The Relationship between Weather and Reproduction of the Barn Owl Tyto Alba in a Semi-Arid Agricultural Landscape in Israel

2017 ◽  
Vol 10 (4) ◽  
pp. 253-258 ◽  
Author(s):  
Motti Charter ◽  
Ido Izhaki ◽  
Kobi Meyrom ◽  
Shauli Aviel ◽  
Yossi Leshem ◽  
...  

Even though the Barn Owl ( Tyto alba) is distributed worldwide, little information is available on how weather affects Barn Owl breeding outside of Europe and North America. For instance, if cold temperatures can negatively influence population dynamics in temperate regions, heat could have a similar negative effect in arid regions. We have studied a breeding population of Barn Owls in a semi-arid agricultural environment over 13 years in Israel in order to determine whether lack of rain and hot ambient temperatures impair Barn Owl reproductive success. The percentage of nest boxes occupied by Barn Owls was not related to any of the weather variables, whereas the number of nestlings per Barn Owl pair and the percentage of pairs that succeeded to fledge young was lower in years when it started to rain later in the season and when the minimum daily temperature was higher during the breeding season. In comparison to temperate regions, heat is detrimental to Barn Owl breeding and early precipitation is probably important in boosting vegetation and, in turn, the abundance of small mammals, the Barn Owl's staple food.

2016 ◽  
Vol 66 (2) ◽  
pp. 219-228 ◽  
Author(s):  
Boyan Milchev

Coexistence of predator species often depends on behaviours or preferences that result in spatio-temporal reduction of competition. In this study, the diets of coexisting barn owls (Tyto alba) and eagle owls (Bubo bubo) in an agricultural landscape of SE Bulgaria were compared. White-toothed shrews (Crociduraspp.), voles (Microtusspp.) and mice (Musspp.) were the main prey of barn owl (86.3% by number, 81.2% by biomass) with significantly different frequencies in annual diets. The principle biomass (64.8 ± 6.2%) of the significantly different eagle owl annual diets comprised much heavier prey such as white-breasted hedgehog (Erinaceus roumanicus), European hare (Lepus europaeus) and non-passerine birds of wetlands and open habitats. The two owl species preferred and hunted on different prey size groups in the same territory, and this difference explained the low level of food competition (6.0 ± 3.6% diet overlap according to prey biomass). Voles were the only prey of the two owls with significantly different frequencies for the annual diets in intraspecies comparisons. The proportions of voles in both diets showed similar trends during the study. Eagle owl predation on barn owls was slightly affected by their coexisting breeding despite the high levels of food stress of eagle owl. These findings provide insight into how preying habits can predict successful coexistence of potentially competing predator species.


Author(s):  
Vivien Cosandey ◽  
Robin Séchaud ◽  
Paul Béziers ◽  
Yannick Chittaro ◽  
Andreas Sanchez ◽  
...  

AbstractBird nests are specialized habitats because of their particular composition including nest detritus and bird droppings. In consequence, they attract a specialized arthropod community considered as nidicolous, which includes species only found in bird nests (strictly nidicolous) or sometimes found in bird nests (facultatively nidicolous). Because the factors influencing the entomofauna in bird nests are poorly understood, in autumn 2019, we collected nest material in 86 Barn Owl (Tyto alba) nest boxes. We investigated whether the invertebrate species richness was related to Barn Owl nest box occupancy, the density of available nest boxes and the landscape structure. We found 3,321 nidicolous beetle specimens belonging to 24 species. Species richness of strictly nidicolous beetles was 2.7 times higher in nest boxes occupied by a family of Barn Owls the previous spring compared to unoccupied nest boxes. It was also higher in sites that were more often occupied by Barn Owls in the five previous years and in areas surrounded by a higher proportion of crop fields. For facultatively nidicolous beetles, the density of Barn Owl nest boxes enhanced the species richness. In conclusion, our study suggests that the strictly nidicolous beetles benefit from occupied nest boxes of Barn Owls, whereas facultatively nidicolous beetles look for nest boxes independently of whether Barn Owls occupy them. Our study highlights the importance of bird nests for a suite of invertebrates.


