Given the many problems caused by humans to the various species living on Pacific Islands, their rapid decline seems inevitable, but to a degree this process was happening naturally, long before we showed up. Such losses and gains were, and still are, dependent upon many factors, but as a general rule, smaller islands exhibit a greater turn over than do larger islands; and the arrival of man has now pushed the losses to the level of a major extinction event, with both New Zealand and Hawaii exhibiting clear examples of the problem.
I mentioned Hawaii’s carnivorous caterpillars in a previous article, and do so again because they are such a great example of the unusual directions that evolution can take on islands largely isolated by distance. So far as we know, meat eating caterpillars occur only on the islands of Hawaii.
How plants and animals get to be on a remote island in the first place depends on several things: the size and topography of the island, and its position in relation to other nearby islands is important; as is the distance these islands are from major land areas that might act as starting points for new arrivals, and this is critical both to what will arrive and how frequently; any organism capable of parthenogenesis (the development of embryos without the need for fertilisation) will have a better chance of getting started than will animals that require both males and females for reproduction.
Each and every island has a unique story held in its geology. Consider Australasia – around a 100 million years ago this huge land mass separated from Godwana (which was at the time a supercontinent). The split from Antartica happened between 37 and 35 million years ago as it moved northward. The land that would eventually be New Zealand started moving away from the larger mass we now call Australia between 60 to 85 million years ago.
It is possible thatNZ once formed part of a drowned continent, but for the millions of years the two main islands have remained above water in one form or another, extensive changes have occurred — including climatic extremes which will have eliminated many life forms.
Initially, when New Zealand sat alongside Australia, both were set in the same sub-tropical waters and in consequence had similar floras, but as the two separated, the sea flooded into the rift between them and formed the Tasman Sea. In consequence the New Zealand flora became isolated and new species began to evolve.
For the last 55 million years N.Z. has held its current position at around 2,000 kilometres to the south-east of Australia and experiences a much cooler climate than it once did, but ironically it now appears to be moving slowly back.
Apart from a few marine mammals and a couple of bat species, no other mammals have survived on these islands;
and none managed to colonise successfully until the arrival of Polynesian settlers less than a thousand years ago; this was followed by a second wave of mammalian competitors that came along with Europeans when they began settling little more than 250 years ago, with dire consequences to the established native species.
Prior to the arrival of humans and their entourage of plants and animals, New Zealand had been populated by a very distinctive flora and fauna that developed in isolation of the many mammalian predators evolved elsewhere. A European botanist arriving for the first time might initially consider that they had landed on another planet, because the invertebrates, amphibians, reptiles and birds that fill the niches taken up by mammals elsewhere, are so extraordinary.
New Zealand has been around for some time, but the Hawaiian Islands were formed far more recently and exclusively by volcanic activity — they quite literally erupted from the depths of the mid-Pacific and are about as remote from any other land area as it is possible to be. The first island, Kaui, started to push above water around 5 to 6 million years ago and is now the most westerly island in the chain. To the east at the opposite end is the Big Island (Hawai’i), and at less than a million years of age is still volcanically active.
Hawai’i is not huge, but nevertheless, it is big in comparison with the other islands in the chain. At around 10,500 square kilometres it is larger than the rest of the Hawaiian Islands put together, making up more than 60% of their total landmass.
Once the islands were formed, the possibility of a new plant or animal arriving on these tiny specks in the Pacific Ocean became a lottery. Miss the islands by only one mile or by a thousand, and the result would be the same — oblivion. Small organisms produced in large numbers will have had the best chance of arriving, with spores, seeds and tiny creatures the most likely candidates to be carried successfully on mid-altitude air currents to land against the odds on distant islands, although most of course will have perished.
Some species might have arrived carried across the surface of the ocean on any material that could stay afloat long enough to make landfall, but again the attrition rate would have been high and the chances of success slim.
It was a long shot that birds would arrive on Hawaiian Islands at all, given the distances involved, but when it did happen they would most likely have been carried on mid-altitude air currents. It is quite possible that only one or a small number of finch species arrived to become the honey creepers that radiated out across the Islands filling different habitats as they evolved into the 56 species that have been recorded, 18 of which are now extinct.
trying to convince plants to grow when I was buzzed by a drone – an exceedingly stealthy one. I didn’t see it, but certainly I heard it, hovering behind my head before making off at speed.
