Source: Smiles like a reptile!
Bocage’s Wall Lizard (Podarcis bocagei) is only found in the NW corner of the Iberian Peninsula, including Galicia, Spain. It is a small lizard which is often seen on wooden broad-walks, where it pops up to bask in the sunshine. They quickly disappear beneath the planks when heavy footed humans get near!
The sexes are differently coloured: the mature males have a green upper (dorsal) surface, whilst the females have a brown one, usually! As well as a green back, the males also have brown flanks (as shown below). These little lizards only live for about four years. The males quickly turn green once they have reached sexual maturity, and have only 2-3 years as an adult (1).
Many animals, from butterflies to lizards, are faced with conflicting demands in terms of their biology. Whilst they need to remain hidden – inconspicuous and cryptically coloured – to avoid predation, they also need to be bright and conspicuous in order to signal their sexual prowess, or fitness. Males are usually, but not always, the sex which signals their overall genetic fitness in terms of bright colouration and showy displays. The females choose who they want to mate with, based on these colours or displays.
I took this photo (top and below) of a nice bright green male Bocage’s Wall Lizard (Podarcis bocagei) in May, this year. The breeding season runs from April to July. He let me get quite close; I guess he didn’t want to move out of this warm, sunny spot unless he had to!
Breeding males also turn a bright yellow colour on their under (ventral) sides, during the reproductive period. Unfortunately, I was not quick enough to catch this one and turn it over! It is difficult enough to get sufficiently close to get a good photograph.
Somewhat confusingly, a small proportion (less than 10%) of female lizards of this species turn green after mating, particularly in coastal areas (2). I blogged about this phenomenon previously (3). So it’s possible he is a she! And it does look quite fat, as though it was gravid (pregnant). Some things we will never know!
Photographs taken near Morouzos beach, Ortigueira, Galicia, Spain.
- Galán, P. (2008). Ontogenetic and sexual variation in the coloration of the lacertid lizards Iberolacerta monticola and Podarcis bocagei. Do the females prefer the greener males?. Animal Biology, 58(2), 173-198.
- Galán, P. (2000). Females that imitate males: dorsal coloration varies with reproductive stage in female Podarcis bocagei (Lacertidae). Copeia, 2000(3), 819-825.
If ant numbers get too high, the plant may in effect be paying too high a price for the protection it receives. Too many bodyguards! Nectar is expensive to make. And if there are no, or few threats to the plants from leaf feeding herbivores, well the plant is paying the ants for nothing. Idle bodyguards!
Common vetch plants (Vicia sativa) are much favoured by ants. The reason being that they have tiny glands – called extrafloral nectaries – which produce a nectar solution which the ants imbibe. The plants provide the ants with food and in return the ants protect the plant from being eaten by other insects. A mutualistic relationship. The precise relationship is probably highly variable and undoubtedly more complex than it at first appears. If ant numbers get too high, the plant may in effect be paying too high a price for the protection it receives. Too many bodyguards! Nectar is expensive to make. And if there are no, or few threats to the plants from leaf feeding herbivores, well the plant is paying the ants for nothing. Idle bodyguards! And boy do they like their nectar!
The ants benefit in two ways: they get nectar from the plant and they also get to eat (some of) the herbivores they find on the plant. Others they just throw off the plants. More bouncers than bodyguards (or plantguards). The plant also benefits in a number of ways; it suffers less feeding damage and it sets more seeds (probably because fewer get eaten thanks to the bodyguards!).
Ants undoubtedly do their protection job well, and remove external feeders such as caterpillar larvae. When the nectaries were artificially removed from plants by scientists, the ants stayed away and the vetches suffered more leaf damage. So not surprisingly, this investment – in providing food for the ants – pays off for the plant. But there are some insects that are either too tough for the ants to remove (some weevils) or have found ways of avoiding these ‘pugnacious bodyguards’ (a wonderful terms coined by Bentley ).
The purple glandular nectaries are found on stipules which occur at the base of the leaf petiole. Ants can be seen with their heads in the hood-shaped stipules, feeding on the glands inside, in these photos which I took in Spain (Galicia). I don’t know what the ant species are, but I think this is narrow-leaved vetch (Vicia sativa ssp. nigra) which occurs in coastal areas.
