Pseudophilotes sinaicus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Arthropoda Insecta Lepidoptera Lycaenidae

Scientific Name: Pseudophilotes sinaicus Nakamura, 1975
Common Name(s):
English Sinai Baton Blue

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(i,ii,iii,iv,v)c(iv)+2ab(i,ii,iii,iv,v)c(iv) ver 3.1
Year Published: 2012
Date Assessed: 2010-11-09
Assessor(s): Thompson, K. & Gilbert, F.
Reviewer(s): Lewis, O. & Bohm, M.

The Sinai Baton Blue (Pseudophilotes sinaicus) has a very restricted distribution. It is confined to high elevation areas of the Mt Sinai massif in Egypt, with an extent of occurrence (EOO) no greater than 7 km² and an area of occupancy (AOO) less than 2 km². Its distribution is sufficiently small as to be considered a single, fragmented, location which could be threatened by a single drought event. Droughts have already had devastating implications for this species and its host plants over the past decade. The distribution of this butterfly is limited by that of its host plant, which has a highly fragmented distribution and which is subject to ongoing human exploitation. There is a continuing decline in habitat quality for this species; for example, between 2002 and 2010 the patch with the highest local population size of P. sinaicus lost 43.4% of its resource area, along with the death of 53% of the plant individuals and a reduction in average condition of the surviving plants (K. Thompson unpublished data). Climate change is projected to further reduce the EOO and AOO of this species, which is limited to high-elevation habitats. There are also extreme fluctuations in the number of mature individuals: population survey data for a single patch between 2002 to 2010 show that the species undergoes dramatic population cycles with severe crashes every three years. Such fluctuations could lead to stochastic local and global extinction (Gilbert et al. 2010).

Geographic Range [top]

Range Description:

The Sinai Baton Blue is endemic to Egypt, occurring only at altitudes above 1,800 m within the Ring Dyke of St Katherine Protectorate, with its stronghold on Gebel Safsafa, the massif of Mt Sinai. The entire known extent of occurrence (EOO) is about 7 km²; its area of occupancy (AOO) is less than 2 km².

Countries occurrence:
Egypt (Sinai)
Additional data:
Estimated area of occupancy (AOO) - km2:2Continuing decline in area of occupancy (AOO):Yes
Estimated extent of occurrence (EOO) - km2:7
Continuing decline in extent of occurrence (EOO):Yes
Number of Locations:1
Lower elevation limit (metres):1800
Range Map:Click here to open the map viewer and explore range.

Population [top]


The butterfly has been found to live on 25 of the 39 discrete patches of the host plant, existing in a classic metapopulation. Because of the small area and the prevailing threats, this makes up a single location. In 2001, the total global population size was estimated at approximately 2,300 adults.

From surveys conducted over consecutive years in a single patch, the species has been inferred to undergo severe fluctuations. This is based on observed tenfold population increases between 2009–2010, and ninefold decreases observed in the 2002–2003 season. It is likely that fluctuations such as these are characteristic of the population as a whole, since they reflect environmental stochasticity acting at a range-wide scale rather than deterministic local habitat changes or demographic stochasticity within a patch.

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:2302Continuing decline of mature individuals:Yes
Extreme fluctuations:Yes
Continuing decline in subpopulations:Yes

Habitat and Ecology [top]

Habitat and Ecology:

The larvae feed exclusively on the flowers of Sinai Thyme (Thymus decussatus) Benth., 1834 (Labiatae), which is a near-endemic to the Ring Dyke and the nearby Asir Mountains of Saudi Arabia. The caterpillar has a facultative relationship with the ant Lepisiota which it appeases with sugar solution, and which in return protects the caterpillar from predatory ants such as Crematogaster. Adults are observed in a single generation during April–July but are poor dispersers due to their small size (James 2006a,b).

Continuing decline in area, extent and/or quality of habitat:Yes

Threats [top]

Major Threat(s):

Anthropogenic climate change is a current threat to this species: with the host plant already restricted to mountain tops, any increase in temperature is likely to lead to a reduction in available habitat for this butterfly (Hoyle and James 2005). Climate change around the Mediterranean basin is likely to result in a 2ºC temperature rise along with an additional month of drought each year, resulting in a reduction in available resources for the butterfly and larvae. The butterfly exists in a metapopulation and is threatened by increasing fragmentation/habitat isolation, whilst small population size also increases its extinction risk. Other threats include yearly environmental variation in this butterfly's host plant (Thymus decussatus), with a 40% reduction in the number of inflorescences noted between years. This would have a direct impact on the survival of the species (Hoyle and James 2005). Its host plant has been threatened by over-collection for medicinal purposes, and is currently listed as Endangered in the 1997 IUCN plants Red List (Walter and Gillett 1998). Hoyle and James (2005) also include overgrazing as a threat, but this is now not thought to be a significant threat; on the contrary, grazing might actually be required to maintain plant vigour.

Conservation Actions [top]

Conservation Actions:

This butterfly’s distribution is entirely within the St Katherine Protectorate with the rangers continuing to monitor the species by carrying out 9–14 survey days each year (Gilbert et al. 2010). Recent conservation efforts are mainly focused on the endangered host plant. The thyme was previously threatened by over-collection due to its high medicinal value in Cairo. The Protectorate has recently banned collection with enforced fines for anyone caught. A fence has recently been erected around a patch found to contain a large butterfly population to prevent public access to stop further plant collection and to control grazing. Two dams were also built in this patch to hold more water in the soil to improve the condition of the thyme. The rangers have also tried to increase public awareness for this butterfly, considered as a flagship species for the Protectorate (El-Deen 2010). 

Citation: Thompson, K. & Gilbert, F. 2012. Pseudophilotes sinaicus. The IUCN Red List of Threatened Species 2012: e.T195289A2376696. . Downloaded on 19 September 2018.
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