Old nest material functions as an informative cue in making nest-site selection decisions in the European Kestrel (Falco tinnunculus)

Abstract

Background: For secondary cavity-nesting bird species that do not add lining materials to nests, the presence of old nest material or organic remains that have accumulated within nest cavities from previous breeding events may be a cue of nest-site quality. These materials potentially contain information about past breeding success in con-and heterospecifics and may improve the thermal insulation of eggs during incubation. However, few studies have addressed whether the presence of old nest materials serves as a cue for cavity-nesting raptors when choosing specific nest sites. Methods: We conducted a 9-year nest box experiment to test whether old nest materials from con-and heterospecifics serve as informative cues to the European Kestrel (Falco tinnunculus) when making nest selection decisions, as this species uses nest boxes without adding nesting material. Results: The presence of old nest materials and entrance size best discriminated nest boxes occupied by European Kestrels from unoccupied boxes. Nest boxes containing conspecific organic remains, artificial dry leaf and branch material, and material left behind by Great Tits (Parus major) were reused at higher rates, especially those containing conspecific nest material, than nest boxes containing true or simulated nest materials from predators. In 2010, no single nest box was occupied by the same banded individual that occupied the box in the previous year (10 females and 2 males were banded in 2009). Conclusions: European Kestrels preferred nest boxes containing old nest material over empty boxes, which is consistent with previous findings that they exploit con-and heterospecific cues when deciding where to settle and breed, as old nest or organic material provides substrate for incubating females. Kestrels may be able to assess the predation risks associated with a specific nest site based on experience or the presence of prey remains. The repeated use of nest boxes across breeding seasons by kestrels cannot be entirely ascribed to philopatry. This study provides evidence that old nest materials are potentially used as informative cues when making nest-site selection decisions in European Kestrels.

Combining social information use and comfort seeking for nest site selection in a cavity-nesting raptor

“…Our results are in line with studies of other bird species showing a greater and/or earlier occupancy of cavities containing old nest material compared to empty cavities (e.g. eastern bluebirds, Sialia sialis, Davis, Kalisz, & Wells, 1994; pied flycatchers, Ficedula hypoleuca, Olsson & Allander, 1995; burrowing owls, Athene cunicularia, Riding & Belthoff, 2015; European kestrels, Mingju et al, 2019, Sumasgutner, Vasko, Varjonen, & Korpimäki, 2014reviewed in Mazgajski 2007). Choosing a soft substrate for species that do not add any lining material may be selected for if it reduces the risk of egg breakage, improves the insulation of the cavity and/or is a source of beneficial bacterial strains (Díaz-Lora et al, 2019;Mazgajski, 2007).…”

“…Accordingly, such proof of previous occupancy has been proposed to be used as a source of information in several bird species (e.g. Gergely, Mészáros, Szabad, & Székely, 2009;Hoi, Krištín, Valera, & Hoi, 2012;Loukola et al, 2014;Mingju et al, 2019;Podofillini et al, 2018;Sumasgutner, Vasko, Varjonen, & Korpimäki, 2014), triggering either attraction or avoidance depending on the species and on the environmental or social context (see Mazgajski, 2007).…”

“…migrants, Loukola et al, 2014), but also for species that do not add lining material to their nest (e.g. the European kestrel, Falco tinnunculus, Mingju et al 2019). Third, in contrast, individuals may avoid nesting on top of old nest material due to the higher risk of infection by ectoparasites and pathogens surviving in nest material across years (Rendell & Verbeek, 1996), and to avoid infection by ectoparasitic flies seeking out hosts (Tomás, Ruiz-Castellano, Ruiz-Rodríguez, & Soler, 2020).…”

Geographical variation in nest defense among cinereous tit populations in China

“…The study site is located in the hill region of the Changbai Mountains and transitions to plains with an altitude of 200–530 m ( Fan et al 2021 ). The forest here is mainly consists of secondary growth deciduous woodland and the climate is temperate and subject to the eastern monsoon climate ( E et al 2019 ). The Dongzhai National Nature Reserve (hereafter DZ, 31 ο 28ʹ–32 ο 9ʹ N, 114 ο 18ʹ–114 ο 30ʹ E) is in Henan, Central China.…”

Nonideal nest box selection by tree swallows breeding in farmlands: Evidence for an ecological trap?

“…Only the first breeding attempts of each box were kept for the analyses because second clutches are uncommon (11% of all tree swallows’ breeding attempts between 2009 and 2018) and often result from first clutch failure. Focusing on first breeding attempts also allowed us to reduce the potential bias that could arise from individuals choosing a nest box that already contained a nest (as in Mingju et al, 2019 ). Monitoring ended when all nestlings had fledged on a given farm, which occurred between June 15 and August 5 during the study.…”