| Great Tit (Parus major) | | 2021-06-10 | 2021-05-20 | | Bjørlien skole (Akershus, Norway) | |
| Marsh Tit (Poecile palustris) | | 2017-06-16 | 2017-05-15 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2017-06-16 | 2017-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Nuthatch (Sitta europaea) | | 2017-06-16 | 2017-05-15 |  | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2017-06-16 | 2017-05-15 | | Bjørlien skole (Akershus, Norway) | |
| Marsh Tit (Poecile palustris) | | 2017-06-13 | 2017-05-15 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2015-06-23 | 2015-05-28 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2015-06-23 | 2015-05-18 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2015-06-23 | 2015-05-28 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2015-06-23 | 2015-05-28 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2015-06-23 | 2015-05-28 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2015-06-23 | 2015-05-21 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2015-06-23 | 2015-05-28 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2014-06-06 | 2014-05-16 | | Bjørlien skole (Akershus, Norway) | |
| Nuthatch (Sitta europaea) | | 2014-06-06 | 2014-05-09 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2014-06-06 | 2014-05-16 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2014-06-06 | 2014-05-13 | | Bjørlien skole (Akershus, Norway) | |
| Coal Tit (Periparus ater) | | 2014-06-06 | 2014-05-06 | | Bjørlien skole (Akershus, Norway) | |
| Coal Tit (Periparus ater) | | 2014-06-06 | 2014-05-09 | | Bjørlien skole (Akershus, Norway) | |
| Coal Tit (Periparus ater) | | 2014-06-06 | 2014-05-09 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2014-06-06 | 2014-05-09 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2013-06-14 | 2013-05-31 | | Bjørlien skole (Akershus, Norway) | |
| Pied Flycatcher (Ficedula hypoleuca) | | 2013-06-14 | 2013-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2013-06-14 | 2013-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2013-06-14 | 2013-05-31 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2013-06-14 | 2013-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2013-06-14 | 2013-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2013-06-14 | 2013-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Nuthatch (Sitta europaea) | | 2013-06-14 | 2013-05-19 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2013-06-14 | 2013-05-17 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2013-06-14 | 2013-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Nuthatch (Sitta europaea) | | 2013-06-14 | 2013-05-10 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2013-06-14 | 2013-05-24 | | Bjørlien skole (Akershus, Norway) | |
| Goat Willow (Salix caprea) | | 2013-02-15 | 2013-02-14 | | Bjørlien skole (Akershus, Norway) | |
| Chaffinch (Fringilla coelebs) | | 2013-02-15 | 2013-02-13 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2013-01-14 | 2013-01-14 | | Bjørlien skole (Akershus, Norway) |  |
| Great Tit (Parus major) | | 2013-01-14 | 2013-01-14 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2012-12-11 | 2012-12-10 | | Bjørlien skole (Akershus, Norway) | |
| Marsh Tit (Poecile palustris) | | 2012-12-11 | 2012-12-10 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2012-12-11 | 2012-12-10 | | Bjørlien skole (Akershus, Norway) | |
| Coal Tit (Periparus ater) | | 2012-12-11 | 2012-12-10 | | Bjørlien skole (Akershus, Norway) | |
| Nuthatch (Sitta europaea) | | 2012-12-11 | 2012-12-10 | | Bjørlien skole (Akershus, Norway) | |
| Eurasian Red Squirrel (Sciurus vulgaris) | | 2012-12-11 | 2012-12-10 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2012-12-03 | 2012-12-03 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2012-12-03 | 2012-12-03 | | Bjørlien skole (Akershus, Norway) | |
| Nuthatch (Sitta europaea) | | 2012-11-30 | 2012-11-30 | | Bjørlien skole (Akershus, Norway) | |
| Great Tit (Parus major) | | 2012-11-30 | 2012-11-30 | | Bjørlien skole (Akershus, Norway) | |
| Blue Tit (Cyanistes caeruleus) | | 2012-11-30 | 2012-11-30 | | Bjørlien skole (Akershus, Norway) | |
| Coal Tit (Periparus ater) | | 2012-11-30 | 2012-11-30 | | Bjørlien skole (Akershus, Norway) | |
| Willow Tit (Poecile montanus) | | 2012-11-29 | 2012-11-28 | | Bjørlien skole (Akershus, Norway) | |
Sustain.no is provided by the Norwegian Centre for Science Education