Ring-necked parakeets, sparrowhawks and crows are among the birds the RSPB is asking Harrow residents to look out for this weekend for its Big Garden Birdwatch.
The event is celebrating its thirtieth year, as it asks people to tally avian visitors to their garden over a two-day period.
Last year more than 800 people in Harrow contributed to the survey.
RSPB spokesman Tim Webb said: "We’re asking people to spare us an hour of their time at a convenient moment this Saturday or Sunday.
"A snapshot of the number and variety of birds tells us a lot when we compare the findings with those from previous years."
The top ten most frequent birds spotted in Harrow in 2008 were:
1. Wood pigeon
3. Blue tit
4. House sparow
8. Feral pigeon
9. Great tit
Exotic birds have also been increasing in number, with ring-necked parakeets appearing in one in five gardens in Harrow.
Mr Webb said: "Personally I think they add a note of exoticism and wonder and are a great way to get people to notice wildlife. It makes them more aware of the diversity of creatures that live in London alongside us all."
This week Harrow Observer reader Ian Herridge snapped this picture of a ring-necked parakeet in a tree in Harrow.
Have you seen any exotic or interesting birds in your garden? Email email@example.com or send us your pictures here .
To take part in the Big Garden Birdwatch visit www.rspb.org.uk .