Ian Newton

Abstract The Bullfinch Pyrrhula pyrrhula has presented problems for fruit growers in Britain since at least the sixteenth century. By feeding on the blossom buds of fruit trees, it can greatly reduce the subsequent fruit crop. The species became especially abundant in southern Britain during the 1950–70s, creating a major problem for commercial fruit growers. Killing the birds proved to be the only viable way to reduce the damage. This paper gives, for the first time, details of the numbers of Bullfinches killed on particular farms in Britain during the 1960s, and examines the sex and age ratios of the birds involved. Extrapolation from the figures gained from these farms shows that the total number of Bullfinches killed each year in Britain could have exceeded 800,000. Most of the birds killed were in their first year of life, and males predominated over females. The findings throw light on various aspects of Bullfinch biology.

Introduction

The Bullfinch Pyrrhula pyrrhula has long been regarded as a pest in orchards, stripping the fruit buds from trees and thereby reducing the crop. It was listed as a pest as long ago as the sixteenth century and, during various periods, bounties were paid for the killing of birds in major fruit-growing areas (Roach 1962; Lovegrove 2007). From the 1950s to the 1970s, Bullfinches in southern Britain occurred in exceptional abundance and caused serious and extensive damage in commercial orchards. Most stands of plums and pears, and some stands of apples, suffered damage every year and, in some cases, whole orchards were almost totally denuded of buds by Bullfinches (Newton 1964). At that time, the Bullfinch was judged to be the most serious economic threat to fruit growing in Britain. Various scaring devices were trialled, as were deterrent chemicals that were sprayed onto the trees, but none proved effective for more than a few days at a time. The only cost-effective method of reducing damage was by killing the birds themselves, in an attempt to reduce the local population. 

At that time, Bullfinches had no legal protection in fruit-growing areas and could be shot or trapped at any time of year. Because of the extent of the damage, most commercial fruit growers were driven to control them. Cage-traps were based on the French ‘Chardonneret’ traps: small wire cages that contained a compartment for a live ‘call bird’, and one or more open compartments baited with a common food source, such as seeding dock stems. These traps worked on the same principle as a modern ‘Larsen trap’ used to catch corvids, but were much smaller, with each trap compartment about 15 x 20 cm in cross section and 12 cm deep. When a bird hopped down onto a perch in the trap, the lid was triggered to close and the bird was caught. These traps, most loaded with a decoy, were placed around the orchard and nearby hedgerows at about one per 1–3 ha, and visited once or twice per day to provide food and water for the decoy bird and to remove any trapped birds. Initially, most growers undertook control measures only in late winter and spring, when bud-eating occurred, but were soon driven to set traps year-round in desperate attempts to reduce numbers. Some growers positioned two traps such that call birds could not see one another but were within earshot, so that they continued to call to one another. This constant calling increased the chance of wild birds being attracted. Growers reported no difference between males (cocks) and females (hens) in their effectiveness as call birds, except during the breeding season, when females produced bigger catches: ‘up to a dozen cock birds in a week just in one cage’. 

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238. Male Bullfinch Pyrrhula pyrrhula feeding on buds, Norfolk, March 2021.

David Tipling

Year-round trapping had another benefit for the grower in that it reduced the rate at which natural winter seed supplies were reduced, ensuring that they lasted longer, thus delaying the date when birds switched to serious bud-feeding. Some growers also used shooting as a means of control – but not commonly, since it was expensive, time-consuming and liable to damage the trees. In contrast, traps could operate throughout the daylight hours, day after day throughout the year, and needed minimal attention. 

