a comprehensive survey of breeding by swans in the Dublin region. This revealed high nest occupancy rates, with 42 pairs successfully producing cygnets, an increase on the last survey 25 years ago. The monitoring of these breeding attempts is ongoing, with 20 pairs still with cygnets. The new habitat provided by the artificial lakes constructed in parks in the Dublin suburbs (such as Tymon Park in Tallaght), seems to have been a significant boon to the swan population. Breeding success was particularly high in these parks, likely helped by members of the public regularly feeding the swans in these areas.
The results of the swan breeding survey have raised more questions. While breeding success seems to be high, bachelor herds (groups of juveniles who have been forced out by their parents and adult birds who have yet to win a territory) are much reduced in traditional locations. To gain a better understanding of the population dynamics and movements of the Dublin region swan population, the IMRG has commenced a colour ringing scheme. The colour rings are yellow darvic rings with a unique inscription in black letters fitted to the swan’s leg.
Catching the swans for ringing is greatly aided by the fact that many of them are used to being fed bread by the public, but it can still be a daunting task to the uninitiated. Mute Swans are powerful birds, with a reputation for being aggressive (a reputation which some individuals certainly live up to!). They are caught by hand when they come to feed on bread, taking care to prevent them from flapping and straining their wings. The ring is quickly attached and they are released back onto their patch. The swans quickly recover and don’t seem to hold any grudge, as ringed individuals often return to take bread from the team which ringed them!
To date, over 60 swans have been colour ringed. Re-sightings of these rings allow the lives of individual swans to be followed without any further disturbance. Of particular interest is the dispersal of juvenile swans and the recruitment of bachelor birds into the breeding population. This project is already beginning to generate data as the first juveniles begin to disperse to join bachelor herds, with ringed juveniles moving from Tallaght to the Grand Canal, Swords estuary and Bray Harbour. The furthest dispersal distance so far has been 18km. The colour rings are large enough to be easily read by members of the public, promoting community engagement with the project. Any re-sightings would be greatly appreciated and can be sent to firstname.lastname@example.org.
A special thanks to Graham Prole for coordinating this project, to all IMRG members who helped at the catches and to South Dublin and Kildare County Councils who provided permission and financial support. This work was carried out under licence from the National Parks and Wildlife Service and British Trust for Ornithology.
Collins, R. and Whelan J. (1994) Movements in an Irish Mute Swan Cygnus olor Ringing and Migration. 15: 40-19. doi: 10.1080/03078698.1994.9674070
A reminder for the photo competition. We’ll extend the deadline until the 10th June. You can submit one photograph to this album here. Just log in with username ecoevoblog and password is the same. Don’t make it obvious that it’s your image in case it biases the judge. The theme is ‘Fowl Play’.
Early morning flights are a pain: nobody likes rolling out of bed at the crack of dawn. But if you’ve spent a few bleary-eyed mornings at airports, spare a thought for the local residents. Birds rely on their song to find a mate and keep intruders out of their territory: not an easy task when you’re competing with the roar of a 747 taking off at 290 km/h. Now, research by scientists in Spain and Germany has found that birds living near major airports sing earlier in the morning to avoid being drowned out by aircraft noise.
Researchers from the National Museum of Natural History in Madrid and Freie Universität in Berlin recorded the dawn chorus at sites around 5 major airports. As lead author, Dr. Diego Gil explained, “the idea came one day that I was taking a very early flight and when I arrived at the airport I heard blackbirds singing very early. I thought that perhaps they were trying to get their voices heard before the planes would start flying”. His hunch turned out to be correct.
The team found that many birds such as robins, blackbirds, cuckoos and blue tits that live near airports sing earlier than is normal for their species. Variation in light pollution and daylight length at each site did not affect the tweeting birds so it seems that noise pollution from the airports is the key factor. This shift in the birds’ normal behaviour appears to be an evolutionary response to the pressures of living in an environment dominated by humans. The research was published in Behavioural Ecology.
