Predation by sparrowhawks decreases with increased breeding density in a songbird, the great tit

  title={Predation by sparrowhawks decreases with increased breeding density in a songbird, the great tit},
  author={Frank G{\"o}tmark and Malte Andersson},
Predators may regulate prey populations if predation rate increases with prey density. Alternatively, if space-limited (e.g. territorial) predators become ‘satiated’ when prey exceed a certain density, increased prey abundance may lead to reduced predation rate. These alternatives have been difficult to test experimentally for mobile prey in the wild. We present such a test, manipulating the density of great tits (Parus major) by adding nest boxes in territories of sparrowhawks (Accipiter nisus… 

Predators target rare prey in coral reef fish assemblages

It is hypothesized that when faced with multiple prey species predators may initially focus on rare, conspicuous species to overcome the sensory confusion experienced when attacking aggregated prey, thereby minimizing the time required to capture prey.

Diet of Eurasian Sparrowhawks in a Northwest Iberian Hedgerow Habitat throughout the Year

The autumn-winter and spring-summer diet of this raptor species in Northwest Spain in a hedgerow habitat is concerned, with Eurasian Sparrowhawk Accipiter nisus feeding mainly on medium-sized birds that often forage on the ground at some distance from shrubs and trees.

Sparrowhawk Accipiter nisus presence and winter bird abundance

The significant negative effects detected suggest that there is a temporal matching between increased predation pressure and decreases in bird abundance for certain species, but there was no strong evidence that Sparrowhawk re-colonisation was linked to long-term declines in population size.

Large body and small brain and group sizes are associated with predator preferences for mammalian prey

Predation biases were positively associated with early age at maturity, supporting the role of mortality in driving life-history characteristics and several theoretical models of predation including its role as a selective force driving evolutionary changes in life history, brain size and sociality, optimal diet theory, and antiapostatic predation.

Predator-Specific Effects on Incubation Behaviour and Offspring Growth in Great Tits

The effects of the presence of either a nest predator or a predator targeting adults and offspring after fledging on female incubation behaviour in great tits (Parus major) are assessed, and the subsequent effects on offspring morphological traits are assessed.

Assessing factors associated with changes in the numbers of birds visiting gardens in winter: Are predators partly to blame?

Significant negative relationships were found between Eurasian Sparrowhawk Accipiter nisus and three of the 10 species analyzed, namely house Sparrow Passer domesticus, starling Sturnus vulgaris, and blue tit Cyanistes caeruleus.

Predator swamping and supplementary feeding do not improve reintroduction success for a threatened Australian mammal, Bettongia lesueur

Neither predator swamping nor supplementary feeding enhanced reintroduction success at the authors' sites but results suggested that supplementary feeding should be explored as an aid to reintroductions success for Australian mammals.

Ecological conditions influence sentinel decisions

Do sex-specific densities affect local survival of free-ranging great tits?

Experimental evidence is revealed for both negative effects of density on adult local survival and positive sex-specific effects on juvenile local survival, which shape sex- specific fitness prospects and might thus also alter optimal sex allocation decisions.


OF THESIS HABITAT SELECTION OF THE CERULEAN WARBLER IN EASTERN KENTUCKY Successful forest management requires an understanding of the habitat requirements of individual species at multiple spatial



Prey Selection by Sparrowhawks, Accipiter nisus: Relative Predation Risk for Breeding Passerine Birds in Relation to their Size, Ecology and Behaviour

Most predation was due to the smaller male hawks, providing food for their mates and young, RPR increased with prey body size up to a mass of about 40 g, then declined with increasing body size (larger prey being more difficult to catch), RPR decreased with increasing relative density of prey species.

Predicting Effects of Predation on Conservation of Endangered Prey

The observed predation curves conformed to the predictions of predator-prey theory and suggest a protocol for an experimental management program for the conservation of sensitive prey species.

Conspecific Attraction and the Conservation of Territorial Songbirds

These results provide the first experimental evidence that territorial songbirds use the presence of conspecifics when deciding where to settle and suggest that conspespecific attraction may provide a valuable conservation tool.

Natural selection and sexual dimorphism : sex-biased sparrowhawk predation favours crypsis in female chaffinches

Female chaffinches spent more time foraging and were more active and closer to the ground than males; they were therefore probably easier to detect and catch for sparrowhawks, and predation probably selects for crypsis in female chaffinch.

The widespread declines of songbirds in rural Britain do not correlate with the spread of their avian predators

Large–scale, long–term data from a national bird census scheme is used to examine whether magpies and sparrowhawks could have depressed the rates of year–to–year population change in 23 songbird species, finding that they are unlikely to have caused songbird declines.

Apparent lack of impact of Sparrowhawks on the breeding densities of some woodland songbirds

Most species increased in density over the whole study period and, in four, the rate of increase slowed towards the end of the study, although it was impossible to tell whether this slowing in population growth was caused by the return of Sparrowhawks or by other factors, such as habitat effects.

Predation and Limitation of Bird Numbers

While food supply and other resources provide the ultimate check on bird numbers, some populations might be held by predators below the level that resources would permit, at least part of the mortality they inflict must be “additive” to other mortality, and not simply “compensatory,” replacing other forms of death.

The effects of predators on fragmented prey populations: A case study for the conservation of endangered prey

The simulation model showed that at small population sizes the stochastic factors were always significant, whereas environmental variation and habitat change had the greatest impact on large populations over the long term.

Artificial colour mutation: do red-painted great tits experience increased or decreased predation?

A predation cost for bright mutants may initially be low or absent, later increasing with the frequency of the mutant, and tit parents fed red fledglings more often than controls, indicating a possible parental preference for red.

Conspecific Attraction and Aggregation in Territorial Species

  • J. Stamps
  • Environmental Science
    The American Naturalist
  • 1988
For many years, field studies of birds have suggested that territorial individuals may be attracted to one another, forming territorial clusters independent of resource distributions. However,