Population trends, historical and current distribution a) At the national scale
Currently present only in the Mediterranean bioregion. The Italian population fell from an estimated 71 pairs in 1970 (Latium 4, Tuscany 1, Campania 2, Apulia 5, Basilicata 6, Calabria 12, Sicily 41), to 58 in 1980 (Apulia 4, Basilicata 4, Calabria 10, Sicily 41), 19 in 1990 (Apulia 1, Basilicata 2, Calabria 10, Sicily 6), 20 in 2000 (Apulia 1, Basilicata 2, Calabria 6, Sicily 11) and 10 in 2005 (Basilicata 1, Calabria 3, Sicily 6). Between 2000 and 2005, the number of breeding pairs in Italy fell by 50% (Ceccolini et al. 2006).
b) At the biogeographical scale
There is no estimate of the number of breeding pairs in Italy before the 1970’s, despite the fact that the species was considered a breeder in the Maritime Alps, in the Maremma region of Tuscany (including the island of Giglio), in Latium, Apulia, Calabria, Basilicata and Sicily (Arrigoni degli Oddi 1929, Martorelli 1931). Moltoni (1945) considered it as no longer breeding in the Alps in the mid-1940’s, but resident in Tuscany, Latium, and Sicily. Later, Bologna (1976, 1977) provided the first numerical estimates of the Italian breeding population: Latium 1970-71: 1-2 pairs, 1972-1974: extinct; Campania 1 pair; Basilicata 3-5 pairs; Calabria 1-2 pairs; Apulia 1 pair and Sicily 20 pairs. He reported the following causes of decline: i) use of poisoned bait, ii) illegal killings, iii) reduction in semi-wild sheep rearing, iv) impoverishment of natural habitats.
Historical data thus show that the species’ distribution was concentrated in central and southern Italy, probably due to environmental, climatic, and migration related factors (Liberatori & Massa 1992, Liberatori 1993).
In the early 1970’s in continental Italy, 29 breeding sites were distributed fairly evenly in four areas of southern and central Italy: i) Ionian Sea area (12 breeding sites), ii) Gravine - Pollino area (11 breeding sites), iii) Campania (2 breeding sites), iv) Maremma region of Tuscany and Latium (4 breeding sites). At the beginning of the 1980’s, the population breeding in continental Italy decreased, with only 18 breeding sites, with a uniform distribution in three of the above mentioned areas (Ionian Sea area, 9 breeding sites; Gravine – Pollino area, 7 breeding sites; Maremma region of Tuscany and Latium, 2 breeding sites; Liberatori & Penteriani 2001).
According to Cortone & Liberatori (1989), the Egyptian Vulture was already extinct in Tuscany by 1987-1988 (as stated earlier by Baccetti & Meschini 1986), Latium (Corsetti 1988, 1989), Campania (Scebba 1993) and Apulia. In Basilicata, at least 2 pairs were thought to be present, while in Calabria, Mirabelli (1981) and subsequently Cortone & Mirabelli (1986) estimated 10-12 pairs, dropping to 5 in 1988 (Cortone & Liberatori 1989), while Cortone et al. (1991) and Liberatori & Cortone (1991) respectively estimated 6 and 8 for peninsular Italy at the end of the 1990’s. In Apulia, Sigismondi et al. (1995) estimated that one pair was still present in the 1990’s (Gargano), but subsequently went extinct (Sigismondi 2008).
Thus, at the end of the 1980’s, the overall population in continental Italy had 13 breeding sites between the Ionian Sea area (7 breeding sites) and the Gravine – Pollino area (6 breeding sites).
