Diet and habitat selection in Cantabrian Capercaillie (Tetrao urogallus cantabricus): ecological differentiation of a rear-edge population

Abstract

Cantabrian capercaillie Tetrao urogallus cantabricus is a peripheral population with distinctive phenotypic, biogeographic, and genetic characteristics. Hence, the population may also show substantial ecological differentiation associated with its habitat in purely deciduous forests. We assessed seasonal diet selection, smallscale habitat selection, and patterns of trophic niche width in Cantabrian capercaillie over two years. Diet was found to be a driver of small-scale habitat selection, a result consistent with previous studies of stand-scale habitat selection. Diet and habitat selection showed the importance of beech Fagus sylvatica, holly Ilex aquifolium, bilberry Vaccinium myrtillus, and ferns in Cantabrian capercaillie's resource selection. Conversely, the abundant oaks Quercus petraea, birches Betula pubescens, and heaths Erica sp. were used below their availability. The reliance on bilberry appears as a unifying characteristic between central and peripheral capercaillie populations. Cantabrian capercaillie showed stronger reliance on understory resources than range-central populations. It also showed wider trophic niche and higher specialization of feeding events. Trophic niche patterns and reliance on ground resources indicated a marked ecological differentiation, which stresses the need for local data and specific conservation actions.

The Mediterranean Quercus pyrenaica oak forest: a new habitat for the Capercaillie?

“…Finally, this study supports what is suggested by Quevedo et al (2006a, b) and Blanco-Fontao et al (2010), that many general considerations for the species overall are not fully useful for the Cantabrian Capercaillie, and suggests a wider adaptation and plasticity of this species than previously thought. For example, the near absence of bilberry and holly in the studied area suggests that Capercaillie can maintain viable populations without this important summer and winter food resource for the Cantabrian population and elsewhere (Storch 2001;Blanco-Fontao et al 2010).…”

“…For example, the near absence of bilberry and holly in the studied area suggests that Capercaillie can maintain viable populations without this important summer and winter food resource for the Cantabrian population and elsewhere (Storch 2001;Blanco-Fontao et al 2010). Future research could address a detailed comparison of suitable Capercaillie habitat between the two different biogeographical regions.…”

“…However, the Cantabrian subspecies T. u. cantabricus (Cantabrian Mountains, NW Spain) resides mainly in pure deciduous forests of beech Fagus sylvatica, birch Betula pubescens and sessile oak Quercus petraea, as well as mixed forests of beech and oaks (Quercus robur, Q. petraea, and Q. pyrenaica; Bañuelos and Quevedo 2008). In these forests, holly Ilex aquifolium provides a key, evergreen winter food resource for Cantabrian Capercaillie (Storch 2001;Blanco-Fontao et al 2010), whereas it relies on bilberry in summerautumn (Blanco-Fontao et al 2010). Previous studies showed, however, a negative selection to Quercus pyrenaica forests by Cantabrian Capercaillie at the northern slope of the Cantabrian range (Quevedo et al 2006b).…”

Diet composition of a declining steppe bird the Little Bustard (Tetrax tetrax) in relation to farming practices

“…Microhistological analysis is a method widely used to assess diet composition of herbivorous species (La Morgia and Bassano 2009, Blanco-Fontao et al 2010, Whitney et al 2011, Kobayashi and Takatsuki 2012, Xu et al 2012, Freschi et al 2014. However, results from microhistological analysis of droppings could have a potential bias derived from differential digestibility of plant species.…”

The Changes in Rural and Forest Landscape and Their Use in the Slovenian Alps in the Last Centuries - A "Back to Nature" Tourism with Impacts, a Case of Western Capercaillie

“…Several different habitat disturbances were recognised as causes of Western capercaillie decline in temperate Europe (Adamič 1987;Čas 2001a, 2010Eiberle 1984;Klaus et al 1997;Saniga 2002Saniga , 2004Storch 1999Storch , 2007Thiel et al 2007). The populations at the southern edge of the species' distribution range have suffered the most severe population reduction (Adamič 1987;Bajc et al 2011;Blanco-Fontao et al 2009;Čas 1999, 2010Cattadori & Hudson 2000;Gonzales & Ena 2011;Poolo et al 2005;Radović et al 2003;Quedo et al 2006;Storch 2007;Zeiler 2001;Zubić 2009), and shrinkage of habitat in the last decades due to forest and climate change (Anič et al 2009;Čas 2006;Kutnar & Kobler 2011).…”