This species was described by Hernández et al. (2000), but the name first appeared in Barbadillo et al. (1999) and this is therefore the correct authority.

This species is endemic to Europe, where it is restricted to the Canary Islands, Spain. It is assessed as Endangered (EN A4a, B1ab(ii,v)+2ab(ii,v)) because the species has an extent of occurrence below 300 km² and an area of occupancy greater than 10 km² but likely to be below 50 km², it is considered on a precautionary basis to occur as a severely fragmented population, and a decline in both the number of mature individuals and the area occupied within the largest subpopulation (here presumed to correspond to a decline in area of occupancy) has been recorded between 2004 and 2019. The population is projected to continue to decline to extinction, potentially as soon as 2050, and over a 10 year time window between 2020 and 2030 this is projected to be at a rate of around 50%.

This species was discovered in 1996 in the Macizo de Teno in the extreme northwest of Tenerife Island, in the Canary Islands (Spain). It is now known from a small area of coastline in the extreme west of the island, and also from Montana de Guaza in the extreme south. It is believed that the species was once widespread throughout much of Tenerife.

In the species' remaining stronghold, Ginovés et al. (2005) estimated that the total population in the species' remaining stronghold, Montaña de Guaza, was between 884 and 1,100 individuals. Two subsequent censuses in the same area estimated a population size of between 529 and 867 (Albadelejo and Rodríguez 2014), or 587 (Padilla et al. 2019). There are 40 other, isolated subpopulations along 9 km of coastline in Teno, estimated to contain approximately 280-460 animals as of Rando (2002). Based on these estimates it is possible that the largest subpopulation contains more than 50% of the global population, however, this is not certain and the remaining subpopulations are small and isolated. As such the population is considered to be severely fragmented on a precautionary basis.

Comparing results of sampling between 2004 and 2014, Albadelejo and Rodríguez (2014) found that the proportion of large individuals in samples had declined by approximately 50% over the intervening decade, and the overall population by 25%. At individual sampling sites, densities fell by as much as 83% in this period (Albadelejo and Rodríguez 2014). These authors plot the extrapolated population trend for the Guaza subpopulation between 2004 and 2050, projecting a decline potentially in excess of 50% from 2020-2030. Based on minimum and median estimated population sizes as of 2004, Albadelejo and Rodríguez (2014) project the extinction of this subpopulation between 2035 and the late 2040s. For the maximum estimated population size, the species was projected to persist in 2050 but with approximately 250 individuals, a decline of around 75% since 2004.

This species inhabits rugged terrain, with rocks and boulders, often found on small rock ledges with sparse vegetation. The species is presumed to have once occurred in a variety of habitats across Tenerife. The species is largely herbivorous. It is an egg-laying species. Its life history has not been characterised, but it is similarly-sized to species such as Gallotia galloti that mature at three years of age (Castanet and Báez 1991, M.A. Carretero pers. comm. 2023). Members of this genus generally attain sexual maturity relatively early and some species continue to grow after sexual maturity (Molina-Borja and Bohórquez-Alonso 2023). If this is the case for G. intermedia, subpopulations will exhibit a high degree of overlap in adult size classes (M.A. Carretero pers. comm. 2023). Smaller, younger males may have fewer reproductive opportunities than larger males, which may result in a generation length exceeding three years, however as the population declines younger animals may form a larger portion of the breeding population (M.A. Carretero pers. comm. 2023). For the purposes of this assessment a minimal three year period is taken to represent generation length. The holotype of this species (which was described from a living animal) was still alive more than 20 years after it was described (M.A. Carretero pers. comm. 2023).

The main threat to this species is predation by feral cats and, to a lesser degree, by rats. Most Gallotia exhibit slow life histories, distributing lifetime reproductive effort over many years, and so are likely to be especially sensitive to elevated mortality, particularly of large individuals (M.A. Carretero pers. comm. 2023). It is presumed that the historical decline in this species was largely due to predation by cats. A study undertaken within the Montaña de Guaza "critical area" found this lizard in the diet of cats sampled between December 2019 and February 2020, and that the proportion of reptiles in cats' diet in this region had increased from 3.6 to 11.5%, hypothesised to result from declines in rabbit populations that comprise the cats' usual primary prey (Ravelo and Reyes 2021). Padilla et al. (2019) observed that declines in Montaña de Guaza were greatest in areas of ravines most accessible to cats, while noting that this apparent trend requires confirmation with repeat sampling. The cats' diet also included rubbish likely from the nearby urban centres of Los Cristianos and El Palmar, suggesting that free-ranging animals from urban sites as far as a kilometre away pose a threat to the lizard. Several of the smaller subpopulations, consisting of a few individuals, may be threatened by the effects of inbreeding, and a review of unpublished genetic data (M.A. Carretero pers. comm. October 2022) is recommended.

Tourism development and activities could impact the southern subpopulation at Montaña de Guaza, but this requires confirmation (M.A. Carretero pers. comm. October 2022).

There is no known use of or trade in this species.

Measures to control access by cats to some of the remaining subpopulations, such as fencing, had reportedly been implemented by the time of a prior Red List assessment, however at least in Montaña de Guaza these appear not to be in place. Fencing off at least part of this subpopulation is recommended (Ravelo and Reyes 2021).

A recovery action plan has been developed for this species. There is a need for better control of free-roaming domestic cats, and the prohibition of feeding cats in public spaces is necessary (Ravelo and Reyes 2021). The species may still survive in other inaccessible parts of Tenerife, and more field surveys are urgently needed. It occurs in at least one protected area. Cat control is expensive, so fencing is probably the most cost-effective conservation action that can be implemented (M.A. Carretero pers. comm. October 2022).

There is some limited ex situ breeding of the species.