title: Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes.
abstract: Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January-October 2009-2011). In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity.
authors.affiliation: Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, Mexico; Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Cuatianquiz Lima
authors.affiliation: Instituto de Ecología, Universidad Nacional Autónoma de México , Ciudad de México , Mexico.
authors.forename: Constantino
authors.initials: C
authors.lastname: Macías Garcia
keywords: Forest management; La Malinche; Nest-site availability; Secondary cavity-nesters; Trans-Mexican volcanic belt