Spatio-Temporal Patterns of Owl Territories in Fragmented Forests are Affected by a Top Predator (Ural owl)

Kajtoch, Łukasz; Matysek, Marcin; Figarski, Tomasz

doi:10.5735/086.053.0405

Cited by 11 publications

(19 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because jaegers do not reuse old nests, the position of the nesting site is a new decision every year. Nonetheless, the presence of a large and close competitor did not affect the distribution of nesting jaegers contrary to what was observed in a guild of forest owls (Kajtoch et al, 2015(Kajtoch et al, , 2016.…”

Section: Spatial Resource Partitioningcontrasting

confidence: 87%

Resource partitioning among avian predators of the Arctic tundra

Seyer

Gauthier

Fauteux

et al. 2020

Journal of Animal Ecology

View full text Add to dashboard Cite

1. Interspecific competition can play a key role in structuring ecological communities. The Arctic tundra is a low productivity ecosystem supporting simple food webs, but several predators often feed on the same prey species, lemmings, known for their large-amplitude population fluctuations. 2. We examined mechanisms involved in reducing intra-guild competition and allowing coexistence of four avian predators (snowy owls, glaucous gulls, rough-legged hawks and long-tailed jaegers) feeding on a pulsed resource (brown and collared lemmings). We compared the size and species of prey consumed by predators to see if resource partitioning occurred. We also verified if spatial segregation in nesting areas could be another mechanism allowing coexistence. Finally, we tested if the absence of the snowy owl, a dominant and irruptive species, triggered a competitive release on the smallest predator, the jaeger, with respect to prey size and nesting area used. 3. We monitored the breeding of predators and lemming abundance over a 14-year period on Bylot Island, Canada. We mapped their nesting sites and collected regurgitation pellets to recover lemming mandibles, which were used to infer prey species and size. 4. The size of lemmings consumed varied among species with the largest predators consuming the largest lemmings and the smallest predators consuming the smallest lemmings. All predators consumed more collared than brown lemmings compared to their availability although owls and jaegers consumed relatively more brown lemmings compared to gulls and hawks. Jaegers consumed larger lemmings in the absence of owls than in their presence, suggestive of a short-term competitive release. We found moderate to low overlap in nesting areas among predators and no evidence of their expansion in the absence of owls, suggesting that spatial distribution is caused by species-specific habitat preferences. 5. The main mechanism to partition food resources among these avian predators is spatial segregation, and secondarily prey size and species. However, we found evidence that food competition is still present and leads to a niche shift in the smallest predator of the guild. Interspecific competition may thus be a pervasive force in simple, low productivity food webs characterized by pulsed resources.

show abstract

Section: Spatial Resource Partitioningcontrasting

confidence: 87%

Resource partitioning among avian predators of the Arctic tundra

Seyer

Gauthier

Fauteux

et al. 2020

Journal of Animal Ecology

View full text Add to dashboard Cite

show abstract

“…Consequently, playback methods have been widely applied for censusing owl populations and developing ecological and behavioural studies (Zuberogoitia & Campos , Barnes & Belthoff , Kajtoch et al . , Tempel et al . ).…”

mentioning

confidence: 99%

Factors affecting spontaneous vocal activity of Tawny Owls Strix aluco and implications for surveying large areas