My wife sitting in a nearby lounger was able to make a more realistic observation – I was standing on the flight path of a rufous hummingbird, a creature weighing no more than a spoonful of sugar… it was attempting to visit a bee balm flower. Not quite a drone then, but even the most technically advanced machinery can’t come close to the manouvreability of a hummingbird – this the only bird that can fly backwards due to some fairly unique muscle structures that control the wings… wings that can quickly carry them from a standing start to a top speed of 30 m.p.h.. Right now the brain of a tiny bird easily outstrips anything human technology can achieve, but who knows, maybe one day?
The odd thing about rufous hummingbirds is just how noisy they can be as they fly past you, their wing feathers thrumming loudly as air rushes through them and usually the first indication that the birds are around. They can also be quite vociferous with their repetitive vocal clicking – usually directed at other birds but also sometimes at me, when I’m standing in the wrong place!
My most recent hummingbird encounter is one of many; thinking back to earlier wildlife filming trips when I first started coming out to the Americas, there was hardly a visit when I didn’t see one. Living as I now do in the Vancouver area doesn’t provide a huge hummingbird species count, but I’m just happy to be seeing them right through the year. If I had to make a list of my favourite things, only Africa would get a higher rating, and yes, I do get how odd it is to make a comparison between a large continent and a small bird.
Hummingbirds are a New World species that most likely originated in South America; these ever resourceful birds can now be found as far north as central Alaska, and as far south as the tip of Tierra del Fuego.
When my family and I first arrived in Canada we had only a balcony to attract wildlife and so we put up a bird feeder – a big cedar provided an agreeable background which like so many trees in Canadian gardens was attempting to take over the whole plot. My bird photography was going well, then one day to my surprise a hummingbird showed up and started licking at the peanuts and we responded by putting a hummingbird feeder in place. Soon after a family of Anna’s hummingbirds were regular visitors – there was an adult male, a female and three youngsters… each sibling completely intolerant of the others, aggressively buzzing their brothers or sisters whenever they started to feed. They seemed to have a real attitude problem, but that’s a very human response – all they are really doing is ‘grabbing’ at their best chance of survival.
The next year, I’m guessing it was the same pair of adults that showed up again and things went much the same way as they had done the previous year. The fall came and the rufous hummingbirds I had seen feeding in the park moved on, but I left the feeder out for stragglers… and then something interesting happened, the Anna’s hummingbird just kept coming and continued to do so right through the winter and this surprised me.
This never got old –
you’d be washing up on another desperately miserable day, and this beautiful bird would suddenly appear and hover just a few feet infront of your face – eliciting a feel good factor much appreciated in the middle of winter – these seemingly delicate creatures just the other side of a kitchen window in conditions that a human would not so easily deal with if they gave up on the chores and walked out of the back door.
Early one frosty morning I noticed a hummingbird working the nectar feeder at a really odd angle, and I soon realized that it was cold enough (at about -7ºC) for the sugar water in the container to freeze and make feeding a problem. From then on I would check every morning before doing anything else and thaw out the enegy drink whenever it was necessary. We were soon to move house and my first thought was that we couldn’t leave during the winter because the local hummingbirds had become reliant on the high energy food we were providing.
Our winter feeding Anna’s hummingbirds would get a jump start on potential nesting sites when they moved further north the following spring, and some might travel as far north as Alaska – a neighbour told me that it was proven that hummingbirds hitch a ride on the backs of geese, although I’m not quite sure which nursery rhyme she got that one from!
Living on the Edge.
It was a surprise to see hummingbirds waiting out winter in difficult conditions at the back of our house and I began to wonder how these little birds managed to survive so many cold nights when it was clear their feathers provided very little insulation.
The answer to this question sounds more like science fiction than science fact: each cold night the birds endure a near death experience; an evolutionary adaptation of their metabolic system which provides them with an extreme solution to an almost insurmountable problem.
They are able to survive falling temperatures by going into a form of suspended animation which parallels the Zuni claim that hummingbirds can slow down time. For the birds it is as if life is standing still; their existence hanging on a thread as they become hypothermic and go into torpor, with body temperatures dropping well below their active daytime body temperatures which are usually maintained at over 100˚ F.