During the 1960s, I was studying Bullfinch populations in Wytham Woods, Oxfordshire, in a project that involved mist-netting and ringing them. This led me into the orchard problem. I visited and encouraged growers in all major fruit-growing areas to keep records of the numbers of Bullfinches killed (which most did anyway) and to send me figures and carcases for my study. I provided polythene bags and stamped envelopes for posting and, on almost every day across several years, parcels arrived. My initial aim was to analyse gut contents for information on diet, but most trapped birds contained no identifiable food apart from that used to bait the traps. Shot birds were more useful for studying diet but were few in number. Nevertheless, the carcases provided unequivocal evidence of the numbers killed at different times of year, as well as information on sex and age ratios, as I was able to separate them into juveniles (up to the end of post-juvenile moult), first-year birds (up to the first complete moult in the second calendar-year), and adult (all older birds). First-year birds were recognised by retained juvenile alula, carpal and greater (secondary) coverts (Newton 1966b; Svensson 2023). In my own study at Wytham, several hundred Bullfinches were ringed and released as juveniles and, of the many that were later recaught, all had retained the alula and carpal coverts and most also one or more secondary coverts through to the first adult moult, confirming the reliability of this method of ageing. Through the same ringing study, I also discovered how to sex juveniles before they started their post-juvenile moult: in males the innermost (smallest) tertial feather was tinged pinkish-grey on the outer web, whereas in females it was brownish. Towards the end of my programme, instead of requesting whole carcases, which were messy to deal with, I encouraged fruit growers to remove the right wing from each bird killed and send me these wings in batches. The wings were enough to reveal the age and sex of each bird killed. 

My aims in this paper are to document the numbers of Bullfinches killed on particular farms, together with their ages and sexes. To my knowledge, no information of this type has been previously published. The sample sizes in tables 1–4 vary according to the information obtained; growers who provided information only by correspondence gave numbers killed, while some also separated sexes and juveniles, but only for the birds whose carcases or wings I had received could I sex pre-moulting juveniles and also separate, after the post-juvenile moult, first-years from older birds.

Orchards in the 1960s

Fruit growing in Britain was very different in the 1960s compared to now. At that time, a huge amount of top fruit was grown, mainly in Kent and Essex, but also in Norfolk, Suffolk, Cambridgeshire, Sussex, Berkshire and Hampshire in the southeast, and in Herefordshire and Worcestershire in the West Midlands, with small areas in many other counties. The total area of commercial orchard land (apples, pears, plums and cherries) in Britain in 1960 was estimated at around 95,000 ha and in 2020 as 21,000 ha, representing a 78% decline over 60 years (Barnes & Williamson 2021). These figures include commercial cider apple orchards, but exclude the old traditional orchards, found mainly in the West Midlands, that are used chiefly for sheep grazing. In these non-commercial orchards, Bullfinches were not relevant or systematically controlled. 

The orchards themselves also changed markedly over this period. In the 1960s, many had been planted in small units, surrounded by tall, straggling Hawthorn Crataegus monogyna and Bramble Rubus fruticosus agg. hedges, serving as windbreaks and also as good Bullfinch habitat. Weed control was less effective than now, and many orchards supported an abundance of Bullfinch food plants between the rows of trees, such as Dandelion Taraxacum officinale and Sowthistle Sonchus oleraceus in summer and docks Rumex spp. and Fat-hen Chenopodium album in autumn and winter. Nowadays, as weed control in orchards is much more effective and the alleys are mowed frequently, it is rare to find weeds in abundance anywhere. In the 1960s, fruit farms probably offered the best year-round habitats for Bullfinches; in addition to hedgerows, fruit buds and weed seeds, many contained patches of cultivated blackberries and raspberries, whose dried, unpicked fruits provided seeds in winter. One fruit grower wrote that, in a 2.8 ha patch of cultivated blackberries, he caught 186 Bullfinches in one trap during October–December of one year, before the old fruiting canes were cut out.

The Bullfinch problem caused many fruit-growers to remove the old hedgerows and replace them with other windbreaks, such as lines of poplar Populus or alder Alnus, which are of little or no value to Bullfinches. Weed control became more effective, reducing the seed supply that Bullfinches could eat. The problem of bud damage ended in the 1970s, when Bullfinches declined nationally and growers no longer felt the need to control them; soon after, the species was given protected status. Subsequently, fruit growing became less profitable as import costs dropped and home-production costs rose, forcing many growers to grub up their orchards and turn to more lucrative arable cropping. The decline of fruit growing in Britain occurred long after the main period of serious bud damage, and the Bullfinch could have played no role in this decline. 