In Sicily, Iapichino & Massa (1989) described a rapid population decline. Di Vittorio et al. (2000) estimated 23 breeding pairs at the end of the 1970’s; Seminara in Massa (1985) reports 20 breeding pairs in the mid-1980’s. At the end of the 1980’s, 10-15 breeding pairs remained, falling to 3-4 in 1999 and increasing to 10 in 2000 (Di Vittorio et al. 2000); Cortone et al. (1991) report 10-15 pairs in 1988, Sarà & Di Vittorio (2003) 3 pairs in 1997; subsequent estimates reported up to 10-13 pairs in 2000, falling to 5 in 2007 (Ceccolini in Bellini & Giacoia 2008). Still in Sicily, Salvo (1993) describes a decline from 12 to 3 pairs in 1984-1992 in a 1200 km² area in the central part of the island. With the reduction of the number of breeding pairs, the breeding range shrank from 2400 km² in 1980 to 500 km² in 1998, climbed back up to 1100 km² in 2002, then climbed back up to 1997-1998 levels in 2005-2007 (Ceccolini et al. 2006).
a) Breeding success and productivity in Italy
Some pairs have been known to fledge two chicks over several consecutive years, while others have occupied their nests for three or more consecutive years without ever laying eggs (La Rotonda & Mirabelli 1981, Seminara, in Massa 1985, Cortone & Liberatori 1989).
In the 1970’s and 1980’s, breeding success was higher in Sicily than in continental Italy (Liberatori & Massa 1992) and closer to that of other areas in the Mediterranean basis (Bergier & Cheylan 1980). On that island, the fledging rate was 1.37 in the period 1984-1992 (Salvo 1993). On the other hand, breeding success was generally lower in continental Italy, between 0.20 and 0.60 in 1985-1988 (Liberatori & Massa 1992), although in Calabria, Cortone & Mordente (1997), reported a productivity of 0.96 ± 0.53, and breeding success of 0.62 ± 0.55 for the period 1985-1996.
In the period 1986-1999, in continental Italy (Basilicata-Apulia and Calabria), Liberatori & Penteriani (2001), noted that 65% of breeding pairs laid at least one egg and 49.2% raised at least one chick. The average number of fledged chicks per pair was 0.99±0.66, without significant differences between years. Out of62 pairs that nested successfully, 45 raised one chick (72.6%) and 17 fledged 2 chicks (27.4%), with a fledging rate of 1.3. The average annual number of fledged young in continental Italy was 5.6 ± 2.1 for an overall total of 79 fledged young (Liberatori & Penteriani 2001).
Sarà & Di Vittorio (2003) report the following productivity values for Sicily: 1980: 1.03; 1985: 1; 1987: 0.88; 1988: 1; 1990: 0.78; 1991: 1.17; 1992: 1.29; 1993: 1.17; 1994: 1; 1995-96: 1.2; 1997-1998: 0.67; 1999: 0.5; 2000: 0.70; 2001: 0.80; 2002: 1.38 (with an average of 0.97 ± 0.25 d.s. and no evident trends).
b) Breeding success and productivity in other European countries
Breeding success recorded as being between 74.1% and 96.5% and productivity between 0.8 e 1.5 in Spain, Portugal, France, and Russia (Gallardo et al. 1987, Bergier & Cheylan 1980, Bergier 1985, Braillon 1979, 1987, Vasconcelos 1987, Marco & Garcia 1981, Donazar & Ceballos 1988, Abuladze & Shergalin 1998).
b) Factors influencing breeding outcome
A significant correlation between the frequency of occupancy of nest sites (cliffs) and distance from a man-made feeding site, such as a landfill (Liberatori & Penteriani 2001), suggests that food availability is one of the key factors influencing the productivity and quality of the nest site, as evidenced by the higher productivity of pairs breeding closer to man-made feeding sites (Donazar & Ceballos 1988).
Egyptian Vultures might be able to recognise variations in habitat quality and respond by colonising high-quality territories (Liberatori & Penteriani 2001), in agreement with certain theoretical distribution models (Fretwell & Lucas 1970). Human disturbance certainly affects productivity, as shown in Georgia (Abuladze & Shergalin 1998).
In Sicily, the likelihood of a high quality breeding site increases with the height at which the nest located on the nesting cliffs, as it does with the distance from roads; nest site quality instead diminishes the higher the urban surface near the nest (Sarà & Di Vittorio 2003).
