Here are a few of my observations:
1. I remember going for walks in the countryside in Malta (mostly the Mellieha area) when I was a child (that's over 30 years ago ) and seeing lizards all over the place. In fact we used to go lizard hunting in the fields in Mellieha where I grew up and often catch 10 lizards from a small stretch of rubble wall (we used to let them go unharmed of course ). Unfortunately, over a few years I noticed that the lizards disappeared and instead there was an abandance of skinks for some time (this must have been ~1985) (my cat used to love ctaching skinks and bringing them home half dead as prizes). Soon after even these disappeared - although you do still see the occasional skink even now.
2. This disappearance does not seem to have ocurred in Gozo, where you still see hundres of lizards wherever you walk in the countryside.
3. Strangely enough lizards in Malta are still quite abundant in urban areas. You see many around the streets of Attard where I live (my kids and I feed one-winged flies to our adopted lizard in the back yard). Even Marsa Industrial Estate where I work is full of them.
4. Having read the sad story of the Selmunett lizard's apparent extinction in this forum, I question whether this can definitely be attributable to rats or whether it is part of the overall decline in lizard rural poputation in Malta.
The most logical explanation is that possibly pesticides may have killed the lizards in Malta, but wouldn't they use the same pesticides in Gozo as in Malta. And would this explain the disappearance of lizards in Malta even from remote areas far from agricultural land?
Maybe a disease that did not make it to Gozo? But why would populations in urban areas not be affected? And why wouldn't populations recover after so many years? It should not be so difficult for lizards to move from urban to rural areas.
Maybe a predator or poisonous plant introduced in the Maltese coutryside but not in Gozo or urban Malta?
Does anyone have a better explanation?
Maybe you can make an excercise and see what pesticides they sell in agric. shops in Malta and compared them with those sold in Gozo. I would say that only places were there are many fields are effected, though this needs more deep study rather than a tentative assumption.
I admit that this 2 years i seen a decrease in numbers of lizards.
And also, they seem to be doing perfectly well in an urban environment.
I am not convinced of the pesticide link, they are not present in large numbers even in areas where the land is not cultivated, etc, and anyway anything used in Malta is used in Gozo, not to mention that today's pesticides (technically, insecticides) are very selective indeed.
Every theory I have has massive holes.
Rats? Plenty in Gozo, too.
Cats? This would possibly result in an inverse situation.
Disease? Why not the urban lizards affected too, and most certainly at some point in time lizards have crossed the channel and still do, aboard cargo/vehicles, etc.
Other predators? Snakes, but probably far more in Gozo than Malta.
Something I am just thinking of at the moment - maybe we have here an introduced alien insect or something that attacks the lizard's eggs, and this alien is found predominantly in the countryside and not urban environments?
Re the skinks, I have always noted these to be relatively plentiful, I have not noted any spike in populations.
AntonB, I also noticed that lizards in the Maltese countryside have practically disappeared over recent years. It is an interesting research question, but one which is probably rather difficult to answer. I definitely have no plausible explanation.
Another hypothesis could be that a disease wiped out most lizards in Malta (maybe including St. Paul's Islands) but spared a few isolated communities in urban Malta and did not spread to Comino and Gozo (maybe a short-lived aggressive disease). If this were the case we would hope that with time some lizards will migrate back to the countryside and repopulate it.
It would be interesting to try to introduce a few lizards from urban Malta to some countryside site and see whether they survive and multiply. (This would be a good school project - except that most students are too busy studying English, Maths, Maltese and Religion to have time to waste on an interesting project like this!).
I have one place in mind which I very clearly remember in my childhood that was absolutely full of lizards, and very tame ones at that. It's the valley that leads to Mgiebah bay from Selmun.AntonB wrote:... I have not seen a single lizard in the coutryside in Malta for ages and I hike around many different places with my family every Sunday.
Definitely also countryside, farmland, definitely previously plenty of lizards, nothing has changed since that time, so in a way, a control - basically also everything that reflects Gozo.
I wonder what the situation is nowadays - in a rather unscientific manner of course this would reinforce or otherwise the theory that something has happened to decimate the lizard population.
As an aside and totally unrelated, I am seeing a number of black snakes in the countryside, and actually handled a rather large one last week, one of the largest I have seen for ages. A side effect of the spring trapping/hunting ban is that probably more of these will escape a load of buckshot.
I happened to be in the next valley over towards St. Paul's Islands just yesterday and I can assure you there was not a single lizard! There were a few beautiful pyramidal orchids, but no lizards!I have one place in mind which I very clearly remember in my childhood that was absolutely full of lizards, and very tame ones at that. It's the valley that leads to Mgiebah bay from Selmun.
The biggest difference between centre park area and garigue area which could affect the population of lizards: There are big fat cats everywhere within the park area and absolutely none in the garigue.
Education: Botanist, University of Copenhagen
Cats is one of the enemies of the poor lizards. Indirectly, men is also an enemy of the lizards mainly due to application of pesticides and pollution of water. I think skinks are much more timid from lizards and do not give cats much chance of play. The bright green colour of the lizards might also be more attractful for the eyes of the cats.
Enjoy your holiday!