20 research outputs found
Killer Whale (Orcinus orca) Occurrence in the Moray Firth, Northeast Scotland: Incidental Sightings,Behavioural Observations, and Photo-Identification
No full textThe article reports on the killer whale, known as Orcinus orca and its occurrence in the Moray Firth, Northeast Scotland. Topics discussed include the incidental sightings of this species, its behavioural observations, and photo-identification. Also being discussed are the white-beaked dolphins called Lagenorhynchus albirostris, and annual pupping season of the common seal called Phoca vitulina
Female reproductive success and calf survival in a North Sea coastal bottlenose dolphin (Tursiops truncatus) population
No full textBetween-female variation in reproductive output provides a strong measure of individual fitness and a quantifiable measure of the health of a population which may be highly informative to management. In the present study, we examined reproductive traits in female bottlenose dolphins from the east coast of Scotland using longitudinal sightings data collected over twenty years. From a total of 102 females identified between 1997 and 2016, 74 mothers produced a collective total of 193 calves. Females gave birth from 6 to 13 years of age with a mean age of 8. Calves were produced during all study months, May to October inclusive, but showed a seasonal birth pulse corresponding to the regional peak in summer water temperatures. Approximately 83% (n = 116) of the calves of established fate were successfully raised to year 2-3. Of the known mortalities, ~45% were first-born calves. Calf survival rates were also lower in multiparous females who had previously lost calves. A mean inter-birth interval (IBI) of 3.80 years (n = 110) and mean fecundity of 0.16 was estimated for the population. Calf loss resulted in shortened IBIs, whilst longer IBIs were observed in females assumed to be approaching reproductive senescence. Maternal age and size, breeding experience, dominance, individual associations, group size and other social factors, were all concluded to influence reproductive success (RS) in this population. Some females are likely more important than others for the future viability of the population. Consequently, a better knowledge of the demographic groups containing those females showing higher reproductive success would be highly desirable for conservation efforts aimed at their protection.
Massed trial Overtraining Effects on Extinction and Reversal Performance in Turtles (Geoclemys reevesii)
No full textM asato Ishida Osa ka U niversity of E duca tion, Osa ka , J a pa n M auricio R. Papin i Texa s Christia n U niversity, Fort Worth, Texa s, U.S.A. Two exp erim en ts w ith tu r tles (Geoclemys reev esii) exam ined th e overtrain ing extin ction effect (O E E ) an d th e overtraining reve rsal effect (O RE ), u n d er m assed train ing con d ition s. In E xp erim en t 1, th ree g ro u ps of tur tles received 7, 14, or 21 session s of tr ainin g in a r u nw ay situ atio n for food reinforcem en t, follow ed by 15 se ssio ns of extin ction . E xtin ctio n w as faster, th e greater th e nu m ber of acqu isitio n sessio ns. In E xp erim en t 2, the tw o g ro u ps of tu rtles lear ned a sp atial discrim ination for food reinforcem en t either to a criterio n (19 of 20 cor rect re sp o ns es), or to th at criterion plu s 100 add ition al trials of overtr ainin g. W h en th e validity of th e p osition s w as reve rsed , lear nin g w as faster for th e over tr ain ed gro u p than for th e gro u p tr ained to a criterion . T his eviden ce of th e O E E and the O R E is th e ® r st yet rep or ted for a re ptile. T h e resu lts are d iscu ssed in th e fr am ew or k of com p arative re sear ch on rew ardsc hed u le effects. Turtles 1 trained und er m assed cond ition s show g reater resistance to extin ction after acq uisition w ith partial than co ntinuous rein forcem ent. T his phenom en on, called the partial rein forcem ent extinction effect (P RE E ), w as reported in three studies in w hich several trials per sessio n an d a relatively short intertrial interval (IT I) w ere u sed (Ishida & K itam ura, 1988; M urillo, D iercks, & C ap aldi, 1961; W ise & G