Basking sharks- heading towards extinction in New Zealand’s waters
09 May 2011
The basking shark is the second largest fish in the world, reaching a size of up to 12 metres. These spectacular sharks have declined rapidly in New Zealand’s waters in the last 20 years. There are now serious concerns about the conservation of basking sharks in New Zealand.
While schools of basking sharks were sighted frequently in Canterbury’s inshore waters up until the mid- 1990’s, few sharks have been seen in recent years. The Department of Conservation is keen to place satellite transmitters on basking sharks, yet despite trying hard to locate sharks, they have failed to do so for several years now. DOC is urgently asking fisherman and members of public to report basking shark sightings, real time, so that satellite transmitters can be placed on them so we can learn more about this enigmatic species.
Basking sharks often come close inshore over the spring and summer months. They are at risk from entanglement in set nets and cray-pot ropes. Each year basking sharks are also taken as by catch by trawlers. Often destroying the net due to their large size. Yet the sharks are valuable and the livers and fins from an individual shark may reach $10, 000. The species is monitored by the international conservation groups. Basking sharks may also be at risk from increasing amounts of plastic pollution as they are a plankton feeding species. Basking sharks are also preyed upon by Orca. In 2009 DOC processed requests for the export of basking shark fins from about seven fish
In anyone sees a basking shark they are encouraged to report it to their nearest Department of Conservation Office as soon as possible. The satellite tracking project is being funded by National Geographic. Hopefully some sharks will be found to tag. Basking sharks are recognised by their large black triangular fin and habit of swimming slowly on the surface- hence their name. The shark’s body appears quite black from a distance, but at closer range is a blackish- brown mottle. It is ultimately the basking sharks large size that distinguishes them from most other shark species. It would be a pity to lose this giant of our ocean realm.
Sunday, May 8, 2011
Tuesday, April 19, 2011
Monday, April 18, 2011
Rock wren have small and fragmented residual populations in Canterbury. Available data suggests that their have been recent declines in the numbers of this bird. There are no dedicated predator trapping programs in Canterbury, to my knowledge to protect this iconic bird of our alpine environments. Sadly the rock wren's close relative , the bush wren became extinct in the mid 1960's- are rock wrens heading down the some track in Canterbury ?
Sunday, April 10, 2011
Discarded lines and lures kill birds
11 April 2011
Recently I was sent some photographs of a oystercatcher which had eaten a string of soft baits which imitates the birds prey of shrimps. Sadly the bird died. It is important that all anglers take care not to leave behind or discard any fishing gear such as traces with soft baits or fishing lines.
According to Rosemary Tully of Whakatane Bird Rescue “many seabirds and others get caught not only in bait and hooks but the lines wrapping around the legs and wings etc. Shags, Gulls, Penguins, Gannets, and Oyster-catchers have all come into care (some dead) with these problems. “
As more and more people use our coastlines for fishing and recreation there is an increasing amount of pressure on our marine and coastal birds. As anglers much of the experience of heading out fishing is about the wildlife, scenery and catching fish. So take care out there with your fishing gear so that we can conserve the wildlife along our coastlines. Always collect all fishing gear at the end of the day. If anyone finds any birds or wildlife entangled with fishing gear phone the DOC hotline- 0800 362 468 and hopefully an attempt will be made to get the bird to a nearby rescue centre.
It is testament of just how natural and effective that soft baits imitate the real prey that birds will consume them. Birds have much sharper eyesight and are more discerning overall than fish.
Anglers can do their part by picking up discarded fishing line they find on a beach, such as bungles of nylon, which are often deadly to birds. Sadly in addition to recreational anglers, the entanglement of rare seabirds by commercial fishing gear remains a major problem.
Photograph- shows a rare variable oystercatcher at Maketu Spit, with a national population of only several thousand birds, lethally caught in a string of soft baits. (Photo by Julian Fitter).