The birds start singing early in the morning before the airport is active so they are not simply responding to immediate noisy cues. Instead, they appear to have evolved over many generations to adapt their behaviour to deal with the very predictable high noise levels from airports (starting around 6am and increasing throughout the morning). This ties in with previous research which showed that robins are more likely to sing at night in noisy cities and blackbirds start to sing earlier in areas with high traffic noise. With individual planes generating noise four times louder than bird song, it’s easy to understand why birds have opted for a strategy of avoidance rather than competition with their airport neighbours.
Changing their singing behaviour could put energetic stresses on the birds. Whether you consider it a melodious wake-up call or a chattering irritation, the dawn chorus is actually a bragging competition. Birds sing to defend their territories (“keep out this is mine”) or else to attract mates (“I’m big and strong so let’s make babies”). Singing costs both time and energy and must be balanced with the need to go and find food. As Dr. Gil commented, “I would think that singing earlier than what is expected for a given species would modify the energy budget for the birds. Of course, it is possible that there is an optimal solution for this, a kind of plan B, and that birds manage to compensate for it, but it surely brings about a challenge.”
The next step will be to determine the consequences of earlier singing times for birds near airports. The researchers plan to study general activity patterns and feeding behaviour to see if the birds are physiologically affected by their shift in singing times.
So, the next time you grumble about getting up for an early flight, think of your feathered neighbours who have to rise for the early shift each morning to sing their wake up songs and beat the airport rush hour.
Let’s run another photo competition. Starting today and running until Monday 18th May anyone can submit one photograph to this album here. Just log in with username ecoevoblog and password is the same. Don’t make it obvious that it’s your image in case it biases the judge. The theme for this month will be ‘Fowl Play’. Prizes will be determined in due course.
These days I’m writing up the discussion of my sensitivity analysis paper on missing data using the Total Evidence method (more about it here and here). One evident opening for proposing future improvement on my analysis is the obvious “let’s-do-it-again-with-more-data” one… But a recent Science paper by Jarvis et al made me reconsider that. Is more the always better?
Jarvis and his numerous colleagues just published one of the biggest bird phylogenies that contrasts with the previous reference one (by Jetz et al in Nature). In Jetz’s paper, the authors were interested in the relations among modern birds (read “non-dinosaurs ones”) and tackled the question by trying to sample the whole of bird biodiversity (9,993 species!). However, as in most analyses of this kind, the molecular data can be fairly poor (note that they still managed to collect a maximum of 15 genes for 6663 species). Even though the global picture of avian diversity is clear, some regions are less resolved than others and an obvious way to fix that would be to sample more genes per species. And that is, in a way, exactly what Jarvis and his colleagues tried to achieve.
In this new study, the authors went on sampling not 15, 70 or 150 genes but 8251 genes per species! This led to a really deep and long analysis – over 400 CPU years, and I thought 150 was long! – of the complete genome of birds. By the way, they use the name Total Evidence nucleotide tree (TENT) to design the results of their analysis which is pretty confusing since a total evidence tree means something quite different to me. But that’s just a semantic rant. Using this massive TENT, the authors fixed some previously poorly resolved nodes, redefined the names of ancient divergences among birds (with the Passerea – tits and relatives – and the Columbea – pigeons and relatives), demonstrated an explosive (“big-bang”) radiation after the K-T event and determined the patterns of certain traits evolution (such as raptoriality or vocal learning). In short a thorough work that allowed the authors to say: “The conflict we observe with other data types can no longer be considered to be due to error from smaller amounts of sequence data”. I feel that writing something like that in a paper is a nice achievement!
