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New Brunswick Forest Hawk and Spring Woodpecker Survey

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New Brunswick Forest Hawk and Spring Woodpecker Survey New Brunswick Forest Hawk and Spring Woodpecker Survey 2002 Report Steven D’Amato May 2003 Becky Whittam Atlantic Canada Program Manager Atlantic Region / Région de l’Atlantique P.O. Box/B.P. 6227, Sackville, NB Canada E4L 1G6 www.bsc-eoc.org Table of Contents Introduction ...........................................................................................................2 Methods ................................................................................................................3 Random Route Selection............................................................................3 Scouting Routes .........................................................................................4 Volunteer Training ......................................................................................5 Playback equipment ...................................................................................5 Survey protocol...........................................................................................5 Database Structure.....................................................................................6 Results ..................................................................................................................6 Discussion.............................................................................................................7 Changes to Protocol for 2003.....................................................................8 Acknowledgements ...............................................................................................8 Literature Cited......................................................................................................9 Tables and Figures..............................................................................................10 Appendix A Birds detected on each route run in 2002 ........................................15 NB Forest Hawk and Spring Woodpecker Survey Page 1 2002 Report Introduction The New Brunswick Forest Hawk and Spring Woodpecker Survey was designed to monitor the population trends of Broad-winged Hawk and Northern Goshawk, and to gather more information on the status of Red-shouldered Hawk and Red-tailed Hawk across New Brunswick (Makepeace 2002). Northern Goshawk and Broad-winged Hawk have been identified as indicators of Old Hardwood Habitat (OHWH) in NB; they are thought to use this habitat type for nesting and hunting, often putting their nest in the first crotch of a large hardwood tree. In NB, objectives for specific amounts of OHWH have been put in place for crown land. Monitoring Goshawks and Broad-winged Hawks, along with the amount of old hardwood forest in the province, should help wildlife managers assess management strategies to maintain these species in NB (Makepeace 2002). Red-shouldered Hawk and Red-tailed Hawk have been identified as species of conservation concern by the New Brunswick Department of Natural Resources and Energy (NB-DNRE)’s Species at Risk program. The Red-shouldered Hawk is listed as May be at risk, and the Red-tailed Hawk is listed as Sensitive. The conservation concern for these species can primarily be attributed to their small population sizes and the fact that not much is known about their population trends or relative abundance in NB. The results of this monitoring program will be used to monitor and evaluate the conservation status of these hawks in New Brunswick. Presently, forest hawks are not well monitored in New Brunswick. Red-shouldered hawks have never been observed in New Brunswick on any monitoring program such as the Breeding Bird Survey (BBS) or Christmas Bird Count (CBC). Goshawk, Red- tailed Hawk and Broad-winged Hawk are counted on the BBS and the CBC, but are not observed in numbers high enough to be useful in evaluating changes in their abundance (Makepeace 2002). Raptors are wide-ranging and fast-moving, and they nest at low densities and are widely dispersed. They are therefore somewhat more difficult to study than many other bird species (Fuller and Mosher 1987). Therefore, in 2002 a hawk-specific survey was developed by the DNRE and Bird Studies Canada (BSC) to evaluate forest hawk abundance (Makepeace 2002). The first year of this survey was intended to be a pilot year; playbacks of Broad-winged Hawk and Northern Goshawk calls were used by volunteers to census hawks along randomly- chosen routes passing through areas of extensive forest cover in NB. Northern Goshawks are very responsive to alarm calls when they have nestlings or fledglings (Kimmer and Yahner 1990, Watson et al. 1999, Joy et al. 1994, Kennedy and Stahlecker 1993). Broad-winged Hawks will also respond during the nesting period, although research hasn’t yet shown at which stage they are the most responsive (Makepeace 2002). Other hawk species were also expected to respond to these heterospecific calls. An additional component of the hawk survey is to gather information on the distribution and abundance of woodpeckers in New Brunswick’s forests. Woodpeckers often NB Forest Hawk and Spring Woodpecker Survey Page 2 2002 Report respond to the calls of hawks and owls by approaching and calling, allowing some species of woodpeckers to be surveyed during the hawk survey (Badzinski 2003). Northern Flicker, Pileated, Downy, Hairy and Black-backed woodpecker are all considered indicators of various types of forest (based on composition and development stages) by the NB-DNRE; their population trends are therefore of interest to provincial forest managers. The goals of the NB Forest Hawk and Spring Woodpecker Survey are: 1. To detect changes in the relative abundance of Broad-winged Hawk and Northern Goshawk in New Brunswick, both on crown land and on privately-owned land, through the development of a long-term volunteer-based survey; 2. To collect data on Red-tailed Hawk and Red-shouldered Hawk in order to monitor and update their conservation status; 3. To use the results of the monitoring program to assess the performance of DNRE’s Old Forest Habitat supply strategy for crown lands; and 4. To collect data on woodpecker presence along survey routes, and to assess the ability of the survey to monitor woodpecker populations in New Brunswick. This report summarizes the methods and basic results of the first year of the survey (2002). Methods Random route selection Hawk survey routes were chosen by NB-DNRE staff in the same manner as were routes for the NB Nocturnal Owl Survey (Whittam 2001). Scott Makepeace (NB-DNRE) prepared a map of the province showing all roads that would be drivable in May & June (primary and secondary Department of Transportation roads, and primary forest roads), as well as the three main land bases (crown, private, federal). Maps also indicated areas of non-forest. He then overlaid a 50 x 50 km grid on this map. To be able to compare population trends on crown (provincial) and private land, he attempted to place two routes per square – one on crown land, and one on private land. The following rules were applied: 1. In order for a route to qualify as “crown” or “private”, 8/10 stops had to fall on that particular land base. It was decided ahead of time (before random numbers were chosen, see below) which roads would be acceptable for crown or private routes in each square. Some squares could only contain one type of route (i.e. because there were no roads in crown land, or private land). In these cases, two routes of the same type of land base were placed in the square. 2. Squares that were less than 1/3 covered with land were not used in the process. NB Forest Hawk and Spring Woodpecker Survey Page 3 2002 Report 3. A 10 x 10 mini-grid was created on a sheet of transparency. This grid covered one 50 x 50 km square. Two random numbers from 0-10 were chosen to locate a point on the 10 x 10 grid. This point marked the vicinity of the starting point of the route. The starting point was placed on the closest road of the appropriate land base (crown or private) to that point. 4. The direction of travel was often limited (because crown land stretched only to the east, or the road ended 2 km to the north, meaning that south was the only direction left to travel), but when it wasn’t, it was randomly chosen. Once the road and direction was chosen, that road and direction were followed, if possible, for the duration of the survey. In other words, no turns were taken unless necessary (i.e. unless a t-junction was reached, or unless a turn was necessary to stay on crown or private land roads). 5. When a turn was required and it was not dictated by crown or private land, the direction was chosen randomly. 6. Routes did not have to stay within the 50 x 50 km square; these squares were used solely to determine the starting points of routes. 7. Routes could not overlap, or run parallel within 4 km of each other. Scouting Routes NB-DRNE and BSC staff attempted to scout most survey routes on private land before the survey period. Crown land routes were not scouted because of time restrictions (and because it was generally believed that routes on crown land were more likely to fall in forested areas compared with routes on private land). Scouting a route involved driving to the randomly chosen start location and GPSing each stop along the route. The following criteria were used to determine the suitability of each route: 1. The route should pass through mostly-forested habitat. If the route is on a road that is heavily settled with many houses or farms, it may not be suitable. 2. The road(s) followed on the route should
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