Wyniki wyszukiwania

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Movement patterns of adult Laughing Gulls Larus atricilla during the nesting season

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Dosch J. J.

Acta Ornithologica

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2003

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tom 38

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nr 1

2

Caching prey in trees by Eurasian lynx

100%

Cerveny J., Okarma H.

Acta Theriologica

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2002

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tom 47

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nr 4

Two cases of Eurasian lynx Lynx lynx (Linnaeus, 175S) caching prey (roe deer Capreolus capreolus) jn trees were documented: in southeastern Polami in February 1996 and in southwestern Czech Republic in November 19911. Both carcasses were

3

Foraging behaviour of White-backed Woodpeckers Dendrocopos leucotos in a primeval forest (Bialowieza National Park, NE Poland): dependence on habitat resources and season

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Czeszczewik D.

Acta Ornithologica

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2009

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tom 44

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nr 2

Detailed knowledge of the foraging behaviour of endangered species, especially in relation to available resources, may be useful in conservation management. I studied the year-round foraging behaviour of the White- backed Woodpecker in broadleaved, primeval Białowieża Forest (NE Poland), and investigated how foraging time was divided among various substrates and foraging techniques. Of the 13 tree species used for foraging, woodpeckers were most frequently recorded utilising the three most common tree species: hornbeam Carpinus betulus, lime Tilia cordata and spruce Picea abies (totalling 61-68% of observed time), and the proportional use of tree species did not change seasonally. Observations of birds foraging on snags increased and foraging on fallen trees decreased from spring to winter. Foraging was most frequently recorded on dead substrates (72-85%), usually those covered with bark. Mean time of foraging on an individual tree increased significantly from spring to winter. The foraging techniques most often used by woodpeckers were bark-pecking (29-11%) and superficial wood-pecking (12-27%). During winter, foraging techniques did not change significantly in relation to weather. These results suggest that forest stand composition is less important to this species than tree condition. Most broadleaved tree species and, under some conditions, spruce can be utilised for foraging by this woodpecker if they provide dead or dying substrates.

4

Factors affecting anvils utilization by Great Spotted Woodpecker Dendrocopos major

84%

Kedra A. H., Mazgajski T. D.

Polish Journal of Ecology

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2001

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tom 49

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nr 1

5

Foraging behavior and spatial use of a rock specialist: the southern vizcacha (Lagidium viscacia), and the exotic European hare (Lepus europaeus) in rocky outcrops of northwestern Patagonia, Argentina

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Galende G. I., Raffaele E.

Acta Theriologica

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2013

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tom 58

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nr 3

The southern vizcacha (Lagidium viscacia) and the exotic European hare (Lepus europaeus) are two medium-sized herbivores that inhabit rocky outcrops in Patagonian steppe. These species overlap in diet and spatial use at medium distances from rocky outcrops in summer. We evaluated the spatial use through feces distribution in winter and determined seasonal foraging intensity in relation to the distances from rocky outcrops in order to elucidate how these herbivores use food and spatial resources in food scarcity periods. The vizcacha utilized the habitat close to rocky outcrops (<40 m) independent of season, while the hare exploited the space more widely, especially distances >40 m. However, in winter, at medium distances from rocky outcrops, there was partial spatial overlap because hares' activities were closer to rocky outcrops. Foraging intensity increased significantly in areas used by the vizcacha closer to rocky outcrops when food availability decreased, and the grasses Stipa speciosa, Poa sp., and Festuca pallescens were strongly foraged. In contrast, foraging intensity showed no changes in further distances to rocky outcrops and more use by the hare. The spatial and feeding behavior of the vizcacha, restricted to vicinity of rocky outcrops, showed high vulnerability to food availability changes. In resource scarcity situations, the spatial opportunistic behavior of the hare and the overlap in diet with the vizcacha constitutes a threat to this native herbivore. It is necessary to monitor populations of hare, since high densities could lead to food competition, impacting the small colonies of the southern vizcacha.

6

Echolocation behaviours of the Japanese pipistrelle bat Pipistrellus abramus during foraging flight

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Ma J., Jones G., Zhu G., Metzner W.

Acta Theriologica

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2010

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tom 55

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nr 4

The acoustic structure of echolocation pulses emitted by Japanese pipistrellePipistrellus abramus (Temminck, 1840) bats during different phases of aerial hawking is described here for the first time. Behavioural observations of the foraging flight in conjunction with acoustical analysis of echolocation pulses indicated a flight path consisting of four distinct phases following the reconnaissance or search phase. Short (∼4.68 ms) and relatively broadband frequencymodulated (FM) pulses (∼23.55 kHz bandwidth) were emitted at a repetition rate of 15 Hz during presumed target approach. Presumed insect capture consisted of an early and a late buzz phase. Both buzz types were emitted at high repetition rates (111 Hz in early to 222 Hz in late) and consisted of very short, broadband FM pulses (1.26 ms in early to 0.3 ms in late). There was also a characteristically sharp drop in both the peak and terminal frequencies of each echolocation pulse during the transition from early to late buzz. No pulses were recorded during the final phase of foraging referred to as a “post-buzz pause”. Thus the foraging behaviour of this species consisted of five sequential phases involving four broad types of echolocation pulses.

7

The influence of a local temperature inversion on the foraging behaviour of big brown bats, Eptesicus fuscus

67%

Arbuthnott D., Brigham R. M.

