Wednesday, June 29, 2011

It's bird spotting time!

It's time again for the annual New Zealand garden bird survey. You've got until this Sunday (3 July) to add to the annual national effort to document birds in our gardens. All you need to do is spend one hour noting the maximum number of each bird species that you see at any one time.

Eric Spurr, the project coordinator, told us the following about last year's survey.

Silvereye returned to the top of the table of species counted in greatest numbers, with house sparrow second, starling third, and blackbird fourth. A grand total of 187,858 birds were counted in 4193 gardens (an average of nearly 45 birds per garden). This included 55,543 silvereyes, 52,779 house sparrows, 11,837starlings, and 11,156 blackbirds. These species have been the top four in all four years of the survey. As in previous years, the only other native species apart from silvereye to make the top 10 were tui and fantail.

These annual surveys are a useful way to document which birds are using our gardens and how our bird communities are changing.

Instructions and a summary of past years' findings can be found at the New Zealand Garden Bird Survey. The results of the past bird surveys are all available through NZBRN (Eric is still following up on some unusual observations in the 2010 data).

If you miss this survey or get enthused about documenting the birds using your garden at other times of the year, you can store and share your garden observations on NZBRN at any time (and not just of birds but also other animals, plants, and fungi). If birds and only birds are your thing, another good web option is eBird.

NZBRN distribution maps come to nzbutterfly info

Those of you who like butterflies have likely already discovered Robert Arter-Williamson's excellent compendium of information at There's lots of information about all of New Zealand's butterfly species. You can now also view live NZBRN distribution maps for each species from the webpages of

For example, if you go to the red admiral page, you'll see an NZBRN logo on the right-hand column. Clicking it will pop up a map showing all red admiral observations in NZBRN. Handy!

If you want to add maps like this to your own website, we have a blog post of instructions all about it.

The other thing you'll note if you explore these maps is that we need a lot more observations to properly map out the distributions of these butterflies. Get ready to spot butterflies in the spring, and if you have any old butterfly observations, please consider sharing them with the world using NZBRN.

Saturday, June 4, 2011

How old is that bird?

Those of you entering bird records may have noticed that NZBRN has an unusually detailed list of options for Age.

This is generally met with confusion by non-birders, including me. What it means is a bird's minimum age in years. If a bird is within the first year of its life, it's 1cy (unless it's an egg, or a chick if it hasn't fledged). If it's one or more years old, but you don't know how old, you should use 1cy+. If you know a bird is more than one year old but less than two years old, use 2cy. And on it goes. If that's a tad too obtuse, you can just choose from egg, chick, 1cy for fledged juveniles, and adult. (You can also leave Age blank.)

How would you even know how old a bird is? Some species have distinctive signs in their plumage in the first few years of life. For example, all blackbirds start out with brown plumage and dull-coloured beaks when they fledge in spring-summer. In autumn, the male birds moult their plumage to become black, except for their primary flight feathers on their wings which remain brown (have a careful look at the first photo above). At around this time, they'll take on the yellow-orange beak colour of adult birds. In the second year, male blackbirds moult again and take on their distinctive complete black plumage. So, it you'd got a brown blackbird with a dull beak colour, it's 1cy. If you see a black male with an orange beak in spring or summer that still has brown primary feathers, it's 2cy. If it's an all-black male, it must be more than a year old so it's 2cy+.

For older birds, your only hope of aging them is if some clever ornithologist caught it in the past and banded it. Whenever you see colour bands on a bird, it is exceptionally useful to record in your comments the colours and their order on both the right and left legs. If you find a dead bird with a metal leg band, it's also very helpful if you send in all the details including the band number to the National Banding Office at the Department of Conservation.

In these abbreviations, "cy" means "calendar year", which is a hang-over from northern hemisphere ornithology (and the Swedish web code origins of the current NZBRN system). Bird breeding seasons up north conveniently span one calendar year from spring to autumn, Seasons in the Southern Hemisphere do not behave so well with our Northern Hemisphere calendar. When you use NZBRN, "1cy" still applies to <1 year old birds, etc.