After a cold night, it takes a while for hummingbirds to come back from the dead, and they do so by vibrating muscles in a similar manner to a moth or bumblebee generating heat before taking off from a cold start. Then it’s a race to find food; there are no lazy hummingbirds, individuals get busy as soon as their flight muscles will allow and quickly begin searching for food just to stay alive.
Small warm blooded animals have a large surface area in relation to their body mass, which means they lose heat far more quickly than do larger animals; in consequence hummingbirds are continually seeking out food, living fast food lifestyles without the downside of obesity.
Hummingbirds are exceptional in many ways:
they can achieve the highest heartbeat of any animal when fully active – at about 500 beats per second; and have the ability to convert sugar into energy far more quickly than any other warm blooded animal with adaptations to the digestive system that allow for rapid absorption of liquid sugars. The gizzard/stomach is comparatively large in relation to the bird’s size and the solution can pass quickly into the hummingbird’s intestine facilitating the generation of energy in a very short space of time. Hummingbirds however cannot survive entirely on the sugary juices provided by flowers and bird feeders, they require proteins gained from searching out invertebrates such as insects and spiders; this is necessary for growth and essential metabolic functions, and especially important during the rearing of offspring.
A Bit Flash
The skin, hair and feathers of most animals are usually made up of pigmented surfaces that absorb some light wavelengths and reflect others which we see as colour. Hummingbirds also have the advantage of irridescent plumage which is made all the more noticeable with sudden flashes of bright colour.
Irridescent feathers have a different structure from non-iridescent feathers which allows light to be refracted rather than reflected back; the process occurs at different levels in the feather and the light combination results in irridescence – some wavelengths combine and cancel one another out, while others combine and intensify the colours we see. The angle that light hits the feathers and our view point results in us seeing bright flashes of intense colour as the bird moves.
The great thing about hummingbirds is that you don’t have to go far to see them.
In the summer of 2014 I spent a week photographing rufous hummingbirds coming to feed on bee balm flowers in our local public gardens not far from the house. It was clear that when we had a garden of our own we might easily plant appropriate flowers to attract the birds in, and anybody living in the Americas can do the same. I noticed the birds had feeding patterns – early in the morning was best if the light was good, because they were eager to get started and the flowers were brimming with nectar. Young birds had recently come off the nest and I had to be quick to get shots of them because the siblings were very competitive over this small patch of food scrapping and chasing one another relentlessly.
Hummingbirds do well feeding in small gardens, but sadly they have to run the gauntlet of urban cats. This isn’t a favourite subject for some cat owners who are in denial about what their cats really get up to once out of doors. Domestic cats kill more hummingbirds in North America than any other predator, and by a large margin so it makes sense for those who wish to attract wild birds into their gardens not to keep one.
When we lived in New Zealand I created a native wildlife garden from scratch and it didn’t take long to realise that the key to success in attracting native birds was improved pest control, available nesting sites, and the provision of appropriate food plants. Coming from Europe, nectar feeding birds were a novelty and so we were especially keen to attract in the honeyeaters – these members of the Meliphagidae family which includes tuis and bellbirds, species that were almost non-existent in our garden when we arrived in 2002, but prolific by the time we left in 2010.
Today, our New Zealand neighbours are woken by a dawn chorus of native birds, something that would have been unthinkable on our bird silent property when we arrived. The native garden not only provides an important energy source in the form of nectar for birds, it also feeds many insects which provide the honeyeaters with their essential proteins – and the same is true for hummingbirds in the Americas.
Planting a rich nectar source in a garden is a no brainer, but it must be done withouth the use of toxic insecticides, which in any case shouldn’t be necessary if a garden is busy with insectivorous birds.
A recent trip to Mexico provided us with a chance to see a variety of hummingbirds that we never get in Canada, and at the start of the rainy season there was no shortage of opportunities to observe them. With that intention we spent several days in Vallarta Botanical Gardens, a place so packed with flowers, it fulfils an important secondary purpose supplying energy to nectar feeders.
A cinnamon hummingbird getting angry with just about anything that came close to him.
Outside of the gardens in the surrounding environment it was possible to see the occasional hummingbird, but in the gardens where there was a super-source of food, there were dozens to be observed through the course of a day with very little effort.