Thursday, April 7, 2011
Blue times for blue ducks in Canterbury
6 April 2011
A survey in February this year found an alarmingly low number of blue ducks ( Whio) in Arthur’s Pass National Park. The survey was very comprehensive throughout Arthurs Pass involving helicopters for access and also the use of tracking dogs to find birds that may have been concealed along the river margins during the survey. Over several days three survey teams only found six birds.
With the Arthur’s Pass population of blue ducks being so small the regional population is now under threat. Within Canterbury only the odd individual blue duck is found outside Arthurs Pass and outside of the park there are no other known viable breeding populations in Canterbury. The hope is now, and it is at the eleventh hour, that the population will slowly recover in response to predator trapping that has been taking place along the rivers in Arthurs Pass for blue ducks in since 2004.
Blue ducks used to be common in Canterbury, even being on the Avon River- but like many native birds have retreated in their range to higher altitude and remote locations. There were about 50 blue ducks remaining in Canterbury in the early 1980s but since then the population has continued to decline with a corresponding contraction in the bird’s range. Sadly nowadays these populations are being hit by stoats. Without a doubt now it is known that blue duck populations will not survive in the wild unless predator trapping takes place along river margins.
Blue ducks only nationally number about 3000 and the species is considered nationally vulnerable by DOC. The department’s Waimakariri Office is always keen to hear of any sightings of blue ducks from trampers especially in the Canterbury Region and any breeding records any sightings of blue ducks with ducklings would be very significant.
Predator trapping to protect blue ducks specifically is a recent development in Arthurs Pass and has been funded by sponsorship from the Coast to Coast and other sources. Yet the trapping is relatively recent and may need refining as it has been shown in many other areas in New Zealand such as Fiordland and on the West Coast that blue duck’s breeding productivity, and survivorship, increases dramatically after stoat trapping takes place. Stoats are recognised as being the number one predator of eggs, chicks and even on occasions adults. That there are a few isolated blue ducks in other parts of Canterbury may be due to the fact that blue ducks are relatively long-lived ducks with records of birds living over 13 years of age.
For many whom venture into the outdoors the blue duck is a symbol of our remoter wilderness waterways. I hope that we can keep this iconic bird in the wild Canterbury. Our wilderness rivers will see very empty without them !
Sunday, February 27, 2011
Kea - The world’s most intelligent bird and the bird that flies closest to the stars.
C. Peter Langlands
Keas are nothing less than a joy to encounter. For me they are always the highlight when passing through any of our major alpine passes, and are like visiting a long lost friend. Our kea is perhaps the worlds’ most intelligent bird and I have to wonder when I watch them, are they are watching me back just as intensely. Maybe waiting for me to walk just far enough from my car so that they can have a good chew on the rubber around my cars’ window ?
Recently while at the Homer Tunnel I walked up from the car park , to view an array of alpine plants, and looking down on the car park all the keas seemed to have miraculously disappeared. Then I looked at my car, with a sea kayak on it, in the corner of the car park, and then I noticed, with a mild level of shock, all the keas perched on the edge of my cockpit having a good chew. Fortunately I got back down to my car before they hit the bungy chords, which would have been a mess. Oddly they liked chewing on the hard rim, perhaps sharpening their beaks on the entrée before the main course !
Of course we may have simply mistaken the kea’s apparently mischievous nature for just a general sense of curiosity. Living in an alpine environment keas have to be naturally curious to survive, and in many areas have become opportunistic, feeding in a range of seasonally available foods. Indeed it is the keas ability to quickly learn new behaviours that has also got them into to trouble.
While farmers have rumoured, for over a hundred years, that certain rouge kea will hop onto the backs of sheep and peck away at the live animal, aiming for it’s kidney, and often causing blood poisoning, this fact has only been proved in recent decades. Night viewing gear has allowed cameramen to document these attacks, in which only a small number of birds participate. The “bikey” gang of the kea clan. Under special permit these rogue bird have been shot , before the behaviour spreads amongst the other birds.
