Territorial calls in the Little Owl (Athene noctua): spatial dispersion and social interplay of mates and neighbours (original) (raw)
Related papers
2016
Most owl species exhibit territorial behaviour in order to have sufficient resources to maintain their fitness and biological success. The Little Owl (Athene noctua) has been considered a territorial species, although some authors have pointed to movements and social interactions outside a particular territory. We hypothesise that the spatial behaviour and social organisation of Little Owl follows a complex pattern, which varies throughout the year. We radio-tracked nine Little Owls in an area of 10 km2 over nine months, paying particular attention to home range variation, social interaction and vocal behaviour. Home range size and overlap varied markedly throughout the year, with maximums in winter, and minimum size and overlap during the breeding season. Little Owls showed exclusive home ranges during the breeding season, whereas home range overlap was frequent in winter. Owls which had lost clutches increased their home ranges and shared the same for-aging areas with other owls. ...
Vocal behaviour and neighbour spatial arrangement during vocal displays in eagle owls (Bubo bubo)
Journal of Zoology, 2007
We quantified temporal and spatial patterns of adult eagle owl Bubo bubo vocal behaviour throughout an entire year. The duration of adult eagle owl vocal displays showed significant differences during different periods of the year: there was one major peak in the pre-laying period, when duets of mates were also more frequent. The daily distribution of adult vocalizations showed a similar pattern among the different periods, with vocal activity being most intense at sunset and sunrise. Analyses of the characteristics of call posts showed that the choice of such focal points was guided by the trade-off between the need to defend the territory and within-pair communication inside the core areas, as well as efficient communication with neighbours. 8 Vocal behaviour in eagle owls M. M. Delgado and V. Penteriani
Seasonal dynamics in social behaviour and spacing patterns of the Little Owl Athene noctua
2007
Most owl species exhibit territorial behaviour in order to have sufficient resources to maintain their fitness and biological success. The Little Owl (Athene noctua) has been considered a territorial species, although some authors have pointed to movements and social interactions outside a particular territory. We hypothesise that the spatial behaviour and social organisation of Little Owl follows a complex pattern, which varies throughout the year. We radio-tracked nine Little Owls in an area of 10 km 2 over nine months, paying particular attention to home range variation, social interaction and vocal behaviour. Home range size and overlap varied markedly throughout the year, with maximums in winter, and minimum size and overlap during the breeding season. Little Owls showed exclusive home ranges during the breeding season, whereas home range overlap was frequent in winter. Owls which had lost clutches increased their home ranges and shared the same foraging areas with other owls. Vocal activity was low all year round, except in the months immediately prior to courtship. Increase of vocal behaviour was therefore also associated with a reduction in home range.
Alarm calls modulate the spatial structure of a breeding owl community
Proceedings of the Royal Society B: Biological Sciences, 2012
Animals should continuously assess the threat of predation. Alarm calls inform on predation risk and are often used as cues to shape behavioural responses in birds and mammals. Hitherto, however, the ecological consequences of alarm calls in terms of organization of animal communities have been neglected. Here, we show experimentally that calls of a resident nocturnal raptor, the little owl Athene noctua , triggered a response in terms of breeding habitat selection and investment in current reproduction in conspecifics and heterospecifics. Little owls preferred to settle in territories where calls of conspecifics, irrespective of their type (i.e. alarm versus contact calls), were broadcasted, indicating that either conspecific attraction exists or calls are interpreted as foreign calls, eliciting settlement as a mode of defence against competitors. Also, we found that little owls seemed to invest more in current reproduction in safe territories as revealed by conspecific calls. Inno...