If the loss of natural habitats continues at the present rate, gardens and reserves may provide the best chance of survival for many species of plants and small animals. Certainly hummingbird nesting habitat is rapidly disappearing and although a great garden surrounded by protected woodland and scrub isn’t a longterm solution, until we wake up to the problems of habitat loss and instigate a more harmonious relationship with nature, it is the sort of place that will help and, in the end, may prove essential.
Seldom have I felt more comfortable than in Vallarta Botanical Gardens at the beginning of the rainy season when it is busy hummingbirds.
A restaurant on the top floor of the visitors centre provides great margaritas and fine Mexican food; it also offers stunning views, not just over the river and surrounding forest, but closer to the balcony rail there are hummingbird feeders that are constantly busy.
One thing I saw in the garden I’d never seen before was hummingbirds feeding on bromeliads. the botanic garden has an extensive collection and it is difficult to know which plant will be getting the next visit. My wife Jen acted as a spotter, which is very considerate with afternoon temperatures pushing past 100ºF.
On returning to B.C. we quickly discover that there is little change in our local weather since we left, but despite less than ideal conditions, hummingbirds were still visiting our garden flowers.
We moved to our new house in the spring of 2015 and almost before I did anything else I was putting in plants with flowers attractive to the hummers and it didn’t taken long for rufous hummingbirds to find them – this year the flower count is higher and the rufous are now here feeding on a daily basis. Maybe we will get to stage where we don’t stop whatever we are doing to marvel at their extrordinary beauty and stunning aerial ability… but so far, there seems to be no chance of that happening.
I will continue to take pictures of hummingbirds wherever I see them. If you have local birds that are easily captured on camera then please do the same – keeping a pictorial record of species whenever possible is essential because we can never be certain how much longer they will be with us; even if it were true that every time a hummingbird arrives – time stands still.
Any European botanist arriving in New Zealand for the first time might just as well be landing on a different planet – so extraordinarily is the plant life on these South Pacific islands.
It took four or five years to see any positive results when trying to establish our native New Zealand garden. The one thing that grew easily was flax, and this was encouraging, because I’d seen nectar feeding birds visiting flax flowers elsewhere – so, it wasn’t difficult to join up the dots… soon I was dividing and planting out as many locally grown flax as I could get my hands on.
One day I looked out of my office window and noticed the beautiful dusky red flowers of rewarewa blooming in the bush behind the house; and not long after an excitable tui began visiting several times a day to feed upon the nectar, but as soon as the flowers went over, so did the bird, quite literally – it flew over and away without hesitation. This was disappointing, but suddenly it dawned on me that we should be providing a whole range of appropriate flowering plants to attract birds in through spring and summer.
Tui feeding on Rewarewa in trees behind the house.
As nectar appeared to be the key, I started playing detective, following tuis to see what they were feeding on. In spring one of the first visits they made was to the beautiful sulphur coloured flowers of kowhai, and there the guilty bird’s faces were soon covered in pollen. Almost everybody in New Zealand must have seen this, but it was a revelation to me. On the day of my discovery, I set about searching for kowhia seedlings, which were easily found growing close by adult trees and were soon potted up and placed in a shade behind the house to establish.
Kowhai flowers are perfectly shaped for pollination by the curved beaks of tui and bellbird and once our first flowering kowhai were over, the birds moved quickly on to fresh rewarewa flowers in the trees behind the house. They sought out the colourful blooms just as our first visiting tui had done a few years earlier. I was excited by this minor progress – the nectar timeline availability had been doubled with the planting of a single species.
Next in line was the mountain flax, which flowers after rewarewa, and filled a gap until the familiar New Zealand flax started to provide a nectar bonanza in early summer – this progression carried us through the period when tui and bellbird rear their young, and if we could get them to stay and nest we were home and dry – tui feed their young primarily on insects and spiders and there is now no shortage of these. Things were looking up. My flax planting habit now bordered on an obsession, with hundreds of plants going in over just a few days – a hopeful invitation to a future nectar feeding frenzy.
As summer progressed, the nectar feeders (insects as well as the birds), moved onto pohutukawa that had been planted around the garden. Tui more naturally feed upon closely related rata flowers in the bush, but possum stripped them out before our arrival, although now the possum are under control the ratas are growing back.
