Conspecific Attraction and the Conservation of Territorial Songbirds

Abstract

Conspecific attraction, the tendency for individuals of a species to settle near one another, is well described in colonial species, especially birds. Although this behavior may occur in territorial birds, evidence has been lacking. If territorial birds do exhibit this behavior, it would have major conservation implications. Birds could potentially be attracted to specific sites with artificial stimuli, making conservation of those species more efficient. In 2001 and 2002, we tested whether conspecific attraction occurs in an endangered, territorial songbird, the Black-capped Vireo (Vireo atricapilla) by playing vireo vocalizations in unoccupied habitats at Fort Hood, Texas. We were successful in attracting 73 birds to five experimental sites in 2001 and 75 birds to seven experimental sites in 2002. No birds settled on comparable control sites. Many birds attracted to the vocalizations paired and bred. At most research sites the primary threat to the species, the brood-parasitic Brown-headed Cowbird (Molothrus ater), was controlled, allowing vireos to achieve high nesting success relative to a nearby, unmanipulated population. Second-year birds were more responsive to conspecific vocalizations than older birds, as they were more common on experimental sites than in the established population. In 2002 birds recolonized experimental sites from 2001 where vocalizations were not played in 2002, indicating that 1 year of playbacks may be sufficient to establish a population. Our results provide the first experimental evidence that territorial songbirds use the presence of conspecifics when deciding where to settle and suggest that conspecific attraction may provide a valuable conservation tool. Resumen: La atracción conespecífica, tendencia de los individuos de una especie a establecerse cerca de otro de la misma especie, está bien descrita en especies coloniales, especialmente aves. Aunque este comportamiento puede ocurrir en aves territoriales, se carece de evidencia. Si aves territoriales muestran este comportamiento, tendría implicaciones mayores en la conservación. Las aves potencialmente serían atraídas a sitios específicos mediante estímulos artificiales, haciendo más eficiente la conservación de esas especies. En 2001 y 2002, probamos si ocurre la atracción conespecífica en una especie de ave canora territorial, en peligro, Vireo atricapilla, con la reproducción de vocalizaciones de vireo en hábitats desocupados en Fort Hood, Texas. Tuvimoś exito al atraer a 73 aves a cinco sitios experimentales en 2001 y 75 aves a siete sitios experimentales en 2002. No se establecieron aves en sitios controles comparables. Muchas de las aves atraídas a las vocalizaciones formaron pareja y se reprodujeron. En la mayoría de los sitios, la principal amenaza para la especie, el parásito Molothrus ater, fue controlada, lo que permitió un elevadoéxito de anidación a los vireos en comparación con una población no manipulada cercana. Las aves de dos años tuvieron mayor respuesta a las vocalizaciones conespecíficas que las aves más v...

Using conspecific broadcast for Willow Flycatcher restoration

“…We did not include any vocalizations that were typical of aggressive interactions between flycatchers. Similar to other studies of conspecific attraction, no broadcasts were used at control sites (Ward and Schlossberg 2004).…”

“…Why Willow Flycatchers so rarely recolonize newly restored, high-quality habitat remains unknown but there is some indication that behavioral constraints may play a role. Some territorial passerine species are known to rely on social cues such as the presence of conspecifics' songs to assess the quality of possible breeding habitat and are reluctant to establish territories where conspecifics are not present (Muller et al 1997, Ward and Schlossberg 2004, Andrews et al 2015. For many species, especially those with short breeding seasons, the presence of other members of their species might be used as an indirect way for naïve individuals to infer habitat quality and quickly find a suitable territory without investing substantial time (Hahn and Silverman 2006).…”

Evaluation of Conspecific Attraction as a Management Tool across Several Species of Anurans

“…By deploying conspecific cues such as decoys or recordings in unoccupied but suitable areas, researchers have found that they can attract individuals to settle and breed in these areas [9]. While this technique was originally employed to re-establish breeding populations of colonial-nesting waterbirds [13], it has since been tested in numerous avian species and is considered a viable tool for the conservation of threatened and endangered songbirds [9,11]. Other non-avian species have also been found to use a variety of conspecific cues when selecting habitat: common noctule bats (Nyctalus noctula) use acoustic cues to locate roosts [14], coral reef fish use chemical cues to find reef habitat [15], and bronze anoles (Anolis aeneus) make settlement decisions based on conspecific presence [16].…”

“…Conspecific attraction relies on the premise that individuals use conspecific presence when determining where to settle, resulting in individuals of the same species settling near each other [10][11][12]. By deploying conspecific cues such as decoys or recordings in unoccupied but suitable areas, researchers have found that they can attract individuals to settle and breed in these areas [9].…”

The effectiveness of nest-box supplementation for the conservation of European rollers (Coracias garrulus)

“…The various components of habitats, such as vegetation structure and habitat composition , Tome 2004, Remacha & Delgado 2009, Lopez et al 2010, may also play a role in nest site selection, influencing occupancy rate of artificial nest-boxes. Besides nest-box design and habitat characteristics, birds may use the presence/absence or breeding success of conspecifics and/or species with similar ecological requirements that provide valuable information on nest site suitability (Danchin et al 2001, Pajero et al 2004, Ward et al 2004.…”