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239. Male Bullfinch, Norfolk, February 2023.

David Tipling

Numbers killed

For growers who consistently provided records, the numbers of Bullfinches killed in different years are shown in table 1. These varied by three orders of magnitude between farms. In addition to these numbers, many other growers reported totals for single years. Annual totals for most farms were in the order of a few hundred birds. In general, figures of more than 1,000 per year came from the larger orchard areas, exceeding 50 ha, and smaller numbers, not surprisingly, came from smaller orchards. However, many factors, other than orchard size, influenced the totals, including the amount of suitable woodland and hedgerow on the farm and in the surrounding area, the varieties of top fruit grown, and the effort put into Bullfinch control. Unfortunately, information on these aspects was not sufficiently available to enable me to carry out a statistical analysis to assess the relative importance of each to the numbers killed.

Some of the larger farms employed someone full-time for Bullfinch control, which entailed both trapping and shooting. As one Kent orchard owner wrote: ‘We found that the most effective way of destroying Bullfinches is by shooting, and this is because one of our employees is skilled in whistling the birds to him by imitating the bird itself.’ This employee shot 276 Bullfinches in 13 days, and the annual totals of birds killed on this 324-ha orchard in four successive years were 3,469, 2,961, 2,574 and 1,487. These totals declined through time, but not necessarily because of the control operations; in other orchards, the numbers killed increased over time or fluctuated from year to year, with no obvious overall trend (table 1). 

Even in relatively small areas, surprising numbers could be killed in a year. One farmer wrote that he grew less than 1 ha of blackcurrants but lost his entire crop through bud removal by Bullfinches. So, the following year, he operated traps and, in this small area, killed 82 Bullfinches during the year. Another grower reported shooting 27 Bullfinches in the same single Ash Fraxinus excelsior tree in just six days. 

The large numbers of Bullfinches killed in each orchard presumably resulted not only from a large population but from a continual flow of birds into the orchards from outside. As one grower wrote: ‘I clear them all out and then, a few days later, more appear; I clear them out, and the same happens again.’ The implication was that Bullfinches were not only much more numerous than they are now but also continually on the move. 

From the amount of damage that Bullfinches were causing, and its effects on farm budgets, the incentive to remove them was strong, as exemplified in this published account: ‘After several seasons of trapping and shooting Bullfinches, with an average kill of 300–500, it then became obvious that this figure was not good enough since populations were still increasing. For the season 1961–62, a target of 1,000 was set, but in actual fact it was passed, 1,500 birds being killed in seven months. The target for 1962–63 will be 2,000. Only when I fail to achieve my target by a substantial margin shall I be satisfied that, at last, I am getting the birds under control’ (Wickham & Whiffen 1962). In correspondence, I learnt that the target for 1962–63 was also surpassed, with more than 3,000 killed. It is remarkable to think that the numbers caught per trap on this farm were around 100–150 per season.

Age and sex ratios

Bullfinches were classed as juveniles up to the end of post-juvenile moult, and as first-year birds up to the end of August in the second calendar-year, after which they were deemed ‘adults’. In any case, by September, most birds hatched in the previous year were so far through their first adult moult that they could no longer be distinguished from older birds. The striking feature of the orchard samples was the great proportion of juveniles/first-winter birds in the samples from August–November, with ratios of more than about 22 young to every adult bird trapped over this period as a whole (fig. 1; table 2). These ratios were clearly much greater than could be achieved by reproduction, as they would entail Bullfinches producing an average of more than 40 young per pair in a season. Moreover, they were much greater than the ratios obtained by mist-netting in Wytham Woods, which, over a five-year period, reached averages of 1.16 young per one adult in August, 2.80 in September, 3.65 in October and 2.69 in November (table 2). All these Wytham ratios were within the range expected from known breeding success, with a peak in October equivalent to 7.3 young per pair per season. From high ratios in August–November, the orchard ratios fell substantially through December, and reached levels more similar to those for Wytham in the months February–April, after which breeding began. The general implication was that the widespread killing on fruit farms fell heavily on young birds in their first few months of life.

