Demography and Populations

Age at First Breeding

Breeding begins in the first year (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 ).

Intervals Between Breeding

Breeds annually.

Clutch Size and Number of Clutches per Season

Clutch size is quite variable. 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 ) listed the following factors that influence clutch size: date of laying (second clutches smaller than first), habitat (larger in richer habitats), population density (denser population lead to smaller clutches); age of female (younger females have smaller clutches), size of cavity (smaller clutches in smaller cavities), latitude (bigger clutches in northern areas) and individual variation. Examples of mean clutch sizes: in England, across years mean clutch size varied 7.8–12.3 (n = 7–86 pairs/yr) (167 Lack, D. (1964). A long-term study of the Great Tit (Parus major). Journal of Animal Ecology 33:159–173. Close ); in Belgium, the mode clutch across sites was 9 (n = 1,277 nests) (168 Dhondt, A.A., Adriaensen, F., Matthysen, E. and Kempenaers, B. (1990). Nonadaptive clutch sizes in tits. Nature (London) 348: 723-725. Close ); in Algeria, mean clutch 7.43 ± 0.29 SE over a three year period (2007–2009) (n = 30 broods; maximum clutch: 11 eggs; 169 Adamou, A. E., M. Bańbura, and J. Bańbura (2020). Subtle differences in breeding performance between Great Tits Parus major and Afrocanarian Blue Tits Cyanistes teneriffae in the peripheral zone of the species geographic ranges in NE Algeria. The European Zoological Journal 87(1):263–271. Close ). See 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 ) for a summary across further studies.

Annual and Lifetime Reproductive Success

23.3% of nests in southern England were depredated by Least Weasel (Mustela nivalis): 5.9% during laying, 9.8% during incubation, and 7.6% during the nestling stage (n = 4131 monitored nests, 1947–1975; 134 Dunn, E. (1977). Predation by weasels (Mustela nivalis) on breeding tits (Parus spp.) in relation to the density of tits and rodents. Journal of Animal Ecology 46(2):633–652. Close ). There is significant interannual variability in nest failure predation rate, ranging from 6.6–52.9% annually (1957–1972; 134 Dunn, E. (1977). Predation by weasels (Mustela nivalis) on breeding tits (Parus spp.) in relation to the density of tits and rodents. Journal of Animal Ecology 46(2):633–652. Close ). Nest predation by weasels is proportionately more severe in years of higher Great Tit density or lower rodent density (134 Dunn, E. (1977). Predation by weasels (Mustela nivalis) on breeding tits (Parus spp.) in relation to the density of tits and rodents. Journal of Animal Ecology 46(2):633–652. Close ). There is also variation across a season, with later nests having a higher predation rate (134 Dunn, E. (1977). Predation by weasels (Mustela nivalis) on breeding tits (Parus spp.) in relation to the density of tits and rodents. Journal of Animal Ecology 46(2):633–652. Close ).

Reproductive success is higher in mature woodland (170 Riddington, R., and A. G. Gosler (1995). Differences in reproductive success and parental qualities between habitats in the Great Tit Parus major. Ibis 137(3):371–378. Close ). In natural forest nests in Poland, 71.4% of nest failures during egg laying and incubation were caused by predation (n = 49 nest failures), and 66.7% of failures during the hatching and nestling period were due to predation (n = 60 nest failures)(137 Maziarz, M., T. Wesolowski, G. Hebda, M. Cholewa, and R. K. Broughton (2016). Breeding success of the Great Tit Parus major in relation to attributes of natural nest cavities in a primeval forest. Journal of Ornithology 157:343–354. Close ). Fledging success was 81.72% over a three year period (2007–2009) in Algeria (n = 30 broods; 169 Adamou, A. E., M. Bańbura, and J. Bańbura (2020). Subtle differences in breeding performance between Great Tits Parus major and Afrocanarian Blue Tits Cyanistes teneriffae in the peripheral zone of the species geographic ranges in NE Algeria. The European Zoological Journal 87(1):263–271. Close ).

