Breeding

Pair Formation

Pair formation occurs as mixed-species flocks break up, which in the UK happens during warm days in September‒October and again during the early spring (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Nest Building

During the autumn both males and females start to inspect potential nest holes, and during the winter the male inspects some cavities briefly whilst the female apparently pays little attention to this behavior; however, in March and April potential cavity inspection by both sexes become more earnest (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

First Brood

There is a lot of variation in the egg-laying period, which depends on the onset of nest building, but usually starts after the nest is ready (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close , 19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ). In the Western Palearctic, egg laying generally begins in April, or later into May at higher latitudes and elevations, and March-April or earlier in the south of the range (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ). Egg laying dates have generally been shifting earlier in recent decades as a response to increasing spring temperatures (147 Matthysen, E., Adriaensen, F. and Dhondt, A.A. (2011). Multiple responses to increasing spring temperatures in the breeding cycle of Blue and Great Tits (Cyanistes caeruleus, Parus major). Global Change Biol. 17: 1-16. Close , 148 Visser, M. E., M. Lindner, P. Gienapp, M. C. Long, and S. Jenouvrier (2022). Recent natural variability in global warming weakened phenological mismatch and selection on seasonal timing in great tits (Parus major). Proceedings of the Royal Society B: Biological Sciences 288:20211337. Close ; see Conservation and Management: Effects of Human Activity).

Second/Later Broods

The second clutch can be laid as early as the start of June until late July; very rarely there is a third clutch (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ). Broods sometimes overlap, even in the same nest, and second broods are occasionally initiated with eggs laid before the previous brood has fledged from the same nest; in Poland, 7 of 69 nests showed overlapping broods, and the first brood nestlings were 17–19 days old when the second clutch was initiated (149 Surmacki, A., and P. Podkowa (2022). An extreme type of brood overlapping in wild-living birds. The European Zoological Journal 89:527–534. Close ).

Selection Process

Hinde (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ) divide the site selection process into two parts. First, the inspection of one or more suitable sites. The female chooses the cavity from among those suggested by the male and this behavior is communicated by a Hole Inspection Display (150 Nethersole Thompson, C., and D. Nethersole Thompson (1943). Nest-site selection by birds. British Birds 37:70–74, 88–94, 108–113. Close ), wherein the male inspects the cavity, poking his head into the entrance hole, whilst the female is nearby. He then starts to tap, and if the female doesn’t show interest, the male leave the hole but returns immediately after trying to attract the female’s attention. When the female shows interest, she will get steadily closer to the hole slowly while shivering her wings, which will become more intense as she gets nearer. By this point the male will inspect the cavity again, then the female will enter when the male leaves. Finally, the female will enter the hole and start to tap inside for several minutes, sometimes entering multiple times. The second part of the selection process is choosing the definitive site, which involves carrying nest material into multiple suitable sites until only one nest is finished. A started nest can be abandoned and another one started. Hinde (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ) says "the final selection of the nest-site thus seems to involve a process of conditioning to one particular site during the period of incomplete building" which is strongly linked with urgency of their reproductive drive.

Site Characteristics

The habitats used for nesting typically include mature woodland (151 Maziarz, M., T. Wesołowski, G. Hebda, and M. Cholewa (2015). Natural nest-sites of Great Tits (Parus major) in a primeval temperate forest (Białowieża National Park, Poland). Journal of Ornithology 156:613–623. Close ), gardens, and urban forest hedges. The Great Tit primarily breeds in tree cavities and in artificial nest boxes, and rarely in walls or other man-made structures with cavities, squirrel nests, and dense thickets of plant debris among branches (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ). When nest boxes are provided, they are preferred, and whole populations can come to rely on them (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ). See Van Balen et al. (152 Van Balen, J. H., C. J. H. Booy, J. A. Van Franeker, and E. R. Osieck (1982). Studies on hole-nesting birds in natural nest sites. 1. Availability and occupation of natural nest sites. Ardea 70:1–24. Close ) for the distribution of characteristics of natural nests in the Netherlands. There is a significant preference for holes under 4 m in height (mean 2.6 m ± 0.9 SD; maximum > 6 m; n = 33), and for entrance holes with a diameter < 3.4 cm (mean 3.9 cm ± 1.4 SD; maximum > 5.4 cm; n = 33); cavities had a mean diameter of 13.0 cm ± 3.4 SD and bottom area of 139.2 ± 64.3 cm² (n = 33)(152 Van Balen, J. H., C. J. H. Booy, J. A. Van Franeker, and E. R. Osieck (1982). Studies on hole-nesting birds in natural nest sites. 1. Availability and occupation of natural nest sites. Ardea 70:1–24. Close ).

