I have found 3 dead house martens under one nest over the past few days. Any ideas why? They appear to have been thrown out of the nest.
Do you also have house sparrows?
No. We have 3 nests in a row where the house martens appear to be doing well and then 1 nest about 15 foot away which seems the problem
If you have no house sparrows at all in the area of your garden/property, it suggests a house martin has taken over the nest. Not had that myself in terms of throwing out young. How developed were the young? Well feathered or still very small?
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They have all looked like this and are under the nest which is under the eaves