Broods laid later in the season result in fewer total fledglings (171 Bukor, B., G. Seress, I. Pipoly, K. Sandor, C. Sinkovics, E. Vincze, and A. Liker (2022). Double-brooding and annual breeding success of great tits in urban and forest habitats. Current Zoology 68:517–525. Close ). Double-brooded females produce more total fledglings annually than single-brooded females (171 Bukor, B., G. Seress, I. Pipoly, K. Sandor, C. Sinkovics, E. Vincze, and A. Liker (2022). Double-brooding and annual breeding success of great tits in urban and forest habitats. Current Zoology 68:517–525. Close ). Females that double brood produce more offspring that recruit into focal populations than single-brooded females (1.32 recruits/year ± 0.05 SE versus 0.75 ± 0.02 SE) (172 Husby, A., Kruuk, L.E.B. and Visser, M.E. (2009). Decline in the frequency and benefits of multiple brooding in Great Tits as a consequence of a changing environment. Proc. Royal Soc. London (Ser. B Biol. Sci.) 276: 1845-1854. Close ). In five study populations in the Netherlands (spanning 1955–2004), a total of 12,506 first broods resulted in 8,670 recruits into the population [= 0.69 recruits/brood], and 2,713 second broods resulted in 840 recruits [= 0.31 recruits/brood] (172 Husby, A., Kruuk, L.E.B. and Visser, M.E. (2009). Decline in the frequency and benefits of multiple brooding in Great Tits as a consequence of a changing environment. Proc. Royal Soc. London (Ser. B Biol. Sci.) 276: 1845-1854. Close ).

Number of Broods Normally Reared per Season

In Hungary, 36% of forest habitat females (n = 227) and 44% of urban habitat females (n = 234) were double-brooded (171 Bukor, B., G. Seress, I. Pipoly, K. Sandor, C. Sinkovics, E. Vincze, and A. Liker (2022). Double-brooding and annual breeding success of great tits in urban and forest habitats. Current Zoology 68:517–525. Close ). Females have a higher probability of double brooding after their first year (171 Bukor, B., G. Seress, I. Pipoly, K. Sandor, C. Sinkovics, E. Vincze, and A. Liker (2022). Double-brooding and annual breeding success of great tits in urban and forest habitats. Current Zoology 68:517–525. Close ).

In five study populations in the Netherlands (spanning 1955–2004), a total of 12,506 first broods were followed by 2,713 double broods [= 21.7% of females double brooding] (172 Husby, A., Kruuk, L.E.B. and Visser, M.E. (2009). Decline in the frequency and benefits of multiple brooding in Great Tits as a consequence of a changing environment. Proc. Royal Soc. London (Ser. B Biol. Sci.) 276: 1845-1854. Close ). However, the probability of double-brooding in the Netherlands has declined over several decades (particularly 1973–2004). This is likely a result of phenological mismatches as caterpillar abundance shifts earlier in the season due to warming springs, and consequently fitness declines and reduced recruitment from second broods (172 Husby, A., Kruuk, L.E.B. and Visser, M.E. (2009). Decline in the frequency and benefits of multiple brooding in Great Tits as a consequence of a changing environment. Proc. Royal Soc. London (Ser. B Biol. Sci.) 276: 1845-1854. Close ).

Proportion of Total Females that Rear >= One Brood to Nest-Leaving

Information needed.

The oldest recorded wild individual was 16 years and 7 months, located in the Netherlands (173 Fransson, T., T. Kolehmainen, D. Moss, and R. Robinson (2023). EURING list of longevity records for European birds. Close ).

There is high interannual variation in survival of both juveniles and adults (174 Clobert, J., C. M. Perrins, R. H. McCleery, and A. G. Gosler (1988). Survival rates in the Great Tit Parus major in relation to sex, age, and immigration status. Journal of Animal Ecology 57(1):287–306. Close , 175 Horak, P., and J.-D. Lebreton (1998). Survival of adult Great Tits Parus major in relation to sex and habitat; a comparison of urban and rural populations. Ibis 140(2):205–209. Close , 140 Naef-Daenzer, B., F. Widmer, and M. Nuber (2001). Differential post-fledging survival of great and coal tits in relation to their condition and fledging date. Journal of Animal Ecology 70(5):730–738. Close ). Annual adult mortality ranges from ~40–60% across populations and studies, occasionally higher, and higher in the first year (reviewed in 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 ).

