Skip to main content
×
Home
    • Aa
    • Aa

Crop vegetation structure is more important than crop type in determining where Lesser Kestrels forage

  • CARLOS RODRÍGUEZ (a1), LUIS TAPIA (a1) (a2), EMANUEL RIBEIRO (a1) and JAVIER BUSTAMANTE (a1)
Abstract
Summary

We studied foraging habitat selection by Lesser Kestrel Falco naumanni throughout the breeding period in south-west Spain by means of transects on which foraging observations were recorded. We focused on the effects of habitat and crop type, but also on the effect of vegetation structure and the presence of agricultural activities in the field on Lesser Kestrel use. We considered both the accumulated use of the foraging area during the breeding season and the instantaneous foraging habitat selection by kestrels. Foraging habitat selection was highly dynamic following crop development and agricultural activities. Almost all major arable crop types showed positive selection during some part of the breeding cycle. Accumulated use by kestrels demonstrated positive associations with wheat and cotton fields and negative selection of permanent habitat types, such as forested areas, woody crops and built-up areas that have no prey or are not used by the species due to unfavourable structure. Vegetation structure appears to play a major role in instantaneous foraging selection. Lesser Kestrels select fields with short vegetation and intermediate cover. They also forage on field margins and where agricultural activities such as ploughing or harvesting that facilitate access to prey are being conducted. Our results help to clarify apparent controversies among previous studies on the subject, highlighting the importance of the heterogeneity of agricultural landscapes around colonies (crops at different growth stages which provide variable vegetation height and cover during the breeding cycle) and the effect that agricultural activities have on facilitating access to prey. Beyond the species-specific approach, our work encourages further studies on habitat selection by farmland birds to account not only for human-based categorisation of habitats (e.g. crop type) but also on objective measures such as vegetation height and cover that influence access to prey and better reflect the high dynamism of agricultural landscapes.

Resumen

Se estudió la selección del hábitat de caza del cernícalo primilla Falco naumanni a lo largo del ciclo reproductivo en el suroeste de España mediante transectos en los que se registró el comportamiento de los individuos observados. Se evaluó el efecto de los usos del suelo, tipo de cultivo, estructura de la vegetación y presencia de actividades agrícolas en el uso acumulado y la selección instantánea del hábitat de caza de los cernícalos. La selección del hábitat de caza demostró ser muy dinámica en función del desarrollo de los cultivos y las actividades agrícolas. Casi todos los cultivos herbáceos mostraron una selección positiva por parte de los cernícalos en algún momento del ciclo reproductivo. El uso acumulado mostró relaciones positivas con el trigo y el algodón y una selección negativa de hábitats o cultivos permanentes que o bien son pobres en presas o son rechazados por la especie por su estructura, como las áreas forestales, los cultivos leñosos o las zonas urbanas. La estructura de la vegetación parece que juega un papel preponderante en la selección instantánea del hábitat de caza. Los cernícalos seleccionaron áreas con vegetación baja y con cobertura intermedia. También cazaron sobre lindes y allí donde se estaban llevando a cabo actividades agrícolas, como el arado o el cosechado, que facilitan el acceso a las presas. Nuestros resultados contribuyen a esclarecer las aparentes controversias entre estudios previos, subrayando la importancia de la heterogeneidad del paisaje agrícola alrededor de las colonias (cultivos en diferentes estados de crecimiento que ofrecen variabilidad en la altura de la vegetación y cobertura a lo largo de todo el ciclo reproductivo) así como el efecto de las actividades agrícolas que podrían estar facilitando el acceso a las presas por parte de los cernícalos. Más allá de la aproximación específica, nuestro trabajo incentiva la utilización de variables objetivas como la altura y la cobertura de la vegetación –en lugar de clasificaciones de interés humano como el tipo de cultivo– que reflejan mejor la disponibilidad de presas y el gran dinamismo estructural de los paisajes agrícolas.

Copyright
Corresponding author
*Author for correspondence; email: carlos_r@ebd.csic.es
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

H. Akaike (1974) A new look at the statistical model identification. IEEE Transactions on Automatic Control 19: 716723.

J. Bustamante (1997) Predictive models for Lesser Kestrel Falco naumanni distribution, abundance and extinction in Southern Spain. Biol. Conserv. 80: 153160.

I. Catry , T. Amano , A. M. A. Franco and W. J. Sutherland (2012b) Influence of spatial and temporal dynamics of agricultural practices on the Lesser Kestrel. J. Appl. Ecol. 49: 99108.

I. Franco Catry , A. M. A. and W. J. Sutherland (2012a) Landscape and weather determinants of prey availability: Implications for the Lesser Kestrel Falco naumanni. Ibis 154: 111123.

J. A. Donázar , J. J. Negro and F. Hiraldo (1992) Functional analysis of mate-feeding in the Lesser Kestrel Falco naumanni. Ornis Scand. 23: 190194.

