4. RESULTS & DISCUSSION   continued

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4.11 Eyries - aspect

Aspect of the eyries varied and was unpredictable. Predominantly major cliffs in Northern Kosciuszko face west. However it was found that a higher proportion of nest ledges faced north, this aspect would give the eyrie protection from the prevailing weather (see table 4).

Extensive research would have to be done at each eyrie in order to come to any conclusion with regards to linking eyrie aspect and breeding success. The number of hours of sun exposure on each site would have to be measured as well as the amount of protection from the elements in and around the eyrie. During this study it was observed that once young are sufficiently mobile they seek the shaded area of a ledge. Overheating due to their large amount of down may be the cause.

TABLE 4: CLIFF ASPECT OF EYRIES

Cliffs	1996	1997	1998	1999
Number of nests with a Northerly aspect	7	9	14	16
Number of cliffs with a Northerly aspect	9	8	13	15
Number of nests with a Southerly aspect	3	4	6	6
Number of cliffs with a Southerly aspect	2	3	3	3
Number of nests with a Westerly aspect	6	3	9	11
Number of cliffs with a Westerly aspect	8	6	9	11
Number of nests with an Easterly aspect	5	6	10	12
Number of cliffs with an Easterly aspect	5	6	8	10

During the 1999 season, a pair was found using a disused quarry. This eyrie was extremely easy to access and looked to have been used for a number of years. The interesting thing about this site is that there is a natural cliff not that far away. When this area was first visited the natural cliff was first searched for a possible nest site. Each ledge that appeared suitable for an eyrie was accessed. Given that there were no other cliffs in the area, it was confusing that an eyrie could not be found on the natural cliff, especially given that at least two ledges appeared to have been used a long time ago. There was also a lot of recent peregrine sign, ie fresh casts and recent roosting. The eyrie was eventually located in the quarry. It seems as though the falcons had moved from the natural cliff to the quarry. It is considered that the quarry eyrie provides better protection from the weather, although this site is extremely vulnerable to foxes.