Seasonality in birds and birdwatchers

Seasonality in birds and birdwatchers

One of the characteristic sounds of spring in New Zealand is the clear, upward-slurred whistle of the shining cuckoo. Along with its long-tailed cousin, the two cuckoos are the only New Zealand forest birds that migrate away from New Zealand after breeding. This is in sharp contrast to temperate countries in Europe, Asia and North America, where a large proportion of land birds are migratory.

An adult shining cuckoo shows its iridescent dorsal plumage. Image: Nathan Hill, New Zealand Birds Online
An adult shining cuckoo shows its iridescent dorsal plumage. Image: Nathan Hill, New Zealand Birds Online

To hear the call of the shining cuckoo, follow this link, then click on ‘Male song’ under Sounds in the right-hand column.

Like most cuckoos, shining cuckoos are brood parasites, laying their eggs in the nests of other small birds, and then reneging on all further parental duties. The main host of the shining cuckoo on mainland New Zealand is the grey warbler, replaced by the Chatham Island warbler on the Chatham Islands.

An adult grey warbler (left) feeds a recently fledged shining cuckoo chick. Image: Malcolm Pullman, New Zealand Birds Online
An adult grey warbler (left) feeds a recently fledged shining cuckoo chick. Image: Malcolm Pullman, New Zealand Birds Online

Shining cuckoos spend the New Zealand winter north-east of Papua New Guinea, in the Bismarck Archipelago and the Solomon Islands. They return to New Zealand about the beginning of September, being first heard in the northern North Island, and spreading south to be found throughout the country by early October.

Shining cuckoos are often secretive, but are unmistakeable when seen well. Image: Duncan Watson, New Zealand Birds Online
Shining cuckoos are often secretive, but are unmistakeable when seen well. Image: Duncan Watson, New Zealand Birds Online

While the seasonal occurrence of shining cuckoos in New Zealand is well understood, the effect of their migration on the behaviour of birdwatchers has not been documented previously. The New Zealand Birds Online website was launched in June 2013, and provides an objective measure of community interest in different New Zealand bird species. A previous Te Papa blog (New Zealand’s favourite bird) reported that the tui was by far the most visited species page on the website during the first 12 months, with 14,969 views. The shining cuckoo came in at number three, with 8276 views.

Delving deeper into the user statistics, it is apparent that there was a strong seasonal pattern in viewer interest in shining cuckoos that is not found for any of the other ‘popular’ bird species. Interest in shining cuckoos closely matched the presence of the birds in New Zealand, with visits to the cuckoo page, rising in August and September, peaking in October, and staying high throughout the cuckoo breeding season. Interest declined after February, when the cuckoos call less often then quietly depart the country for their tropical winter retreat.

Shining cuckoo graph

The close correlation between the presence of cuckoos and hits on the shining cuckoo webpage suggests that contact with native New Zealand birds is the major driver for people to seek information about them. As reported in the previous blog, this also explains why the top six birds visited on the website are all native species that are commonly found in one or more of our major cities.

If you wish to contribute to a citizen science project logging sightings (or ‘hearings’) of shining cuckoo or long-tailed cuckoo, click on the following links:

Shining cuckoo records

Long-tailed cuckoo records

11 Comments

  1. Hi Colin
    Yes I did take a photo. I have since had another one in one of my new starling boxes.

  2. Author

    Hi Karyn
    That sounds very intriguing – I have never heard of starlings rearing shining cuckoos. Did you take photographs of any of the chicks?
    Kind regards
    Colin

  3. I heard a shining cuckoo tonight 10th October at 10pm – is it unusual for that bird to be calling at this hour?

    1. Author

      Hi Melinda
      That is unusual. I have never heard a shining cuckoo calling after dark. They are most vocal around the middle of the day.
      Colin

    2. I have heard then at night before…I was led to believe it is when they first arrive from migrating and they have jetlag !

    3. I heard a shining cuckoo last night a 1.15 am going for ages . very unusual.

  4. Great blog post Colin. Interesting to see the seasonal variation in page visits. I wonder if it would be possible to see how closely page visits correlates with sightings of shining cuckoo arrivals. It could be a useful measure of interannual variation in arrival dates. Thanks for the mention of my citizen science project too.

  5. Nice one Colin.
    I’d be interested to know if the shining cuckoo receives more hits than the tui, while present in New Zealand.

    1. Author

      Hi Ant
      Yes, the shining cuckoo received more hits than tui in October 2014 (735 vs 500) and November 2014 (812 vs 810), and ran it close in September (368 vs 372). It was this surge in cuckoo page visits in the monthly analytics summary that alerted me to the relationship between cuckoo arrival and page views.
      Cheers
      Colin

  6. Thanks Colin – I am sure that I have heard one around here in Hataitai last week. Would that be possible?

    1. Author

      Hi Tony
      Yes – that is highly likely. Shining cuckoo calls were reported from Wainuiomata and Tinui, Wairarapa on 21 September, and Waikanae yesterday (22 September). But one trap to be aware of is that starlings often mimic shining cuckoo calls. Starlings usually embed the calls among a longer song sequence, and rarely add the downward-slurred notes at the end of the call that are diagnostic of full shining cuckoo song.
      Cheers
      Colin

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