Adaptive Harvesting of Source Populations for Translocation: a Case Study with New Zealand Robins

Reintroductions are conducted frequently throughout the world, and some source populations are harvested repeatedly to provide animals for translocation. The responses of these source populations to harvest should be monitored, and the resulting data used to refine population models will guide management. After North Island Robins ( Petroica longipes) were reintroduced to Tiritiri Matangi, New Zealand, in 1992, the population became a source for robins for additional reintroductions in the region. We constructed an initial model for the population on the basis of the data collected from 1992 to 1998 and used it to predict the population's response to the first translocation of robins from the island in the autumn (March) of 1999. We then analyzed postharvest data on survival (with mark-recapture analysis) and fecundity (with generalized linear-mixed modeling) to reassess and update the model. In the initial model, juvenile survival was assumed to be limited by the island's fixed carrying capacity, with excess juveniles dying over winter; hence, the autumn harvest was expected to cause an immediate increase in juvenile survival. In postharvest analysis, however, most juvenile mortality occurred before autumn, and the best predictor of juvenile survival was the number of breeding pairs present the previous spring (start of the breeding season). Consequently, the updated population model predicted sustainable harvest levels about half those given by the initial model, and this model has been used to guide the number of individuals removed for two subsequent translocations. The ongoing development of the model has been invaluable for assuring conservation authorities that the population is not being unsustainably harvested, which has allowed surplus animals to be used to establish new populations. Our case study illustrates the value of an adaptive approach to harvesting source populations for reintroduction and illustrates the value of such studies for understanding the density-dependent mechanisms regulating populations.

[1]  J. Kikkawa,et al.  Density dependence in an island population of silvereyes , 2000 .

[2]  C. S. Robbins.  Release of captive-reared or translocated endangered birds: What do we need to know? , 1987 .

[3]  Ian Newton,et al.  Population regulation in sparrowhawks , 1986 .

[4]  J. M. Scott,et al.  Release of captive-reared or translocated endangered birds: What do we need to know? , 1987 .

[5]  J. M. Scott,et al.  Translocation as a Species Conservation Tool: Status and Strategy , 1989, Science.

[6]  R. S. Davidson,et al.  Population dynamics of reintroduced forest birds on New Zealand islands , 2002 .

[7]  D. Norton,et al.  Ecological restoration at Mainland Islands in New Zealand , 2001 .

[8]  WILLIAM L. KENDALL,et al.  EVALUATING MALLARD ADAPTIVE MANAGEMENT MODELS WITH TIME SERIES , 2004 .

[9]  T. Garland,et al.  Predictors of Avian and Mammalian Translocation Success: Reanalysis with Phylogenetically Independent Contrasts , 2022 .

[10]  C. Pfister,et al.  Patterns of variance in stage-structured populations: evolutionary predictions and ecological implications. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[11]  E. Cooch,et al.  Environmental degradation, food limitation and reproductive output: juvenile survival in lesser snow geese , 1993 .

[12]  B. G. Murray.  Can the Population Regulation Controversy Be Buried and Forgotten , 1999 .

[13]  R. Holdaway,et al.  A working list of breeding bird species of the New Zealand region at first human contact , 2001 .

[14]  Doug P. Armstrong,et al.  Developing population models for guiding reintroductions of extirpated bird species back to the New Zealand mainland , 2006 .

[15]  D. Whitfield,et al.  Modelling the effects of persecution on the population dynamics of golden eagles in Scotland , 2004 .

[16]  C. Walters.  Challenges in adaptive management of riparian and coastal ecosystems , 1997 .

[17]  J. Tinbergen,et al.  Density dependent survival in an isolated great tit population: Kluijvers data reanalysed , 1985 .

[18]  D. Saltz.  A long‐term systematic approach to planning reintroductions: the Persian fallow deer and the Arabian oryx in Israel , 1998 .

[19]  P. Turchin.  Population regulation : a synthetic view , 1999 .

[20]  A. Dhondt.  Summer dispersal and survival of juvenile Great Tits in southern Sweden , 1979, Oecologia.

[21]  R. Alatalo,et al.  DENSITY-DEPENDENCE IN BREEDING SUCCESS OF THE PIED FLYCATCHER (FICEDULA HYPOLEUCA) , 1984 .

[22]  B. Sæther,et al.  Life History Variation, Population Processes and Priorities in Species Conservation: Towards a Reunion of Research Paradigms , 1996 .

[23]  Mark A. Burgman,et al.  The importance of demographic uncertainty: An example from the helmeted honeyeater Lichenostomus melanops cassidix , 1994 .

[24]  R. Wolfinger,et al.  Generalized linear mixed models a pseudo-likelihood approach , 1993 .

[25]  F. Johnson,et al.  Conditions and Limitations on Learning in the Adaptive Management of Mallard Harvests , 2002 .

[26]  E. Matthysen,et al.  Population Dynamics and Regulation of a High Density Blue Tit Population , 1990 .

[27]  S. Nilsson.  Limitation and regulations of population density in the nuthatch Sitta europaea (Aves) breeding in natural cavities , 1987 .

[28]  K. Burnham,et al.  Program MARK: survival estimation from populations of marked animals , 1999 .

[29]  J. Faaborg,et al.  Juvenile Survival in a Population of Neotropical Migrant Birds , 1997 .

[30]  David R. Anderson,et al.  Model selection and multimodel inference : a practical information-theoretic approach , 2003 .

[31]  T. Royama.  Population Persistence and Density Dependence , 1977 .

[32]  Carl J. Walters,et al.  Adaptive Management of Renewable Resources , 1986 .

[33]  J. Blondel,et al.  Population biology of passerine birds : an integrated approach , 1990 .

[34]  C. S. Holling.  Adaptive Environmental Assessment and Management , 2005 .

[35]  Andy W. Sheppard,et al.  Frontiers of population ecology , 1997 .

[36]  Donald Ludwig,et al.  Stability, Regulation, and the Determination of Abundance in an Insular Song Sparrow Population , 1992 .

[37]  J. Gaillard,et al.  Temporal Variation in Fitness Components and Population Dynamics of Large Herbivores , 2000 .

[38]  Reintroduction: challenges and lessons for basic ecology , 1997 .

[39]  F. Sarrazin,et al.  Reintroduction: challenges and lessons for basic ecology. , 1996, Trends in ecology & evolution.

[40]  Gunnar Gunnarsson,et al.  Ecological basis of sustainable harvesting : is the prevailing paradigm of compensatory mortality still valid? , 2004 .

[41]  T. G. Lovegrove.  Island releases of saddlebacks Philesturnus carunculatus in New Zealand , 1996 .

[42]  L. Eberhardt.  A PARADIGM FOR POPULATION ANALYSIS OF LONG‐LIVED VERTEBRATES , 2002 .

[43]  I. Jamieson,et al.  Successful island reintroductions of New Zealand robins and saddlebacks with small numbers of founders , 2005 .

[44]  S. Beissinger,et al.  CAN PARROTS BE CONSERVED THROUGH SUSTAINABLE HARVESTING , 1992 .

[45]  A. Sinclair,et al.  Population regulation in animals , 1989 .

[46]  J. Ewen,et al.  Dynamics and Viability of a New Zealand Robin Population Reintroduced to Regenerating Fragmented Habitat , 2002 .

[47]  M. Boyce,et al.  Adaptive management for reintroductions: Updating a wolf recovery model for Yellowstone National Park , 2006 .

[48]  I. Mclean,et al.  New Zealand translocations: theory and practice , 1995 .