Sunday, December 10, 2017
The rat eradication programme is getting far better results than expected this early on. It is now important that we get the tracking tunnels out into the field to get accurate data on the rat population. We were fortunate to be donated old corr-flute election signs. These have been cut into tracking tunnels. The tunnels will be installed in the field over the next few weeks so that monitoring can start early in the New Year.
With the pest eradication going on, one of the first bird species to increase will be the grey warbler. These little birds are often heard but difficult to see. They busy themselves fossicking around in the undergrowth looking for invertebrates to feed on. They have at least two broods a season. The second brood can be targeted by the migrating shining cuckoo that lay their eggs in the warbler nest. These cuckoos are very rarely seen because of their green plumage that blend into their surroundings. If you happen to be observing a warbler by its nest while a cuckoo is calling https://tinyurl.com/shining-cuckoo-call the warbler can get quite agitated. They obviously understand the threat.
Photo of nest from: http://nzbirdsonline.org.nz Grey Warbler song DOC,
Photo of eggs http://www.informedbirds.com
|Grey gergone is the warbler|
With the increase in tui activity in Mangaiti gully we have been frequently asked what a tui nest looks like. A Trust member was staying at a holiday home at Opoutere on the Coromandel and found G. J. H. Moon’s book Refocus on New Zealand Birds published in 1967 with some excellent photos and notes on his personal observations of bird activity around the nest while observing from his hide. I have reproduced the tui photo that shows the nest structure and summarised his notes to help you to identify a possible tui nesting site in your area.
From Moon’s notes:
· The male is slightly larger than the female
· Their diets consists of a wide variety of insects, small berries and nectar
· Being nectar feeders they are ecologically important in transferring pollen from one flower to another
· The nesting season normally extends from November to January but he has found nests in October.
· In his district (Warkworth, North Auckland) the favourite nesting sites were in the outer branches of Totara and in the upper canopy of tall manuka but some nests are built in kahikatea, kowhai, and macrocarpa, from 10 feet (3 metres) to 50 feet (15 metres) above the ground.
· The nests are up to 10 inches (24cm) in diameter and built as per the photos. Two to four eggs form the usual clutch; these are pale pink or white, with brownish specks at the broader end. Incubation takes 14 days.
|Get your Forest and Bird calendar for 2018|
from your local book shop.
We are planning a very long term programme of planting canopy trees that attract our native wood pigeon back into Hamilton Gullies. Some say there is food that they eat already in Hamilton but this is only bread and butter for them. We want to offer them ice cream and jelly. Their ice cream and jelly is the fruit of nikau, tawa, miro and pigeon wood. We will be targeting the whole 30 hectare Mangaiti gully system. Area size matters when planning something like this.
These trees do have some challenges though. Nikau is easy to grow from seed but is very slow growing. Tawa and pigeon wood are easy to grow from seed but frost tender when young so shelter is necessary. Miro is very hard to grow from seed but is frost hard and grows at a reasonable rate for a canopy tree. For miro collecting seedlings from under a tree where a pigeon roosts is the best bet. We have 40 plants on hand at varying sizes up to about a metre.
All four tree varieties will not tolerate wet feet so will have to be planted on the lower gully slopes.
A hundred odd school pupils from Rototuna Primary gave us a hand to plant an area of the gully again this spring. The student thoroughly enjoy the activity. This was supported by Hamilton City Council by supplying the plants. Back in the class room the students wrote and decorated lots of thankyou cards. The school have their own area within the school that they are planting.This year the school was rewarded for their efforts by being winning the NZ School of the Year for plant conservation. Well done Rototuna Primary.
GHOSTS OF GONDWANA
The History of Life in New Zealand
Fully revised Edition (2016)
By George Gibbs
Published by Potton & Burton
ISBN978 0 947503 08 6
Have you ever wondered why New Zealand’s plants and animals are so different from those in other countries? GHOSTS OF GONDWANA is the remarkable story of how and why life evolved in New Zealand.
The first thing you have to get your head around when reading GHOSTS OF GONDWANA, is the 85 million year time span within which the discussions take place. When you consider that Homo sapiens have been wandering the earth for just 500,000 years, it brings it into perspective.
The 85 million years ago as a starting point, is when Zealandia started moving away from Australia with the breaking up of Gondwana land. The formation of Zealandia as an independent land mass (being at times no more than a group of relatively small islands) and the evolutionary development of our flora and fauna over that time period, consisted of continual change in land forms caused by the rise and fall of sea level and land movement from tectonic plate activity. This had a direct bearing on the evolution of our ecosystem as we know it today.
The book explains the difference between endemic (organisms that are restricted to one place and not found elsewhere) and indigenous or native (a species that is shared with another place). The line between the two is not always clear and at times requires molecular analysis (molecular phylogenetics) to resolve.
GHOSTS OF GONDWANA surveys the research of thirty case histories (birds, insects and plants) in its attempt to explain the what, where, when and how of each case. No two cases are the same. There tends to be a considerable amount of theory and assumption within these case studies despite the recent use of molecular phylogenetics to answer many questions. The time frame is vast, evolution is slow and there is not always a trail of fossils left for our convenience.
The book is very well presented and is written in a very readable format. The subject is thoroughly interesting, but this is a specialist’s book so may well have limited appeal. It is however, highly recommended to anyone who has a deep interest in New Zealand’s natural history.