Courgettes without male flowers?

[PMW]

Am I right in thinking that pollination from a male flower is necessary to produce a succesful courgette?

I have only ever grown black beauty courgettes before and have found that initally a few fruits have not grown properly, which I had assumed was a pollination problem. This year I have two courgette plants - 1 x defender F1 and 1 x black beauty. The defender plant has so far produced two succesfully harvested courgettes although there have been no male flowers yet from either plant.

I realise its possible they have been pollinated from another garden, but I am not aware of any neighbours growing any (plus with all the rain pollinating insects have been a rare sight) and just wondered if my previous assumptions were wrong?

[Capsid]

Usually pollen from another plant is preferred and is the reason why flowers mature at different rates to ensure cross pollination. But there are also self fertile varieties.

[realfood]

There are also new varieties that do not need pollination at all so could be grown in a greenhouse.
Parthenon F1 and Cavili F1. These two have a “parthenocarpic” habit