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The role of woodpeckers (family: Picidae) as ecosystem engineers in urban parks: a case study in the city of Madrid (Spain)

DOI:10.1007/s11252-020-01087-y
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Patricia Catalina at Complutense University of Madrid
Patricia Catalina
Carlos A. Martín at Complutense University of Madrid
Carlos A. Martín
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Abstract

Many species of the family Picidae, such as the woodpeckers, excavate the tree-cavities where they nest. Frequently the cavities are used during a single breeding season and subsequently abandoned, which allows their use by non-excavator species for nesting or roosting. Here we analyze the role of woodpeckers as providers of nesting and refuge places in two urban parks in the city of Madrid. The environmental characteristics of the woodpecker nest-sites were also studied. Prior to the breeding season 75 trees bearing woodpecker-excavated cavities and 142 control trees (i.e. without woodpecker cavities) were located, georeferenced and characterized by a set of variables relative to the tree and its environment. During the breeding season the cavities were monitored with an endoscopic camera to verify occupation and user identity. Additionally, 71 non-excavated tree-cavities were monitored to measure their occupancy and make comparisons with those excavated by woodpeckers. Woodpeckers showed a strong preference for trees of the genus Populus: 54 of 75 (72%) woodpecker-cavities were in poplars, which comprised only 7–10% of available trees. The excavated cavities were found mainly in the trunk of the trees, north oriented and away from paths. The occupancy rate by bird species was higher, although not significantly, for excavated cavities than for natural cavities (36.0% and 23.9% respectively). The richness and composition of cavity-user species also differed between types of tree-cavities. This work shows the importance of woodpeckers as providers of nesting and refuge places for other cavity-user birds and highlights their role as ecosystem engineers in urban parks. Finally, we consider that these results can guide biodiversity conservation efforts in urban planning.
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The role of woodpeckers (family: Picidae) as ecosystem engineers
in urban parks: a case study in the city of Madrid (Spain)
Patricia Catalina-Allueva
1
&Carlos A. Martín
1
Accepted: 14 December 2020
#The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature 2021
Abstract
Many species of the family Picidae, such as the woodpeckers, excavate the tree-cavities where they nest. Frequently the cavities
are used during a single breeding season and subsequently abandoned, which allows their use by non-excavator species for
nesting or roosting. Here we analyze the role of woodpeckers as providers of nesting and refuge places in two urban parks in the
city of Madrid. The environmental characteristics of the woodpecker nest-sites were also studied. Prior to the breeding season 75
trees bearing woodpecker-excavated cavities and 142 control trees (i.e. without woodpecker cavities) were located,
georeferenced and characterized by a set of variables relative to the tree and its environment. During the breeding season the
cavities were monitored with an endoscopic camera to verify occupation and user identity. Additionally, 71 non-excavated tree-
cavities were monitored to measuretheir occupancy and make comparisons with those excavated by woodpeckers. Woodpeckers
showed a strong preference for trees of the genus Populus: 54 of 75 (72%) woodpecker-cavities were in poplars, which
comprised only 7–10% of available trees. The excavated cavities were found mainly in the trunk of the trees, north oriented
and away from paths. The occupancy rate by bird species was higher, although not significantly, for excavated cavities than for
natural cavities (36.0% and 23.9% respectively). The richness and composition of cavity-user species also differed between types
of tree-cavities. This work shows the importance of woodpeckers as providers of nesting and refuge places for other cavity-user
birds and highlights their role as ecosystem engineers in urban parks. Finally, we consider that these results can guide biodiversity
conservation efforts in urban planning.
