Every
year, around the end of April and the early days of May, a particular
insect appears that hovers in the air in large numbers around
woodland edges, hedges and rough grass. We always see them on
the ‘Green Road’, the path above Vico Road which
is a real sun trap. Last year there seemed to be a higher proliferation
than usual and any time we were there they seemed to cause a
degree of consternation with passing walkers since they hover
at head height and don’t make any attempt to avoid approaching
people. A neighbour asked me were they flying ants. I heard
somebody else wondering were they mosquitoes as they swatted
them out of the way while somebody else sitting on a bench pronounced,
with great authority, that they were horseflies, which have
a very unpleasant bite.
But they weren’t horseflies,
nor were they ants or mosquitoes. They are in fact a type of
fly, Bibio Marci, more commonly known as St. Mark’s Fly
since they first appear with great regularity around the date
of that saint’s feast day, April 25th. Sizeable creatures,
shiny black and hairy with a long abdomen, they hang in the
air almost motionless with long legs dangling underneath them.
Their ‘in your face’ mannerisms adds to their lack
of appeal making them seem even slightly sinister and threatening
but in fact they’re totally harmless to humans and can
be very beneficial to the environment. The
ones hanging in the air are the males of the species which only
live for a week. They hover or sluggishly move up and down to
attract females and according to buglife.org.uk ‘the male’s
eyes are divided by a groove and have separate connections to
the brain. This allows the males to use the upper eye part to
look out for females and the lower part to monitor their position
in relation to the ground, allowing them to hover in the same
position. After mating the females lay eggs in the ground. When
the larvae hatch they develop in soil where they feed on roots. |
They can cause damage to vegetables and plants in a garden but
they themselves can be a important food source for birds to
feed to their chicks. Buglife, anorganisation dedicated to insects
with the charming motto ‘Saving the small things that
run the planet’ goes on to say the adults are ‘very
useful creatures, they feed on nectar, making them important
pollinators of fruit trees and crops’ so if you encounter
one be merciful, it won’t harm you despite its threatening
stance.
We were very surprised when Lucy spotted
a lizard beside the path on Dalkey Hill in the last week of
February. Normally Common Lizards, our only native reptile,
wouldn’t be coming out of hibernation until March but,
of course, normal barely exists any more as regards to the climate
and seasons. A lizard needs to increase its body temperature
to near 30 degrees Celsius (86 degrees Fahrenheit) before it
can hunt effectively and the mini heatwave at the end of February
created record high temperatures. This lizard was motionless,
warming in the sunshine, its greenish brown colouring making
it virtually invisible and it was only when a spider got too
close we saw it suddenly transformed into a blur of motion as
it dived on the spider and swallowed it. The following day Lucy
spotted one again and we knew it was a different individual.
The one we’d seen the previous day had a shorter dark
tail with concentric circles indicating it had utilised its
only defence against predators, the ability to shed its tail
when attacked, leaving the confused predator, possibly a cat
or kestrel holding a still twitching severed tail.
The tail will grow back but much darker
and stubbier. It’s not the only part of their body they
can lose and another day my sharp-eyed companion found a coil
of shedded skin a lizard had discarded, the lizard presumably
wanting to begin its year with a fresh new wardrobe! At no small
expense, we upgraded our bird feeders getting new peanut, fatball
and sunflower feeders which all claim to be squirrel-proof and
so far, thankfully, they have proven true to their word. Grey
squirrels were taking loads of seeds as well as keeping the
birds away and attempts to make the feeders squirrel-proof under
upside down hanging flower pots on elongated wire hangers, only
proved a minor temporary irritation to the greys. A previous
‘squirrel-proof’ feeder I had bought should more
accurately have been described as a squirrel back support since
the squirrel would easily squeeze through the vertical bars
and stand with its back pressed against them as it nibbled away
but the new ones we got are of much better construction with
horizontal as well as vertical bars. Most are feeders inside
a wire cage through which no squirrel could fit but one is a
very clever device which is weight sensitive so if anything
heavier than a bird lands on it the seed holding part retracts
closing the feeding apertures. You’d nearly feel sorry
for the squirrels trying in vain to get at the seeds so near
and yet so far and not even being able to shake them out on
to the ground. Able to put out peanuts again in the new feeder,
within days we were delighted to have Long Tailed Tits and Siskin
feeding from it. |
St.
Mark’s Fly, not the most handsome of beasts but a
very useful pollinator. Image: M. Ryan |