Hobbies And Interests

Hawk Topics

Hawks are small or medium-sized avian raptors. They hunt mainly small mammals, but also some smaller birds and reptiles. Topics related to these birds vary and may include aspects of their biology, habitat and behavior. Research on hawks has been conducted for many years, and new findings continue to be unearthed by scientists across the globe.
  1. Pesticide Effects

    • The effects of pesticides on wildlife have long been a topic of consideration for biologists, ecologists, agriculturalists and those in related disciplines. In 1969, a study published in the journal "Science" stated that two common organochlorine pesticides, dieldrin and DDT, caused increased egg disappearance, increased egg destruction by parents and reduced eggshell thickness in American sparrow hawks. These effects extended to other European and American raptor species. Modified, or entirely new, contemporary pesticides should be checked for similar or other detrimental effects on hawk species.

    Island Inbreeding and Disease

    • Hawk populations on islands, like other island species, see a greater amount of inbreeding due to low population diversity levels. This influences those hawks by lowering their ability to produce natural antibodies, thereby increasing their susceptibility to disease. A study published in 2006 in "The Proceedings of the Royal Society of Biological Sciences" reported that the Galapagos hawk experienced this link between inbreeding and disease susceptibility, which probably hastened extinction in the endemic species. One topic to consider is the way other island hawk species are affected and if this same phenomenon can be seen among other endemic island species, avian or otherwise.

    Scanning for Prey

    • One interesting topic relating to hawks and other raptor species was brought up in a 2010 research article funded by the National Science Foundation. The research found that there are species-specific head movements related to gathering visual information on prey while perching. The research posits that different hawks scan and follow prey from their perch in different ways, based on their environment. Cooper's hawks use quick head movements, while red-tailed hawks have long intervals between consecutive head movements. These behaviors are both consistent with their environment; Cooper's hawks live in dense forests and red-tailed hawks live in open-space environments.

    Hawk and Prey Populations

    • A study published in 1977 in "The Great Basin Naturalist" suggested that there was a direct correlation between a decline in nesting pairs of ferruginous hawks and a decline in jackrabbit numbers in the Great Basin area of west-central Utah. Jackrabbits are an essential prey of this species. Therefore, a decline in prey species means there will be a decline in hawk populations that hunt them. This is possibly true of all hawk species. While this may seem like an obvious finding, it suggests that hawks are not good at finding alternative sources of food when their main source suddenly dwindles. It also brings up the importance of looking into prey population decline that is related to human activity, as it can indirectly affect hawk populations.


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