Juvenile mortality in Switzerland is highest immediately upon fledging, with 32% of young birds dying in the first four days after fledging, and 47% dying in the first 20 days (n = 342 nestlings), and predation causing most of this early mortality (140 Naef-Daenzer, B., F. Widmer, and M. Nuber (2001). Differential post-fledging survival of great and coal tits in relation to their condition and fledging date. Journal of Animal Ecology 70(5):730–738. Close ). After those initial high period with daily mortality > 10%, mortality reaches a level of ~2% per day (140 Naef-Daenzer, B., F. Widmer, and M. Nuber (2001). Differential post-fledging survival of great and coal tits in relation to their condition and fledging date. Journal of Animal Ecology 70(5):730–738. Close ). Mortality varies across each breeding season, and is highest for broods that fledge later in the season (140 Naef-Daenzer, B., F. Widmer, and M. Nuber (2001). Differential post-fledging survival of great and coal tits in relation to their condition and fledging date. Journal of Animal Ecology 70(5):730–738. Close ). In Sweden, mortality of fledglings is high and constant across the summer (13% per week; n = 506 nestlings) (176 Dhondt, A. A. (1979). Summer dispersal and survival of juvenile Great Tits in southern Sweden. Oecologia 42:139–157. Close ). Fledgling mass is a strong predictor of mortality, as is mass of juveniles across their first winter, with heavier individuals more likely to survive (176 Dhondt, A. A. (1979). Summer dispersal and survival of juvenile Great Tits in southern Sweden. Oecologia 42:139–157. Close , 177 Tinbergen, J. M., and M. C. Boerlijst (1990) Nestling weight and survival in individual Great Tits (Parus major). Journal of Animal Ecology 59:1113–1127. Close , 140 Naef-Daenzer, B., F. Widmer, and M. Nuber (2001). Differential post-fledging survival of great and coal tits in relation to their condition and fledging date. Journal of Animal Ecology 70(5):730–738. Close ,178 Rodriguez, S., A. J. van Noordwijk, E. Alvarez, and E. Barba (2016). A recipe for postfledging survival in great tits Parus major: be large and be early (but not too much). Ecology and Evolution 6(13):4458–4467. Close ). Juvenile survival in the first winter is low (mean 0.152 in Spain; 178 Rodriguez, S., A. J. van Noordwijk, E. Alvarez, and E. Barba (2016). A recipe for postfledging survival in great tits Parus major: be large and be early (but not too much). Ecology and Evolution 6(13):4458–4467. Close ).

In Europe, survival is correlated with the crop of beech (Fagus sylvatica) seeds (174 Clobert, J., C. M. Perrins, R. H. McCleery, and A. G. Gosler (1988). Survival rates in the Great Tit Parus major in relation to sex, age, and immigration status. Journal of Animal Ecology 57(1):287–306. Close , 179 Perdeck, A. C., M. E. Visser, and J. H. van Balen (2000). Great Tit Parus major survival and the beech-crop cycle. Ardea 88(1):99–106. Close ); this is likely due to food limitation during winter directly affecting survival, as food supplementation experiments show increased survival of juveniles and adults in winter during years of low beech crops (179 Perdeck, A. C., M. E. Visser, and J. H. van Balen (2000). Great Tit Parus major survival and the beech-crop cycle. Ardea 88(1):99–106. Close ). Mean survival rates in Oxfordshire, England were 0.427 for resident males and 0.399 for resident females; survival estimates were higher for older birds than yearlings (174 Clobert, J., C. M. Perrins, R. H. McCleery, and A. G. Gosler (1988). Survival rates in the Great Tit Parus major in relation to sex, age, and immigration status. Journal of Animal Ecology 57(1):287–306. Close ). Summer survival (between the breeding season and September) for adults in the Netherlands varied across years, ranging from 66.7–87.8% for males and 52.6–65.8% for females (180 Drent, P. J. (1984). Mortality and dispersal in summer and itss consequences for the density of Great Tits Parus major at the onset of autumn. Ardea 72(2):127–162. Close ). Male survival (but not female) is negatively related to the density of Eurasian Blue Tit (Cyanistes caeruleus), possibly as a cost of territory defense (174 Clobert, J., C. M. Perrins, R. H. McCleery, and A. G. Gosler (1988). Survival rates in the Great Tit Parus major in relation to sex, age, and immigration status. Journal of Animal Ecology 57(1):287–306. Close ). In Estonia, urban survival is higher than rural survival, and higher in females than males: mean survival 0.47 for urban females, 0.38 for rural females, 0.34 for urban males, and 0.26 for rural males (175 Horak, P., and J.-D. Lebreton (1998). Survival of adult Great Tits Parus major in relation to sex and habitat; a comparison of urban and rural populations. Ibis 140(2):205–209. Close ).