2006 ◽  
Vol 54 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Á. Klein ◽  
Margit Kulcsár ◽  
Virág Krízsik ◽  
R. Mátics ◽  
P. Rudas ◽  
...  

The basic patterns of thyroid hormones [thyroxine (T4) and 3,3',5-triiodothyronine (T3)] and the T4 and T3 responses induced by thyrotropin releasing hormone (TRH) are reported in captive female barn owls (Tyto alba) during the non-breeding period. The main findings of the study, conducted on a total of 10 owls, are as follow: (1) The thyroid gland of barn owl can be stimulated by the classical TRH stimulation test. (2) T3 response was much more pronounced both under cold (around 10°C) and warm (around 20°C) conditions, whereas T4 response ranged so widely that we could not point out any significant change in it. (3) Basal T3 plasma level was significantly (p = 0.036) higher in birds exposed to cold temperature, and they responded to TRH treatment with a lower plasma T3 elevation than the birds kept in a warm chamber. This pattern, however, cannot be explained by increased food intake, but is in agreement with the fact that enhanced T3 level may account for higher avUCP mRNA expression, which results in higher heat production on the cell level. From the results it is concluded that altering T3 plasma level plays a significant role in cold-induced thermoregulation.


The Auk ◽  
2002 ◽  
Vol 119 (2) ◽  
pp. 515-519 ◽  
Author(s):  
Alexandre Roulin

Abstract In double-brooded species, the sex that contributes less to breeding success may desert offspring before the end of the rearing period to start a new breeding attempt with another partner. I evaluated that prediction in the Barn Owl (Tyto alba), a species in which the male feeds the brood on average twice as often as the female. Among birds that produced a second brood, 46% of females and 4% of males deserted their offspring before completion of parental duties to remate with another partner at a distance of 1 to 10 km. Offspring desertion did not appear to incur a reproductive cost to the deserter, because deserting females at the first nest produced a similar number of offspring as nondeserting ones. In most cases, the new mate of deserting females had not been previously captured in the study area, and hence had probably not previously bred that season. Although the second clutch of deserting females was larger and produced two weeks earlier than that of nondeserting females, their nesting success did not differ.


2019 ◽  
Vol 2 ◽  
Author(s):  
Girgina Daskalova ◽  
Peter Shurulinkov ◽  
Georgi Popgeorgiev

The Barn Owl (Tyto alba Gould, 1837) is a rare and endangered species in Bulgaria, included in the Red Data Book (Golemansky 2015) as “Vulnerable”, with national population estimated at 200–700 pairs. Barn Owl presence was surveyed using sound provocation during the night at 161 points in 52 small to medium-sized settlements in Sliven and Yambol districts (Thracian plain, SE Bulgaria). The studied territory was about 1190 km2. The habitats presented in a 3-km radius around the presence and potential absence points were statistically analysed. The species was found to be a quite common breeding species in the study area – a total of 56 Barn Owls were registered, at 50 points (31.1%), in 31 settlements (62% of all studied). Clear defensive behavior was observed against the source of the sound in many occasions. The average density of the population was 4.2 occupied territories / 100 km2. The occupied locations were situated mostly in settlements laying in deforested lowland areas (far from large forest patches), with flat or hilly relief, covered by agricultural lands, pastures and steppes. The number of presences was found to be scarce in villages along heavily used motorways. Traffic-caused mortality of Barn Owls is commented as a probable explanation.