Construction Process

The nest is built exclusively by the female inside cavities in trees or nest boxes. The female starts by carrying large quantity of moss used to shape the cup by pushing the material to the sides, leaving a depression on the middle. Adding the nest lining starts just before the first egg is laid and continues until incubation begins; whilst the female builds the nest, the male sits nearby to drive off any intruders (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Structure and Composition

The nest mass and composition varies among habitats due the availability of material to build the nest (153 Álvarez, E., E. J. Belda, J. Verdejo, and E. Barba (2013). Variation in Great Tit nest mass and composition and its breeding consequences: a comparative study in four Mediterranean habitats. Avian Biology Research 6:39–46. Close ). In general, the bottom of the nest is mostly made of moss with some dry grass and the lining is usually composed of fur, hair, wool, silk, plant or synthetic threads, grass, leaves, and moss (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close , 154 Alabrudzińska, J., A. Kaliński, R. Słomczyński, J. Wawrzyniak, P. Zieliński, and J. Bańbura (2003). Effects of nest characteristics on breeding success of Great Tits Parus major. Acta Ornithologica 38:151–154. Close ).

Dimensions

The size of the nest is variable since the building of the nest continues after the first egg is laid (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ). Alabrudzińska et al. (154 Alabrudzińska, J., A. Kaliński, R. Słomczyński, J. Wawrzyniak, P. Zieliński, and J. Bańbura (2003). Effects of nest characteristics on breeding success of Great Tits Parus major. Acta Ornithologica 38:151–154. Close ), in Poland, measured n = 29 nests (in nest boxes) and found the height range was 4.5‒15.0 cm (mean 8.27 cm) and the mass range was 11‒93 g (mean 50.8 g).

Microclimate

A study showed that spring temperature plays an important role in influencing the mass of the nest cup lining, where the mass of the nest decreased with increasing temperature, creating an appropriate nest microclimate for both parents and offspring (155 Mainwaring, M. C., I. R. Hartley, S. Bearhop, K. Brulez, C. R. du Feu, G. Murphy, K. E. Plummer, S. L. Webber, S. J. Reynolds, and D. C. Deeming (2012). Latitudinal variation in blue tit and great tit nest characteristics indicates environmental adjustment. Journal of Biogeography 39:1669–1677. Close ). Maziarz and Wesołowski (156 Maziarz, M., and T. Wesołowski (2013). Microclimate of tree cavities used by Great Tits (Parus major) in a primeval forest. Avian Biology Research 6:47–56. Close ), in Poland, measured temperature and humidity in natural nests. During the incubation period (n = 40) the temperature range inside the nest was 8.4–18.5°C (mean 12.9°C) and outside the nest it was 7.8–16.3°C (mean 11.6°C); during the nestling period (n = 24) the temperature range inside the nest was 13.1–22.1°C (mean 16.8°C) and outside 9.2–19.0°C (mean 13.2°C). The humidity during the incubation period (n = 15), inside the nest, ranged 73.1–96.8% (mean 89.1%), outside ranged 54.9–93.1% (mean 77.8%), during the nestling period (n = 8) the humidity inside the nest ranged 78.7–97.5% (mean 87.5%) and outside 72.1–93.9% (mean 80.6%).