Keywords Cavity-nesting .Endoscopic camera .Excavator species .Keystone species .Nest-site selection .Secondary cavity
users
Introduction
In ecosystems there are species that show a great influence on
ecological processes, affecting a large number of both animal
and plant species and the interactions that occur between
them. These species are called keystone species because they
play a fundamental role, above their abundance or biomass, in
the maintenance of the ecological system to which they be-
long (Paine 1969; Mills et al. 1993; Tellería 2012). Frequently
keystone species are also ecosystem engineers as they physi-
cally modify or create habitat characteristics and provide crit-
ical ecological resources for other species, thereby affecting
their presence and abundance (Jones et al. 1994;Wrightand
Jones 2002).
Woodpeckers (family Picidae) are considered keystone
species and ecosystem engineers because with their excava-
tion activities, they create a variety of potential niches for
other organisms (Daily et al. 1993; Jones et al. 1994; Floyd
and Martin 2016). Thus, cavities excavated by woodpeckers
are used by other bird species, mammals and invertebrates for
nesting, resting or sheltering from predators or inclement
weather (Wiebe 2006; Aitken and Martin 2007; Myczko
et al. 2016). Additionally, through their excavation activities
associated with nesting and foraging, woodpeckers accelerate
decomposition cycles of forests, increasing the recycling of
nutrients, facilitating the dispersion of wood-decaying fungi
and intervening in the control of insects (Winkler et al. 1995;
Farris et al. 2004;Faytetal.2005; Drapeau et al. 2009).
*Patricia Catalina-Allueva
biopatcat@gmail.com
Carlos A. Martín
ca.martin@bio.ucm.es
1
Departamento de Biodiversidad, Ecología y Evolución, Universidad
Complutense de Madrid, C/ José Antonio Novais, 12,
28040 Madrid, Spain
https://doi.org/10.1007/s11252-020-01087-y
/ Published online: 3 January 2021
Urban Ecosystems (2021) 24:863–871
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... For the first level of study, two buffers were created around each new nest: one with a radius of 100 m, which would represent the habitat selected to place the nest; and another with a radius of 1000 m, which would represent the available habitat. In both cases, the percentage of surface occupied by tree masses (nesting habitat) and open habitat (feeding areas) was calculated from the information For the second level of study, the following data were taken from the nest tree: tree species, height of tree and nest, diameter at breast height (hereafter, DBH), tree state (living tree, tree with dead branches, and dead tree) and presence of fungi (Melletti and Penteriani 2003;Kosinski and Kempa 2007;Urkijo-Letona et al. 2020;Catalina-Allueva and Martín 2021). This last parameter was developed by visual examination of the external fruiting bodies (Urkijo-Letona et al. 2020). ...
... The same parameters were recorded in four other trees of the wood stand that were used to represent the tree availability in those sectors actually used by woodpeckers for nesting (Melletti and Penteriani 2003;Catalina-Allueva and Martín 2021). The choice of these trees was carried out according to the following criteria: DBH of more than 30 cm (Touihri et al. 2015), distance of approximately 15 m from the tree that has the nest and oriented to the north, south, east and west, respectively (Urkijo-Letona et al. 2020). ...
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... Furthermore, in areas with many small non-native trees and tree plantations such as the one here in consideration there is a lack of natural tree cavities (Lindenmayer & Franklin 2002, Hartley 2002, Remm & Lõhmus 2011. Therefore, the role of the Great Spotted Woodpecker as ecosystem engineer could be essential for the conservation of secondary-cavity nesters and other forest species that rely on the holes excavated by it (Hardin et al. 2021, Catalina-Allueva & Martín 2021. ...
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... Technological advances, specifically the ultra-small video cameras used in inexpensive (ca. $US 100) modern borescopes now make it possible to record such data (e.g., Catalina-Allueva and Martín, 2021;Griffiths et al., 2017;Silva-Santos et al., 2012). With further miniaturization, network technology may also provide similar behavioral data in the future (Ripperger et al., 2020). ...