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Fig. 1. Number of young (juvenile and first-winter birds) Bullfinches Pyrrhula pyrrhula per adult trapped in Wytham Woods, Oxfordshire, and commercial orchards in different months, years combined (1962–67).

Another striking finding among the orchard samples was a predominance of males throughout the year (fig. 2). This would have been expected in the breeding season, from mid April to mid September, when many females would be on nests and unavailable for capture. In the main breeding months of May–July, females formed only around 14% of the adult Bullfinches killed. However, a surplus of males was also apparent in the non-breeding season: in a sample of 3,351 individuals killed between October and March, 52.5% were males and 47.5% were females, equivalent to a ratio of males/females of 1.10, or 11 males to every 10 females (χ2= 4.16, df = 1, P<0.05; table 3). Nevertheless, the ratio varied slightly among the birds from different counties (years combined; table 3) and different years (counties combined; table 4). In each individual year, and in most of the counties, the recorded differences in sex ratio did not achieve statistical significance; only for Berkshire was the surplus of males significant. Interestingly, juveniles that had not yet started their post-juvenile moult showed an equal sex ratio, with 86 individuals of each sex, implying that any disparity developed later.

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Fig. 2. Percentage of females among Bullfinches killed in commercial orchards in different months, years combined (1963–67). Sample sizes above columns.

Discussion

The numbers of Bullfinches killed in commercial orchards during the 1960s reflected their general abundance at the time. It is inconceivable that such large numbers could be killed nowadays, when the overall Bullfinch population of Britain is so much smaller. The BTO monitoring schemes (CBC and BBS) imply that Bullfinch breeding numbers in Britain declined by 60% between 1970 and 2020, with the steepest rate of decline occurring during 1977–82 (Siriwardena et al.2001). Most fruit growers gave up killing Bullfinches in the 1970s or 1980s, when bud damage no longer had a significant impact on their operations. The species was given full legal protection from 1998.

It was not only the overall abundance of Bullfinches that contributed to the numbers killed in specific orchards, but their continual movements. British ringing recoveries of Bullfinches indicate that most movements are over relatively short distances, with 90% of recovered birds found within 5 km of the original ringing site (Newton 2002). However, if a single trap could, over time, attract birds from a radius of up to 5 km, the area involved would amount to 78.5 sq. km (or 30.3 sq. miles). This explains how such large annual numbers could be caught in a single trap in orchards of less than one ha and why the numbers caught per ha declined with increasing orchard area. Radio-tracking studies in orchard areas also showed that Bullfinches do not move far, as these individuals stayed in an area of 1–1.5 ha for a time, occasionally moving up to a few hundred metres outside it before shifting to another area up to a few kilometres away (Greig-Smith 1985).

For those farms in table 1 for which I knew the size of the orchard, I could calculate the average number of Bullfinches killed per ha per year, which worked out at around 8.5. The total area of commercial orchards in Britain at that time was around 95,000 ha, so if the figures for those farms were typical, more than 800,000 Bullfinches would have been killed overall per year. This figure has no firm statistical basis but, again, it hints at the exceptional abundance of Bullfinches in Britain at that time.