Zuberogoitia¹,

Burgos

González‐Oreja

et al. 2018

Ibis

View full text Add to dashboard Cite

To use vocalizations properly for the estimation of owl population size, it is important to identify how environmental factors affect owl calling behaviour. Here, we analyse how intrinsic and extrinsic factors modify the vocal activity of Tawny Owls Strix aluco in two areas of northern Spain. From March 2013 to May 2015, we radiotracked 20 Tawny Owls and also undertook a systematic survey in which we collected data on spontaneous vocal activity (hoot/call) of the tagged owls, plus their mates and neighbours (36 untagged owls). After 223 nights in Valle de Mena and 224 in Duranguesado we obtained a total of 8791 records of vocal activity. The annual proportion of surveys on which an owl called was 6.3% and did not differ between the study areas. Vocal activity of Tawny Owls varied with sex, annual cycle stage and weather. Male owls were significantly more vocal than females year-round, and vocal activity peaked during the incubation and post-breeding periods. Wind and rain adversely affected vocal activity of both sexes throughout the year. Tagged owls were detected more often than untagged owls, which we interpret as an observer effect because the systematic survey ensured that short distances to tagged owls increased the probability of detecting vocal activity. In fact, 2.8% of variation in vocal activity was due to detectability differences between tagged and untagged owls. We conclude that if fieldwork is carried out during the optimum period of the year for vocal detection (i.e. incubation, which in our case was around mid-April), and under good weather conditions (dry and calm nights), censuses based on spontaneous vocal activity would detect only approximately 12% of the true Tawny Owl population.

show abstract

“…We also modeled interspecific competition as the presence of Boreal and Northern Saw-whet Owls at the same site, because these owls potentially compete for nest sites and prey. Interactions within the nocturnal predator guild can alter spatial distribution of owls (Kajtoch et al 2016, Morosinotto et al 2017; however, there are few published accounts of competition between our study species (but see Lane 1991). Although reports of direct predation of larger owls on smaller owls are rare, diet studies have reported smaller owls, including Northern Saw-whet Owls, as prey items for Great Horned Owls (reviewed by Cromrich et al 2002).…”

Section: Predictor Variablesmentioning

confidence: 97%

“…In this study, we considered the presence/absence of nesting facilitators, competitors, and potential predators as potential predictors. We analyzed Pileated Woodpeckers as facilitators of owl nesting because both Boreal and Northern Saw-whet Owls breed almost exclusively in cavities created by primary cavity excavators (Hayward et al 1993, Johnsgard 2002, Korpimäki and Hakkarainen 2012. We also modeled interspecific competition as the presence of Boreal and Northern Saw-whet Owls at the same site, because these owls potentially compete for nest sites and prey.…”

Section: Predictor Variablesmentioning

confidence: 99%

See 1 more Smart Citation

Spatial distribution of the Boreal Owl and Northern Saw-whet Owl in the Boreal region of Alberta, Canada

Domahidi¹,

Shonfield²,

Nielsen³

et al. 2019

ACE

View full text Add to dashboard Cite

Understanding what factors influence the occurrence and distribution across the landscape is necessary for species conservation and management. Distribution data for many owl species are inadequate because of their nocturnal behavior and cryptic nature. We examined the role of climate, land cover, and human disturbance in shaping spatial distribution of the Boreal Owl (Aegolius funereus) and Northern Saw-whet Owl (Aegolius acadicus) in northern Alberta. Using autonomous recording units, we conducted passive acoustic surveys to detect owls of both species throughout Alberta's boreal forest. We compiled data on environmental variables at each sample site corresponding to a local scale and at landscape scale. A boosted regression tree analysis identified average minimum winter temperature as the most important predictor of Boreal Owl distribution. Boreal Owls were more likely to be present in cool environments with cold winters, and a low percentage of grassland cover at the landscape scale. Cropland cover at the local scale was the most influential factor in the final distribution model for the Northern Saw-whet Owl, and they were more likely to be present in areas where cropland was interspersed with deciduous-dominated forests. Furthermore, these areas generally had cool summer temperatures and received less precipitation as snow. Linear features at the landscape scale negatively influenced distribution of Boreal Owls, but edges created by linear features at local scale positively influenced Northern Saw-whet Owl distribution. Our study provides new information about habitat use that can be applied in management and conservation of these two poorly studied species of owls.

show abstract

Spatio-Temporal Patterns of Owl Territories in Fragmented Forests are Affected by a Top Predator (Ural owl)

Cited by 11 publications

References 19 publications

Resource partitioning among avian predators of the Arctic tundra

Resource partitioning among avian predators of the Arctic tundra

Factors affecting spontaneous vocal activity of Tawny Owls Strix aluco and implications for surveying large areas

Spatial distribution of the Boreal Owl and Northern Saw-whet Owl in the Boreal region of Alberta, Canada

Contact Info

Product

Resources

About