Disease

Avipoxvirus infections, which produce nodular skin lesions, mainly on the head, have been recorded in the Great Tit in central Europe since 2005 (181 Literak, I., P. Kulich, B. Robesova, P. Adamik, and E. Roubalova (2010). Avipoxvirus in great tits (Parus major). European Journal of Wildlife Research 56:529–534. Close ).

Infection by the bacterium Suttonella ornithocola was likely responsible for an epidemic in Germany in 2020, although other pathogens including Chlamydia psittaci may have had a role (182 Fischer, L., M. Peters, S. Merbach, M. Eydner, A. Kuczka, J. Lambertz, M. Kummerfeld, K. Kahnt, A. Weiss, and H. Petersen (2021). Increased mortality in wild tits in North Rhine-Westphalia (Germany) in 2020 with a special focus on Suttonella ornithocola and other infectious pathogens. European Journal of Wildlife Research 67:56. Close ).

Body Parasites

The tick Ixodes ricinus is common on adults, but with an skewed distribution in which a few individuals harbor many ticks and most harbor few or none; the mean tick load in Belgium is 1.03 ± 0.04 ticks/bird (range: 0–25; n = 3,940 birds)(183 Heylen, D., F. Adriaensen, S. Van Dongen, H. Sprong, and E. Matthysen (2013). Ecological factors that determine Ixodes ricinus tick burdens in the great tit (Parus major), an avian reservoir of Borrelia burgdorferi s.l. International Journal for Parasitology 43(8):603–611. Close ). Less than 1% of adults host Ixodes arboricola (183 Heylen, D., F. Adriaensen, S. Van Dongen, H. Sprong, and E. Matthysen (2013). Ecological factors that determine Ixodes ricinus tick burdens in the great tit (Parus major), an avian reservoir of Borrelia burgdorferi s.l. International Journal for Parasitology 43(8):603–611. Close ).

Feather mite genera include Uniscutalges, Proctophyllodes, Strelkoviacarus, Pteronyssoides, Monojoubertia, Analges, Microlichus, with the most common mite on wing feathers being Proctophyllodes stylifer (184 Galvan, I., and J. J. Sanz (2006). Feather mite abundance increases with uropygial gland size and plumage yellowness in Great Tits Parus major. Ibis 148:687–697. Close and references therein). Birds in central Spain had a wing feather mite prevalence of 65.1% (n = 43), and a mean mite load of 15.0 ± 35.7 (range 1–170), with mites most common on secondaries relative to primaries or tertials (184 Galvan, I., and J. J. Sanz (2006). Feather mite abundance increases with uropygial gland size and plumage yellowness in Great Tits Parus major. Ibis 148:687–697. Close ). Individuals with larger uropygial glands had more feather mites, which feed on uropygial gland oil spread on feathers (184 Galvan, I., and J. J. Sanz (2006). Feather mite abundance increases with uropygial gland size and plumage yellowness in Great Tits Parus major. Ibis 148:687–697. Close ). Feather mite load is negatively correlated with hatching success and breeding success (184 Galvan, I., and J. J. Sanz (2006). Feather mite abundance increases with uropygial gland size and plumage yellowness in Great Tits Parus major. Ibis 148:687–697. Close ).