The period during the 1950s to 1970s, when Bullfinches were most abundant, coincided with the period when Eurasian Sparrowhawks Accipiter nisus were effectively absent from all the main fruit-growing areas. Their decline was attributed to their extreme vulnerability to organochlorine pesticides, notably DDT, aldrin and dieldrin, which were then in heavy use (Ratcliffe 1970; Newton & Haas 1984; Newton 1998). Reduction in Sparrowhawk predation on Bullfinches during this period may not have been important but, in the absence of Sparrowhawks, Bullfinches were able to range out and feed much further from protective cover. This was obvious at the time, and greatly increased the food available to Bullfinches, and may have underpinned their rise in numbers (Newton 2013) As organochlorines were phased out, through the 1970s and 1980s, Sparrowhawks returned, in sequence from west to east, and Bullfinches declined. However, these relationships remain as correlations, so cannot be accepted as causal. In addition, however, the virtual absence of Sparrowhawks from fruit-growing areas during the 1950s to 1970s may have helped in the survival of call birds, making this method of trapping them more viable than it might otherwise have been.

Over the years of high Bullfinch populations, the numbers killed in orchards did not generally decline over time. This implied that, despite the numbers killed, control operations – while almost certainly lessening damage to fruit trees at the time – were not reducing Bullfinch breeding numbers in the long term. The same conclusion was drawn by many individual fruit growers: ‘In one square mile of Sandhurst, [Kent] we collectively destroy annually 1,500 Bullfinches, with no apparent reduction in their numbers.’ In an independent study in a 4-ha orchard in Herefordshire, about 200 Bullfinches were trapped and killed annually for five successive years. Despite this killing, the numbers caught did not decline over that period, and the population in the surrounding area of 9 km2 remained at 60–90 pairs (Evans 1984). However, even if control operations did not bring about decline, it remains possible that they may have prevented further increase.

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240. Female Bullfinch, Norfolk, February 2023.

David Tipling

Age ratios

The large proportions of juveniles/first-winter birds killed in orchards in the late summer and autumn are far greater than expected from reproductive rates. At Wytham in the 1960s, the ratios of juveniles/adults in October over five years varied between 2.8 and 5.5, with an overall average of 3.65 (Newton 1999a,b). These figures were within the range expected from known reproductive rates. Similar ratios, based on ringers’ catches, were later reported from other areas in central England (Proffitt 2002). All these birds were caught in mist nets and quickly released back into the population. In contrast, in commercial orchards, where the equivalent ratios during August–November were around 22 to one, Bullfinches were continually being removed, creating almost ‘vacant’ habitat, open to newcomers. More importantly, however, the orchard figures imply that juveniles were much more mobile than adults during the August–November period, forming the bulk of fresh immigrants. Juveniles might be inherently more dispersive than adults in these months but, in addition, their wings are fully functional throughout this period. That is in contrast to adults, whose flight efficiency is reduced by a wing moult lasting about 10–11 weeks in each individual, and up to 17 weeks across the adult population as a whole (late July to mid November) (Newton 1966b; Newton & Rothery 2000). An earlier study revealed that, while adults stayed near cover during moult, juveniles were more likely to forage in relatively open areas (Newton 1966b). No one has analysed post-breeding dispersal in Bullfinches, but comparison of natal and breeding dispersal from ringing recoveries shows that juveniles disperse about twice as far from their natal sites to their to first breeding sites than adults move between breeding sites in different years (arithmetic mean natal dispersal distance = 4.6 km, arithmetic mean breeding dispersal distance = 2.5 km; Paradis et al. 1998). So, the hypothesis that juveniles are more dispersive than adults in the months after breeding is plausible. It is not only the distances that may differ between age groups, but also the frequency of moves. Additionally, juveniles may be easier to trap and shoot than adults owing to a degree of naivety, but, in this case, one might expect a similar difference with respect to birds trapped in mist nets. Nevertheless, birds in their first few months of life may be more likely than older ones to respond to call birds.

