Adaptation of Owls to Urban Life: A Review of Owls’ Dietary and Behavioural Responses to Worldwide Anthropogenic Challenges and Environmental Change |Chapter 03 | Research Perspective on Biological Science Vol. 9

 

Ever-increasing urban expansion has led to worldwide habitat destruction, fragmentation, and degradation, posing serious threats to wildlife. As the world’s only nocturnal avian apex predator, owls not only have to adapt to anthropogenic challenges, such as artificial light and noise (ALAN), but also adapt to hunting different prey species. Here, we review more than 140 owl diet studies representing 20 different owl species inhabiting rural and urban landscapes in Europe, North America, South America, North Africa, South Africa, India, Southeast Asia and Australia. Primarily, we investigate whether there was a relationship between the degree of urbanisation surrounding nest/roost sites, and the proportion of synanthropic rodents (the Brown Rat Rattus norvegicus, Black Rat Rattus rattus and House Mouse Mus musculus) and birds in their diet. The similarity index was calculated to show the degree of differences in two compared components of the urban and rural diet of the studied owl species. In total, SI for 20 owl species was 0.32 in urban rats/house mice vs. rural rats/ house mice, and 0.50 in urban birds vs. rural birds. High rats/house mouse consumption in urban environments has been documented for most owl species living in cities. Similarly, suburban and urban owls often eat many more birds than their rural counterparts, but the difference is less prominent, as shown by a higher similarity index. Although interactions with powerlines and roads are primarily problems in rural and natural environments, we have presented them here as further anthropogenic obstacles for owls to navigate. Studies such as this one may help form environmental mitigation strategies for future urban expansion.

 

Author(s)details:-

 

Heimo Mikkola
University of Eastern Finland, Koskikatu 9B31, 80100 Joensuu, Finland.

 

Alan Sieradzki
Global Owl Project, USA.

 

Please see the book here:- https://doi.org/10.9734/bpi/rpbs/v9/6617

Discarded Knowledge: Unlocking the Secrets of Owl Pellets | Chapter 10 | Research Perspective on Biological Science Vol. 4

Bird pellets are an accumulation of undigested food items consumed by birds and cannot be excreted as faeces but are regurgitated by mouth as compact packages. These contain hard, and not easily digested, material which is of little nutritional value to the bird – the bones, claws, beaks or jaws and teeth of mammals, birds, reptiles, amphibians and fishes; the thorax or wing-cases of insects and seed husks and other coarse vegetable matter. Hard materials are then usually encased by the softer, and equally indigestible, material of mammal fur, bird feathers or vegetable fibres. Often characteristic, these pellets can provide valuable clues to diet. Of the many hundreds of bird species that produce pellets, owls make the pellets that, when dissected and analysed, can provide the most accurate record of the diet of any bird.

 

Here, we look at how the owl's pellet is produced and how the dissection and analysis of them are crucial to so many fields of study:  – entomology (distribution of arthropod species, their communities and their environments), mammalogy (diversity and structure of small mammal assemblages), ornithology (diet and distribution), palaeontology and taphonomy (taphonomic and taxonomic analyses of bones and teeth of microvertebrates contained in ancient owl pellets and markers of human actions), education and citizen science (an exciting and interactive introduction to environmental studies and how amateurs can contribute to data gathering), botany (owl-mediated seed dispersal), ecology (evidence of environmental contamination and pollution) and finally, we tell how owl pellets, the discarded remains of a meal, themselves become a food source, serving as a snack for vultures. Although discarded in nature, owl pellets hide a host of secrets just waiting to be unlocked.

 

Author (s) Details

Alan Sieradzki
Global Owl Project, USA.

 

Heimo Mikkola
University of Eastern Finland, Koskikatu 9B31, 80100 Joensuu, Finland.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/rpbs/v4/5628