Blood parasites in Sweden include Haemoproteus, Leucocytozoon, Hepatozoon, Plasmodium, and Trypanosoma (185 Dufva, R. (1996). Blood parasites, health, reproductive success, and egg volume in female Great Tits Parus major. Journal of Avian Biology 27(1):83–87. Close ). Trypanosoma infection in females is associated with smaller eggs, lower hatching success, and reduced body condition of nestlings (185 Dufva, R. (1996). Blood parasites, health, reproductive success, and egg volume in female Great Tits Parus major. Journal of Avian Biology 27(1):83–87. Close ). The blood parasite Leucocytozoon hamiltoni (Haemosporida, Leucocytozoidae) was described from subspecies P. m. bokharensis in Turkmenistan (186 Valkiunas, G., T. A. Iezhova, and S. V. Mironov (2002). Leucocytozoon hamiltoni N. sp. (Haemosporida, Leucocytozoidae) from the Bukharan Great Tit Parus bokharensis. Journal of Parasitology 88:577–581. Close ).

The nematode Serratospiculum amaculata, which infects the respiratory system, has been found in the Great Tit in Slovakia (187 Königová, A., L. Molnár, G. Hrčková, and M. Várady (2013). The first report of serratospiculiasis in Great Tit (Parus major) in Slovakia. Helminthologia 50:254–260. Close ).

Blow fly larvae (Protocalliphora sp.) parasitize broods: across years (2007–2009; n = 30 broods), there were 8.02 ± 1.09 SE, 0.41 ± 0.41, and 0.47 ± 0.29 blow fly larvae per nest in Algeria; the degree of infestation did not affect fledging success (169 Adamou, A. E., M. Bańbura, and J. Bańbura (2020). Subtle differences in breeding performance between Great Tits Parus major and Afrocanarian Blue Tits Cyanistes teneriffae in the peripheral zone of the species geographic ranges in NE Algeria. The European Zoological Journal 87(1):263–271. Close ).

Baardsen et al. (188 Baardsen, L. F., L. De Bruyn, F. Adriaensen, J. Elst, D. Strubbe, D. Heylen, and E. Matthysen (2021). No overall effect of urbanization on nest-dwelling arthropods of great tits (Parus major). Urban Ecosystems 24:959–972. Close ) identified 22 orders of arthropods inhabiting Great Tit nests in Belgium (n = 186 nests, 186,728 arthropods). 81% of all arthropods found could be classified as parasites, with fleas (Spihonaptera: Ceratophyllidae: Ceratophyllus gallinae, Ceratophyllus garei, and Dasypsyllus gallinulae) occurring in 91.4% of nests, hematophagous mites (Mesostigmata: Dermanyssidae: Dermanyssus carpathicus, Dermanyssus longipes, Dermanyssus sp.) in 74.2% of nests, parasitic flies (Diptera: Calliphoridae: Protocalliphora azurea; Diptera: Carnidae sp.) in 31.2% of nests, and ticks (Ixodida: Ixodidae: Ixodes arboricola, Ixodes frontalis, Ixodes ricinus) in 13.4% of nests (188 Baardsen, L. F., L. De Bruyn, F. Adriaensen, J. Elst, D. Strubbe, D. Heylen, and E. Matthysen (2021). No overall effect of urbanization on nest-dwelling arthropods of great tits (Parus major). Urban Ecosystems 24:959–972. Close ). Nest arthropod communities were generally similar between rural and urban habitats (188 Baardsen, L. F., L. De Bruyn, F. Adriaensen, J. Elst, D. Strubbe, D. Heylen, and E. Matthysen (2021). No overall effect of urbanization on nest-dwelling arthropods of great tits (Parus major). Urban Ecosystems 24:959–972. Close ).

Information needed.

Individual Distance

Frequent agonistic interactions among individuals in a flock (see Agonistic Behavior) serve to keep free a malleable amount of space around each individual; approaches within two feet or closer induce increasingly aggressive threat postures (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 ).

Territory Size

Breeding territories vary in size by habitat and population, but are most often 0.5–1.5 ha, and sometimes up to 3 ha in size (reviewed in 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 ).

Home Range Size

Winter flocks have home ranges of approximately 4–8 ha, sometimes overlapping neighboring flocks (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 ).

