2007 |
Breeding season summary
There were about 120 adults in Jun and 150 chicks fledged during the breeding season.
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2008 |
Breeding season summary
The first chicks of the year fledged from a nestbox in the lambing shed on 16 May; to have four chicks surviving to fledging this early in the season was an unusual occurrence. The adult population was estimated to be between 80 and 100 individuals at most, with definite records of at least 44 different individuals (Ian Cleasby). A female was still feeding fledglings on 5 Sep.
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2009 |
Breeding season summary
The breeding season was remarkably early, with the first chicks fledging on 1 May, indicating that egg-laying must have commenced around the beginning of Apr. During the previous two breeding seasons no eggs had even hatched until the start of May. A large number of first-year birds were present in the spring, suggesting high recruitment in 2008 (Ian Cleasby).
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2011 |
Breeding season summary
The 2011 breeding season was very successful, with 151 clutches laid, beginning on 3 Apr, and 475 nestlings hatched. The post-breeding population was composed of at least 230 individually marked birds, including 102 adults and 128 successfully fledged young. Sparrowhawks routinely entered the lambing shed to hunt during the autumn and winter, leading to a significant drop in sparrow numbers. While 123 marked individuals (of all ages) were recorded in Nov, only 41 were caught in Feb 2012 (Isabel Winney & Yu-Hsun Hsu).
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2012 |
Breeding season summary
See comment above concerning the impacts of winter 2011/2012 Sparrowhawk predation.
The 2012 breeding season started late, with the first egg laid on the latest date since comprehensive monitoring began in 2000. This led to a delay in the first fledglings, with none before June, in contrast with past breeding seasons. The mean number of chicks ringed annually from 2000 to 2011 was 179 (range 68 – 335). In 2012, the University of Sheffield team ringed 200 chicks. So, despite the late start to the season, 2012 was more productive than the average year, but was not exceptional (Isabel Winney).
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2013 |
Breeding season summary
On 8 Aug the post-breeding population was estimated at 230 individuals, composed of 130 breeding adults and 100 young of the year (Isabel Winney). On 13 Nov the research team estimated the population to be about 200 individuals.
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2014 |
Breeding season summary
The 2014 breeding season started very early, with the first egg laid on 15 Mar – the earliest date since comprehensive monitoring began in 2000 (though monitoring in previous years generally did not begin as early as it did in 2014, which probably reduced the likelihood of recording any very early clutches). 2014 was also a record year in terms of fledglings ringed (553) and almost a record year in terms of number of broods recorded (241, the record being 248). A few birds bred up to four times, something very unusual in the Lundy population. By the end of Jul, only a handful of birds were risking new breeding attempts and by 19 Aug (the date that the sparrow research team left the island), only two pairs were still feeding chicks. Many of the 2014 fledglings as well as many of the adults were caught in two subsequent winter trips. In Dec 2014, 100 individuals were caught, followed by 85 in Feb 2015.
The highest field count of the year was 160 on 26 Aug, immediately after the breeding season. As in some previous years, a small number of individuals appeared to have learnt how to make a living from picking about under the tables inside the Tavern; three birds were watched doing this on 27 Oct.
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2015 |
Breeding season summary
The 2015 breeding season was average in terms of starting time and number of fledglings ringed. The first egg was laid on 11 April. Surprisingly, the totals for pairs, broods and fledglings were reduced by 50%, 50% and 60% respectively, when compared to the breeding season of 2014. However, it’s important to keep in mind that the breeding season of 2014 involved the biggest population ever recorded. During 2015 the sparrow research team recorded a total of 122 broods and ringed 227 fledglings from April to August. The main reason for the reduction in the number of breeding pairs in the summer of 2015 might have been the continuous presence of Sparrowhawks and Merlins during the previous winter.
