Spatial and temporal separation between the golden jackal and three sympatric carnivores in a human-modified landscape in central Bulgaria

AbstractThe effects of lineatin enantiomer ratios, lineatin release rate, and trap length on catches and the flight periods of three sympatric species of Trypodendron Stephens were investigated in field bioassays using multiple-funnel traps. The ambrosia beetle, Trypodendron betulae Swaine, was caught in similar numbers in baited traps and blank control traps, showing that this species does not respond to lineatin. Our results confirmed that Trypodendron lineatum (Olivier) is attracted only to (+)-lineatin. Trypodendron rufitarsus (Kirby) and Trypodendron retusum (LeConte) were shown to utilize lineatin and like T. lineatum were caught only when (+)-lineatin was present. These results indicate that lineatin does not govern reproductive isolation among these three species. There was no effect by (+)-lineatin release rate within the range tested. The flight of T. rufitarsus commenced earlier and ceased before the peak of the T. lineatum flight, suggesting that temporal separation may be an important component of reproductive isolation between these two species. The flight period of T. retusum was similar to that of T. lineatum. Host odours may aid in reproductive isolation of these two species. Enantiomer blend did not significantly affect sex ratio in any species; however, sex ratio differed among species, indicating that different species responded differently to the traps or that natural sex ratios differ. Catches of T. rufitarsus and T. retusum increased with trap length when pheromone release per trap was held constant and when release was held constant relative to trap length. Trap length and release rate did not affect sex ratio.

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Habitat use of golden jackals (Canis aureus) in riverine areas of northern Bosnia and Herzegovina

European Journal of Wildlife Research ◽

10.1007/s10344-021-01457-7 ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Aldin Selimovic ◽

Eva Maria Schöll ◽

Larissa Bosseler ◽

Jennifer Hatlauf

Keyword(s):

Habitat Use ◽

Bosnia And Herzegovina ◽

Agricultural Practices ◽

Binary Logistic Regression ◽

Food Sources ◽

Golden Jackal ◽

Canis Aureus ◽

Logistic Regression Models ◽

Habitat Analysis ◽

Group Density

AbstractRecently confirmed expansion of golden jackals (Canis aureus) into countries without any previous records poses questions, one of them focusing on the species potential and possibly varying habitat use. In this study, we investigated the presence and distribution of golden jackals in northern Bosnia and Herzegovina, where knowledge about golden jackal distribution and habitat use is still scarce. We used bioacoustic stimulation as a non-invasive tool to gather data on golden jackal presence. Habitat structures potentially selected by the species were assessed at 92 calling stations and used as input for binary logistic regression models. Our study area covered approximately 1150 km2, and bioacoustic stimulation within this area resulted in an estimated minimum relative group density of 3.5 territorial groups per 100 km2. We found territorial groups at distances between 15 and 38 km southwards from the river Sava but always within a maximum range of 3 km to perennial watercourses. Habitat analysis identified shrub vegetation and pastures as structures with a significant effect on the presence of resident golden jackals. Probability that golden jackals answered at calling stations increased with increasing surface area covered with pastures and shrubs. Distances between golden jackal territories and the nearest human settlement were relatively small. Our results indicate that structures like transitional woodland-shrubs and pastures, together with other potential influencing factors like local agricultural practices, low hunting pressure, diverse natural and anthropogenic food sources, could have benefited the settlement of golden jackals in the northern lowlands of Bosnia and Herzegovina.

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Helminth parasites of the endangered Iberian lynx (Lynx pardinus) and sympatric carnivores

Journal of Helminthology ◽

10.1017/s0022149x07869203 ◽

2007 ◽

Vol 81 (4) ◽

pp. 377-380 ◽

Cited By ~ 13

Author(s):

Javier Millán ◽

Joan Carles Casanova

Keyword(s):

Lynx Lynx ◽

Helminth Parasites ◽

Toxocara Cati ◽

Iberian Lynx ◽

Lynx Pardinus ◽

Feral Cats ◽

Sierra Morena ◽

Sympatric Carnivores ◽

Adult Cats ◽

Herpestes Ichneumon

AbstractFive critically endangered Iberian lynxes (Lynx pardinus) and 35 other sympatric carnivores (19 feral catsFelis catus, 12 Egyptian mongoosesHerpestes ichneumon, and 4 common genetsGenetta genetta) were analysed for helminths in Sierra Morena and Doñana area (southern Spain).Ancylostoma tubaeforme, which was believed to be harmful for lynx cubs according to a previous study, was present in the only lynx and in 53% of cats analysed in Doñana (80% in adult cats). Other species shared in both areas wereToxocara cati(1 lynx, 31% of cats),Joyeuxiella pasqualei(1 lynx, 21% of cats) andMesocestoidessp. (2 lynxes, 5% of cats). Only one mongoose was parasitized, harbouring larvae of two acantocephalan species not previously reported in the Iberian peninsula (Centrorhynchus(Sphaerirostris)lanceaandCentrorhynchus(Longirostris)undulatus). Feral cats may be a reservoir for hookworms and other helminths affecting the Iberian lynx. In contrast, mongooses and genets may not play a role in the epidemiology of these species.

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Hysteretic behavior for transmission curve and soliton temporal separation in multi-pulsing regime for mode-locked fiber lasers

Laser Physics ◽

10.1088/1555-6611/ac1072 ◽

2021 ◽

Vol 31 (8) ◽

pp. 085103

Author(s):

Cecília L. A. V. Campos ◽

Lúcio H. Acioli ◽

Marcio H. G. de Miranda

Keyword(s):

Fiber Lasers ◽

Hysteretic Behavior ◽

Transmission Curve ◽

Temporal Separation

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Effect of background clutter on neural discrimination in the bat auditory midbrain

Journal of Neurophysiology ◽

10.1152/jn.00109.2021 ◽

2021 ◽

Author(s):

Kathryne M Allen ◽

Angeles Salles ◽

Sanwook Park ◽

Mounya Elhilali ◽

Cynthia F. Moss

Keyword(s):

Acoustic Scattering ◽

Object Discrimination ◽

Complex Environments ◽

Acoustic Features ◽

Temporal Separation ◽

Complex Sounds ◽

Electrophysiological Recordings ◽

Background Clutter ◽

Spatio Temporal ◽

Neural Underpinnings

The discrimination of complex sounds is a fundamental function of the auditory system. This operation must be robust in the presence of noise and acoustic clutter. Echolocating bats are auditory specialists that discriminate sonar objects in acoustically complex environments. Bats produce brief signals, interrupted by periods of silence, rendering echo snapshots of sonar objects. Sonar object discrimination requires that bats process spatially and temporally overlapping echoes to make split-second decisions. The mechanisms that enable this discrimination are not well understood, particularly in complex environments. We explored the neural underpinnings of sonar object discrimination in the presence of acoustic scattering caused by physical clutter. We performed electrophysiological recordings in the inferior colliculus of awake big brown bats, to broadcasts of pre-recorded echoes from physical objects. We acquired single unit responses to echoes and discovered a sub-population of IC neurons that encode acoustic features that can be used to discriminate between sonar objects. We further investigated the effects of environmental clutter on this population's encoding of acoustic features. We discovered that the effect of background clutter on sonar object discrimination is highly variable and depends on object properties and target-clutter spatio-temporal separation. In many conditions, clutter impaired discrimination of sonar objects. However, in some instances clutter enhanced acoustic features of echo returns, enabling higher levels of discrimination. This finding suggests that environmental clutter may augment acoustic cues used for sonar target discrimination and provides further evidence in a growing body of literature that noise is not universally detrimental to sensory encoding.

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