SAFA Skysailor Magazine

SKY SAILOR 25 May | June 2020 They vocalise when mating, when disturbed from a nest, and when defending a nest site – the rest of the time they are silent. Their hearing is about the same as ours – so they will hear your vario, radio, and abuse – all of which will be interpreted as fight- ing rather than flirting! I say this with confidence as I have never had a vocalising wedgie drop a stick or shredded rabbit in front of me – which is the wedgie equivalent of showering with flowers and diamonds – so fight it is. Amated pair will loosely maintain a territory, but will not normally defend it against other wedgies (or flying contraptions), and territories commonly overlap. Territories vary in size depending on how plentiful food is and range from less than 10km 2 to more than 100km 2 . Wedgies do, however, defend active nest sites, and each territory can have several nests, either clustered or scattered throughout. Nests are rarely used in consecutive years, except in areas where nest site options are limited. Nesting sites vary according to terrain, but on the hilly stuff we like to fly from, nests will normally be mid-slope, usually in a large, live, emergent tree that catches some morning sun and has a commanding view. On the flatlands, however, they will simply find the highest live tree. Breeding season is heralded by aerial displays and games (courting) usually starting late in autumn. This is followed by some sex (about six seconds worth), then eggs laid in winter (all a bit later in Tasmania). From the time the chicks hatch until they fledge (about three months) the parents will aggressively defend the airspace around the nest – which is typically a little bit bigger than 1km 2 with no apparent ceiling (try to visualise a very tall cylinder to the clouds). When defending nest sites from intruders, wedgies avoid the potential for dangerous injury through the issue of warnings – flight displays and vocalisations. When these warnings are ignored, physical conflict ensues, occasionally resulting in injury or death. A pilot’s take from this is that a wedgie will avoid physical contact with our wings if at all possible up until the point where they perceive us as a direct threat to their chicks – then all bets are off. Mated pairs co-operate in hunting and defence – strategically. One distracts, while the other attacks. If you happen to surprise them and buzz their nest, you can expect no warning, just immediately attack by both – they don’t like surprises in the airspace around their nest. On the nicer side, wedgies are inquisitive, playful and, when mated, very affectionate toward each other. Outside of breeding season they should be good thermal partners, and should even tolerate a bit of noise if we forget to turn our varios and radios down… theoretically. Predictable behaviours – choice or instinct I have watched wedgies in the wild for countless hours, listened to flying stories, and watched videos on the web showing wedgie attacks on paragliders and hang gliders, and most pilots and eagles display predicable behaviours. Pilots appear to hold a strong reluctance to relinquish lift, or yield airspace, to wedgies. There is a lot of yelling and device noise, overt gestures (arms and or wing), and sometimes even attempted bluff – it appears that pilots choose to yield only when their wings are directly threatened or have been damaged. Wedgies act on instinct. They must protect their offspring, however, they will avoid injury to themselves where possible (so they can success- fully raise their chicks), and that is by giving warn- ings if you are getting close to their chicks. They will only risk injury if you choose to ignore their warnings, attacking you as you proceed toward their chicks. They give up attack when you are no longer a perceived threat. Behaviours based on ‘choice’ are easily changed – one’s based on ‘instinct’ are not. Protected treasure in the centre of nest’s airspace Photo: Todd Dennis