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This is my spot : What are the characteristics of the trees excavated by the Black Woodpecker ? A case study in two managed French forests
Article
The Black Woodpecker (Dryocopus martius L.) is both an ecosystem engineer and an umbrella species: it has the capacity to modify its environment through cavity excavation, which in turn favors a large range of species that depend on cavities but are unable to dig them themselves (secondary cavity nesters). However, the factors driving cavity excavation by the Black woodpecker at the tree scale remain poorly known. We analyzed the characteristics of trees bearing Black Woodpecker cavities to assess the bird's local habitat requirements and their conservation potential as habitat trees. We compared the traits and characteristics of trees bearing Black Woodpecker cavities (n=60) and control trees (n=56) in two managed lowland broadleave-dominated forests in France. We hypothesized that: (i) Cavity-trees would have lower wood density and display more conks of fungi than control-trees; (ii) The local environment of cavity-trees would be less crowded than those of the control trees. In particular, the first branch would be higher up, and their first neighboring tree would be further away from cavity-trees compared to control-trees; (iii) Cavity-trees would display a higher number of other woodpecker cavities and more saproxylic microhabitats than the control-trees. We validated most of our hypotheses and showed that cavity trees differed significantly from their control counterparts. Black Woodpeckers excavate trees with softer wood and higher first branches in a less crowded environment, thus minimizing both the energy dedicated to cavity excavation and predation risk. Second, cavitytrees bear more microhabitats and play a complementary umbrella role than what was documented before. They also appear a good candidate for habitat-tree conservation. In terms of biodiversity-friendly management measures, it would be beneficial to favor large isolated standing trees devoid of low branches (notably beech), especially in stands dominated by other tree species.
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Tree cavity densities and characteristics in managed and unmanaged Swedish boreal forest
Article
In forests worldwide, ∼10−40% of bird and mammal species require cavities for nesting or roosting. Although knowledge of tree cavity availability and dynamics has increased during past decades, there is a striking lack of studies from boreal Europe. We studied the density and characteristics of cavities and cavity-bearing trees in three categories of forest in a north-Swedish landscape: clearcuts with tree retention, managed old (>100 years) forest, and unmanaged old forest. Unmanaged old forests had significantly higher mean density of cavities (2.4±2.2(SD) ha⁻¹) than managed old forest (1.1±2.1 ha⁻¹). On clearcuts the mean cavity density was 0.4±2.3 ha⁻¹. Eurasian aspen (Populus tremula) had a higher probability of containing excavated cavities than other tree species. There was a greater variety of entrance hole shapes and a higher proportion of cavities with larger entrances in old forest than on clearcuts. Although studies of breeding success will be necessary to more accurately assess the impact of forest management on cavity-nesting birds, our results show reduced cavity densities in managed forest. To ensure future provision of cavities, managers should retain existing cavity-bearing trees as well as trees suitable for cavity formation, particularly aspen and dead trees.
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Nest cavity characteristics, reproductive output and population trend of naturalised Amazon parrots in Germany
Article
  • Feb 2017
Although many parrot species are decreasing in their native range, introduced parrot populations can be found in urban areas around the globe. We thus need to understand how they adapt to this novel environment and to assess the possibility of a range expansion that might threaten native species. We studied population growth, nest site requirements, as well as limiting factors like reproductive output and mortality of the only European population of Yellow-headed Parrots (Amazona oratrix) in the city of Stuttgart, southwest Germany, to assess the risk of a possible range expansion. Although offspring could be seen on a regular basis, parrot numbers hardly increased during the last 5 years (51 individuals in spring 2015, including 12 breeding pairs). Ten accessible nest cavities were studied in detail: they were located exclusively in large, old London Plane (Platanus × acerifolia) trees in an area of less than 1 km2 in the city’s public parks and were at least 65 cm deep. Average reproductive output was 1.3 fledglings/pair, which is high in comparison to data from birds in their native range. Mortality, especially of young parrots, appears to be high due to risks in urban areas such as collisions with vehicles and windows and could partly explain slow population growth. This slow population growth in combination with the need for sufficiently large nest cavities may hinder a range expansion of this species in future years.
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