Maintenance or Reuse of the Nests

Birds are likely to reuse nest sites after a successful brood (157 Harvey, P. H., P. J. Greenwood, and C. M. Perrins (1979). Breeding area fidelity of Great Tits (Parus major). Journal of Animal Ecology 48:305–313. Close ), and sometimes even begin laying the second brood in the nest before the first brood has fledged (149 Surmacki, A., and P. Podkowa (2022). An extreme type of brood overlapping in wild-living birds. The European Zoological Journal 89:527–534. Close ). Divorced females tends to move further away to use new nest sites (157 Harvey, P. H., P. J. Greenwood, and C. M. Perrins (1979). Breeding area fidelity of Great Tits (Parus major). Journal of Animal Ecology 48:305–313. Close , 158 Könczey, R., L. Toth, and J. Török (1997). Site fidelity of great and blue tits in the Pilis-Visegrád mountains. Opuscula Zoologica (Budapest) 29–30:103–11. Close ).

Shape

Subelliptical (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ).

Size

Selected measurements from Cramp and Perrins (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ), which see for more:

• P. m. major 14.6‒19.9 × 11.9‒14.7 mm, n = 470 (mean 17.69 × 13.93 mm).
• P. m. newtoni 16.0‒20.5 × 12.5 mm, n =100 (mean 17.98 × 13.62 mm).

Mass

P. m. major 1.50‒1.75 g; n = 24 (mean 1.63 g) (see 19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ).

Color and Surface Texture

Smooth, not glossy. White, with a variable amount of reddish-brown speckles or spots, concentrated in the wider end (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ).

Eggshell Thickness

In Finland, mean 75 µm (n = 79 clutches) (159 Eeva, T., and E. Lehikoinen (1995). Egg shell quality, clutch size and hatching success of the great tit (Parus major) and the pied flycatcher (Ficedula hypoleuca) in an air pollution gradient. Oecologia 102:312–323. Close )

Clutch Size

Clutch size is variable, generally 3‒18 eggs, with mean clutch sizes of approximately 9–11 in many populations (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ); see Demography and Populations: Measures of Breeding Activity.

Egg Laying

The female starts to lay before the nest is completed; one egg is laid every day, usually before dawn (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Onset of Broodiness and Incubation in Relation to Laying

Incubation can start between three days before until four days after the last egg is laid (160 Gibb, J. A. (1950). The breeding biology of the Great and Blue Titmice. Ibis 92(4):507–539. Close ), usually starting in the afternoon and continuing in the afternoon for the first few days (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Incubation Patch

Only found on females.

Incubation Period

The incubation period is typically 12–16 days, but can appear longer due to delays in incubation start after the last egg is laid (160 Gibb, J. A. (1950). The breeding biology of the Great and Blue Titmice. Ibis 92(4):507–539. Close , 19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ).

Parental Behavior

Only the female incubates, but the male stays close to the nest for the first few days and feeds the female either inside or outside the nest (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

The eggs hatch early in the morning, and both parents keep coming in and out of the cavity (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ); the hatching period last about two to three days (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ).

Condition at Hatching

Hatchlings are mostly pinkish and naked, with closed eyes, a pale yellowish fleshy gape, and with a sparse amount of dark smoky-gray down (that later becomes paler gray) located in tufts on the crown, back, and the scapulars and wings (see 19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ).

Growth and Development

In Finland, chicks weigh about 1.1–1.7 g at hatching, and grow by 0.3–0.8 g in the first day (161 Orell, M. (1983). Nestling growth in the great tit Parus major and the willow tit P. montanus. Ornis Fennica 60:65–82. Close ). Nestling growth rate increased in the first few days and was highest at 3‒7 days, with the third day having the highest increase in weight at 1.7 g (161 Orell, M. (1983). Nestling growth in the great tit Parus major and the willow tit P. montanus. Ornis Fennica 60:65–82. Close ). In the UK, mean nestling mass was 1.3 g on hatch day (n = 8), and weight gain for the first 12 hrs was 0.3 g per nestling; the daily increase was highest on day 6 and day 7 with 1.8 to 1.9 g, and weight gain declining steadily and to less than 1 g on day 12 and less than 0.1 g on day 16 (160 Gibb, J. A. (1950). The breeding biology of the Great and Blue Titmice. Ibis 92(4):507–539. Close ). Secondaries emerge on days 8–9, and primaries on days 10–11 (160 Gibb, J. A. (1950). The breeding biology of the Great and Blue Titmice. Ibis 92(4):507–539. Close ).

