Bird song-sharing like verbal sparring

While singing the same songs as your neighbours may sound harmonious, research conducted at Queen’s University Biological Station (QUBS) suggests that song-sharing amongst song sparrow populations is actually an aggressive behavior, akin to flinging insults back and forth.

“It’s been hypothesized that repertoire size and song complexity is about the singer’s ability to advertise their quality as a mate,” says lead author Janet Lapierre, a visiting biologist from the University of Western Ontario (UWO). “Song-sharing, where birds sing a smaller number of their species’ greatest hits, is a more aggressive and attention-seeking behaviour. It’s also a behaviour most often displayed by belligerent older males.”

Ms Lapierre and fellow QUBS researchers Daniel Mennill (University of Windsor) and Beth MacDougall-Shackleton (UWO) used a 16-channel acoustic location system to investigate whether male song sparrows preferentially choose to sing highly shared song types or whether they use all song types interchangeably. They found no general tendency amongst the sparrows to either preference.

Instead, they found that the performance of highly shared songs is determined more by individual differences like age and the kind of neighbourhood the sparrows live in. ‘Tougher’ neighbourhoods had a higher percentage of sparrows who engaged in more aggressive song-sharing bouts, whereas ‘mild-mannered’ neighbourhoods tended to support more conflict-averse sparrows that avoid using shared song types.

Older male sparrows were the most likely to engage in more aggressive or attention-seeking song-sharing bouts, suggesting that older males may be more willing or able to risk conflict and may also have more experience in which songs are effective signals in their local area.

“The novelty of this study was that we looked at how birds use songs rather than just examining the content of their repertoires,” says Dr. MacDougall-Shackleton, a biology professor from the University of Western Ontario and a regular QUBS researcher. “We really could not have done this research without the longstanding study population of song sparrows at the Queen’s University Biological Station.”

These findings were recently published in Behavioural Ecology and Sociobiology.
Source: Queen's University press release

Puffins 'scout out' best migration route

The evidence comes from research by a team from Oxford University and Microsoft Research Cambridge which used geolocater tags to track the migration movements of 18 birds: with 8 of these birds being tracked for two consecutive years.
A report of the research appears in PLoS ONE.

The study found that the birds followed a wide range of different migration routes (suggesting their movements were not genetically predetermined) but that they were not merely random as the same bird followed a similar route each year. Because young puffins leave colonies at night, alone, long before their parents, the idea that they might learn a route directly from others also seems extremely unlikely.

‘We think it’s likely that, before they start breeding, young puffins explore the resources the ocean has to offer and come up with their own individual, often radically different, migration routes,’ said Professor Tim Guilford of Oxford University’s Department of Zoology, who co-led the study. ‘This tendency to explore may enable them to develop a route which exploits all the best food sources in a particular area wherever these might happen to be.’

The team believe this kind of ‘scouting’ for good migration routes could also be used by many other species of birds, especially seabirds – which can choose to stop and feed anywhere on the ocean during their migration.

Vermont County Quest Heads into Fall

With August now upon us and early southbound migrants already filtering through Vermont, it's time to revive the County Quest! July was a quiet month for most of us, with the fewest checklists (1007) and number of individual birds (44,693) so far reported on Vermont eBird during 2011. That should change dramatically this month, as we head back out to our favorite haunts to intercept post-breeding dispersers and fall transients.

Some brief perspective to highlight the tremendous response to the County Quest, as measured by eBird:

Through 31 July of this year, 14,786 checklists have been submitted to Vermont eBird, documenting 1,029,384 individuals of 273 species. This essentially doubled totals from the same period in 2010, when 7,667 checklists were logged with 452,410 individuals. Impressive!

Although Addison County maintains a respectable overall lead, with 225 species, the county "race" is far from settled, with 5 months still to go. Four counties have broken the 200 species mark, while 7 others have exceeded 150. The Quest organizers confess to being remiss in not having settled on a reasonable handicap system yet -- we've been too busy birding -- but we won't shirk our duties much longer on that.

It will be hard to top this past May for statewide birding excitement, but there are plenty of species not yet reported to eBird that are reasonable August candidates. A few tantalizing possibilities: Little Blue Heron, American Golden Plover, Stilt or Buff-breasted Sandpiper, Hudsonian Godwit, Little Gull, Yellow-breasted Chat, an early Connecticut Warbler.

Time to grab a birding friend or two, revive the competitive juices, and shoot for 300 species and 30,000 Vermont eBird checklists!

The County Quest Team


Photo: Marbled and Hudsonian Godwits, South Beach, Chatham, MA. August 2010. Courtesy of Bryan Pfeiffer.