Sex ratios

The predominance of males during the non-breeding period (October–March) could only be due to: (1) a genuine surplus of males in the population at large, or (2) some aspect of the behaviour of males which made them more likely to be shot or trapped. Support for the notion of a genuine surplus comes from the study of the annual survival in the two sexes, as assessed from ringing recoveries. With age groups combined, Dobson (1987) calculated the annual survival of males during 1966–78 at 48% (SE 3) and females at 41% (SE 4). With a larger sample over a longer period (1962–95), Siriwardena et al. (1998) gave survival estimates for adult Bullfinches of 43.5 (SE 1.5) in males and 40.1 (SE 2.2) in females, and for first-year Bullfinches of 36.3 (SE 2.7) in males and 35.6 (SE 3.3) in females. In all these estimates, sex differences were statistically significant. Assuming an equal sex ratio at fledging (as reported above), such survival differences would soon lead to a surplus of males among adults, increasing with age. These estimates were made mainly on birds not killed in orchards (only about 13% of recoveries came from birds described as trapped or shot; Dobson (1987)), so the sex-specific mortalities were almost certainly a feature of the wider population. 

This does not exclude the additional possibility of a behavioural difference between the sexes that led to more males being killed outside (as well as within) the breeding season. Ringing recoveries gave no indication that males moved further than females (Newton 2002), but they could not tell us whether males moved more often, and in this way contributed to the excess of males among killed birds. However, a surplus of males was also found in birds assessed by observation (Wilkinson 1982; Hogstad 2006), as well as in mist-netted samples (Newton 1966a; Greig-Smith & Wilson 1984; Wright 2022), and in general ringing recoveries (Siriwardena et al. 1998). Shooting as a control method might also be expected to favour males, which should be more conspicuous than females. I could not examine this possibility because growers who provided carcases did not usually separate shot from trapped birds, although the former were very much in the minority. 

A predominance of males is common among the adults of many bird populations. In one review, the sex ratio in 131 of 173 species examined differed significantly from unity and, in 83% of these, the ratio was male-skewed, sometimes by as much as 30–35% (Donald 2007). Among 92 studies of passerines alone, 3% showed a significant female surplus, 36% a balanced sex ratio and 61% a significant male surplus. The Bullfinch is therefore not unusual in showing an excess of males, but it may be unusual in the fact that the excess is so small (averaging 10%).

Acknowledgments

I would like to acknowledge the help in this study given by large numbers of fruit growers, mostly now long since deceased but who willingly provided both information and birds. Retrospective thanks are also due to my colleagues in the Edward Grey Institute in Oxford, who valiantly tolerated the stench that accompanied each postal delivery over several years.

References

Barnes, G., & Williamson, T. 2021. The Orchards of Eastern England. University of Hertfordshire Press, Hatfield.

Dobson, A. P. 1987. A comparison of sexual and annual mortality for both sexes of fifteen species of common British birds. Ornis Scand. 18: 122–128.

Donald, P. F. 2007. Adult sex ratios in wild bird populations. Ibis 149: 671–692.

Evans, I. I. B. 1984. A thousand Bullfinches. Herefordshire Ornithological Club Annual Report 1984: 171–174.

Greig-Smith, P. W. 1985. Winter survival, home ranges and feeding of first-year and adult Bullfinches. In: Sibly, R. M., & Smith, R. H. (eds.), Behavioural Ecology. Blackwell Scientific Publications, Oxford.

Greig-Smith, P. W., & Wilson, G. M. 1984. Patterns of activity and habitat use by a population of Bullfinches (Pyrrhula pyrrhula) in relation to bud-feeding in orchards. J. Appl. Ecol. 21: 401–422.

Hogstad, O. 2006. Flock composition, agonistic behaviour and body composition of wintering Bullfinches Pyrrhula pyrrhulaOrnis Fennica 83: 131–138.

Lovegrove, R. 2007. Silent fields: the long decline of a nation’s wildlife. OUP, Oxford.

Newton, I. 1964. Bud-eating by Bullfinches in relation to the natural food-supply. J. Appl. Ecol. 1: 265–279.

— 1966a. Fluctuations in the weights of Bullfinches. Brit. Birds 59: 89–100.

— 1966b. The moult of the Bullfinch Pyrrhula pyrrhulaIbis 108: 41–67.

— 1998. Population Limitation in Birds. Academic Press, London.