2019 ◽  
Vol 27 (1) ◽  
pp. 1-31
Author(s):  
László Bank ◽  
László Haraszthy ◽  
Adrienn Horváth ◽  
Győző F. Horváth

Abstract In this study, the results of a long-term nest box installation program of the Common Barn-owl Tyto alba (Scopoli, 1769) in Southern Hungary were evaluated, which program was conducted during a 24-year period (1995–2018). The percentages of occupied nest boxes ranged from 9.72 to 73.44% in the first breeding periods while this varied between 0 and 41.46% in the case of repeated clutches in the same nest boxes with second broods. A total of 1,265 breeding attempts were recorded including 1,020 (80.63%) in the first and 245 (19.36%) in the second breeding periods, from which a total of 210 (16.6%) clutches did not produce any fledglings. The modal clutch size was 7 eggs in both first and second annual clutches. However, the value of productivity was higher in the case of larger clutch sizes and we found significant linear relationship between initial clutch size and fledgling production per nesting attempt in both breeding periods. Significant variation of reproductive parameters was observed among the years. The proportion of egg loss showed significant decline, while the change of hatching success and the variation of annual productivity showed significant slight positive linear trend during the 24 years. Our results suggested that despite the outlier values of reproduction characteristics in the extreme years with negative effect, a relatively stable Common Barn-owl population can be maintained by the placement of nest boxes in the investigated region.


2004 ◽  
Vol 11 (1) ◽  
pp. 46-50
Author(s):  
Abdeslam Rihane ◽  
Patrick Bergier ◽  
Saadia Mahari
Keyword(s):  
Barn Owl ◽  

2018 ◽  
Vol 24 (1) ◽  
pp. 25
Author(s):  
Carolyn S. Mostello ◽  
Sheila Conant

We report here on the diets of four apex predators in Hawai‘i: the native pueo or Hawaiian short-eared owl (Asio flammeus sandwichensis) and three introduced species, the barn owl (Tyto alba pratincola), the feral cat (Felis catus) and the small Indian mongoose (Herpestes javanicus). To better understand dietary relationships between these predators, we studied diet, focusing on areas where they occur together. We collected disgorged owl pellets, and cat and mongoose faecal scats from eight areas located on five of the main Hawaiian Islands and identified prey items to the lowest possible taxonomic level. All species consumed rodents, birds, and arthropods, and the mammal species also included plants in their diets. The two owl species and the cat preyed primarily on rodents, whereas small cockroaches predominated in the diet of the mongoose. Diets of the owl species and the cat, but not the mongoose, varied significantly between areas. Dietary overlap was highest between the pueo and the barn owl and lowest between the owl species and the mongoose. Although barn owls took more rats than pueo, there was no evidence that the two owl species partitioned house mouse prey by size. On islands where there are no mongoose, both owls took a greater proportion of large arthropods in their diet, suggesting that mongoose reduced the abundance of the arthropod species that owls commonly took. There was no significant difference in pueo diets before and after introduction of the barn owl.


Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1777
Author(s):  
Amélie N. Dreiss ◽  
Andrea Romano ◽  
Raphaëlle Flint ◽  
Sarah Bates ◽  
Aurélie Vermunt ◽  
...  

Animals produce vibrations or noises by means of body movements, which can play a role in communication. These behaviors enhance signal transmission or receiver attention and could be specifically used during turn-taking phases of a reciprocal exchange of signals. In the barn owl Tyto alba, nestlings vocalize one after the other to negotiate which individual will have priority access to the impending prey item to be delivered by the parents. Owlets adjust their vocalization to their own hunger level and to their siblings’ vocalization, withdrawing from the contest in front of highly vocal, and hence hungry, motivated nestmates. As sibling negotiation is a multicomponent display, we examined whether body movements could also be part of the negotiation process. To this end, we analyzed whether the vocalizations of one nestling affected its nestmate’s movements in three separate experiments: in natural nests, in the lab, and using a playback procedure. Nestling barn owls move in a variety of ways, such as repeated tapping of the floor with a foot, scratching the floor with claws, or flapping wings. Body movements were more frequent during the turn-taking phases of vocal interactions, when siblings emitted longer calls and at a greater rate. Once an individual monopolized vocal activity, siblings became less vocal and less active. Moreover, owlets produced more noisy body movements during the phases of vocal interactions which are crucial to prevail in negotiation. Non-vocal physical activities might reinforce vocal signals during sibling to sibling (sib–sib) interactions, or reflect owlets’ arousal, in the critical period during which they vocally settle which individual will dominate the competition.


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