Pohutukawa are susceptible to the frosts we get each winter until they are around a metre high; so these trees don’t grow here naturally and are more usually found in coastal regions where the climate is milder. I would cover our young plants every evening through winter until they were old enough to survive.
Pohutukawa flowers brought our nectar feeding season to a close and the birds would then leave in search of other now plentiful foods in late summer. Despite this tui and bellbird became permanent residents for five months or so through spring and summer, and in addition, they started to nest in our bush… Bingo!
Increased nectar availability is a major step forward, but ground cover is also important and I begin to measure success in terms of whether I can see cows in the next door pasture; the flax is beginning to screen them out now, and this is the plant of choice to form corridors along the fence line for birds to move along.
During 2007 we began to see more native birds. As I had hoped, our garden was developing a symbiotic relationship with the bush, and I wondered if this process might be applied more generally to some other conservation areas – providing the gardens can be prevented from moving into adjoining ecosystems.
Mixing wild areas with gardens is usually frowned upon, but if gardens are planted entirely to natives they will provide a concentrated food source for many birds and insects, and do no harm to recovering environments that are still very much out of balance.
And there was a lot else to establish on this land besides flax. Manuka had died out altogether due to a disease that hit the local area sometime before we arrived.
Eventually the manuka were re-established by collecting seedlings from locations where they grew densely, these were potted up to joined the kowhai seedlings behind the house and in a year or two, all were planted out. I learned the hard way that manuka are brittle plants and will snap in a high wind if there is no other growth to shelter them.
By 2010 eight acres of land was supporting a considerable number of birds, even bellbirds were moving along the edge of the paddock through corridors of flax, spreading the birds out and reducing competition.
The bush occupies half the plot with the rest divided between paddock and garden. It would have been great to get rid of the paddock altogether, but in reality this would have reduced our properties resale value. Conservation is often constrained by practicality and it is better to work within such limitations than make life miserable.
In many parts of New Zealand, the old growth forests have largely gone and there is less natural food available in the young densely growing secondary forests that have replaced them. In consequence nature reserves often provide feeding stations to supplement the diet of native birds, but these may also be an invitation to disease, whereas a natural garden has the advantage of providing a super source of food with far less chance of transmitting parasites and pathogens.
As the garden fills out, the number of bellbird and tui increase in number through spring and summer.
The young tuis are everywhere now – they are hanging out at the local nectar bars behaving boisterously and are making a lot of noise. In late summer, things will become quieter as the birds move off to feed elsewhere.
Young Tuis playing at being territorial.
Tuis and bellbirds return in the autumn to feed upon insects, spiders and sap flowing from trees in the bush; they will pick off food mostly at the forest edge where it is warmer, and we see them regularly.
As autumn arrives bellbirds feed behind the house.
Soon after we arrived, fifty lacebark trees were planted down the drive, they are old enough now to flower and supply food for large numbers of insects. In turn, some insects become food for the birds.
Establishing the strangling plant Muehlenbeckia australis behind the house has increased the number of New Zealand copper butterflies that live here; there were very few when we arrived. The adults are now common through January as the females go about laying their eggs on tiny Muehlenbeckia leaves.
I have tried to seal the bush line with native shrubs and trees and this is already reducing wind damage. In future this growth will increasingly protect the margins of this little block of bush.
So that’s the way it ends for us, we are moving on, although I refuse to say ‘to pastures new’. We can’t claim to have saved any species facing extinction, but when rare birds re-establish in the adjoining mountain reserve they will certainly travel down the spur of bush that ends close behind the house.
Currently there is a higher density of native birds here than further up the mountain due entirely to a super abundance of food provided by a diverse and concentrated garden planting regime. In the past at the onset of winter it is likely that birds would have migrated down from the mountain to the lush forests and bogs on the plains below, but almost all of this has now been drained and given over to pasture. Tui will venture further afield for food, but this is as far as most native birds will get.
Some of the birds we have attracted in were previously uncommon. Tomtits showed up in 2009 which was a first for us. The next on the list might be robins, recently re-introduced to the national reserve (further up the mountain) by a dedicated group of conservationists.