— 1999a. Age ratios in a Bullfinch Pyrrhula pyrrhula population over six years. Bird Study 46: 330–335.

— 1999b. An alternative approach to the measurement of seasonal trends in bird breeding success: a case study of the Bullfinch Pyrrhula pyrrhulaJ. Anim. Ecol. 68: 698–707.

— 2002. Bullfinch Pyrrhula pyrrhula. In: Wernham, C. V., Toms, M. P., Marchant, J. H., Clark, J. A., Siriwardena, G. M., & Baillie, S. R. (eds.), The Migration Atlas: movements of the birds of Britain and Ireland. T. & A. D. Poyser, London. 

— 2013. Bird Populations. William Collins, London.

—, & Haas, M. B. 1984. The return of the Sparrowhawk. Brit. Birds 77: 4770.

—, & Rothery, P. 2000. Timing and duration of moult in the Bullfinch Pyrrhula pyrrhula: an appraisal of different analytical procedures. Ibis 142: 65–74.

Paradis, E., Baillie, S. R., Sutherland, W. J., & Gregory, R. D. 1998. Patterns of natal and breeding dispersal in birds. J. Anim. Ecol.67: 518–536.

Proffitt, F. M. 2002. Causes of population decline in the Bullfinch Pyrrula pyrrhula in agricultural environments. PhD Thesis, Oxford University.

Ratcliffe, D. A. 1970. Changes attributable to pesticides in the egg-breakage frequency and eggshell thickness in some British birds. J. Appl. Ecol. 7: 67–107.

Roach, F. A. 1962. The Bullfinch – its past and present position relative to damage to fruit crops. In: Proc. Bird Damage to Fruit Crops Conference 1962. NFU, London. 

Siriwardena, G. M., Baillie, S. R., & Wilson, J. D. 1998. Variation in the survival rates of some British passerines with respect to their population trends on farmland. Bird Study 45: 276–292.

—, Freeman, S. N., & Crick, H. Q. P. 2001. The decline of the Bullfinch Pyrrhula pyrrhula in Britain: is the mechanisms known? Acta Ornithologica 36: 143–152.

Svensson, L. 2023. Identification guide to European passerines. 5th edn. Lullula Förlag, Sweden.

Wickham, R. D., & Whiffen, H. J. 1962. Bullfinch control by trapping: a farmer’s view. In: Bird Damage to Fruit Crops, Conference Proceedings. Infestation Control Laboratory of MAFF & NFU, London.

Wilkinson, R. 1982. Group size and composition and the frequency of social interactions in Bullfinches Pyrrhula pyrrhulaOrnis Scand. 13: 117–122.

Wright, C. 2022. Pair bonding in Eurasian Bullfinches Pyrrhula pyrrhula: observations from a colour-ringing study. Ringing & Migration 35: 103–113

 

Ian Newton; e-mail [email protected]

 

 

Table 1. Numbers of Bullfinches Pyrrhula pyrrhula killed each year on fruit farms, based mainly on records from individual growers.

Location                                      1958–59  1959–60  1960–61  1961–62  1962–63  1963–64 1964–65  1965–66  1966–67

Petham, Kent                                                                             3,469      2,961       2,574     1,487

Petham, Kent                                                                                            1,100         700       750

East Malling, Kent                                                                                      162          205

Wickhambrook, Suffolk                                                                                                             292           428        261 

Bury St Edmunds, Suffolk                                                           396       117           175      263

Elsenham, Essex                                                                           142         83             58

Faversham, Kent                           527          487           216           503        404          573

Canterbury, Kent                                                            500          300         275         150

Maidstone, Kent                            251          370           534         1,361       660          611       

Harwell, Berkshire                                          31           101           183          67            53

Norfolk, Hickling                                                                                                            82       31 

 

Additional data for single years: 

Great Horkesley, Essex, 1965/66 – 350

Swanwick, Hampshire, 1963/64 – 135

Ardleigh, Essex, 1964/65 – 278

Ely, Cambridgeshire, 1963 – 150

Ledbury, Herefordshire, 1963 – 572

Eight farms, Berkshire, 1961/62 – 1,126 (on individual farms: 49, 157, 250, 169, 200, 141,100, 60)

West Bradenham, Norfolk, 1962/63 – 500

 

 

 

 

 

Table 2. Percentage of young birds among Bullfinches trapped each month in Wytham Woods (1962–63) and in commercial orchards (1963–67), years combined. ‘Young birds’ include individuals caught in juvenile or first-winter plumage.

