|
Much of my research looks at the role and context of vocal communication during territory defense in the jays. FSJs are somewhat unusual among temperate species because females play a prominent role in defense, assisting the male when defending against neighbors and accompanying during intrusions onto nearby territories. Both male and female scrub jays vocalize using "weep" and "screech-scold" calls (Fig. 1); however, females also use a sex-specific "rattle" call (Fig. 2). Upwards of 90% of calls given by females during territory defense are the rattle call. As scrub-jays are monomorphic, the rattle call is one of the quickest methods for sexing birds in the field.
Fig.1 A weep call recorded from a breeding male FSJ. Click below to hear the accompanying call.
|
Fig. 2 A rattle call recorded from a breeding female FSJ. Click below to hear the accompanying call.
|
The rattle is a relatively simple, mechanical-sounding call, but there is surprising variation between populations. Woolfenden and Fitzpatrick (1996) describe three main dialects: 1) in the north and on the Atlantic Coast, a rapid series of clicks reminiscent of the California scrub-jay TK-TK-TK-TK; 2) on the Lake Wales Ridge, a two-syllable phrase with an alternating click and soft note whut-TK-whut-TK-whut-TK; and 3) on the Gulf coast, a slower, soft note absent the harder clicks whut-whut-whut.
For simplicity, I call these the rapid, hiccup, and soft rattles, after W&F's terminology and to maintain consistency with the calls of other female corvids.
In addition to our main site at Archbold (ABS, hiccup), I have studied the rattles at Seminole State Forest (SSF, rapid) and Oscar Scherer State Park (OSSP, hiccup-var.). The soft rattle is becoming difficult to find and may be at risk of extinction.
regionalrattledemo.mp3 | |
File Size: | 266 kb |
File Type: | mp3 |
Scrub-jays are nonmigratory and defend their territories year-round. Since they also form long-term pair bonds, we can reliably find the same individuals and entire family groups in a given area throughout the breeding and non-breeding seasons, as well as from year to year. This allows me to study how both social and reproductive contexts affect aggressive interactions, as well as how individual responses change (or do not change) over time.
I am also interested in how behavior and aggressive interactions alter steroid hormone levels (and, vice versa, how steroid hormones affect aggression). The effects of corticosterone (CORT) and activation of the HPA axis form the backbone of many of the questions posed by the lab, while I also am interested in how testosterone (T) influences and is influenced by territory defense.
Selected Conference Contributions
Ferguson, S.M. and S.J. Schoech. A dual-speaker playback experiment in a non-duetting, co-defending passerine. Society for Integrative and Comparative Biology Annual Meeting, Portland, OR. Jan 2016.
Ferguson, S.M., B.C. Jones, S.J. Schoech. Low corticosterone response Florida scrub-jays (Aphelocoma coerulescens) react more aggressively to territorial call playback. Behaviour2015, Cairns, QLD, Australia. Aug 2015.
Ferguson, S.M., Jones, B.C., Schoech, S.J. Equality of the sexes: Territory defense in the Florida scrub-jay. Animal Behavior Society Annual Meeting, Princeton, NJ. Aug 2014
Ferguson, S.M., Small, T.W., Schoech, S.J. We gotta get out of this place: Relationships between corticosterone and dispersal distance in the Florida scrub-jay (Aphelocoma coerulescens). Society for Integrative and Comparative Biology Annual Meeting, Austin, TX. Jan 2014.
Ferguson, S.M. and S.J. Schoech. A dual-speaker playback experiment in a non-duetting, co-defending passerine. Society for Integrative and Comparative Biology Annual Meeting, Portland, OR. Jan 2016.
Ferguson, S.M., B.C. Jones, S.J. Schoech. Low corticosterone response Florida scrub-jays (Aphelocoma coerulescens) react more aggressively to territorial call playback. Behaviour2015, Cairns, QLD, Australia. Aug 2015.
Ferguson, S.M., Jones, B.C., Schoech, S.J. Equality of the sexes: Territory defense in the Florida scrub-jay. Animal Behavior Society Annual Meeting, Princeton, NJ. Aug 2014
Ferguson, S.M., Small, T.W., Schoech, S.J. We gotta get out of this place: Relationships between corticosterone and dispersal distance in the Florida scrub-jay (Aphelocoma coerulescens). Society for Integrative and Comparative Biology Annual Meeting, Austin, TX. Jan 2014.