Fortunately today keas are fully protected. This is only a recent development and up until the mid- 1980’s keas were regularly shot by high country merino sheep farmers. Earlier in the centaury keas had a bounty on them ! Farmers used to use calling birds in cages next to the farm homestead, to bring the birds down from the mountain slopes, where they could be shot with relative ease. In other cases beer bottles were smashed on the mountainside side and the inquisitive keas would come down to investigate the shiny glass, and were shot. Historically the green and orange feathers of the kea were also used for trout flies. A practice that has since ceased.
Today probably only around 5000 keas survive, so we can not be complacent about their survival. They are long-lived birds and breed at a slow rate. It is easy to get an inflated idea of how many keas there are, as they are very gregarious around spots where people stop , hoping to scavenge some food scraps, or when flying through valleys, call loudly over several kilometres, highlighting their presence.
For me seeing, or more often, hearing keas, is a defining part of the alpine experience in the South Island’s high country. In some areas, such as Fiordland, the keas will come down to sea level. Where earlier this year another mob ( from the Homer Tunnel birds) accosted my sea -kayak !. The kea’s close relative, the kaka, is critically endangered. Kakas are also very intelligent, but for survival in alpine environments, where the ability to learn quick to survive, the kea is king.
Monday, February 7, 2011
"just had a call from the kea conservation trust yesterday. There has been an 80% reduction in their numbers in Nelson Lakes and other areas due to predation and lead poisoning. I am sending them cards for sale to support their work. Visit keaconservation.co.nz"
( from Pauline Morse 08/02/11)
( from Pauline Morse 08/02/11)
Saturday, January 1, 2011
Black-fronted Terns Tarapiroe - Agile birds of the river under threat.
For me one of the defining moments of spending time on the river is watching the wildlife. In the South Island black-fronted terns are one of the most conspicuous of riverbed birds. They are constantly in flight, and like giant swallows capture all of their food on the wing. Often it is the tern’s call, which will alert me prior to sighting the birds. Often the terns will be seen gliding effortlessly up the river and will invariably fly into the wind when feeding. For me as an angler the experience of watching the terns is a welcome sight when tramping long distances up the riverbed. Sighting the terns makes the trip go quicker, and the distance between fish shorter. Without them the river would seem an empty place.
Yet as I write the black-fronted tern is classified as a critically endangered species. While they still appear to be very conspicuous, the species is in decline in many areas. A few terns can seem like a lot of birds as they are constantly flying up and down the river’s course. Yet often the some bird will be sighted throughout the day, giving an inflated impression of the numbers of terns. Also the terns we are sighting on the river may also be an aging population. Black fronted terns may, if we look at closely related species, live for at least twenty years.
The reason why terns are so endangered is that they are highly vulnerable to a multitude of factors during their breeding phase. They are ground nesting birds. Their nests consist of inconspicuous scapes in the stones and are easily run over by four wheel drives, stepped on accidentally by anglers, or dogs. Yet of greater concern is the predation of tern nests by stoats, and other introduced mammals, such as hedgehogs, which appear not be as innocent as thought. Wild cats can also wreck havoc on the terns breeding colonies. As terns require areas of open gravel to nest on, vegetation encroachment is also a major factor and greatly reduces the available space for nesting birds. Increasing numbers of black-backed gulls on the rivers also reduce nesting space for the terns. If these factors weren’t enough the terns also have to contend with natural floods, which will often wipe out an entire colony. The eggs and chicks are highly vulnerable and the chicks are also often run over accidentally.
Often you know you are in a tern colony when the birds swoop and squawk relentlessly, and will even when highly agitated lightly hit you on the head. At such times whether walking, or in a four-wheel drive, the best thing to do is to immediately vacate the area. The terns are sensitive to disturbance, and if the colony is in the early stages the birds will readily dessert the colony, after only a low amount of disturbance. Given the fact that the terns are colonial nesters on the riverbed they also literally “put all their eggs in one basket”.
