Factors influencing the flush response and flight initiation distance of three owl species in the Andaman Islands

2021 ◽  
Vol 13 (11) ◽  
pp. 19500-19508
Author(s):  
Shanmugavel Sureshmarimuthu ◽  
Santhanakrishnan Babu ◽  
Honnavalli Nagaraj Kumara ◽  
Nagaraj Rajeshkumar

Effects of anthropogenic pressures on birds of the Andaman Islands have been documented to some extent, however studies on the effect of human activities on the behavioural response of these birds are limited. This study assessed the anti-predatory behaviour (flush response - FR and flight initiation distance - FID) of three owl species (Otus sunia, Otus balli, and Ninox obscura) in response to human stimuli and factors influencing it on the Andaman Islands. In total, 63 % of owls flushed from their roost sites in response to approaching human, and such a response varied between species. Similarly, FID varied widely among the species ranging from 4.23 to 6.73 m. The FR of N. obscura was influenced by the count of climbers, presence of spine, and branch status, while roost height, ambient temperature, and lower count of climbers contributed to a higher FID. For the two Otus species, camouflage and pairing were found to influence their FR while FID of O. balli was influenced by roost height, pairing, and presence of spines. Our results indicated that the anti-predatory behaviour of owls on the Andaman Islands was species- and site-specific and prolonged disturbance to their roost sites may affect the survival and reproductive rate of these owls.  

2016 ◽  
Vol 14 (1) ◽  
Author(s):  
Larissa J. Benevides ◽  
José de Anchieta C. C. Nunes ◽  
Tiego L. A. Costa ◽  
Cláudio L. S. Sampaio

ABSTRACT When confronted by predators, prey need to make an economic decision between continuing their current activity or flee. Flight Initiation Distance (FID), the distance at which an organism begins to flee an approaching threat, has been used to indicate an animal's fearfulness level and a way to examine factors influencing escape decisions. Here we investigated how the FID of the barber surgeonfish, Acanthurus bahianus, responds to the presence of spearfishers in a fishing site in northeast Brazil. Specifically, we examined whether the FID was influenced by body and group size; by the heterogeneity of species in groups formation; and the distance to shelter. Significant differences in FID were observed with increasing body size. We found no significant relationship of FID with size or group formation, neither with distance to shelter. Preferences in forming groups with A. bahianus were seen among some species, and a higher FID was associated with less sheltered substrates. Results obtained here support theories suggesting that spearfishers do influence fish behavior. We highlight that future research should focus on the indirect impacts of spearfishing on the structure of marine communities, emphasizing the anti-predator behaviour of juvenile and adult target fishes.


Ostrich ◽  
2017 ◽  
Vol 89 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Bukola Braimoh ◽  
Soladoye Iwajomo ◽  
Mark Wilson ◽  
Adams Chaskda ◽  
Afan Ajang ◽  
...  

2005 ◽  
Vol 272 (1581) ◽  
pp. 2627-2634 ◽  
Author(s):  
Theodore Stankowich ◽  
Daniel T Blumstein

The amount of risk animals perceive in a given circumstance (i.e. their degree of ‘fear’) is a difficult motivational state to study. While many studies have used flight initiation distance as a proxy for fearfulness and examined the factors influencing the decision to flee, there is no general understanding of the relative importance of these factors. By identifying factors with large effect sizes, we can determine whether anti-predator strategies reduce fear, and we gain a unique perspective on the coevolution of predator and anti-predator behaviour. Based on an extensive review and formal meta-analysis, we found that predator traits that were associated with greater risk (speed, size, directness of approach), increased prey distance to refuge and experience with predators consistently amplified the perception of risk (in terms of flight initiation distance). While fish tolerated closer approach when in larger schools, other taxa had greater flight initiation distances when in larger groups. The presence of armoured and cryptic morphologies decreased perception of risk, but body temperature in lizards had no robust effect on flight initiation distance. We find that selection generally acts on prey to be sensitive to predator behaviour, as well as on prey to modify their behaviour and morphology.