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2016 |
Breeding season summary
After a winter visit in February, when 71 individuals were caught, researchers expected the population to be lower in summer 2016, compared to 2015. However, with slightly higher numbers for both broods and fledglings, the summer of 2016 showed that accurate population predictions for Lundy House Sparrows are difficult to make. The breeding season started with the first egg being laid on 14 April, and ended relatively late with the first egg of the last brood being laid on 11 August. With 22 more broods than 2015, and 146 broods in total, producing 253 fledglings, the summer of 2016 can be classified as an average year. A ringing trip in November 2016 showed high numbers of sparrows. A total of 105 individuals were caught, compared to the 71 in February.
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2017 |
Breeding season summary
The 2017 breeding season started extremely early; by the time of the team’s arrival on Lundy on 22 April, many nests already contained chicks of at least a few days old. The first egg was estimated to have been laid around 31 March. What sparked this early onset of the breeding season is only speculative, but could have been the relatively mild winter, followed by some early warmth in spring. Unfortunately, most of these early broods did not make it; a lot of chicks died during a cold spell that lasted for a few days. Most birds waited for a week or so before they started laying again and this time the chicks fared much better than the first wave. At the end of the season researchers had accounted for 218 broods – a much higher total than in 2016 – and 317 chicks had been ringed. The Lambing Shed was back in business in 2017, hosting many broods. Given that the area remained undisturbed during winter 2016/2017, sparrows had time to prospect and claim nestboxes, which they took full advantage of. In November, the team returned to Lundy for about a week to catch surviving fledglings and adults, trapping a total of 144 individuals, so numbers remained high after a successful breeding season.
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2018 |
Breeding season summary
The breeding season began quite late in comparison to previous years and though sparrows can have up to four broods a year, few had more than two. There were also few adults from the previous year’s fledglings, suggesting that the young birds didn’t fare very well in the cold. Those breeding in the lambing shed appeared to do a bit better, as birds there began breeding before elsewhere on the island (likely due to the shelter provided). Overall however, the breeding season was largely successful. In total, there were 175 broods, a fairly average number compared to other years, but lower than in 2017 when 218 broods were recorded. Interestingly, the number of chicks didn’t vary much between years. In 2018, 309 chicks were ringed (chicks are ringed when 12 days old and fledge when roughly 17 days old), whereas 317 chicks were ringed in 2017. This could be due to parents raising larger broods in 2018 or a higher mortality rate of young chicks (fewer reaching the age of 12 days) in 2017.
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2019 |
Breeding season summary
The 2019 season started very late, with only eight broods in the entirety of May, just one of which contained chicks that survived to fledging. Mainland birds were easily on their second or even third brood by the start of June, whereas the Lundy breeding season had really only just begun to take off. We speculate this was because of cold night-time temperatures throughout May. The spell of warm weather in February 2019 caused many other species to begin breeding very early in the year. However, unlike many other passerines, House Sparrows are not reliant on particular seasonal events (such as tree masting) and therefore can afford to wait until conditions become more suitable. The late season effectively meant that the Lundy sparrows skipped a brood. Typically, the island birds have three broods, with some higher-quality pairs rearing four, but most birds in 2019 had two broods, with only a handful having three. There was a total of 103 broods, compared to 175 in 2018. Ringing occurs when the chicks are 12 days old, with almost all birds reaching this age going on to fledge successfully. Some 217 nestlings were ringed in 2019, compared with 309 nestlings ringed in 2018, so productivity was much lower in 2019. However, the smaller number of fledged birds is not concerning, being due simply to the delayed start to nesting.
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2020 |
Breeding season summary – contributed by Jamie Dunning
Our project monitoring the House Sparrows on Lundy turns 20 in 2021 (excluding the addition of historic back-data), and it is this long-term monitoring, as well as the population’s geographic isolation, which makes the Lundy Sparrow Project so valuable to ecological research. These specific factors allow us to study the genetics of the population without the frequent introduction of new genetic information from immigration/emigration, as would be the case on the mainland. This genetic pedigree, which underpins much of our research, has allowed us to continually record the pairings, infidelities and divorces, births and deaths of more than 10,000 individual sparrows. Complete genetic pedigrees are rare in wild systems because they require continued monitoring without missing a single generation. However, while the Lundy project weathered the foot-and-mouth epidemic of 2001, fieldwork in 2020 presented a particular challenge owing to the coronavirus pandemic. Lucy Winder and I arrived in mid-June to an island in lockdown, having already missed the first two waves of House Sparrow broods. Despite this, we monitored 35 broods up to August, from which 99 chicks fledged (although some of these birds were captured as post-fledglings). Given the late start, it is difficult to compare with data from previous years. In 2019 we ringed 217 chicks from 103 broods, so the number of broods in 2020 may have been slightly down.
