Effects of liberalizing harvest regulations on Canada goose (Branta canadensis) demography in Nebraska.

Harvest regulations are used to manage populations of game species. Across their range, Canada goose Branta canadensis populations have recovered from near extirpation and are now perceived as overabundant and even a nuisance or a threat to human safety in many regions. Like many states, Nebraska has liberalized harvest regulations to increase recreation opportunities for consumptive users and to control increasing numbers of Canada geese. However, the efficacy of harvest regulations to control populations of geese is unclear. We used a live capture-recapture and dead recovery data set of more than 19,000 Canada geese banded in Nebraska 2006-2017 to determine the effect of liberalized harvest regulations on goose survival and overall growth rate. Our goals were to 1) estimate demographic parameters for Canada geese in five different regions in Nebraska 2) estimate the effect of increasing daily bag limits during the early September season and regular season on survival of hatch-year, juvenile, and adult Canada geese and 3) relate the effect of estimated changes in survival to population growth rate. We found survival (0.54-0.87), fidelity (0.14-0.99), and productivity (number of young per adult, 0.17-2.08) varied substantially among regions within Nebraska. We found increasing early season bag limits, but not regular season bag limits, reduced survival in Canada geese. However, this effect was most pronounced when comparing years without an early season to years with the highest daily bag limits used in Nebraska (eight). Survival of juvenile geese (2-3 years post-hatch) were unaffected by changes in daily bag limits during any season, though the probability of reporting was greatest for this age-class. The observed reductions in survival probability of hatch-year and adult geese due to increased daily bag limits during the early season (<10%) had only weak effects on regional growth rates. Regional growth rate estimates appeared more responsive to changes in adult survival, but only decreased ~5% between years with the most liberal early-season daily bag limits to years without an early season. Our results suggest increased bag limits during the early season may reduce Canada goose survival, but has a weak impact on population growth in Nebraska.

Canada Goose (Branta canadensis Linnaeus, 1758).

This chapter describes the common terminologies, taxonomy, morphology, geographical distribution, physiology, diet, behaviour, reproduction, habitats, ecology, invasion pathways, environmental impact, control and human use of the Canada goose (Branta canadensis).

Divorce in Canada Geese (Branta canadensis): frequency, causes, and consequences

Most Canada Geese (Branta canadensis) form lifelong pair bonds (same-mate geese), but some pairs break apart and the geese mate with new partners while their former mates are still alive (divorcees). Over 25 years, we assessed lifelong reproduction of 160 collared Canada Geese that nested for multiple years in New Haven County, Connecticut. We examined whether same-mate geese and divorcee geese differed from each other prior to or after the divorce. Fifteen percent of females and 18% of males divorced during their lifetimes. Divorces were more frequent in pairs that produced fewer hatchlings during their prior nesting year. Most divorcees that nested again did so on their former nesting territories. Replacement partners of divorcees averaged younger and had fewer years of nesting experience than the divorcees’ prior mate. Usually after a divorce, one divorcee of each former pair nested immediately while the other skipped one or more years before nesting again. Under such circumstances, the partner able to nest immediately can increase its direct fitness by finding a new partner and nesting rather than foregoing the opportunity to nest that year. During their first nesting year after the divorce, the reproductive success of divorcees and same-mate geese were similar.

Nuevos registros de aves acuáticas para el interior del Estado de Jalisco: caso Laguna de Sayula, México

El conocimiento de la avifauna en México, es el resultado de muchos años de exploraciones en áreas específicas, sin embargo a pesar del esfuerzo realizado, en algunas regiones de México aún se desconoce su composición y distribución; tal es el caso de los humedales continentales, los cuales representan sitios de invernada y de paso migratorio para una gran variedad de aves acuáticas y terrestres del Neártico, así como sitios de reproducción para especies residentes. Se destacan observaciones realizadas en el Sitio Ramsar Laguna de Sayula, resultado de un estudio avifaunístico a largo plazo con muestreos mensuales durante cinco periodos de migración. Se reportan seis nuevos registros para el humedal y algunos para el interior del estado (Dendrocygna autumnalis, Branta canadensis, Sula leucogaster, Pelecanus occidentalis, Pluvialis squatarola y Charadrius semipalmatus) y se informa la presencia de Anser albifrons y Anser rossii con pocos registros publicados para la zona.