J. A. Donázar , J. J. Negro and F. Hiraldo (1993) Foraging habitat selection, land-use changes and population decline in the Lesser Kestrel Falco naumanni. J. Appl. Ecol. 30: 515522.

A. De Frutos , P. P. Olea , P. Mateo-Tomás and F. J. Purroy (2010) The role of fallow in habitat use by the Lesser Kestrel during the post-fledging period: inferring potential conservation implications from the abolition of obligatory set-aside. Eur. J. Wildl. Res. 56: 503511.

A. M. A. Franco , I. Catry , W. J. Sutherland , and J. Palmeirim (2004) Do different habitat preference survey methods produce the same conservation recommendations for lesser kestrels? Anim. Conserv. 7: 291300.

A. M. A. Franco and W. J. Sutherland (2004) Modelling the foraging habitat selection of Lesser Kestrels: conservation implications of European agricultural policies. Biol. Conserv. 120: 6374.

K. Johst , R. Brandl and R. Pfeifer (2001) Foraging in a patchy and dynamic landscape: human land use and the white stork. Ecol. Applic. 11: 6069.

J. R. Krebs , J. D. Wilson , R. B. Bradbury and G. M. Siriwardena (1999) The second silent spring. Nature 400: 611612.

B. Manly , L. McDonald and D. Thomas (1993) Resource selection by animals: Statistical design and analysis for field studies. London: Chapman and Hall.

M. B. Morales , J. Traba , E. Carriles , M. P. Delgado and E. L. García de la Morena (2008) Sexual differences in microhabitat selection of breeding little bustards Tetrax tetrax: Ecological segregation based on vegetation structure. Acta Oecol. 34: 345353.

D. Ontiveros , J. M. Pleguezuelos and J. Caro (2005) Prey density, prey detectability and food habits: the case of Bonelli’s eagle and the conservation measures. Biol. Conserv. 123: 1925.

S. J. Ormerod , E. J. P. Marshall , G. Kerby and S. P. Rushton (2003) Meeting the ecological challenges of agricultural change: editor´s introduction. J. Appl. Ecol. 40: 939946.

E. C. Pielou (1966) The measurement of diversity in different types of biological collections. J. Theoret. Biol. 13: 131144.

C. Rodríguez and J. Bustamante (2003) The effect of weather on Lesser Kestrel breeding success: can climate change explain historical population declines? J. Anim. Ecol. 72: 793810.

C. Rodríguez and J. Bustamante (2008) Patterns of Orthoptera abundance and Lesser Kestrel conservation in arable landscapes. Biodiv. Conserv. 17: 17531764.

C. Rodríguez , L. Tapia , F. Kieny and J. Bustamante (2010) Temporal changes in Lesser Kestrel Falco naumanni diet during the breeding period in southern Spain. J. Raptor Res. 44: 120128.

D. Serrano and C. Astrain (2005) Microhabitat use and segregation of two sibling species of Calandrella larks during the breeding season: conservation and management strategies. Biol. Conserv. 125: 391397.

J. P. Silva , M. Pinto and J. M. Palmeirim (2004) Managing landscapes for the little bustard: lessons from the study of winter habitat selection. Biol. Conserv. 117: 521528.

W. J. Sutherland and R. E. Green (2004) Habitat assessment. Pp. 251268 in: W. J. Sutherland , I. Newton and R. E. Green , eds. Bird ecology and conservation: a handbook of techniques. Oxford: Oxford University Press.

J. L. Tella and M. G. Forero (2000) Farmland habitat selection of wintering Lesser Kestrels in a Spanish pseudo-steppe: implications for conservation strategies. Biodiv. Conserv. 9: 433441.

J. L. Tella , M. G. Forero , F. Hiraldo and J. A. Donázar (1998) Conflicts between Lesser Kestrel conservation and European agricultural policies as identified by habitat use analyses. Conserv. Biol 12: 593604.

E. Ursúa , D. Serrano and J. L. Tella (2005) Does land irrigation actually reduce foraging habitat for breeding lesser kestrels? The role of crop types. Biol. Conserv. 122: 643648.

A. Rodríguez , J.J. Negro , M. Mulero , C. Rodríguez , J. Hernández-Pliego and J. Bustamante (2012) The Eye in the Sky: Combined Use of Unmanned Aerial Systems and GPS Data Loggers for Ecological Research and Conservation of Small Birds. PLoS ONE 7(12): e50336. doi:10.1371/journal.pone.0050336.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Bird Conservation International
  • ISSN: 0959-2709
  • EISSN: 1474-0001
  • URL: /core/journals/bird-conservation-international
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×
Type Description Title
WORD
Supplementary Materials

RODRÍGUEZ et al. supplementary material
Supplementary tables

 Word (205 KB)
205 KB

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 1
Total number of PDF views: 8 *
Loading metrics...

Abstract views

Total abstract views: 125 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 27th June 2017. This data will be updated every 24 hours.