However – don’t get me wrong, this paper is yet a great example of collaborative work and insight in new methods – the sample size is… 45 species. In other words, Jetz et. al sampled 100% of the species but less than 1% of the data as for Jarvis et al., they sampled 100% of the data for less than 1% of the species. In this case, we have two extreme views of the same question (“how did avian diversity evolve?”) and in both cases, I think the macroevolutionary claims are weakened by the number of species or the amount of data… However, from a practical point of view, I think the method that included more species will be preferred by researchers since their species of interest are more likely to be present in that tree. What’s the best balance? Full genome or full sampling? I’ll leave it to you to decide…
It’s coming up to winter so people will be conscious that our garden birds need a helping hand to get through the cold months. Bird feeders will be stocked, bread served up and water dished out. In the UK alone, almost half of households provide supplementary food for birds throughout the year. And although songbirds are usually the species that come to mind when we think of provisioning food the same principle can apply to more exotic birds, notably vultures. Indeed conservationists have supplied extra food to these scavengers for decades. Instead of bread or berries, a carcass is left out for the vultures to feed on. A recent paper of ours advocates this technique for a population of African White-backed Vultures in Swaziland.
This country is home to the densest breeding population of this species so we should do our best to conserve them given the huge declines suffered by vultures throughout the Old World. In the paper we showed times when there isn’t enough food in Swaziland to feed the whole population which means the birds are forced to forage farther afield, most likely in South Africa. On the face of it this doesn’t seem problematic because South Africa has huge populations of herbivores which could supply carcasses to vultures. But the birds must fly over unprotected areas as well. This increases their chances that they’ll encounter a poisoned carcass, perhaps set out by a farmer to kill the terrestrial carnivores harassing his livestock.
It’s well known that vultures are particularly sensitive to poisons, especially NSAIDs. Their group foraging behaviour makes them even more susceptible too, the discovery of a carcass by one individual will bring in the rest of the soaring birds in visual range. The hope with creating vulture restaurants is the birds will focus on foraging for carrion in Swaziland, minimising the risk of poisoning.
Yet there are well known problems with supplying supplementary food for animals in general. They may act as an ecological trap for instance, drawing the birds into an area only for the fickle humans to stop the supply of food. Carrion is an unpredictable resource so vultures forage in a characteristic way to improve their chance of encountering it. If food is supplied in a predicable way there is a fear we may disrupt these behaviours. Another recently realised danger in providing supplementary food is that it can attract unwanted guests. Sites tailor made for vultures in South Africa were shown to draw in jackals and hyenas.
Given these issues practitioners need to think carefully about how they provide food. Perhaps the best approach is a series of sites supplying food at random which would best represent the distribution of naturally occurring carrion.
The last two years have seen successive record breeding seasons for Little Terns (Sternula albifrons) on the Irish east coast, with over 350 pairs breeding in 2013 and over 400 pairs in 2014. These record years are the result of 30 years of dedicated efforts to rescue Little Terns as an Irish breeding species, after population collapses in the 1980s and 1990s. As part of the BirdWatch Ireland team involved in these two exceptional years, we reflect on the conservation success story which has led to this remarkable tern-around in fortunes.
The Little Tern is Ireland’s second rarest breeding seabird. They breed in three main colonies on the east coast, Kilcoole (Wicklow), Baltray (Louth) and Wexford Harbour, and 10-15 smaller colonies on islands off the west coast. Little Terns breed in Europe, migrating to the west coast of Africa each winter. They arrive in Ireland from late April and leave with their fledged chicks in mid-August. The fledglings spend their first year in Africa, returning to breed in their second year. During the breeding season Little Terns nest on shingle beaches, with their nest being little more than a scrape in the shingle. Their eggs rely on their perfect camouflage for protection. However, this makes them acutely vulnerable to human disturbance, as eggs are easily trampled by people and dogs. The increased use of beaches as a recreational resource from the middle of the 20th century onwards led to severe population losses and the abandonment of many traditional colony sites such as the North Bull Island, Co. Dublin.
