<html aria-label="message body"><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">From Birds of the World:<div><br></div><div><span style="caret-color: rgb(46, 38, 31); color: rgb(46, 38, 31); font-family: CloSans, "CloSans override", "Noto Sans", "Noto Sans Hebrew", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; font-size: 18.08px; background-color: rgb(255, 255, 255);">"For a nest in New York, a</span><span style="caret-color: rgb(46, 38, 31); color: rgb(46, 38, 31); font-family: CloSans, "CloSans override", "Noto Sans", "Noto Sans Hebrew", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; font-size: 18.08px; background-color: rgb(255, 255, 255);">n average of 66 medium-sized (e.g., American Robin) prey items is required to raise a young bird to age 6 weeks.</span><font color="#2e261f" face="CloSans, CloSans override, Noto Sans, Noto Sans Hebrew, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Oxygen-Sans, Ubuntu, Cantarell, Helvetica Neue, sans-serif" size="4"><span style="caret-color: rgb(46, 38, 31);">”</span></font></div><div><span style="caret-color: rgb(46, 38, 31); color: rgb(46, 38, 31); font-family: CloSans, "CloSans override", "Noto Sans", "Noto Sans Hebrew", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; font-size: 18.08px; background-color: rgb(255, 255, 255);"><br></span></div><div><span style="caret-color: rgb(46, 38, 31); color: rgb(46, 38, 31); font-family: CloSans, "CloSans override", "Noto Sans", "Noto Sans Hebrew", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; font-size: 18.08px; background-color: rgb(255, 255, 255);">"Home range of the Cooper's Hawk during the breeding season was estimated at 400–1,800 ha in New York, Michigan, Oregon, and New Mexico."</span></div><div><br></div><div>So a nest with three young, at least in New York, and probably not that different in Seattle, would need around 200 robin-sized birds during that 6-week period. These would be taken from a home range of, say, 1,000 hectares (about 2,500 acres). That doesn’t sound like a huge drain on the population of such birds, one per 12.5 acres.</div><div><br></div><div>That being said, I don’t think I want a pair nesting in my back yard. I don’t know about robin-sized birds, but I have photographed four adult Cooper’s Hawks, three females and a male, taking Band-tailed Pigeons in our yard over the years. It seems like pigeons and doves are really favored prey of bird-eating hawks. Lots to eat and not all that smart.</div><div><br></div><div>I should add that I also photographed an immature female taking an adult Brown Rat.</div><div><br></div><div>Dennis Paulson</div><div>Seattle</div><div>dennispaulson at comcast dot net</div><div><br id="lineBreakAtBeginningOfMessage"><div><br><blockquote type="cite"><div>On Feb 24, 2026, at 3:54 PM, pan via Tweeters <tweeters@u.washington.edu> wrote:</div><br class="Apple-interchange-newline"><div><div style="font-family:arial; font-size:13px;"><div>Tweets,</div><div><br></div><div>I haven't gone back to find the publication/s, but I recall a presentation by a U. W. researcher about part of a long-term marked Song Sparrow project in Seattle, including Discovery Park. This was ongoing in the early 1990's, through the return and establishment of Cooper's Hawks as breeders. He reported that breeding density of Song Sparrows was the same after the hawks, but the demographics of the breeders changed: shorter lives, more turnover. I don't know how other elements of the population changed. </div><div><br></div><div>Good birding,</div><div><br></div><div>Alan Grenon</div><div>Seattle</div><div>panmail AT mailfence PERIOD com</div></div><br><br>-- <br>Sent with https://mailfence.com <br>Secure and private email<br>_______________________________________________<br>Tweeters mailing list<br>Tweeters@u.washington.edu<br>http://mailman11.u.washington.edu/mailman/listinfo/tweeters<br></div></blockquote></div><br></div></body></html>