Using citizen science to assess drivers of Common House Martin Delichon urbicum breeding performance

Abstract

Many hirundine (swallows and martins) species are declining throughout their ranges. The Common House Martin Delichon urbicum is a migratory hirundine that breeds throughout Europe but has shown recent declines in some parts of the UK, particularly in the south. We conducted a large‐scale citizen science survey to assess how the breeding performance of House Martins, measured by the number of attempted broods and nest success, is influenced by nest‐specific, landscape and weather factors. Pairs in eastern parts of the UK started breeding earlier than those in the west, and breeding performance was higher in eastern regions. There was no effect of latitude on either aspect of breeding performance, so our measures of breeding performance alone do not help to explain differences in population trends across the UK. The probability of attempting multiple broods and producing successful nests was higher in previously used nests than in newly built nests, and in artificial nests than in natural nests. Nests built on plastic soffits of buildings were less likely to be multi‐brooded and less likely to be successful compared with other materials. Suggested conservation measures therefore include discouraging the removal of old nests and encouraging the installation of artificial nests, particularly on buildings with plastic soffits. This study provides comprehensive insight into the breeding biology of House Martins, and although our findings do not show conclusively that breeding performance is the sole driver of population trends, they go some way to explain declines in House Martins and ultimately provide information that may help conserve this species.

Farmstead modernization adversely affects farmland birds

“…Our study clearly documented that farmstead modernization is associated with reduced abundance, species richness, and nest densities of artificial burrows, artificial nest cups as well as leaving access to nesting holes in renovated and new farm buildings (see also Kettel et al, 2021;Šálek, Bažant, et al, 2018;Schaub et al, 2015;Teglhøj, 2018). Moreover, nesting availability for mud-nesting hirundine species may be enhanced by using construction material consisting of rough surfaces (e.g.…”

“…This may also result in multiple broods with more nestlings (i.e. earlier laying dates of first clutches, lower costs invested in nest building) and thus increase their breeding performance per season (Kettel et al, 2021; Teglhøj, 2018).…”

“…We propose that a condition for receiving EU funding for farmstead modernization should be a legal obligation to support nesting opportunities in new farmstead buildings for cavity and other building‐nesters to mitigate the loss of nesting sites during modernization/renovation. For instance, breeding opportunities should be supported with the provision of external or integral nest‐boxes, special (swift or sparrow) nesting bricks, other artificial burrows, artificial nest cups as well as leaving access to nesting holes in renovated and new farm buildings (see also Kettel et al, 2021; Šálek, Bažant, et al, 2018; Schaub et al, 2015; Teglhøj, 2018). Moreover, nesting availability for mud‐nesting hirundine species may be enhanced by using construction material consisting of rough surfaces (e.g.…”

Does the Provisioning of Artificial Nest Cups and Nesting Structures Help House Martins Delichon urbicum?

“…The ideas underlying all these well-intended attempts to help breeding House Martins appear to have gone largely untested in explicit ways, although Kettel et al (2021) examined the number of attempted broods and nest success in different types of nests across the UK. This is a missed opportunity, as the provisioning of constructions to accommodate small colonies of House Martins and the supplementation of artificial nests at (often previously used) breeding sites can both be considered 'experiments' to test the assumption that nest sites and suitable nest-building material are key factors currently limiting House Martin populations.…”

Bird Communities and Their Conservation Priorities are Better Understood through the Integration of Traditional and Citizen Science Data: An Example from Brazilian Atlantic Forest

“…Citizen scientists have helped scientists understand population trends in which analyses require long-term studies and many observations. These include behavior, bioacoustics, breeding and reproductive success, evolutionary fitness, migration, occupancy, response to habitat modification, and the spread of diseases (Bhattacharjee 2005;DeGroote et al 2021;Kettel et al 2020;Barbosa et al 2021;Crates et al 2021;Gordo et al 2021). Advantages can come from combining traditional science with CS data because more observers result in larger sample sizes, that are necessary for precise estimations for many topics of study (Bhattacharjee 2005;Lees and Martin 2014;Van der Wal et al 2015;Marrocco et al 2019;DeGroote et al 2021;Robinson et al 2020;Hertzog et al 2021;Weisshaupt, Lehtiniemi, and Koistinen 2021).…”