Spatial behaviour of little owls (Athene noctua) in a declining low-density population in Denmark
Journal of Ornithology, 2009
Knowledge of a species' spatial behaviour is essential for understanding its behavioural ecology, as well as a prerequisite to planning of conservation strategies. The Little Owl (Athene noctua) has shown a substantial decline in north-western Europe and is on the road of extinction in Denmark. To quantify relevant aspects of spatial behaviour in the last remaining Danish population, we followed 27 radio-tagged owls representing 14 territories during a period of 2 years. Mated owls were resident at nesting sites year-round with half of all nocturnal locations found within 125 m. Mean nightly distance from roosts peaked in January at 249 m (95% CI = 195-319) and dipped in May to 89 m (66-121). Distance from roosts varied non-linearly with temperature with the longest distances found at 6°C. Home range size varied with more than a tenfold difference between pairs, with pairs with neighbours maintaining 2-3 times larger ranges than isolated pairs independent of habitat composition. Mean home range size of 14 pairs was 41 (95% CI 27-64) and 2.6 ha (1.5-4.5) for 90 and 50% minimum convex polygons, respectively. Males and females behaved similarly, except in the breeding season where females foraged closer to the nest. Mates overlapped completely in activity distributions and were located closer to each other than expected by chance, suggesting a permanent pair-bond. Inter-mate distances were not shorter prior to egg laying compared to the rest of the year, indicating little male investment in mate guarding. No mates left their partner, but widowed birds left their territory within 6-12 months if unable to attract a new mate.
Post-fledging behaviour of juveniles in the Little Owl (Athene noctua)
Before dispersal, social and spatial behaviour in owls has only been briefly studied. We used radio tracking to monitor age-influenced social and spatial behaviour in 10 juvenile Little Owls (Athene noctua) from nests in Northern Jutland, Denmark. On average, the post-fledging dependency period lasted 35 days (n = 6). Juveniles stayed on the natal territory 45 days (n = 5) from independence to dispersal. Half of the juveniles had dispersed by mid-September, and the other half remained on the natal territory until at least mid-October. The home range size (minimum convex polygons) was 0.56 ± 0.53 ha (mean ± SD) from fledging to independence and 3.25 ± 4.15 ha from independence to dispersal. Within the first 40 days after fledging, the nightly distance from the nest and the distance between siblings increased, and the frequency and intensity of begging calls decreased. These results were consistent with the notion that food provided by the parents decreased as juvenile foraging skills increased.
Intra- and Interspecific Calling in a T ropical Owl Community
We studied the intra- and interspecific r esponses to playback of pre-recorded calls by five tropical humid for est owl species at La Selva preserve in northeaster n Costa Rica fr om April to September 1995. Response to conspecific br oadcast calls differed among species ( X2 = 24.4; df = 1; P < 0.001): V ermiculated Scr eech- owls (Otus guatemalae) responded to 47.6 per cent of br oadcasts, followed by Crested Owls (Lophostrix cristata, 45 percent), Mottled Owls (Ciccaba virgata, 18.3 per cent), and Black-and-white Owls ( C. nigrolineata, 9 percent). Cr ested Owls (x = 16.37, sd = 2.6), Mottled Owls (x = 11.7, sd = 7.1), and V ermiculated Scr eech-owls (x = 10.9, sd = 0.9) responded to interspecific playback mor e than did Black- and-white Owls (x = 2.04, sd = 2) (H = 10.6; P = 0.01). Spectacled Owls (Pulsatrix perspicilata) did not r espond at all during our br oad- casting period. Both types of r esponse showed some monthly varia- tion. Response to the calling of other owls al...
The Condor
From 2004 to 2006 we studied the spatial activity of Long-eared Owls (Asio otus) breeding in the city of České Budějovice, Czech Republic. Two main factors (size and proportion of home range in developed area) clearly distinguished the owls into two groups: urban (n = 5) and suburban (n = 4). Urban owls occupied home ranges >50% in developed area; home ranges of suburban owls were <50% in developed area. We obtained 866 radio fixes from nine individuals while they were feeding offspring, when both males and females participated in hunting. The home ranges of urban owls were larger than those of suburban owls (95% kernels: 446 vs. 56 ha, respectively). Urban males and females used home ranges of similar sizes that overlapped greatly with those of the opposite sex and with those of other breeding pairs. In contrast, suburban male owls had home ranges larger than those of suburban females. Wooded areas and meadows were the vegetation types preferred by both urban and suburban owl...
Ibis, 2018
Burgos for field assistance. This research project was partially funded (half of the telemetry material) by the Basque Government Department of Environment. The Environment Territorial Service of Delegaci on Territorial de Burgos and The Environment Department of Diputaci on Foral de Bizkaia issued the licences to work with this species. During the writing of this paper, J. A. Gonz alez-Oreja was supported by BUAP-VIEP Projects 00625/2017 and 00418/2018, and especially SEP-PRODEP Project BUAP-PTC-522. The article was improved by the comments of two anonymous reviewers. It is given in memory of Mikel Larrea.