KERERU NEWS No. 70 ( 9 April 2009 )

[Dave Houston]

An email newsletter of views and information about and observations of kereru / kuku / kukupa / kokopa / New Zealand pigeon / parea / Chatham Islands pigeon by Ralph Powlesland

New web page for the Kereru Discovery Project – Wayne Linklater
The Kereru Discovery Project has launched its new web page: http://www.kererudiscovery.org.nz/

• You can log on to the site, register what is in your garden, and report your sightings of kereru. We have over 500 reports to date.
• Our objective is to understand how kereru use urban and rural landscapes by compiling a sample of gardens and kereru observations from throughout the country. We look forward to receiving your reports!

DNA sexing of blood, tissue or feather samples – Bruce Robertson
I offer DNA sexing, which includes two molecular tests of sex, at $25 plus GST per sample.  The use of two independent molecular tests of sex is essential as all sex tests use the detection of the female chromosome (the W chromosome: females are ZW), which can for various reasons occasionally not amplify when present.  In such instances, a female will be indistinguishable from a male (ZZ).  The likelihood of the W chromosome not being detected in two successive independent tests is low.  Consequently, this approach to DNA sexing is more rigorous than the use of a single sex test.  DNA sexing can be done on blood, tissue or feathers.

Dr Bruce C. Robertson
Senior Lecturer in Wildlife Management and Conservation Biology, Department of Zoology, University of Otago, PO Box 56, Dunedin 9054
Courier: 340 Great King Street. Email: bruce.robertson@otago.ac.nz

A publication that may be of interest
Morgan, D.K.J.; Waas, J.R.; Innes, J. 2009. An inventory of mammalian pests in a New Zealand city. New Zealand Journal of Zoology 36: 23-33.
 
Abstract:
Urban ecosystems include many habitat types supporting native flora and fauna. These habitats may also sustain populations of introduced mammalian pests, although relatively little is known about the composition or distributions of these species in urban environments. We made a preliminary survey of the distribution and relative abundance of pest mammals across three urban habitat types (gully, amenity park, residential) in Hamilton, New Zealand. Tracking tunnel and WaxTag® surveys showed that: (1) rats (Rattus rattus or R. norvegicus), mice (Mus musculus) and brushtail possums (Trichosurus vulpecula) were detected most often and in highest abundances in gullies, were relatively rare in amenity parks, and were not detected in residential areas; (2) hedgehogs (Erinaceus europaeus) were regularly detected in all habitats; and (3) mustelids were not detected in any habitat. Live trapping in areas where rats were detected captured 21 rats, of which 19 were R. rattus. Scat and animal sign surveys found evidence of lagomorphs in amenity parks and gullies but not in residential areas. Cats (Felis catus) were detected in all habitats. These data suggest that important mammalian pests other than cats are either absent (mustelids) or comparatively rare (rats) in urban Hamilton and largely confined to gully habitats. Further research is needed to determine whether detection probabilities of target species vary significantly between the species and habitats we sampled, and to quantify the impact that mammalian pests might have in limiting populations of other animals, especially avifauna.

Kereru Info
Continuation of where various topics of information about kereru are available, and where the gaps in our knowledge about kereru are (full listing available to DOC staff at docdm-117328)

Release procedures for kereru – May Evans, Rosemary Tully & Karin Wiley
The following suggestions are observations and comments from the people indicated above, plus guidelines taken from Mander, C.; Adams, L.; Riley, A. 2003.  Wild city neighbours: a guide to native bird rehabilitation. Department of Conservation, Wellington.

Prior to release:

• Birds intended for release should not be handled more than necessary so that they do not loose their fear of people. To facilitate this place the bird in an aviary asap once it is feeding itself and doesn’t need to be caught regularly (e.g. for dressing wounds).
• Be acclimatised to weather and photoperiod.
• Exhibit normal feeding behaviour and recognise natural food sources.
• Be in good body condition and have near-perfect plumage.
• Exhibit normal wild behaviour (fear of people).
• Be fully recovered (injuries well healed and feathering complete) from all physical problems (fly and land well in aviary).
• If possible provide some natural foods during the 2-3 weeks prior to release, to juveniles in particular, so that they get experience of feeding on natural foods (not out of a bowl) and will recognise such foods when released.
• It’s important that natural food sources are readily available at the release site, such as fruit, kowhai flowers, tree lucerne foliage or flower buds

Day of release:

• Ensure that the bird has had sufficient time to feed in captivity before being captured for release so that it has some food in its crop when released.
• The weather should be suitable; not raining or particularly windy.

Transportation and release:

• Transport pigeon in a darkened box with adequate ventilation
• Important that the pigeon doesn’t get stressed during transportation
• Put the box on the ground with the head of the bird facing away from people
• Bird will normally fly out of the box once the lid is folded back; it shouldn’t need to be handled.
• Release at an appropriate time (early to mid-morning) so there is ample time during daylight for the bird to find food, water and a suitable night roost site.

Release of a juvenile that came in for care as a nestling (soft release):

• I assume that by the time the resulting juvenile is ready to be released, several weeks after being found, its parents will no longer bond with it and may be re-nesting, therefore being released where it was found is not necessary.
• Ideally the bird should be given a soft release – allowed to fly from an aviary in its own time, and food left inside or preferably on top of the aviary so that it can return for food and water when it wants. Without parental guidance to recognise and find food, and not being fully fit, such a juvenile may initially have problems finding sufficient quality food (fruit, flower buds, flowers) to meet its daily requirements. Having access to food at the release site will enable it to meet its requirements as it gradually gains fitness and learns where to find natural food sources.
• Ideally the soft release aviary is where it was cared for (familiar place) with some forest close by where it can forage and find roosts that shelter it from weather extremes and harriers.

Release of a juvenile that came in for care as a juvenile (hard release – released such that it will have to find all its own requirements (food, water, shelter)):

• Release the bird in the area where it was found as hopefully it will reunite with its parents. This is important because young birds often remain with their parents for months after fledging which enables them to learn about seasonal food sources.
• Even if the bird is not able to reunite with its parents, hopefully there will be other kereru present that it can tag along with to learn what to feed on (see Powlesland, R.G. and Willans, M. 1997. “Hard release” of captive-reared New Zealand pigeons (Hemiphaga n. novaeseelandiae). Notornis 44: 57-59).
• Be aware that resident kereru can be territorial at times (about a nesting area or a food source), forcing interlopers, such as released birds, to move away from the area by chasing and wing hitting them.

Release of an adult (hard release):

• Release the bird in the area where it was found as it will be familiar with the location of seasonal food sources and there is a good chance it will reunite with its mate.

Release of an adult or juvenile when it is unknown where it came from (soft or hard release):

• Soft release the bird if that is an option. There have been individuals that have stayed around release sites for a few days, taking food supplements daily, before disappearing presumably back to their familiar home range.
• If a soft release is not possible, hard release the bird at a site where kereru are present (for juveniles to tag along with). An ideal site is where pest control is on going so that there are few, if any, cats and stoats present.

This guide has been copied to the wiki where more information, photos and observations are welcome.