We returned in October and November to catch, colour mark and DNA sample those birds that we missed as fledglings. Some of these individuals can be retrospectively allocated to natal broods, based on unique genetic information derived from the parents. Despite the increased effort, we caught far fewer birds (73, including 29 ringed prior to 2020) than during the previous year’s winter trip (192), which may suggest a poor breeding season, or high mortality in the early autumn of 2020. As the preceding few seasons were particularly good, it is not unexpected that the breeding population was smaller in 2020. We now hope, without the uncertainty of spring 2020, that our 2021 field season will proceed more normally. The apparently small breeding population may mean that we missed fewer sparrows than we feared, and that those we did miss were subsequently caught, ringed and DNA-sampled in the autumn.
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2021 |
Breeding season summary – contributed by Jamie Dunning
Following a difficult season in 2020, when the uncertainty around access and the ongoing Covid pandemic forced us to reduce our field effort, we arrived in April 2021 to nestboxes already lined with nesting material and horsehair, and a small number of pairs already with full clutches of eggs. The aim of our field season was, as always, to colour-mark individual sparrows so that they can be identified in future without the need for recapture, and to collect genetic material to add another generation to our pedigree. Between Janet Chik (University of Groningen), myself and a handful of specially trained field assistants, we monitored 115 broods, 34 pairs having a second brood, and 15 a third brood. From these we ringed 185 chicks (averaging 1.6 per brood; but note that not all broods were successful in rearing young that survived to the point of ringing at about 12 days old). We also managed to capture and ring 93 birds outside of nestboxes, a mix of unringed sparrows from 2020, as well as chicks from ‘wild’ nests, and 129 retraps of previously ringed birds.
A generous grant award from the Lundy Field Society in 2020 enabled us to replace some of the ancient sparrow nestboxes around the village. Our thanks also to Eleanor Grover, Ben Arkless and Adam Waters for their help in building boxes during stormy weather. In 2021 we also moved to using BTO metal rings obtained by the LFS, bringing our project in line with existing monitoring of other species on the island. LFS bird ringers also contributed by rounding up unringed sparrows in Millcombe (which had at least two pairs again).
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2022 |
Breeding season summary – contributed by Sophie Wilkins
The season started slowly, with the first chicks hatching on 9th May, nearly a month later than in 2021. Through the nesting season a total of 70 broods were found and a total of 129 chicks hatched, with 88 ringed as nestlings. This is a decline from the previous year where 185 nestlings, across 115 broods, were ringed. The differences may be explained by the cold snap experienced in February 2022 and the delayed start to the season.
This trend remained evident when we returned, as usual, in November to ring and take DNA samples from adult birds. This trip also gave us the opportunity to catch any unringed adults born in 2021. However, only 10 birds were caught during the time we were on the island. This is far fewer than the previous year’s 108 captures during the same period and is a record low for the project. This decline has been attributed to the presence of a Sparrowhawk wintering on the island, encouraging the House Sparrows to be more cautious and less likely to be out in the open. However, thanks to the efforts of LFS ringers, an additional 41 unringed birds were captured between August and October, along with 66 retraps.
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Ringing
Colour-ringing movement
One of the Lundy House Sparrows colour-ringed as a nestling by the University of Sheffield on 3 May 2011 was seen in Hartland, North Devon mainland, on 27 February 2012. It was thought to have been in the Hartland area for about two weeks before the sighting was confirmed by Lundy sparrow researcher Isabel Winney. This is the first proven movement of House Sparrows between Lundy and the mainland (or vice versa).
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