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Jeffrey A. Spendelow

Publications and source records attributed to Jeffrey A. Spendelow.

26 records · Page 2Linked to original sources
USGS2002

Individual foraging strategies of kleptoparasitic Roseate Terns

We describe the kleptoparasitic behavior of ten adult Roseate Terns ( Sterna dougallii ) breeding at a colony at Falkner Island, Connecticut, USA between 1995 and 1998. These birds were considered habitual kleptoparasites because they stole fish repeatedly from other terns in every year they were observed at the site. No other breeding individuals were observed attempting to steal fish during our study. Kleptoparasitic techniques included aerial piracy, ground-based attacks, and deceptive behavior, but with one exception, each individual used one method exclusively. Success varied among individuals, but overall, kleptoparasites obtained prey at a significantly higher rate than did 'honest' foragers. Eight of the ten kleptoparasites were females, suggesting a sex-biased tendency in Roseate Terns to engage in this behavior. Our observations indicate that kleptoparasitism by Roseate Terns is a specialized behavior, used regularly by only a few individuals at this breeding colony. This conclusion is consistent with a recent theoretical prediction regarding kleptoparasitism in birds.

Connecticut↗
USGS2001

A pair of Roseate Terns adopts another pair's egg

Most cases of adoption in Common Terns ( Sterna hirundo ) occur when a chick leaves (or is moved from) its nest site and adopts new parents (Ian Nisbet, pers. comm.). It is not known to what extent similar behavior occurs in Roseate Terns ( S. dougallii ), however, because (except for studies of chick-provisioning Richards and Schew 1989, Teets 1998, Shealer 1999) until recently, little behavioral work has been done with chicks of this endangered species (Nisbet 1989, Schew and Richards 1989, Grinnell and Spendelow 2000). Here we report a case where a pair of Roseate Terns abandoned their egg a few days prior to the hatching of the chick. Another pair took over incubation of the egg and then raised the chick to fledging, demonstrating that an adoption can be initiated by adult terns.

Connecticut↗
USGS1997

A pair of roseate terns fledges three young with limited human assistance

Hays (1994) reported that a trio of Roseate Terns ( Sterna dougallii ) raised three fledglings in 1991 at Great Gull Island, New York. Despite the regular occurrence of "supernormal" clutches of three or more eggs (Norton 1988, Hays 1994, Shealer and Zurovchak 1995), we are not aware of any reports of three young being fledged by just two adult Roseate Terns. Here we report a pair that, with limited human assistance given to the initially smallest chick for two weeks, fledged three young in 1994 at Falkner Island off the coast of Connecticut.

Connecticut↗
USGS1995

Estimating annual survival and movement rates of adults within a metapopulation of roseate terns

Several multistratum capture—recapture models were used to test various hypotheses about possible geographic and temporal variation in survival, movement, and recapture/resighting probabilities of 2399 adult Roseate Terns (Sterna dougallii) color—banded from 1988 to 1992 at the sites of the four largest breeding colonies of this species in the northeastern USA. Linear—logistic ultrastructural models also were developed to investigate possible correlates of geographic variation in movement probabilities. Based on goodness—of—fit tests and comparisons of Akaike's Information Criterion (AIC) values, the fully parameterized model (Model A) with time— and location—specific survival, movement, and capture probabilities, was selected as the most appropriate model for this metapopulation structure. With almost all movement accounted for, on average >90% of the surviving adults from each colony site returned to the same site the following year. Variations in movement probabilities were more closely associated with the identity of the destination colony site than with either the identity of the colony site of origin or the distance between colony sites. The average annual survival estimates (0.74—0.84) of terns from all four sites indicate a high rate of annual mortality relative to that of other species of marine birds.

Ecology↗
USGS1994

Two hybrid common x roseate terns fledge at Falkner Island, Connecticut

Although these two similarly-sized species are sympatric throughout much of their breeding range, there are few published records of hybridization between Roseate ( Sterna dougallii ) and Common ( S. hirundo ) Terns. Records include at least five from Europe (Witherby and Ticehurst 1908, Perry 1972, Robbins 1974, Burggraeve 1977, van den Berg 1980) and only one from North America (Hays 1975), but we are aware of several unpublished records of hybridization at colonies in Massachusetts (I. Nisbet, pers. comm.) and New York (J. Burger, pers. comm.). Differences in sexual display probably serve as the principal barrier to hybridization (Palmer 1941 ), and in the northeastem United States where both species breed, Common Terns tend to nest in more open areas while Roseate Terns tend to nest in or under cover (Hays 1975, Nisbet 1981, Spendelow 1982, Burger and Gochfeld 1988). From 1984 through 1993, we recorded several instances of interbreeding in a mixed colony of several thousand Common Terns and a few hundred Roseates at the Falkner Island Unit of the Stewart B. McKinney National Wildlife Refuge. This 2-ha island is located at 41 °13'N and 72° 39'W in Long Island Sound, approximately 5 km off the coast of Guilford, Connecticut. Spendelow (1982) briefly described the island and the areas used by the nesting terns; a more detailed description of the island is in Helander (1988). The mixed pair we observed in 1993 nested in a subcolony of about 25 pairs of Roseates on the southeast section of the island's rocky beach, where we put out 30 boxes to create more protected nest sites for Roseate Terns. Here we present a summary of their successful nesting, which we followed almost daily from several days prior to the laying of the first egg until departure of these birds from the colony site.

Connecticut↗
USGS1989

Annual survival rates of breeding adult roseate terns

Analyses of the capture-recapture data on 910 individual Roseate Terns ( Sterna dougallii ) trapped from 1978-1987 as breeding adults on nests on Falkner Island, Connecticut, estimate the average annual minimum adult survival rate to be 0.74-0.75. There was weak evidence of year-to-year variation in annual survival rates during the study period. The Jolly-Seber models used to estimate survival rates also generated estimates of population size and capture probabilities. To determine the relative importance of adult mortality and permanent emigration in contributing to the estimated annual loss of one-fourth of the breeding population will require further study of intercolony movement between all the major colony sites. Assuming that the loss of birds from the Falkner Island colony site is due mostly to mortality rather than permanent emigration, and that the survival rate of this breeding population is typical of the entire North Atlantic breeding population, then the survival rate of this endangered species is low in comparison to the survival rates of several other marine bird species in the orders Procellariiformes, Pelecaniformes, and Charadriiformes.

The Auk↗