Welcome Swallows in Tasmania

In reply to a question I posed in "Always Welcome" about how common Welcome Swallows were prior to European settlement, Tas. Boskell has researched the subject and replies: As Welcome Swallows were in Australia when Europeans arrived and as structures built by the Aboriginal population would be unlikely nest sites , we must assume the swallows used natural features. John Gould, most probably using information from early naturalists such as George Caley, as well as his own observations, states in his Handbook that the "natural" nest sites of the swallow were in "deep clefts of rock and dark caverns", but began using human structures when the opportunity arose. Littler in his 1910 Handbook of the Birds of Tasmania, includes in his list of nest sites, "the side of a cave, inside of a hollow tree". Louisa Meredith writing in the 1850s, records swallows nesting in farm buildings and also the granite areas of Schouten Island.
It seems clear that swallows did not depend on humans for their nesting sites. However, did the settlements in Tasmania influence the number of Welcome Swallows?
Furneaux in March 1773, Cook in January 1777, and Bligh in February 1792, all visited Adventure Bay on Bruny Island, but Welcome Swallows were not collected or reported. It would be strange indeed if swallows had been present, that they would not have been noticed by members of his party and been reminded of the 'English' Swallow.
The French Expedition under D'Entrecasteaux made its second passage through D'Entrecasteaux Channel in January and February 1793, but there are no records of the swallow. Baudin's Expedition in January and March 1802, not only spent time in the Channel Area, but also visited Maria Island and some islands at either end of Bass Strait. The only record of a swallow is in Baudin's Journal--"a type of swallow which perches in trees". Viellot, (1817) who examined some of the specimens collected on the voyage, describes the Tree Martin which could be the bird referred to by Baudin. As the specimens collected by D'Entrecasteaux were mostly lost and those from Baudin's expedition studied and kept in a disorganised manner, it is possible the Welcome Swallow was among those collected but later lost.
Bass and Flinders visited the Tamar and Derwent Rivers during their October to December circumnavigation of Tasmania in 1798, but there is no mention of swallows amomg the birds they noted for those areas.
As for settler records, the earliest is from G. Hobbler who records swallows about the river near his home at Kilafaddy in late August 1829. In 1834 he records them nesting under his verandah. R.C. Gunn in correspodence with Dr.J. Grant, discusses the classification of the Welcome Swallow and Gunn says a pair nested on the back porch of his Launceston home for six consecutive years--1831 to 1837. T.J. Lempriere records them at Port Arthur in September 1842. According to records compiled by N.J.B. Plomley, the Tasmanian Aborigines in 3 localities of the East Coast, had seperate names for the "swallow". However, the reliability of this information, dating from the 1830s, is questionable due to language and history interpretation issues.
Apart from game (food) birds, information on bird species for the period 1803 to 1835 is very scarce. Specimens and records were generally sent to English authorities for classification. As Gould is credited with officially naming the species in 1842, it seems no credible description or specimen reached Europe before that time.
More information from the time before 1830 is needed before we can be sure about how European settlement affected the numbers of Welcome Swallows, but it is nice to think they actually increased, because they are one of the few species which, in the main, had the goodwill of humans.