Numbers

There is no global estimate of population size. The European population has been estimated at 69.6 million (European Breeding Bird Atlas 2) or 79.3 million (European Red List of Birds) breeding pairs (189 Herrando, S., S. Fraixedas, L. Brotons, D. Marti, A. Staneva, V. Keller, P Voříšek, and I. J. Burfield (2024). Improving national bird population estimates in Europe: insights from comparisons with atlas abundance data. Bird Conservation International 34:e16. Close ).

Densities in southern England (pairs/km²) 20–320 in mixed deciduous woods, 80–330 in oak woodland, 6–53 in pine plantation; in northeast Poland (Bialowieza forest), 24 pairs/km² in alder (Alnus) swamp-forest, 26 in mixed ash-alder (Fraxinus-Alnus) forest, 19–24 in mixed oak-hornbeam (Quercus-Carpinus) forest and 1–2 in mixed coniferous forest.

In the Karakum Desert, Turkmenistan, the subspecies bokharensis occurs in densities (birds/km²) of 8.5 in sand desert, 44.0 in black saksaul (Haloxylon ammodendrum) shrubland, and 1.5 in oases (79 Rustamov, A. K. (1994). Ecology of birds in the Karakum Desert. In: Biogeography and Ecology of Turkmenistan (V. Fet and K. I. Atamuradov, Editors). Monographiae Biologicae, volume 72. Springer, Dordrecht, Netherlands. Close ).

Trends

The global population trend is believed to be increasing (190 BirdLife International (2024) Species factsheet: Parus major. Close ). The European population shows a moderate increase of 0.47% per year from 1980–2022 (PanEuropean Common Bird Monitoring Scheme). Local populations show variations in the population trend. Populations in the UK have increased a total of 25% from 1995–2022 [= ca. 1.08% increase per year] (191 Heywood, J. J. N., D. Massimino, D. E. Balmer, L. Kelly, S. Marion, D. G. Noble, J. W. Pearce-Higgins, D. M. White, P. Woodcock, S. Wotton, and S. Gillings (2024). The Breeding Bird Survey 2023. BTO Research Report 765. British Trust for Ornithology, Thetford, UK. Close ). Populations show annual declines in Denmark (192 Vikstrøm, T., D. P. Eskildsen, M. F. Jørgensen, and N. Y. Ali (2022). Overvågning af de almindelige fuglearter i Danmark 1975-2021. Årsrapport for Punkttællingsprogrammet. Dansk Ornitologisk Forening. Close ): -0.86% (breeding season, 1976–2021), -1.94% (breeding season, 2012–2021), -0.75% (winter season, 1975–2021), -2.17% (winter season, 2011–2021). Populations are increasing 2.2% per year in total across Sweden (1975–2023), but declining -0.70% per year in southern Sweden (https://www.fageltaxering.lu.se/om-oss). Populations in southern Finland show a modest increase from 1959–2012 (193 Fraixedas, S., A. Lehikoinen, and A. Lindén (2015). Impacts of climate and land-use change on wintering bird populations in Finland. Journal of Avian Biology 46(1):63–72. Close ), and are increasing 2.10% per year across Finland (194 Väisänen, R. A. (2005). Maalinnuston kannanvaihtelut Etelä-ja Pohjois-Suomessa 1983–2005. Linnut-vuosikirja 2005:83–98. Close ). Population trends are stable in Estonia from 1987–2012 (195 Kuresoo, A., H. Pehlak, and R. Nellis (2011). Population trends of common birds in Estonia in 1983–2010. Estonian Journal of Ecology 60(2):88–110. Close , 196 Elts, J. (2012). A review of 25 years of mainland winter bird counts in Estonia. Bird Census News 25:43–52. Close ). Populations in northern Italy are increasing from 1992–2007 (197 Bani, L., D. Massimino, V. Orioli, L. Bottoni, and R. Massa (2009). Assessment of population trends of common breeding birds in Lombardy, Northern Italy, 1992–2007. Ethology Ecology & Evolution 21(1):27–44. Close ). Populations in European Russia show a moderate decline from 1988–2019 (198 Preobrazhenskaya, E., and A. Morkovin (2020). PARUS program: wintering land bird monitoring in European Russia. Bird Census News 33:3–13. Close ).

Information needed.