2013 ◽  
Vol 9 (5) ◽  
pp. 20130417 ◽  
Author(s):  
Pierre Legagneux ◽  
Simon Ducatez

Behavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals' mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still unknown. Here, we tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individuals' ability to respond adaptively to local speed limits.


2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Nadezhda Poddubnaya ◽  
Tatyana Korotkova ◽  
Polina Vanicheva

The rapid growth of cities causes behaviour changes in birds in response to urban environmental factors. The avian response to human disturbance has recently been studied by a non-invasive research tool as an alert distance (AD) and a flight initiation distance (FID) assessment. The tolerance of hooded crows (n = 395), jackdaws (n = 394) and rooks (n = 169) to humans was assessed by AD and FID. It was shown that the FID of all species is maximal during the summer, when the parents send clear “danger—fly away” signals to the young and the birds fly away. The AD and FID of the three species reliably correlates with the season. Rooks showed FID species-specificity in seven cities of Eastern Europe. Comparison of the attitude of birds to people in cities that have similarities in human culture showed that tolerance increases with increasing latitude in all species and is statistically significant only in the jackdaw. This should be taken into account in environmental protection measures.


2021 ◽  
Vol 8 (11) ◽  
pp. 3320
Author(s):  
Joe Mathew ◽  
Rajeev S.

Background: Diabetic foot is a very common condition responsible for a major bulk of surgical admissions and out-patient visits. Lack of awareness of many factors influencing the incidence of this disease complex has led to loss of life, limb and quality of life. The site-specific incidence of initial site and initiating factor has not been studied in diabetic foot.Methods: A study has been done over a period of one and a half years which looked into the distribution of initial site of infection in diabetic foot and associated initiating etiologies. The study was cross sectional. History, general inspection of foot, dermatological, neuropathic and vascular assessments were done, in addition to making careful notes about the site and cause of infection.Results:60.7% of patients were >60 years old, 55.3% were male patients. 63.3% of patients had diabetes for more than 10 years. In 29.3% the initial site of infection was the big toe, 22% in the ball of foot, 18% in the other 4 toes together, 14.7% in the interdigital spaces, 10.7% in the heel and 5.3% in the mid foot. In most of the cases the etiology is multifactorial, trauma in 56%, musculoskeletal deformities in 47.3%, callosities in 41.3%, cracks and fissures in 16.7%, fungal infection in 7.3%, nail infection in 6%, no initiating introduction of infection identified in 10.7%.Conclusions: Awareness of and thus particular stress being place on identification of specific site and cause of infection should help in care of the foot in diabetics.


2021 ◽  
Author(s):  
Kenta Uchida ◽  
Albert A. Burkle ◽  
Daniel T. Blumstein

Ecotourism promotes conservation efforts while also allowing for low impact observation of wildlife. Many ecotourists photograph wildlife and photography plays an important role in focusing the public’s attention on nature. Although photography is commonly believed to be a low impact activity, how the visual stimulus of a camera influences wildlife remains unknown. Since animals are known to fear eyes pointed towards them, we predicted that a camera with a large zoom lens would increase animal’s vigilance levels. Using yellow-bellied marmots (Marmota flaviventer) as a mammalian model, and adopting a behavioural approach to identify how marmots responded to cameras, we experimentally quantified vigilance and flight initiation distance towards humans when marmots were approached with and without a camera. While a camera was pointed at an individual, marmots allocated less time to searching predators and increased time to looking at the observer than they did without a camera. However, whether a camera was pointed at a marmot or not had no effect on the distance the marmot flushed. Our results indicated that cameras distracted marmots but did not influence subsequent risk assessment (i.e., flight initiation distance); marmots may be curious about cameras but were not threatened by them. Capturing animals’ attentions reduces searching for predators and may increase the vulnerability to predation. Therefore, regulating photography in locations where predation risk is high or vulnerable species ranges’ overlap with humans may be required to reduce photography’s impact on wildlife.


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