Common Vetch is not a host plant for the little Wood white butterfly (Leptidea sinapis), perhaps because the ants would throw the caterpillars off the plants or eat them! But that does not stop the adults dropping in for a sip of nectar from the flower (above).
These photographs were taken at Morouzos Beach (playa de Morouzos in Spanish), Ria Ortigueira, Galicia, Spain (https://rcannon992.com/2014/10/28/morouzos-beach-a-unique-and-fragile-dune-habitat/).
- Koptur, S., & Lawton, J. H. (1988). Interactions among vetches bearing extrafloral nectaries, their biotic protective agents, and herbivores. Ecology, 278-283.
- Koptur, S. (1979). Facultative mutualism between weedy vetches bearing extrafloral nectaries and weedy ants in California. American Journal of Botany, 1016-1020.
- Koptur, S., Smith, C. L., & Lawton, J. H. (1996). Effects of artificial defoliation on reproductive allocation in the common vetch, Vicia sativa (Fabaceae: Papilionoideae). American Journal of Botany, 886-889.
- Bentley, B. L. (1977). Extrafloral nectaries and protection by pugnacious bodyguards. Annual Review of Ecology and Systematics, 407-427.
Mr Woodlouse reached for his coat and trundled towards the door.
“Shan’t be long love” he said to his wife, as the little woodlice looked searchingly up at their departing father.
“Just popping out to look for some crumbs”.
Mr Woodlouse crawled upwards towards the light, all his legs moving in a wave of harmony.
He didn’t see the large head of the lizard silhouetted against the cloudy sky.
Nor did he see the sudden twitch of attention as the reptile eyed the trundling crustacean, just within reach.
Neither did Mr Woodlouse see the long tongue as it flicked towards him.
The first the Woodlouse knew was the rush of air and then the wet crushing feeling in the lizards mouth.
Before he could think of anything his life was ebbing away and he was sinking into the dark acids of the lizards stomach.
Mrs Woodlouse scurried around her little hollow home, shooing the little woodlice into their sleeping space.
Not thinking, more feeling, she sensed the absence of her partner and felt a sense of loss, in a Woodlouse sort of way.
The Lizard on the other hand felt a sense of satisfaction as his little snack dissolved into his belly and he rested in the morning sunshine.
One animal’s lunch is another animal’s husband!
Tell me? Did a God design this world?
My local museum here in Scarborough has a small exhibition of art works painted by children (1). They were inspired by trays of insects held by the Scarborough museums trust.
They were painted by children of different ages but all are beautifully painted and wonderfully creative.
A tray of museum insects.
A Palmking (Amathusia phidippus palawanus) butterfly which had been pecked right on the eyespot. Also showing the feature at the end of the hind wing – the tornus – with two small black spots, that look rather like eyes. These look a bit like a tiny head, or nose, which might fool predators into thinking that this is the business end.
There are two theories about eyespots on lepidopteran wings. The first is that large conspicuous eyespots can startle or intimidate predators into not attacking, or at least deter them long enough for the insect to make an escape. The other theory, is that they deflect the point of attack, e.g. a peck, away from the vital parts of the insect. There’s no reason why they could not act in both ways I suppose.
One night in April 2016, when I was in Sabang on the island of Palawan in the Philippines, I noticed a number of Palmking butterflies of the local subspecies (Amathusia phidippus palawanus). The next morning I came across a rather battered specimen (below) that had clearly had a run in with a predator of some kind, probably a bird. What stuck me about this butterfly was that it had been pecked right on the eyespot, or ocelli. There are two submarginal ocelli on the underside of the hindwings, and the distal one – situated the furthest away from the centre of the body – had been cut through by damage, presumably a peck of some sort.
This photograph (above) also clearly shows the feature at the end of the hind wing – the tornus – with two small black spots, that look rather like eyes. See also photos on website 3, below. These do look a bit like a tiny head, or nose (‘snout’ ) which might fool predators into thinking that this is the business end. Butterflies which are damaged in this way – see also previous blog called ‘Peck me here’ (2) – are unlikely to be unduly affected; they will still be able to fly and hopefully mate. In this case the deflection seems to have worked.
