Effect of connectivity and habitat availability on the occurrence of the Chestnut-throated Huet-Huet (Pteroptochos castaneus, Rhinocryptidae) in fragmented landscapes of central Chile
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Although small isolated habitat patches may not be able to maintain a minimum viable population, small patches that are structurally isolated may be functionally connected if individuals can cross the gaps between them, in which case, their areas could be added to form a larger habitat patch, eventually surpassing the size threshold for holding a viable population.
We studied whether models based on the size and isolation of habitat patches could be used to predict the distribution of the Chestnut-throated Huet-Huet (Pteroptochos castaneus) in fragmented landscapes of the coastal range of the Maule region, central Chile.
We selected seven 10,000-ha landscapes (8.4–70.7% forest cover). For each habitat patch we made 18 predictions of the presence of the species based on the combination of two thresholds: three critical patch sizes for maintaining a viable population (62.5, 125 and 250 ha) and six critical isolation distances between patches (0, 10, 50, 100, 150 and 200 m). We used playbacks in 59 sampling points to estimate the species’ presence/absence. We used logistic regressions to test whether the output of the patch-matrix models could explain part of the variation in the presence of Pteroptochos castaneus.
The best predictions for the presence of P. castaneus were obtained with the most conservative scenarios (125–250 ha to 0–10 m), including a positive effect of the understory cover and a lack of effect of the forest type (native or exotic).
Our findings suggest that the long term persistence of P. castaneus may depend on the existence of large and/or very connected forest tracts.
KeywordsHabitat fragmentation Functional connectivity Ground-dwelling forest birds Pteroptochos castaneus Central Chile
This study was partially funded by a Fondecyt (1120314) grant to C.F. Estades. The School of Forest Science and Nature Conservation of the University of Chile provided important logistical support during the field work. Three anonymous reviewers made important observations on the first version of this work that helped us improve the quality of our study.
- CONAF (2017) Situación diaria de incendios forestales. http://www.conaf.cl/situacion-nacional-de-incendios-forestales/. Accessed Jan 2017
- CONAF, CONAMA, BIRF, Universidad Austral de Chile, Pontificia Universidad Católica de Chile and Universidad Católica de Temuco (1999) Catastro y evaluación de los recursos vegetacionales nativos de Chile. Informe nacional con variables ambientales, SantiagoGoogle Scholar
- Crooks KR, Sanjayan M (eds) (2006) Connectivity conservation. Cambridge University Press, New YorkGoogle Scholar
- Fahrig L (2002) Effect of habitat fragmentation on the extinction threshold: a synthesis. Ecol Appl 12:346–353Google Scholar
- Forman RTT (1995) Land mosaics: the ecology of landscapes and regions. Cambridge University Press, New YorkGoogle Scholar
- Franklin IA (1980) Evolutionary change in small populations. In: Soulé ME, Wilcox BA (eds) Conservation biology: an evolutionary-ecological perspective. Sinauer Associates, Sunderland, pp 135–149Google Scholar
- Kindlmann P, Burel F (2008) Connectivity measures: a review. Landscape Ecol 23:879–890Google Scholar
- R Core Team (2013) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. http://www.R-project.org/
- Saura S, Rubio L (2010) A common currency for the different ways in which patches and links can contribute to habitat availability and connectivity in the landscape. Ecography 33:523–537Google Scholar
- Tomasevic J, Estades CF (2006) Stand attributes and the abundance of secondary cavity-nesting birds in southern beech (Nothofagus) forests in south-central Chile. Ornitol Neotrop 17:1–14Google Scholar
- Witter AK, Berggren (2007) Natal dispersal in the North Island Robin (Petroica longipes): the importance of connectivity in fragmented habitats. Avian Conserv Ecol 2:2. http://www.ace-eco.org/vol2/iss2/art2/
- Xeno-canto (2015) http://www.xeno-canto.org/species/Pteroptochos-castaneus. Accessed Jan 2015
- Zarri AA, Rahmani AR, Singh A, Kushwaha SPS (2008) Habitat suitability assessment for the endangered Nilgiri Laughingthrush: a multiple logistic regression approach. Curr Sci 94(11):1487–1494Google Scholar