Acta Chiropterologica

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2007

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tom 09

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nr 1

To maximise foraging efficiency, it is reasonable to expect animals to forage in the highest quality patches. Insectivorous bats should therefore travel to and forage at sites with the highest insect abundance. Since insects are ectothermic, their levels of activity should be higher in warmer areas, making these high quality patches for bats. A nightly temperature inversion occurring in the Cypress Hills (Saskatchewan, Canada) presented an opportunity to test our hypothesis that big brown bats (Eptesicus fuscus) select foraging sites based on temperature as a proxy for insect abundance. If temperature is an important determinant of the foraging behaviour of E. fuscus, we expect bats to forage in the warmest site closest to local night roosts. We tracked 18 bats for a total of 111 nights over two years and found that individuals often spent at least some of each foraging bout in an area where the temperature inversion was small or non-existent. Bats sometimes travelled up to 11 km to reach this site. Foraging in areas where the temperature inversion was small provides indirect evidence that local temperature fluctuations are not a major influence on the selection of foraging area by E. fuscus. Also, since there was little difference in the temperature between the nearby predicted foraging sites and actual foraging sites, we argue that the effect of temperature on insect activity cannot be used to predict foraging habitat selection by these bats. We found that the insect community of the foraging area was different than that of the roosting area, and that beetles were more abundant in the foraging site. Our data suggests that insect community composition is potentially a stronger direct influence on bat foraging behaviour than is temperature.

8

Seed predation on the ground or in the tree? Size-related differences in behavior and ecology of granivorous birds

67%

Parea R., Venturas M., Gil L.

Acta Ornithologica

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2014

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tom 49

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nr 1

Seed-eating birds may consume seeds in the tree (pre-dispersal predation) as well as on the ground (post- dispersal predation), usually at contrasting microhabitat conditions. We examined the foraging behaviour and contribution to seed predation of a whole assemblage of seed-eating birds (mostly Fringillidae) at both dispersal phases (pre- and post-dispersal) in a wind-dispersed tree, the European White Elm Ulmus laevis. We found that most seed predators were tree-feeding birds that prey upon seeds for longer periods in the tree and spend shorter periods in larger flocks foraging on the ground. We also obtained significant differences in predation speed among the seed predator species. The overall number of seeds consumed by birds, as well as the amount of time spent foraging in the tree, increased with increasing feeding heights. Seed availability increases with height, which seems to be the main reason why birds spend more time foraging on higher branches. Birds strongly differed in their perching coefficient (PC, ration of feeding height to distance from crown edge). Small finches such as Serins Serinus serinus and Goldfinches Carduelis carduelis had a very high value of PC in comparison to large finches such as Greenfinches Carduelis chloris, Chaffinches Fringilla coelebs, and Hawfinches Coccothraustes coccothraustes. In general, finches showed much higher values of PC than non-fringillid species, indicating a greater adaptation to perch and feed on more flexible stems. Birds increased their overall seed predation and the time allocated to foraging on the ground when they were in flocks. Small finches tended to follow larger finches and flock in multispecies groups when foraging on the ground. We suggest that this behaviour increases both feeding efficiency and safety. Further studies should take into account possible differences in behavior of seed-eating birds throughout the dispersal season since it may have important implications for their adaptive behavior to select new niches.

9

Differences in foraging behaviour between water shrews: Neomys anomalus and Neomys fodiens

67%

Rychlik L.

Acta Theriologica

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1997

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tom 42

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nr 4

The modes and efficiency of foraging in the terrestrial and aquatic habitats in water shrews Neomys anomalus Cabrera, 1907 and N. fodiens (Pennant, 1771) were compared in order to investigate if these species can avoid competition for food when they occur syntopically. Seven individuals of N. anomalus and five of N. fodiens, caught in the Białowieża Primeval Forest, were tested individually in the terrarium of size 3 x 0.5 m, containing a 0.25-m-wide 'stream' with flowing water of an average depth 25 cm. Six experimental variants, simulating different habitat conditions, were established. Each animal was tested in a given variant during 3 succeeding days for 6 h a day. In total, 738 h of shrews' behaviour were recorded in darkness using 2 infra-red sensitive video-cameras. Results obtained on four N. fodiens tested with similar methods (648 h; Ruthardt 1990) were included for comparison. N. anomalus swam and dived significantly shorter than N. fodiens, and they did not take food under water, even when there was no food on land. N. fodiens found and took food placed under water and foraged quite efficiently here. They found on average 17.7% of food portions placed under water in the most similar to natural conditions and 19.4% when there was no food on land. In both species foraging time on land was much longer than in water. The presence of natural structures increased duration and efficiency of foraging, but this influence was stronger in N. anomalus than in N. fodiens. These results and literature data suggest that in the wild: (1) both species forage in shallow water and in muddy grounds of wet habitats (wading foraging mode), and also in drier terrestrial habitats (epigeal and hypogeal foraging); (2) only N. fodiens forage in deep water (aquatic foraging); (3) the competition for food between N. anomalus and N. fodiens may be very weak, when potential aquatic prey are available.

Ograniczanie wyników

Movement patterns of adult Laughing Gulls Larus atricilla during the nesting season

Caching prey in trees by Eurasian lynx

Foraging behaviour of White-backed Woodpeckers Dendrocopos leucotos in a primeval forest (Bialowieza National Park, NE Poland): dependence on habitat resources and season

Factors affecting anvils utilization by Great Spotted Woodpecker Dendrocopos major

Foraging behavior and spatial use of a rock specialist: the southern vizcacha (Lagidium viscacia), and the exotic European hare (Lepus europaeus) in rocky outcrops of northwestern Patagonia, Argentina

Echolocation behaviours of the Japanese pipistrelle bat Pipistrellus abramus during foraging flight

The influence of a local temperature inversion on the foraging behaviour of big brown bats, Eptesicus fuscus

Seed predation on the ground or in the tree? Size-related differences in behavior and ecology of granivorous birds

Differences in foraging behaviour between water shrews: Neomys anomalus and Neomys fodiens