                             numbers in Wytham Woods                         numbers in orchards                                                                                                  months       (a) adults   (b) young birds   % young     (a) adults   (b) young birds   % young

May                     81                   0                  0                     120                  0                    0

June                   109                   0                  0                     172                   1                   0.6

July                     54                  32                  37.2                  76                 80                 51.3 

August               249                289                 53.7                  14                313                95.7

September          144                403                73.7                   13                201                93.9

October              115                420                78.5                   15                441                96.7

November          100                269                72.9                   29                588                95.3

December          137                 312                69.5                   41                318                88.6

January               125                153                55.0                 106                345                76.5

February              38                   65                63.1                   43                  76                63.9

March                  16                   41                71.9                   22                  49                69.0

April                                                                                     30                  45                60.0

 

Table 3. Sex ratios of Bullfinches killed in different fruit-growing counties, October–March 1963–67, years combined.

location                                                males (%)                females (%)         ratio males:females     

Essex (1964–67)                                    341 (53.8)            293 (46.2)                   1.16                                  

Kent (1964–67)                                      489 (52.5)            443 (47.5)                   1.10                     

Sussex (1965–67)                                   136 (57.4)            101 (42.6)                   1.35                

Hampshire (1964–66)                              49 (46.2)              57 (53.8)                    0.86                     

Buckinghamshire (1965–67)                   84 (49.4)               86 (50.6)                   0.98                     

Berkshire (1964–67)                                96 (61.1)               61 (38.9)                   1.57*                     

Suffolk (1964–67)                                  428 (49.7)              433 (50.3)                  0.99                    

Norfolk (1963–65)                                   45 (58.4)                32 (41.6)                  1.41                     

Herefordshire (1965–67)                        91 (51.4)                86 (48.6)                  1.06                    

overall (1964–67)                                1,759 (52.5)            1,592 (47.5)                 1.10*                    

* Statistical significance, Berkshire, χ2 = 3.963, df = 1, P<0.05; overall, χ2 = 4.16, P<0.05. 

 

Table 4. Sex ratios of Bullfinches killed in orchards in different winters (October–March). Data for all counties in table 3 combined.

year                  males (%)        females (%)   ratio males/females  

1962–63             15 (60.0)          10 (40.0)                   1.50                     

1963–64            140 (54.9)         115 (45.1)                 1.22                      

1964–65            352 (52.9)         313 (47.1)                 1.12                                

1965–66            961 (52.6)        866 (47.4)                  1.11                                

1966–67            291 (50.3)         288 (49.7)                 1.01                   

overall           1,759 (52.5)       1,592 (47.5)                 1.10*                    

* The only value in which the sex ratio was significantly different from equal (χ2 = 4.16, df = 1, P<0.05). 

 

 

Fig. 1. Number of young (juvenile and first-winter birds) Bullfinches Pyrrhula pyrrhula per adult trapped in Wytham Woods and commercial orchards in different months, years combined (1962–67).

 

Fig. 2. Percentage of females among Bullfinches killed in commercial orchards in different months, years combined (1963–67). Sample sizes above columns. 

 

001. Male Bullfinch Pyrrhula pyrrhula, Norfolk, March 2021. David Tipling

002. Male Bullfinch, Norfolk, February 2023. David Tipling

003. Female Bullfinch, Norfolk, February 2023. David Tipling

Volume: 
Issue 6
Start Page: 
308
Authors: 
Ian Newton
Display Image: 

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