FRV (Favourable Reference Value)
The minimum viable population for this species varies significantly according to breeding success. Therefore, the FRV is also closely related to breeding success. We consider a single population (Sicily); for the purpose of this analysis we use age of first breeding 5 years, maximum age 20 years, productivity values of 0.97 ± 0.25 (Sarà & Di Vittorio 2003), % of adult females attempting breeding 90 (it is possible that due to the small population, not all individuals are able to find partners each year), mortality of 50% in the first year, 40% in the second, 30% in the third, 10% in the fourth, 5% in the fifth, 3% for adults (calculated from values reported in Donazar et al. 2002 and references therein, for Spanish populations; we considered yearly adult mortality equal to 3%, instead of < 2% as reported for a stable Spanish population in Donazar et al. 2002, as such a low value appeared too optimistic for the declining Italian population). Ceccolini et al. (2006) report a population of 40 pairs in Sicily in the 1970s; the carrying capacity of the island is thus supposed to be 132 individuals (equal to 40 pairs).
The current population (6 pairs, 20 individuals) has a probability of extinction of 90% over the next 100 years, assuming that no effects due to inbreeding depression or other decreases in breeding fitness due to genetic reasons take place. With these parameters, the best situation would be a population equal to the carrying capacity of 132 individuals, which nevertheless shows a probability of extinction P ~ 0.17 in 100 years.
In order for a population of 132 individuals to have P ~ 0.01, breeding success would need to increase, with 78% of adult individuals breeding successfully and a fledging rate of 1.4 juveniles per successfully breeding pair. Alternatively, P ~ 0.01 is achieved also by a population of 30 pairs (102 individuals), with 90% of adults breeding successfully and a fledging rate of 1.4 juveniles per successfully breeding pair. These breeding success values are similar to those recorded in other European countries, such as France and Spain, and thus could realistically be achieved by protection of breeding sites, and if needed by providing additional food sources. The proposed FRV therefore includes two levels: 40 pairs (132 individuals), on condition that breeding success be 78% (with all adults forming territorial pairs) and the fledging rate 1.4; 30 pairs (102 individuals), on condition that breeding success be 90% (with all adults forming territorial pairs) and the fledging rate 1.4.
Conservation status: concluding remarks and ‘traffic light’ classification
In the last 40 years, Egyptian Vulture populations in Italy have decreased by 90%. The most likely causes of this drastic decline include direct human disturbance (poaching, poisoned bait, theft of eggs and chicks), the isolation and ageing of the Sicilian and peninsular population (main consequence: the lowest breeding success in Europe) and a great decrease in optimal (high quality) breeding sites for this species, with a significant reduction in semi-wild sheep rearing and grazing and partial reduction over time of adequate feeding sites (in spite of the species’ eclecticism).
In the case of the Sicilian population, there was a decrease from 41 pairs in 1980 to 6-10 in 1990-2000, accompanied by a significant reduction in breeding range.
Under the current situation (6 pairs and breeding success of 50%), the species is destined to rapid extinction: even without inbreeding depression, probability of extinction is 92% over the next 50 years and 100% in 100 years.
Finally, as stated previously, other negative impacts on the species may come from unfavourable conditions during migration and wintering, which take place almost exclusively outside of Italy.
Increasing the carrying capacity and breeding success through strict protection of breeding sites and creation of artificial feeding sites, in order to increase the currently tiny population as much as possible. The short to mid-term conservation target should be 13 pairs (or 42 individuals); assuming a breeding success rate of 78% and a fledging rate of 1.4, such a population would have fair chances for recovery. If we cannot invert negative trends and achieve this mid-term target as soon as possible, the species is destined for extinction.
Therefore, the most urgent conservation measures including protecting breeding sites from human disturbance, and conserving (and, where possible and necessary, re-creating) the open or semi-open natural habitats this species needs. The creation of adequately managed artificial feeding sites may provide important help for the species at this critical juncture. Apart from enhancing higher breeding outputs through nest-site protection, it is crucial to keep as low as possible (especially adult) mortality, preventing illegal poisoning and realization of wind farms in areas occupied by the species.
With regards to the currently extirpated population in continental Italy, we do not feel that a spontaneous return of the species is possible in the short term.
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