Yet it is in our broader interest that anglers and trampers show concern for the terns, along with other endangered riverbed birds, such as the wrybill and black-billed gull, for these birds act as important icons when advocating water conservation. Terns are a marker of the health of the river. Surely without their presence on our open braided rivers, they would seem like very empty spaces. In the winter the terns vacate the rivers of the South Island to feed on coastal waters on the East Coast, with the Kaikoura region being an important feeding ground. Many birds also feed on the estuaries around the lower North Island.
Black fronted terns are only found in New Zealand (primarily a South Island bird during the breeding season). An estimate published in 1996 is of a population of only 5000 birds. They are critically endangered and as outdoor enthusiasts we must minimise our presence on their breeding colonies when fishing or four wheel driving, and have a responsibility to alert DOC of any riverbed activities that we see that may be putting the birds at threat. Hopefully things will not “tern out” for the worse, for this bird, which characterises the wilderness spaces, open spaces and prolific mayfly populations on our East Coast riverbeds. The black fronted tern is a treasure that is uniquely New Zealand’s.
Paradise in the city
In a time when many native birds are declining it is good to celebrate the success stories. One such species, which has recently increased dramatically in numbers, is the Paradise duck (technically known as the Paradise Shelduck, also known by the Maori name of Putangitangi ). So named by Captain Cook, the paradise duck, or “parrie” for short, is only found in New Zealand. Once a rare sight outside of the high country in Canterbury, parries are now ubiquitous throughout lowland Canterbury and urban Christchurch.
During the 1950’s to 1980’s in Canterbury paradise ducks were often only found in high country regions, and extensive shooting had historically reduced their numbers. Paradise ducks are still shot, and are in some regions, such as the West Coast, an important component of the game birder’s bag. In the last few decades’ parries have shown a high level of adaptability and now paradise ducks roost on the top of buildings in the centre of Christchurch, where as in the not so distant past a cliff in a remote part of the high country would be a more typical setting! Just about every park in Christchurch has a pair of parries in it, often standing in stately manner, as if a centre piece, but much more lively than any statue.
Parries are thought to pair together for life, with the birds having different, yet, complimentary calls to each other. The male is jet black with finely speckled feathers. The female has a white head and chestnut coloured body. Unlike most other ducks, were the male is more colourful, the opposite is true for the paradise duck.
Since 1990 paradise ducks have moved into Christchurch, with the Avon and Heathcote Rivers providing routes for colonization for the birds, right into the city’s heart. Large willow trees, with holes in them, make ideal nesting site for the birds. The ducklings will jump out of the hole, sometimes situated many metres up a tree, and bounce on the ground with their resilient little bodies. The ducklings have a dramatic black and white stripped colouration often attracting the attention of people passing by. Large broods are often sighted and are testament to the fact that paradise ducks are nesting successfully in the “Garden City”.
Birds will often be grazing on lawns along the river bank. Rock statures and memorial plaques become roosting sites for parries, with high rise buildings in the background providing a striking setting. Paradise ducks, like other ducks such as mallards, grey ducks and the native black teal (another bird to recently re-colonize into the city’s rivers) have become fearless of people, often allowing approach to within arms length. Spring sees parries chasing each other with raucous fuss as they defend their prime riverbank real estate. The bird’s tameness combined with their comical, and at times very territorial nature, makes them an ideal subject matter for the photographer, or just an entertaining spectacle while having a picnic in the park.
We are lucky that these majestic birds have graced our city, in which paradise ducks historically thrived. It is good to see our native bird life flourishing in an urban environment. While flocks of paradise ducks in the high country may at times be viewed as a pest, to high country farmers, they area welcome sight in the city, bringing an element of the wild and open spaces with them. Whether perched on top of a building in the city’s centre, or on a cliff top in the high country, the paradise duck is an under stated, yet majestic, and iconic bird of our country, which is simply paradise.