Sex Ratios and Sex Allocation

In the UK, over five years and 871 sexed chicks, the overall sex ratio did not differ significantly from even (162 Radford, A. N., and J. K. Blakey (2000). Is variation in brood sex ratios adaptive in the great tit (Parus major)? Behavioral Ecology 11(3):294–298. Close ). In Germany, over two years, the sex ratio of 665 sexed chicks was significantly male-biased in high quality habitat (54% male; woodland dominated by oak (Quercus spp.) and beeches (Fagus spp.)) compared to low quality habitat (50% male; dominated by conifers; 163 Stauss, M., G. Segelbacher, J. Tomiuk, and L. Bachmann (2005). Sex ratio of Parus major and P. caeruleus broods depends on parental condition and habitat quality. Oikos 109:367–373. Close ). In Hungary, the primary offspring sex ratio (all eggs, nestlings, and fledglings) did not differ significantly from even (n = 126 broods), and did not differ between urban and forest populations (164 Ágh, N., I. Pipoly, K. Szabó, E. Vincze, V. Bókony, G. Seress, and A. Liker (2020). Does offspring sex ratio diff between urban and forest populations of great tits (Parus major)? Biologia Futura 71:99–108. Close ). In Turkey, the sex ratio of eggs, nestlings, and fledglings did not differ from even (165 Kabasakal, B., and T. Albayrak (2012). Offspring sex ratios and breeding success of a population of the Great Tit, Parus major: (Aves: Passeriformes). Zoology in the Middle East 57:27–34. Close ).

Brooding

The female broods the young for at least the first week after hatching, and sometimes longer (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Feeding

The majority of feeding is done by the male until the nestlings fledge, with the female contributing an increasing proportion of the feeding as the nestlings age (166 Kluijver, H. N. (1950). Daily routines of the Great Tit Parus m. major L. Ardea 38:99–135. Close , 84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ). One of the parents will assume the feeding responsibility if the other parent is lost (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Nest Defense

See Behavior: Predation.

Nest Sanitation

On the first days of hatching both parents swallow the fecal sacs, but later the sacs are carried away (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Carrying of Eggs or Young

None known.

Undocumented.

The Great Tit occasionally hosts Eurasian Blue Tit (Cyanistes caeruleus) or European Pied Flycatcher (Ficedula hypoleuca) young (see Sexual Behavior).

The cavity nests are generally too small and inaccessible for the Common Cuckoo (Cuculus canorus) to act as a brood parasite (141 Davies, N. B., and J. A. Welbergen (2008). Cuckoo-hawk mimicry? An experimental test. Proceedings of the Royal Society B Biological Sciences 275:1817–1822. Close ).

Departure from the Nest

The young leave the nest in quick succession, over a duration of around 45 minutes, however occasionally fledging happens over more than one day (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Association with Parents or Other Young

After fledging the adults care for the young for 2‒4 weeks, and the fledglings will be dependent on adults for food during the first week, and beg incessantly with a zi zi zi zi... call while shivering their wings (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ). Young birds seldom fight directly, but compete with one another in the ability to stimulate the parent to feed (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Ability to get Around, Feed, and Care for Self

On the second day after leaving the nest, young attempt to look for food on foliage and start pecking at items in clumsy manner, despite still being provisioned by their parents (84 Hinde, R. A. (1952). The Behaviour of the Great Tit Parus major and Some Related Species. Behaviour Supplement 2. E. J. Brill, Leiden, Netherlands. Close ).

Immatures may form relatively large groups, and join mixed-species foraging flocks for the winter before their first breeding season (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ).