Tuesday, July 17, 2012

Bitterns at Avon- Heathcote

Hi all- I am working on photo identification of birds on lower Avon River. There are at least 7 bitterns there. An eighth bird was sighted in the reeds on the lower Heathcote. This is a very signficant event with almost a fifth of Canterburys bittern population at one site. Yet I am concerned that the birds are vulnerable to predation and sighted three feral cats working the reed beds and noticed several cat predated mallards and one wounded mallard in the reeds. The Christchurch City Council has been notifed and hopefully a trapping program will be underway as most of the bitterns are concentarted in a small area. Also as the site is next to a busy highway the chance of road-kill is quite high as bitterns and cars don't mix. Also there is a Bittern conservation page on Facebook- "Bittern Conservation - New Zealand" If anyone makes any sightings or has any photos I would be interested- langlands@xtra.co.nz Regards Peter Langlands

Thursday, July 12, 2012

spot the bittern ?
Spot the bittern !- photo taken today- Friday 13 th July 2012 at mouth of Christchurch's Avon River- for the first time in living memory there were three bitterns on the Avon Rivers' margin this morning . Not a bad start to Friday 13th !

Wednesday, July 11, 2012

The peek-a-boo bittern by Nicola Toki after an interview with Peter Langlands - Bittern Researcher 12 July 2012 Published on www.stuff.co.nz
Hands up who has been lucky enough to see a bittern in New Zealand? (Puts her hands down - with accompanying sad face.) New Zealand is a stronghold for the makatu or Australasian bittern, but even so, we only have around a thousand left. This is exacerbated by the fragmentation of their habitat and the way they are scattered across the landscape, meaning it's harder for them to find each other across wide areas, and easier for tiny populations of them to get knocked out by chance events or predators. Bitterns are masters of disguise. They have beautifully marked feathers that match their wetland reedy surroundings, and when in danger, they engage in a rather bizarre tactic of adopting a "freeze" position - standing straight and still in the raupo or reeds, pointing their bill to the sky and simply disappearing into the landscape. A friend of mine recently told me that she spent a couple of hours crouched in a wetland on the West Coast hoping to see a bittern, and when she gave up and moved away, one flew up out of the reeds next to her. The strong legs of the bittern mean they eject themselves out of the reeds like a jack-in-the-box so I imagine she got quite a fright! If you haven't seen a bittern, you may have heard one. Like the kakapo, they "boom". The males blow themselves up like a bullfrog and make a low-resonance booming noise that can apparently be heard for up to two kilometres. Given the bittern's incredible camouflage, the booming is often the only way to know that they are present in an area. If you're keen to find out if you have bitterns in your 'hood, listening out at dawn or dusk from now until November is a good way to find out. Bitterns are the apex predator of the wetland, so if your wetland has bitterns it's a good sign you have a healthy, well-functioning ecosystem. The bitterns eat young eels, fish, frogs, freshwater crayfish and insects. Where did all the bitterns go? In the space of 150 years, New Zealand has managed to drain and destroy 90 per cent of our wetlands, which are home to a huge range of native wildlife, including bitterns. Add in the mix the impact of predators and the odd roadkill death and you've got a recipe for a declining population. It's not all bad news though. Occasionally people give bitterns a helping hand, as in the case of Bitty the bittern, who spent a week or so in the Whangarei Bird Rescue Centre, who was fed, housed and then released back into a wetland to get on with his life. Or the story of the young bittern nestling who wandered into a chookhouse and spent three months living alongside his chook "mates".

Monday, June 11, 2012

Botaurus poiciloptilus Status_ne_offStatus_dd_offStatus_lc_offStatus_nt_offStatus_vu_offStatus_en_onStatus_cr_offStatus_ew_offStatus_ex_off Summary Classification Schemes Images & External Links Bibliography Full Account Taxonomy Assessment Information Geographic Range Population Habitat and Ecology Threats Conservation Actions View Printer Friendly Taxonomy [top] Kingdom Phylum Class Order Family ANIMALIA CHORDATA AVES CICONIIFORMES ARDEIDAE Scientific Name: Botaurus poiciloptilus Species Authority: (Wagler, 1827) Common Name/s: English – Australasian Bittern Assessment Information [top] Red List Category & Criteria: Endangered C1 ver 3.1 Year Published: 2009 Assessor/s: BirdLife International Reviewer/s: Garnett, S., Butchart, S., Bird, J. Contributor/s: Herman, K., O'Donnell, C., Blyth, J., Tzaros, C., Bell, B., Garnett, S., Holmes, T., Miskelly, C., Loyn, R., Wakefield, B., Watson, D., Burbidge, A., Jaensch, R., BarrĂ©, N., O'Connor, J., Sherley, G., Ford, H., Christidis, L. Justification: This species is listed as Endangered because it has a very small and rapidly declining population owing to loss and degradation of its wetland habitats. Urgent action is a priority to halt declines in Australia. History: 2008 – Endangered 2006 – Endangered 2004 – Endangered 2000 – Vulnerable 1996 – Endangered 1994 – Endangered Geographic Range [top] Range Description: Botaurus poiciloptilus occurs in the wetlands of southern Australia, New Zealand and New Caledonia (to France). In Australia the population is now estimated to number not more than 1,000 mature individuals15. Consecutive atlas censuses in Australia have shown a marked decrease in reporting rate; the species was recorded in 260 10-minute grid squares in 1977-1981, 142 grid squares in 1998-2003, and just 61 in 2003-200816. The declining reporting rate was particularly pronounced in the Riverina (63%), Tasmania (>90%), and south-west Australia (>90%). This decline in reporting rate is thought to represent a genuine population decline over the period. In Australia, most birds are in the Murray-Darling basin and adjacent coastal areas. In Western Australia, the population was estimated to contain up to 100 pairs in 19807, but it is now much reduced, with the largest concentration in the Albany and Lake Muir wetlands. There have been no confirmed records from the Swan Coastal Plain since 1992 and surveys conducted in 2007 and 2008 found that half the wetlands that supported the species in 1980 now retained no suitable habitat17. There are now only occasional records from Queensland5 and there appears to have been no great influx to remnant wetlands after the recent drought, as might have been expected if they were more common inland. In South Australia, breeding is confined to the south-east, however, loss of suitable habitat at Bool Lagoon, arguably the key site in Australia for this species, and other wetlands in the area due to changes in regional drainage, has probably had a large impact in last 10-20 years13. It is now known from just one site, Hirds Swamp, in Victoria18. In Tasmania the species is now recorded from only handful of sites and several of the major lakes that it once occupied have been dry for some years. In New Zealand, the estimated population was between 580-725 individuals in 19806; numbers may be greater, given the lack of targeted survey work, and the large size of suitable swamps9. In New Caledonia and Uvea, there have been just two recent records of single calling males, and the population is not thought to exceed 50 individuals1,3. Countries: Native: Australia; New Zealand Present - origin uncertain: New Caledonia Range Map: Click here to open the map viewer and explore range. Population [top] Population: In New Zealand, the estimated population was between 580-725 individuals in 1980 (Heather and Robertson, 1997). The population on New Caledonia is not thought to exceed 50 individuals. Following apparently rapid declines, the Australian population is now thought to number fewer than 1,000 mature individuals (R. Loyn in litt. 2008). Population Trend: Decreasing Habitat and Ecology [top] Habitat and Ecology: It has fairly specific habitat preferences, preferring shallow, vegetated freshwater or brackish swamps where there is a mixture of short and tall emergent sedges and rushes4. It has been recorded in paddies in the Murray Darling basin, but it is not thought to use such habitats for breeding18. It usually lays four eggs. It feeds, mostly at night, on fish, eels, frogs, freshwater crayfish and aquatic insects6. The population seems to increase rapidly in good years and decline rapidly in poor ones12. Systems: Freshwater; Marine Threats [top] Major Threat(s): In Australia and New Zealand, the main threats are wetland drainage for agriculture, as well as changes brought about by high levels of grazing and salinisation of swamps2,4,5. In Australia, the species appears able to adapt to the availability of ephemeral wetlands, but is likely to be particularly sensitive to the destruction of drought refugia. Loss of these habitats may explain its decline in Western and South Australia5. The Murray-Darling basin, a former stronghold of the species, has suffered consecutive droughts in recent years and over-extraction of water is an ongoing problem14,15. Shooting and flying into powerlines are additional contributory causes2, but hunting pressure is very low11. Conservation Actions [top] Conservation Actions: Conservation Actions Underway In Australia, Bool Lagoon and Lake Muir are managed specifically for the species5. In Australia, recent initiatives by the Threatened Bird Network to survey Painted Snipe Rostratula benghalensis australis will contribute to the information on the distribution of this species10, 18. Conservation Actions Proposed Complete field surveys to determine current global distribution, status and key sites for conservation1,5,8. Develop methods for assessing population trends5. In New Zealand, determine factors that may be limiting populations8. In New Caledonia, obtain legal protection of representative, low altitude habitats1. Protect remaining sites against drainage or salinisation. Rehabilitate former breeding sites5. Citation: BirdLife International 2009. Botaurus poiciloptilus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. . Downloaded on 11 June 2012. Disclaimer: To make use of this information, please check the . 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Thursday, May 10, 2012

Request for bittern sightings in Canterbury 2010-2012

Hi all - yes I am still working on bitterns- data sets are being analysed on a national level at present by myself and I understand DOC- so to all who contributed sightings up to 2010- thanks . I will be releasing some informal reports this year and am working on a scientific paper on an analysis of bittern mortality-injury records in New Zealand.DOC updated their web page last year with a threatened species profile on bittern which Colin O'Donnell and myself contributed to - about time given the Nationally Threatened status of the species! At present I am keen on any bittern records ( not already sunmitted to me) from Canterbury in the last two years ( back to June 2010) for a research report I am working on at present. All sightings will be acknowledged. Thanks Peter