Rowdy kaka parrots have been seen on the lower slopes of the mountain and I am confident that they will show up here once the trees mature and begin bearing quantities of fruit.
As the bush matures other rare birds (once common here) will also return – no doubt to the delight of future residents living in this carefully sited home.
The North Island Kokako was last seen in the area during the 1990s; the good news is that it has recently been re-introduced to the forest reserve – a process that started during 2017. If this is a success, I am quite certain that one day the bird will return and feed on the property. The South Island Kokako which has an orange-red wattle is now thought to be extinct. Sadly this species has not been seen for a number of years, but some remain hopeful that it is hiding out somewhere and will one day be rediscovered.
It is already possible to see natural New Zealand treasures from the house. A few weeks before we moved out, I counted (within a few minutes), seven species of native bird moving around the garden while I was sat on the deck – a truly rewarding experience.
With a reduction in pests and an increase in food there has clearly been a positive response by visiting and part resident native birds. Our neighbours have also noticed an increase in activity.
Bellbirds are now regularly seen where once there were none and although they are less inclined to leave the bush line than are tui, they do now cross an open paddock to feed in our neighbour’s garden, which is a small thing, but an indication of positive change.
We have left this tiny piece of New Zealand more diverse than we found it; and this is something that almost anybody might do even with a relatively small block of land. It can be easily achieved with a little thought and effort, especially if they don’t keep a cat, and work at effective pest control.
This kind of project might be achieved almost anywhere in the world, although it need not necessarily involve nectar feeders, the priority might for example be to establish a greater abundance of seeds and fruits. Certainly planting for the provision of fruit as the bush matures was an important consideration for us. Tui and native pigeon are key birds for seed distribution in the New Zealand bush and it is clear they are driving regeneration here.
Returning diversity is essential when attempting to conserve ecosystems that have been degraded, and getting the birds and insects back is a necessary but small part of a far bigger picture.
Flowers are the key to feeding a great many animals in the New Zealand garden.
Our family’s carbon foot print has been covered by planting hundreds of trees and shrubs around this property, while the bush has been left to do its own thing, and now that there is no livestock grazing, the under storey is coming back. Parts of the bush are now impenetrable and there is extensive lush regeneration.
Half the land, which includes all of the bush area and quite a bit that was previously sheep pasture is now protected in perpetuity by a QE2 Covenant, and in theory, nobody will be able to fell trees or graze stock in the protected area again.
Each of our actions should be driven by what is realistically achievable, but we must also be hopeful for the future.
Results have not been achieved on this site by using a purists approach, and to a degree there has been a push to move things along. In many conservation areas, the rate of recovery needs to pick up, because for some plants an animals it is a race against time. Whatever the choices we make, it is essential to retain species diversity as our population numbers increase, and natural areas disappear.
I can only hope that future residents enjoy whatever achievements they manage in this extraordinary and interesting place, and that they will find time in years to come to ‘take a picture’, and make comparisons that might lead to further improvement, and in some small way help ‘save the planet’.
2002. Bird species seen in the bush on our arrival: fantail (Maori:- piwakawaka or tiwakawaka) ; grey warbler (Maori:- riroriro) and morepork owl (Maori:- ruru). Species occasionally seen or passing through: silvereye (Maori :- tauhou), tui and the bellbird (with two Maori names :- korimako and makamako).
2002. Bird species occasionally seen: Welcome Swallow (Maori :- warou) – these increased in number by nesting on the eaves of the house – two or three pairs would regularly rear two to three broods a year 2004 – 2010.
2002and2010. Birds speciescommon and nesting: Kingfisher (Maori:- kotare) and Pukeko (the latter a grassland species which is not truly native).
2010: Bird species very common through eight to ten months of the year either in the garden or the bush and also nesting: fantail, grey warbler, silver eye, tui, bellbird and New Zealand pigeon (Kereru).
No change: morepork owl – occasionally seen and often heard.
With thanks to my family and neighbours and especially Alice for helping with the planting in the final stages of our stay.
For the second half of ‘A New Zealand Odyssey’ numbers Six to Eleven in approximately 5 minute sequences, please see below. For Numbers One to Five please view ‘So Long New Zealand and Thanks for All the Sheep’. PART 1.
Pictures don't just tell stories – they change the world