allagher, 1964). Shef® eld (1949) sug gested that the P RE E occurs because the aftereffects of rew ard an d no n-rew ard becom e part of the stim ulu s com plex co ntrolling instr um ental perfor m an ce. Becau se a partial reinforcem ent schedule involves training to respond w hile under the in¯uence of the aftereffects of no n-rew ard, a shift from acquisitio n to extinction is less discrim inable Requests for reprints sh ould be sent to M . Ishid a, D epartm e nt of Psyc holo g y, Osak a U niversity of E ducatio n, 698± 1, 4-C hom e Asahig aok a K ashiw ara-C ity, Osaka , Japan 582 , or to M .R . Papini, D epartm ent of P syc hology, Texas Ch ristia n U niversi ty, Fort Worth, TX 76129 , U.S.A . The re searc h reported in this article was supported by G rant 066100 74 (to M .I.) from the M in istr y of E ducatio n, Japan. The author s would lik e to thank Saek o M aeno for colle cting part of the data. 1 In Britain , sem i-aq uatic chelonians are re ferred to as``terrapin s' ' . The name``turtles' ' is kept here for consiste ncy with its prevaili ng use in the literatu re. Ó 199 7 The E xp erim ental Psyc holo g y S ociety for partially reinforced an imals than it is for co ntinuously reinforced an im als. O n the assum ptio n that stim ulus aftereffects decay in tim e, the car ry-over m echan ism should in¯uence behaviour predom inan tly under relatively m assed condition s of training. H owever, the PR E E has been obtained in experim ents w ith rats in w hich the IT I w as 24 hr long E X PE R IM E N T 1 Typically, resistance to extinction ® rst increases an d then decreases w ith m o notonic increm ents in th e am ount of acquisition trainin g. It is th e later decrease that constitutes the O E E . T he O E E w as observed in som e runw ay an d Skinner box studies w ith rats (e.g. Ishida, 1973; Ison, 1962; N orth & Stim m el, 1960; Senkow ski, 1978; T heio s & Brelsford, 1964 ), alth ou gh it failed to ap pear in other, sim ilar studies (M ackintosh, 1974). T he evidence from experim ents w ith gold® sh is also am biguous. Fo r exam ple, Ishid a (1 977) found no evidence of the O E E in a runw ay experim ent using a 60-sec IT I an d either 21 or 69 acquisitio n trials, an d althou gh Z ych an
Fig 3 -
No full textThe spatial associations of adult and juvenile minke whales in the Moray Firth study area with respect to the eco-geographic variables (a) water depth, (b) bathymetric slope, (c) proximity to shore and (d) sea bottom sediment type.</p
Fig 5 -
No full text“Active” adult minke predation events upon juvenile herring (a and b) and upon pre-wintering sprat (c and d). Photographs: Kevin Robinson.</p
Intra-seasonal changes in minke whale feeding techniques and proximity to shore from 95 feeding events observed between 2002 and 2017.
No full textIntra-seasonal changes in minke whale feeding techniques and proximity to shore from 95 feeding events observed between 2002 and 2017.</p
The mean water depth, slope and proximity to shore of adult and juvenile minke whale sightings recorded in the outer Moray Firth between 2001 and 2022 inclusive (n = 964).
No full textThe mean water depth, slope and proximity to shore of adult and juvenile minke whale sightings recorded in the outer Moray Firth between 2001 and 2022 inclusive (n = 964).</p
Surface feeding specialisations recorded during individual focal follows (<i>n</i> = 238) of minke whales in the Moray Firth between 2001 and 2022.
No full textSurface feeding specialisations recorded during individual focal follows (n = 238) of minke whales in the Moray Firth between 2001 and 2022.</p
Fish prey species sampled from individual feeding events (n = 95) of adult and juvenile minke whales between 2002 and 2017.
No full textFish prey species sampled from individual feeding events (n = 95) of adult and juvenile minke whales between 2002 and 2017.</p
The location of the study area (green border) and the boundaries of the Southern Trench MPA (shaded) along the southern coastline of the outer Moray Firth in northeast Scotland.
No full textThe location of the study area (green border) and the boundaries of the Southern Trench MPA (shaded) along the southern coastline of the outer Moray Firth in northeast Scotland.</p
