5MBC Bird Counts

The entire Okura Bush Walkway consists of coastal broadleaf and kauri forests, a beach, and the globally rare coastal land formation known as Cheneirs.

Volunteers and landowners are putting a lot of effort into protecting and restoring our local native taonga. Monitoring is a commonly used method to indicate if these efforts are helping and helps give us an idea of what more needs to be done.

Volunteer and ornithologist Bernard Michaux keeps track of the shorebird species -visiting the Okura Sandspit, Karepiro Beach and the Stillwater Chenier’s throughout different times of the year and keeping an eye on nesting success during breeding season. His wonderful reports can be read on our Home Page.

Our first baseline 5MBC (5 Minute Bird Count) event in the Okura Bush Reserve, essentially a species inventory, occurred in 2015, and was undertaken annually until the PA pathogen was discovered in the reserve and a rāhui (track closure) was placed in early 2018.

2022 was the first year that some members of FoOB had been provided with a permit to restart predator control on the walkway itself since the closure in 2018, and to undertake bird monitoring since the last monitoring event in November 2017, which observed 21 avian species.

Due to the presence of the pathogen Phytophthora agathidicida (otherwise known as Kauri Dieback Disease) we could not randomise our observation transect lines within the whole ngahere (116 hectares) and the allowable study area meant only 12 observation points were available within the 116 hectares. The same points were repeatedly visited to gain a reasonable study size while attempting to remove potential bias toward factors such as temperature, time of day, weather, and noise.
This means our results are biased to the walkway itself and therefore also biased to where a predator control trapline exists. Similarly, the results cannot be taken as an assumption of what is occurring within the 116 hectares of the reserve, much of which has no or very limited predator control occurring at this current time.

12 Observation points along the walkway within the Okura Bush Reserve were observed on 8 separate occasions, half between 7:30am-12 noon, and half between 3:00-6:30pm. Points along the ridgeline overlooking Weiti Bay Village and Karepiro Beach were excluded in 2022 as this would have changed parts of the monitoring method, as well as the ecosystem type now being monitored.

The 2022 study period has been reported by NIWA as the warmest and wettest for Auckland compared to previous study years. This also created a particularly stormy November. Due to the storms, and restrictions on entering the ngahere following wet weather to mitigate the risk of spreading PA, we extended the study period until 5 December in order to obtain a reasonable sample size.

As the bush is still under a rāhui only 1 to 2 people with a permit are accessing the bush for predator control, meaning the birds are not exposed to humans like they were back in the years prior to the rāhui when it was open to the public and the bush was frequently visited by groups of varying sizes.

These above factors may have altered species behaviour from previous study periods.

Observers at Observation point 6, which was located alongside a stream, had to move four meters back (196m rather than 200m from point 5) due to the rain creating a waterfall in a stream that drowned out any bird calls.

5MBC Bird Observations 2022

• 17 different avian species were recorded during the study period, with additional unrecognised bird observations. These unrecognised calls could include more than one avian species – from discussion amongst the observers it’s considered unlikely its more than one or two different species though.

• Observation point 1 recorded the highest number of different species throughout the study period (13 species), but 5 of these were non-natives, including a chicken from across the western inlet, Eastern Rosellas & Indian Mynas.

• Observation point 6 recorded the highest number of different NATIVE species (8 species).

• Native species not observed in 2022 that were present in the 2017 survey were Tomtit, Chaffinch, Greenfinch, Goldfinch, Welcome Swallow, White faced heron, Pukeko and Yellowhammer. Aside from the Tomtit, this may have been affected by having no observation points up on the ridgeline.

• Our Tauhou or Silvereye was only observed on two survey dates at the very end of the survey period, one individual being seen at OBS4 on one of those dates, one individual being seen at OBS3 and two individuals at OBS6 on the second date. This is a significant reduction since previous surveys, and incidentally had also been noted by members of the local community in Okura Village regarding the lack of their presence in gardens over the 2022 winter months compared to previous years. As discussed previously though, they may have been adversely affected by the higher temperatures, or many of them may have still been nesting and less visible.

• Kāhu / Australasian Harrier were observed in 2022 where they hadn’t been observed in 2017 or 2016.

• Tui observations were the most abundant (110 observations overall) followed by Riroriro and Piwakawaka at 90 and 86 observations respectively. Kōtare came next at 43 and then Keruru at 24. The seasonal visitor Pīpīwharauroa or Shining Cuckoo was next at 15.

• Incidental observations (estuary/wetland birds heard) included a Gull, Spur-winged Plovers, Canadian Geese and Paradise Shelducks.

• Aside from the waterfall that occurred after the stormy weather at point 6, planes flying overhead were by far the greatest noise factor affecting the 5minute periods, followed by the noise of flocks of Canadian Geese in the Estuary.

Overall, the results indicate the following relative likelihoods of observing (seeing or hearing) a particular species, and the average number of individuals, along the walkway in Okura Bush during the month of November within a 5-minute time frame:

If you want to learn more about these birds visit:https://nzbirdsonline.org.nz/

Can you help?

If you would like to be involved in future bird counts please contact us info@okurabush.org.nz.

Test your ability on the free Department of Conservation Bird ID Courses