I am not the first person by any means to have noticed or recorded this phenomenon. A similar photo of a ‘Palm King Amathusia phidippus (showing bird attack evidence of rear false eye)’ is shown on the interesting Spineless Wonders site (1).
For more details about the biology of this species, refer to the excellent Butterflies of Singapore website (3).
The Palawan peacock-pheasant, Polyplectron napoleonis, is endemic to the island of Palawan in the Philippines. I was not sure how easy it would be to see this species during my visit in April, but it proved to be surprising easy.
The best site to see one is probably at the Puerto Princesa (formerly St Paul’s) Subterranean River National Park on Palawan, Philippines. I came across one within five minutes of getting off the boat!
It was very confiding and suggested to me that it was regularly fed, although I could be wrong; certainly it was habituated to humans. Large numbers of people arrive at this site every day to visit the spectacular underground river. A few birders come to see the pheasant (and the underground river!).
The Palawan Peacock Pheasant (Polyplecton emphanum) has declined in number due to habitat destruction and hunting, but a thorough survey in the park (1) led to the numbers being revised upwards. The species’s population is now conservatively placed in the band 20,000-49,999 individuals by BirdLife International (2). I would not be surprised if that is an over-estimate though.
Also hopping around near the back of the generator shed – and looking suspiciously tame – was a hooded pitta. Still, I was very pleased to see it (sorry about the fill-in flash mate!). He/she didn’t seem to mind.
I also came across a pair of Palawan peacock-pheasants, plus chick, at the Palawan Butterfly Eco-Garden and Tribal Village, in Puerto Princesa City. They said they were keeping it for breeding purposes. Well it seems this pheasant is bred all around the world. Google it and you will find that you can buy one for £380! (3)
The background colour of the tail of the peacock-pheasant is black, but finely speckled with buff spots and with two rows of large and conspicuous green-blue ocelli (or eye-shaped spots). The male displays the spectacular tail to the female in a circular fan during courtship (4, 5).
In peacocks, the mating success of the males was correlated with the brightness and iridescence of the blue-green eyespots (6); the females are in effect choosing the fittest males based on these features. It seems likely, that sexual selection of Palawan peacock pheasant males by the females also involves these spectacular iridescent, light reflective, ocelli or eyespots. Why else would males invest so much energy into them? They are probably a true measure of the fitness of the male birds, as in the case of peacocks.
It makes me wonder what happens in the wild? Are there lek sites where the Palawan peacock pheasant females can evaluate a number of different males? If there are, they are deep in the hot forested hills of Palawan.
- Mallari, N. A. D.; Collar, N. J.; Lee, D. C.; McGowan, P. J. K.; Wilkinson, R.; Marsden, S. J. 2011. Population densities of understorey birds across a habitat gradient in Palawan, Philippines: implications for conservation. Oryx 45(2): 234-242.
- Dakin, R., & Montgomerie, R. (2013). Eye for an eyespot: how iridescent plumage ocelli influence peacock mating success. Behavioral Ecology, art045.
Much has been written about the demise of House Sparrows in the UK, which according to the BTO have declined in numbers by nearly 71% since 1977 (1). There are a number of reasons for this decline, including increased pollution, increased predation by resurgent sparrow-hawks and a loss of suitable nesting sites.
Crab or lobster pots (creels) provide the perfect solution for seaside sparrows!
They can quickly dive into the protected interior of the pots to avoid predation. The pots clearly provide a safe haven for the birds. They dive in and out as people walk past.
I’m not sure if the birds nest inside the pots. I think they probably retire to one of the ivy covered buildings nearby to roost.
There are no shortage of creels for the birds to hide in. As long as they don’t linger and get taken out to sea as crab bait!
The sparrows certainly seem to like these creel pots because they are always to be found there. Whether birds in other, non-coastal sites, would benefit from a few lobster pots being placed for their protection, I cannot say. But perhaps it is an idea worth considering?