Does the Threat of European Pine Marten (Martes Martes) Predation Influence the Height of Nests Built by Blue Tits (Cyanistes Caeruleus) and Great Tits (Parus Major)?

Abstract

The major aim of this study was to examine the influence of the European Pine Marten (Martes martes) predation on the heights of nests of Blue Tits (Cyanistes caeruleus) and Great Tits (Parus major) in nestboxes of different security levels. To this end we performed a comparison of nest heights before and after introducing an anti-predator device to two size-types of wooden nestboxes set up in a deciduous forest. Blue Tit and Great Tit nest sizes were influenced by the application of plastic entrance tubes as anti-predator devices that elongated a distance between the entrance and the interior of the nestbox. Nests were taller in nestboxes equipped with anti-predator devices regardless of nestbox size. Nests located in smaller nestboxes were destroyed by Martens more frequently than nests built in bigger nest boxes. Most nest functions in cavity-nesting birds, such as filling the excessive cavity space, maintenance of proper humidity, thermal, light and sanitary conditions for eggs and nestlings, improve with nest sizes. Because, in contrast, the risk of nest predation by martens increases with nest size (height within the nestbox), the nest predation constitute a major factor that constrains cavity-nesting birds in constructing tall nests.

Great Tits Build Shallower Nests than Blue Tits

“…they call it 'deeper') fresh nests than Great Tits, either to be attributed to inter-specific differences in efforts of nest building or nest composition (Smith et al, 2013;J. Smith, personal communication;Kaliński et al, 2014). Here we report the results of a 10-year nestbox study that compared heights of fresh nests in Mediterranean Great Tits and Blue Tits after controlling for other factors that might influence nest height.…”

“…For instance, birds can build bigger or shallower nests when artificial food is provided (Mainwaring and Hartley, 2013;Smith et al, 2013). Nest-builders can also change the composition of the nest in response to a rapid change in experienced ambient temperature (e.g., Nager and van Noordwijk, 1992;Mainwaring et al, 2012;Deeming et al, 2012) or predation risks (e.g., Lima, 2009;Stanback et al, 2013;Kaliński et al, 2014;Mainwaring et al, 2014).…”

Causes and Consequences of Intraspecific Variation in Nesting Behaviors: Insights from Blue Tits and Great Tits

“…Both blue tits and great tits built taller nests within nestboxes with anti-predator devices added to them regardless of nestbox size. This had important fitness consequences as nests in smaller nestboxes were predated more frequently by pine martens (Martes martes) than nests in bigger nestboxes (Kaliński et al, 2014). The height of great tit nests was inversely related to the risk of predation which means that when the risk of predation was high the height of nests was low, so that in turn, the distance between the entrance hole of the nestbox and the nest contents was greater when the risk of predation was high.…”

“…Meanwhile, the absence of any seasonal changes in the mass of the nests' moss base highlights that nests are multi-functional structures. This is because whilst the cup lining material serves to create optimal environmental conditions for embryonic and offspring development, the moss base material serves to protect the offspring from predators (Mazgajski and Rykowska, 2008;Kaliński et al, 2014) or to play a role in sexual selection (Sanz and García-Navas, 2011;Tomás et al, 2013).…”

“…As the deep nestboxes had a greater depth than the shallow nestboxes, then the distance between the nest entrance and the nest rim was kept constant in the two nestbox types. Kaliński et al (2014), meanwhile, added plastic tubes that protruded from the entrance holes of nestboxes so that the distances from the exterior entrance holes to the nest contents were experimentally increased at nestboxes of two different sizes. Both blue tits and great tits built taller nests within nestboxes with anti-predator devices added to them regardless of nestbox size.…”