In response to this population decline the first Irish Little Tern protection scheme was initiated at Kilcoole in 1985 by BirdWatch Ireland and the National Parks and Wildlife Services. A section of the beach was fenced off from the public during the breeding season, with wardens on site to monitor breeding success and ward off potential predators. Coming from a low base of fewer than 20 breeding pairs in the mid-80s, numbers built slowly through the 1990s and Kilcoole was the only Irish Little Tern colony to maintain a breeding presence during this period. Good breeding seasons between 2003-2005 and 2008-2011 (50+ pairs, 100+ fledglings) paved the way for this year’s record success, with 120 pairs producing 219 fledglings.
The recovery of Little Terns was greatly aided by the initiation of a second wardening scheme at Baltray in 2007 by volunteers from the Louth Nature Trust, funded by the Heritage Council. BirdWatch Ireland joined the Baltray scheme as a partner in 2013. That year saw the Baltray colony more than doubling its previous success, with 102 pairs producing 193 fledglings. The 2014 season proved more difficult, with the colony suffering heavily from predation. However, the maintenance of a second wardened colony is hugely important, so that breeding success is no longer entirely dependent on a single site.
While wardened colonies such as those at Kilcoole and Baltray have succeeded in halting population decline in Little Terns in Britain and Ireland, their contraction in range has been much more severe . Their vulnerability to disturbance has seen a shift towards fewer, larger colonies in the remaining areas where they are free from human disturbance, mostly in fenced off wardened areas or on offshore islands. This brings its own problems. Little Terns would naturally breed in smaller colonies, widely spread along shingle beaches. The more densely inhabited protected colonies are a beacon to predators, especially mammalian predators such as foxes, hedgehogs and mink, which can clean out a colony in a single night. Most wardened colonies have had to adopt elaborate fencing and 24-hour wardening to protect against heavy predation. While these fenced off areas are far from a natural environment, these wardening schemes have ensured the continued existence of the Little Tern as a breeding species, as well as having a positive knock on effect for breeding waders and other species which depend on the shingle beach habitat.
2014 was also a special year because we were lucky enough to be the first wardens to colour ring Little Terns in Ireland. Green darvic colour rings were used, with a unique three letter code in white writing, beginning with ‘I’. Between Kilcoole and Baltray 159 Little Tern chicks were colour ringed in Ireland this year. In addition to the Irish scheme Little Terns are being colour ringed with yellow colour rings engraved with black writing on the Isle of Man and at various other British sites. This will give us a much better understanding of the movements of Little Terns between colonies within the Irish Sea, their pre-migration staging posts and the routes they take through Europe on migration. It will also allow us to gain a greater insight into aspects of their biology such as pair fidelity, recruitment rate of fledglings into the breeding population, individual preference in nest location and adult longevity.
We have already started to reap the rewards as Kilcoole fledglings have been re-sighted at Hilbre Island in the Dee estuary, south Devon, Brittany and Lisbon. These first few sightings have already given us insight into how Little Terns move through Europe on migration. Hopefully these are the first of many sightings and we eagerly await summer 2016, when the first Little Terns colour ringed in Ireland should be returning to breed for the first time!
While 2013 and 2014 were unparalleled successes, Little Terns colonies are extremely vulnerable to predation and inclement weather. This was illustrated in 2012 when the east coast colonies experienced almost zero breeding success due to a series of storms. Therefore the continuation of current conservation measures are necessary for their survival. As well as its conservation value, the BirdWatch Ireland tern colonies have also proved an invaluable educational resource, providing a point of contact with the public. They have also provided inspiration, training and employment for many budding conservationists.
For more information about the Kilcoole project see the recent RTÉ news report on the project’s record year:
The 2013 Baltray and 2014 Kilcoole Little Tern Wardens
With a special thanks to Niall Keogh, Cole Macey, Jerry Wray, Tony Glass and Maurice Conaghy, our co-workers on many an early morning and late night, project manager Dr Stephan Newton and all the volunteers who make Baltray and Kilcoole tick.
Balmer, D., Gillings, S., Caffrey, B., Swann, B., Downie, I. and Fuller, R. (2013) Bird Atlas 2007-11: the breeding and wintering birds of Britain and Ireland. HarperCollins, UK.